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HomeMy WebLinkAboutPR16-000503_HEX REPORT_KCTransmittal_05-11-2018_Final.pdfCritical Area Regulation RMC 4-11-140 Definitions: NATIVE GROWTH PROTECTION EASEMENT: A restrictive area where all native, predevelopment vegetation shall not be disturbed or removed except for removal pursuant to an approved enhancement program. The purpose of an easement is to protect steep slopes, slopes and/or riparian corridors. King County Comment: Requirement of NGPE on the landscaped wet area (FNA: Wetland “A”); does not fall within the Renton’s defined purpose of an NGPE. This area was landscaped after being used for staging during several different previous projects at the treatment plant and is outside of a riparian corridor and was not restored as project mitigation. RMC 4-3-050 G 3. Native Growth Protection Areas: a. Required: A native growth protection area shall be instituted to protect a critical area from any proposed development for a non-exempt activity as follows: i. Protected slopes and their associated buffers. ii. Very high landslide hazard areas and their associated buffers. iii. Class F, Np, and Ns, as defined in subsection G7 of this Section, streams or lakes and their associated buffers. iv. Category I, II, III, or IV wetlands, as defined in subsection G9c of this Section, and their associated buffers. King County Comment: Category IV wetland Critical Areas shall institute Native Growth Protection. The code does not specify that the protection shall be an NGPE. Furthermore, the wetland would have to meet criteria as a regulated critical area and it does not. Critical Area Regulation Applicability RMC 4-3-050.B.1 1. Lands to Which These Regulations Apply and Non-regulated Lands: The following critical areas are regulated by this Section. Multiple development standards may apply to a site feature based upon overlapping critical area(s) and/or critical area classifications: a. Flood hazard areas. b. Steep slopes (must have a minimum vertical rise of fifteen feet (15')), landslide hazards, erosion hazards, seismic hazards, and/or coal mine hazards or on sites within fifty feet (50') of steep slopes, landslide hazards, erosion hazards, seismic hazards, and/or coal mine hazards classified under RMC 4-3-050G5a which are located on abutting or adjacent sites. c. Habitat Conservation Areas. d. Streams and Lakes. All applicable requirements of this Section apply to Class F, Np, and Ns water bodies, as defined in subsection G7 of this Section or on sites within one hundred feet (100') of Class F, Np, and Ns water bodies, except Type S water bodies, inventoried as “Shorelines of the State,” are not subject to this Section, and are regulated in RMC 4-3-090, Shoreline Master Program Regulations, and RMC 4-9-190, Shoreline Permits. e. Wellhead Protection Areas. f. Wetlands, Categories I, II, III, and IV or on sites within two hundred feet (200') of Category I, II, III, and IV wetlands. Critical Area Regulation Wetlands created or restored as a part of a mitigation project are regulated wetlands. Regulated wetlands do not include those artificial wetlands intentionally created from nonwetland sites, including, but not limited to, irrigation and drainage ditches, grass-lined swales, canals, detention facilities, wastewater treatment facilities, farm ponds, and landscape amenities, or those wetlands created after July 1, 1990, that were unintentionally created as a result of the construction of a road, street, or highway. King County Comment: The landscaped wet area does meets criteria of a Category IV wetland, it does not meet criteria as a regulated wetland. Regulated wetlands do not include artificial wetlands created from landscape amenities. Critical Area Regulation - Photos Location of Landscaping and past construction at South Plant 1998 2000 2002 2005 2007 2009 2012 2013 2015 ~1998 Critical Area Regulation - Photos 1995 – Waterworks garden staging area Critical Area Regulation - Photos 2004 - Cogeneration Project Staging Area Essential Public Facility WAC 365-196-550 Essential public facilities. (3) Preclusion of essential public facilities. (a) Cities and counties may not use their comprehensive plan or development regulations to preclude the siting of essential public facilities. Comprehensive plan provisions or development regulations preclude the siting of an essential public facility if their combined effects would make the siting of an essential public facility impossible or impracticable. (i) Siting of an essential public facility is "impracticable" if it is incapable of being performed or accomplished by the means employed or at command. (ii) Impracticability may also include restrictive zoning; comprehensive plan policies directing opposition to a regional decision; or the imposition of unreasonable conditions or requirements. (iii) Limitations on essential public facilities such as capacity limits; internal staffing requirements; resident eligibility restrictions; internal security plan requirements; and provisions to demonstrate need may be considered preclusive in some circumstances. King County Comment: South Plant is an essential public facility. WAC 365-196-550, prevents Cities from using development regulations from precluding the siting of essential public utilities. In this case, the HEX Report decision requiring placement of a Native Growth Protection Easement (defined as: A restrictive area where all native, predevelopment vegetation shall not be disturbed or removed except for removal pursuant to an approved enhancement program.) over this location on the South Plant site would preclude the siting of expansion buildings and facilities necessary to provide a public service. With such a restrictive condition on the land use, it would be impossible and impractical to use this space for the future expansion needs of the site. Essential Public Facility Proposed future expansion configuration 1 – South Plant ~Location of NGPE requirement. Prevents future digester 8. Essential Public Facility Proposed ultimate layout for full expansion configuration 1 – South Plant 1991 facility plan ~Location of NGPE requirement. Prevents future digester 8. | South Plant Biogas and Heat Systems Improvement i ESA / 150513 Wetland Assessment May 2018 TABLE OF CONTENTS South Plant Biogas and Heat Systems Improvements Project Page 1.0 PROJECT AUTHORIZATION AND SCOPE OF WORK ................................................... 1 2.0 EXECUTIVE SUMMARY ..................................................................................................... 1 3.0 PROJECT OVERVIEW ....................................................................................................... 1 3.1 Project Description ..................................................................................................... 1 3.2 Site Conditions ........................................................................................................... 2 4.0 METHODS ........................................................................................................................... 3 4.1 Review of Existing Information ................................................................................... 3 4.2 On-site Investigation ................................................................................................... 3 4.2.1 Determining the Presence of Wetlands and Delineating Wetland Boundaries ................................................................................................... 3 4.2.3 Assessing Wetland Functions ........................................................................ 4 5.0 REVIEW OF EXISTING INFORMATION ............................................................................ 4 5.1 Soils Mapping ............................................................................................................. 4 5.2 Wetland Inventories .................................................................................................... 4 6.0 RESULTS ............................................................................................................................ 5 6.1 Wetland Delineation ................................................................................................... 5 6.1.1 Wetland B ....................................................................................................... 5 6.1.1 Landscaped Amenity “wet area” (previously identified as “Wetland A”) ................................................................................................................. 6 7.0 REGULATORY REQUIREMENTS ..................................................................................... 7 7.1 Federal Regulatory Requirements ............................................................................. 8 7.2 State Regulatory Requirements ................................................................................. 8 7.3 Local Regulatory Requirements ................................................................................. 8 8.0 PROJECT IMPACTS ......................................................................................................... 10 8.1 Project Impacts Reviewed Under RMC 4-3-050 – Critical Areas Regulations ........ 10 8.2 Project Impacts Reviewed Under RMC 4-3-090 - Shoreline Master Program Regulations ........................................................................................................... 11 9.0 CONCLUSIONs ................................................................................................................. 11 10.0 LIMITATIONS .................................................................................................................. 11 11.0 REFERENCES ................................................................................................................ 12 South Plant Biogas and Heat Systems Improvement ii ESA / 150513 Wetland Assessment May 2018 Appendices A. Wetland Definition ........................................................................................................ A-1 B. Wetland Determination Data Sheets ............................................................................ B-1 C. Washington State Wetland Rating System and Rating Forms .................................... C-1 Figures and Photos Figure 1. ................................................................................................................. Project Limits Figure 2. ................................................................................................................... Vicinity Map Figure 3. ......................................................................................................... Wetland Locations Photos Table of Contents Page South Plant Biogas and Heat Systems Improvement iii ESA / 150513 Wetland Assessment May 2018 Acronyms and Abbreviations COR City of Renton Ecology Washington State Department of Ecology ESA Environmental Science Associates GPS Global Positioning System HERB Heat and Energy Recovery Building HSSG high pressure scrubber sludge gas iMap Interactive Mapping NRCS Natural Resources Conservation Service NWI National Wetlands Inventory PHS Priority Habitats and Species PSE Puget Sound Energy South Plant South Treatment Plant USFWS U.S. Fish and Wildlife Service WDFW Washington Department of Fish and Wildlife WRIA Water Resource Inventory Area WTD King County Wastewater Treatment Division South Plant Biogas and Heat Systems Improvement 1 ESA / 150513 Wetland Assessment May 2018 1.0 PROJECT AUTHORIZATION AND SCOPE OF WORK Environmental Science Associates (ESA) was retained by Brown and Caldwell, on behalf of King County Wastewater Treatment Division (WTD), to conduct a critical areas review for the South Treatment Plant Biogas and Heat Systems Improvements Project. At the request of WTD, ESA conducted wetland determinations on the project site and delineated wetland boundaries north of the project site, and prepared this technical report. This report is organized to meet the requirements of City of Renton Critical Areas Ordinance (Renton Municipal Code [RMC] 4-3-050). ESA’s scope of work was limited to the identification and delineation of wetlands within the project area and within 200 feet of the project area as required by (RMC 4-3-050(B)(1)(f)). Other types of critical areas regulated by the City, such as streams, critical aquifer recharge areas, geologically hazardous areas, and frequently flooded areas, are not addressed in this report. 2.0 EXECUTIVE SUMMARY Review of the existing information did not indicate the presence of any wetlands within the project area. One wetland (Wetland B) was identified and delineated off-site to the north in the Waterworks Gardens during the September 2017 site visit (Figure 3). This wetland meets the regulatory definition of wetland under RMC 4-30-050.B.1. During the field investigation on November 2016, ESA also identified a small landscaped area with shallow surface water and wetland tolerant plants at the southwest end of a shallow swale south of the proposed building location. This feature was initially identified as “Wetland A” in the January 2018 Wetland Assessment Report. After further investigation, including review of historic aerial photos and discussions with King County Wastewater Treatment Division staff regarding past South Treatment Plant activities, this area was determined not to meet the regulatory definition of wetland under RMC .4-30-050.B.1. This report has been updated to describe this finding. 3.0 PROJECT OVERVIEW 3.1 Project Description King County proposes to replace South Plant’s Biogas Upgrading System (BUS) and heating system to improve the beneficial use of digester gas at South Plant while also reliably supplying heat to meet process and space heating demands. The King County South Plant Biogas and Heating Systems Project includes construction of a Heat and Energy Recovery Building (HERB), a new thermal oxidizer, heating system improvements within the existing Digester Equipment Building, and utility connections. The approximately 11,862 square foot (SF) HERB would be located in an area allocated for future plant expansion to meet capacity needs and regulatory requirements, where spoils from previous South Plant construction and expansion projects at the site were placed, forming a mound. The site slopes gradually South Plant Biogas and Heat Systems Improvement 2 ESA / 150513 Wetland Assessment May 2018 to the east towards the existing Solids MCC building and is maintained lawn grass over the mounded spoils. Previously placed spoils would be removed and the existing slope would be re-graded as part of building construction. Spoils excavated for the HERB (approximately 11,000 CY) would be moved to a separate spoils placement location on the South Plant site, located south of the HERB and the existing digesters within an open lawn area. Spoils would be compacted and seeded and planted to match existing grades and vegetation type. The project would include installation of new thermal oxidizer equipment located outside on a new concrete pad (approximately 2,437 SF) immediately south of the existing waste gas burners. The thermal oxidizer will combust waste gas from the BUS. See Figure 1, Project Limits. 3.2 Site Conditions The project is located at King County WTD’s South Plant, in an industrial area of the City of Renton at 1200 Monster Road SW. The project would occupy King County Parcel Numbers 2423049097 and 2423049006, which are located in the NE Quarter, Section 24, Township 23 North, Range 9 East. The subject parcels have been previously developed for South Plant construction and related expansion projects. The project site consists of maintained lawn grass on sloped terrain, created by fill from previous expansion projects. The entire site is located within Water Resource Inventory Area (WRIA) 9, the Green - Duwamish Watershed and the Lower Green River Subwatershed (King County, 2017a). The Green and Black rivers join the Duwamish River to the northwest of the South Plant. The Green River comes from the southwest of the South Plant while the Black River starts at a large wetland complex to the north and continues to the west and joins the Green River (Figure 2). Springbrook Creek flows along the east perimeter of the plant site before joining the Black River to the north. The proposed site for the HERB is currently a gently sloping area of maintained lawn grass that was filled and graded as part of previous South Plant construction and expansion projects. A shallow swale is located to the east and to the south of the proposed building location. The site where the new thermal oxidizer would be constructed is currently a gravel area with adjacent grass/lawn areas immediately south of the existing waste gas burners. Immediately north of the South Plant is Waterworks Gardens, a King County WTD-owned 8-acre public park. The gardens feature public use trails and constructed detention ponds and wetlands established to treat stormwater runoff from South Plant. These stormwater facilities feed into a natural wetland system that eventually outfalls through a culvert to Springbrook Creek. South Plant Biogas and Heat Systems Improvement 3 ESA / 150513 Wetland Assessment May 2018 4.0 METHODS 4.1 Review of Existing Information ESA reviewed existing literature, maps, and other materials to identify wetlands in the study area. These sources can only indicate the likelihood of the presence of wetlands; actual determinations must be based on data obtained from field investigations. Key sources of information included the following:  Natural Resources Conservation Service (NRCS) soils mapping (2017).  National Wetlands Inventory (NWI) mapping (USFWS, 2017).  Washington Department of Fish and Wildlife (WDFW) Priority Habitats and Species (PHS) data (2017).  King County Interactive Mapping (iMap) Tool (King County, 2017b).  City of Renton Critical Areas Map Series (City of Renton, 2017).  Washington Natural Heritage Program (WNHP) rare plant species and vegetation communities mapping (WNHP, 2017). 4.2 On-site Investigation 4.2.1 Determining the Presence of Wetlands and Delineating Wetland Boundaries The characteristics of an area that result in its classification as “wetland” have been formally defined by federal and state agencies, as described in Appendix A. Methods defined in Regional Supplements to the U.S. Army Corps of Engineers 1987 Wetlands Delineation Manual were used to determine the presence and extent of wetlands in the study area (Environmental Laboratory, 1987; Corps, 2010). The Washington State Department of Ecology (Ecology) repealed Washington Administrative Code (WAC) 173-22-080 (the state wetland delineation manual) and replaced it with a revision of WAC 173-22-035 that states that delineations should be done according to the currently approved federal manual and supplements (effective March 14, 2011). The methodology outlined in the manual is based on three essential characteristics of wetlands: (1) hydrophytic vegetation; (2) hydric soils; and (3) wetland hydrology. Field indicators of these three characteristics must all be present in order to determine that an area is a wetland (unless problem areas or atypical situations are encountered). The “routine on-site determination method” was used to define the wetland boundaries at the project site. The routine method is used for areas equal to or less than 5 acres in size, or for larger areas with relatively homogeneous vegetative, soil, and hydrologic properties. South Plant Biogas and Heat Systems Improvement 4 ESA / 150513 Wetland Assessment May 2018 Formal data plots were established, where information regarding each of the three wetland parameters (vegetation, soils, and hydrology) was recorded. This information was used to distinguish wetlands from non-wetlands. Wetland B, located off-site to the north, was investigated at a reconnaissance level, and formal data plots were not established. The southern boundary of Wetland B was delineated with sequentially numbered colored flagging imprinted with the words WETLAND DELINEATION. The southern boundary of Wetland B is shown on Figure 33. Data plot locations were also marked with colored flagging. Flagged points were recorded using a Global Positioning System (GPS) Trimble unit. Wetland determination data forms are included in Appendix B. 4.2.3 Assessing Wetland Functions Wetlands and buffers play important roles that provide valuable benefits to the environment and society. Because detailed scientific knowledge of wetland functions is limited, evaluations of the functions of individual wetlands are somewhat qualitative and dependent upon professional judgment. For this project, wetland functions were assessed using Ecology’s Wetland Rating System for Western Washington (Hruby, 2014). Although this system is designed to rate wetlands, it is based on whether a particular wetland performs a particular function and the relative level to which the function is performed. An assessment of wetland functions is inherent in the rating system. This system was developed by Ecology to differentiate wetlands based on their sensitivity to disturbance, their significance, their rarity, our ability to replace them, and the beneficial functions they provide to society. Appendix C provides additional information about the rating system, wetland categories, and completed rating forms for Wetland B. 5.0 REVIEW OF EXISTING INFORMATION 5.1 Soils Mapping The NRCS maps soils within the site as Puyallup fine sandy loam. Puyallup fine sandy loam is not considered a hydric soil type, although it has minor hydric inclusions. It is described as a well-drained soil, typically found on terraces and floodplains. This soil forms in alluvium in areas with average annual precipitation of 35 to 60 inches and mean annual temperature about 50 degrees Fahrenheit. Slopes are typically 0 to 2 percent. Minor components in the soil include Briscott (hydric), Newberg (hydric), Woodinville (hydric), Nooksack (nonhydric), and Oridia (hydric) (NRCS, 2017). 5.2 Wetland Inventories Wetland maps prepared by the NWI do not indicate the presence of any on-site or off-site wetlands within 200 feet of the project area. NWI mapping does show a riparian area associated with Springbrook Creek, which is several hundred feet east of the project area (USFWS, 2017). The WDFW PHS database does not identify any wetlands in the study area (WDFW, 2017). South Plant Biogas and Heat Systems Improvement 5 ESA / 150513 Wetland Assessment May 2018 City of Renton (COR) Critical Areas Mapping (City of Renton, 2017) does not identify any wetlands on the project site. COR mapping identifies a regulated shoreline associated with Springbrook Creek, east of the study area. In addition, an off-site wetland is mapped north of the project area within Waterworks Gardens. No rare plant species or high-quality vegetation communities are mapped in the study area or vicinity (WNHP, 2017). 6.0 RESULTS To identify and delineate wetlands on the project site, ESA biologists conducted two field investigations. The site was first visited by Claire Hoffman and Michael Muscari on November 22, 2016, and again by Tobin Story and Michael Muscari on September 7, 2017. The following sections describe the results of the two field visits. 6.1 Wetland Delineation Review of the existing information did not indicate the presence of any wetlands within the project area. On-site investigations also concluded that no wetlands occur within the project area. One wetland (Wetland B) was identified and delineation off-site to the north in the Waterworks Gardens during the September 2017 site visit (Figure 3). During the field investigation on November 2016, ESA also identified a small area with shallow surface water and wetland tolerant plants at the southwest end of a shallow swale south of the proposed building location. Review of the existing information did not indicate the presence of any wetlands within the project area. One wetland (Wetland B) was identified and delineated off-site to the north in the Waterworks Gardens during the September 2017 site visit (Figure 3). This wetland was found to meet the regulatory definition of wetland under RMC 4-30-050.B.1. During the field investigation on November 2016, ESA also identified a small landscaped area with shallow surface water and wetland tolerant plants at the southwest end of a shallow swale south of the proposed building location. This feature was previously identified as “Wetland A” in the January 2018 Wetland Assessment Report. After further investigation, including review of historic aerial photos and discussions with King County Wastewater Treatment Division staff regarding past South Treatment Plant activities, this landscaped area was determined not to meet the regulatory definition of wetland under RMC 4-30-050.B.1. Conditions in Wetland B and in the landscaped wet area are described in detail below. 6.1.1 Wetland B Overview. Wetland B consists of a series of depressions separated by a gravel pedestrian path, located north of the South Plant fence. The wetland has a gentle slope to the east, toward Springbrook Creek. Due to its offsite location, Wetland B was investigated at a reconnaissance level. Only the southern boundary was delineated by ESA, and total wetland size was not estimated. Formal data plots were not established for Wetland B. Confirmation of wetland presence and delineation of the wetland boundary was based on the presence of obligate wetland vegetation, clearly visible hydrology indicators, and South Plant Biogas and Heat Systems Improvement 6 ESA / 150513 Wetland Assessment May 2018 landscape topography. The wetland contains both palustrine emergent and palustrine forested vegetation communities. The wetland appears to be an enhanced or modified wetland feature associated with the constructed Waterworks Gardens, and only the south edge (nearest the property boundary and proposed project) was delineated; the wetland continues further north. Flag locations were surveyed using a handheld Trimble GPS unit. Photo 3 shows one of the seasonally ponded areas of Wetland B that was dry during the September 2017 site visit. Hydrology. The gravel path appears to be permeable and allows water exchange between depressions. A portion of the wetland is a wide swale. Hydrology for the wetland appears to enter from stormwater ponds to the west and north, and appears to exit through a 24-inch standpipe in the far eastern corner of the wetland (Photo 4). Water exiting the wetland through the standpipe drains to Springbrook Creek. Flow is unidirectional, as the standpipe elevation is approximately 15 feet higher than that of Springbrook Creek. Water was not observed at the standpipe during the site visit, but clear signs of prolonged inundation were observed in the vicinity. The wetland meets hydrology indicators B1, water marks, and B8, sparsely vegetation concave surface. Soils. Formal data plots were not established for Wetland B. Vegetation. Two Cowardin vegetation classes were observed in Wetland B. Forested areas observed on site consist of a forested overstory dominated by black cottonwood and red alder (Alnus rubra) with a shrub understory of dogwood (Cornus alba), salmonberry (Rubus spectabilis), and Himalayan blackberry (Rubus armeniacus). Vegetation in the palustrine emergent pockets consists primarily of cattail (Typha latifolia), although other native emergent species may be present in small amounts. Wetland Functions. Wetland B was rated as a depressional wetland. The wetland received an overall score of 20 points, which corresponds to a Category II rating. The wetland received a moderate score for water quality improvement functions (7 points); the wetland receives pollution inputs from several sources and has significant vegetative cover necessary to filter pollutants. The water quality functions provided by Wetland B have a high value to society, as Springbrook Creek, the Black River, and the Green River are all on the Washington State 303d list for water quality. Wetland B received a high score for hydrologic functions (8 points) due to a highly constricted outlet and significant depth of flooding during wet periods. The hydrologic functions provided by Wetland B have a high value due to providing flood attenuation for frequently flooded downstream reaches. Wetland B received a moderate score (5 points) for habitat functions. The wetland has a diverse number of habitats and hydroperiods, but lacks the landscape potential to support habitat since most of the surrounding landscape is highly developed. The wetland buffer is generally disturbed. 6.1.1 Landscaped Amenity “wet area” (previously identified as “Wetland A”) The landscaped area that extends along the east and south sides of the HERB project site was investigated with four data plots; locations for DP1, DP2, DP3, and DP4 are shown on Figure 3. At one of the data plots (DP3) conditions met all three wetland parameters. Data sheets are included in Appendix B. The wet area was estimated to be less than 2,000 square feet in size. Shallow surface water on highly South Plant Biogas and Heat Systems Improvement 7 ESA / 150513 Wetland Assessment May 2018 compacted soil was observed in November 2016 (Photo 6). Photo 7 shows the southwest end of the constructed swale that appears to bring surface flows to this wet area. Based on the young age of the trees and shrubs, and the constructed nature of the landscaped area, it appears as though this area is only recently developing wetland characteristics due to past development activities. The landscape in the project area has been reworked many times over at least the last 30 years and conditions are considerably different than the natural state. King County Wastewater Treatment Division staff have indicated that this area was constructed as a landscape amenity following a major project to upgrade South Treatment Plant’s secondary treatment. Review of aerial imagery (Google Earth) shows that in 1990 this entire area was an open field (Photo 8). In the mid-1990s, this area was used for heavy equipment staging during the plant’s secondary treatment upgrade (Photo 9). An aerial image from 2002 shows relatively new landscaping including grading, construction of a pathway, and planting of trees (Photo 10). Relatively current conditions are show in a 2017 aerial image (Photo 11). This series of aerial photos shows that the landscape was altered in the past, including stockpiling of spoils from other projects in the center of the field, use as staging area for construction, and landscaping including construction of a walking path and planting of trees and shrubs. The shallow swale flows south and then west along the edge of the field and terminates near the area we observed shallow surface ponding in November. RMC 4-30-050.B.1 exempts some artificially created wetlands from regulation. Regulated wetlands do not include those artificial wetlands intentionally created from nonwetland sites, including, but not limited to, irrigation and drainage ditches, grass-lined swales, canals, detention facilities, wastewater treatment facilities, farm ponds, and landscape amenities, or those wetlands created after July 1, 1990, that were unintentionally created as a result of the construction of a road, street, or highway. It is our conclusion that the area near DP3 containing wetland conditions is not a regulated wetland by City of Renton Municipal Code 4-30-050.B.1. The area around DP3 was created as a landscape amenity for the wastewater treatment facility in a location that is poorly drained due to previous soil compaction. Plants tolerant to poorly drained conditions were installed during landscaping. The landscape amenity appears to have been created in an area that was not previously wetland, based on our site observations and the aerial imagery discussed above. Water from this area does not flow out into the roadway to the west. Water ponds on the compacted soil and remains in the area until evaporated or transpired by plants, causing wetland conditions to develop in this artificially created feature. This wet area is isolated from any downslope wetlands and streams. 7.0 REGULATORY REQUIREMENTS This section provides an overview of regulations that may apply to the South Plant Biogas Project. Before approving a project that will impact wetlands, agencies require project applicants to document South Plant Biogas and Heat Systems Improvement 8 ESA / 150513 Wetland Assessment May 2018 that impacts have been avoided and minimized in accordance with the following preferred sequence for mitigation (e.g., WAC 197-11-768): a) Avoiding the impact altogether by not taking a certain action or parts of actions; b) Minimizing impacts by limiting the degree or magnitude of the action; c) Rectifying the impact by repairing, rehabilitating, or restoring the affected environment; d) Reducing or eliminating the impact over time by preservation and maintenance operations during the life of the action; or e) Compensating for the impact by replacing, enhancing, or providing substitute resources or environments. Applicants for permits to alter wetlands or their buffers must demonstrate that the above sequence has been followed to the greatest extent possible. Wetland impacts that cannot be avoided through the first two steps of the above sequence will require compensatory mitigation. 7.1 Federal Regulatory Requirements The U.S. Army Corps of Engineers regulates discharges of dredged or fill materials into waters of the United States, including wetlands and streams, under Section 404 of the Clean Water Act. The South Plant Biogas Project does not propose fill or other impacts to wetlands or waters of the U.S. As such, a Section 404 permit is not anticipated. 7.2 State Regulatory Requirements State permitting for activities in wetlands is administered by Ecology. The state certification process under Section 401 of the federal Clean Water Act is usually triggered through a Section 404 permit application. The South Plant Biogas Project does not propose fill or other impacts to wetlands or waters of the U.S., and a Section 404 permit is not anticipated. As such, a Section 401 permit is not anticipated. 7.3 Local Regulatory Requirements The City of Renton regulates critical areas and associated buffers through RMC 4-3-050, which requires that wetlands be rated using the Washington State Wetland Rating System for Western Washington 2014 update (RMC 4-3-050(G)(9)(c)). Using the 2014 Wetland Rating System, Wetland is classified as a Category II wetland with moderate habitat function (5 points). Wetland B requires a standard buffer width of 150 feet (RMC 4-30-050(G)(2)). In addition, RMC 4-3-050(G)(9)(d)(iv) requires applicants to document that increased wetland buffers are not warranted. Increased buffer widths may be required if: South Plant Biogas and Heat Systems Improvement 9 ESA / 150513 Wetland Assessment May 2018 a) The wetland is used by species listed by the federal or the state government as threatened, endangered, and sensitive species and state-listed priority species, essential habitat for those species or has unusual nesting or resting sites such as heron rookeries or raptor nesting trees or evidence thereof; or b) The buffer or adjacent uplands have a slope greater than 15 percent or is susceptible to erosion and standard erosion control measures will not effectively prevent adverse wetland impacts. c) The area is very fragile, or when a larger buffer is necessary to protect wetland functions and values. To the extent of our knowledge, Wetland B is not utilized by federal or state-listed species, nor does it provide essential habitat for those species. Although the far eastern portion of the wetland is relatively close to Springbrook Creek, it is physically disconnected from the creek, separated by approximately 15 feet vertically and 150 feet horizontally. The elevation difference precludes water from Springbrook Creek entering the wetland, and thus there is no apparent connection for listed salmonids to access habitat in Wetland B. A portion of the Wetland B buffer is located on slopes greater than 15 percent; however, these slopes are heavily vegetated, and no clearing, grading, or other impact is proposed on these slopes. Neither the wetland nor its buffer are especially fragile, and functions and values provided by this wetland are adequately protected by the standard width buffer. South Plant Biogas and Heat Systems Improvement 10 ESA / 150513 Wetland Assessment May 2018 8.0 PROJECT IMPACTS 8.1 Project Impacts Reviewed Under RMC 4-3-050 – Critical Areas Regulations As found in RMC 4-3-050(B)(1)(g), the City of Renton may not regulate certain upland sites separated from critical areas, based on the following conditions: sites are separated from critical areas by pre- existing, intervening, and lawfully created structures, roads, or other substantial existing improvements, which must: a) Separate the upland property from the critical area due to their height or width; and b) Substantially prevent or impair delivery of most functions from the subject upland property to the critical area. In the case of this project, the north plant road separates Wetland B from all project areas. The north plant road is approximately 20 feet wide, constructed of impervious material, with raised curbs approximately 6 inches in height (Photo 5). In addition, an approximately 8-foot wide paved path is located adjacent to road. The substantive width of the existing, impervious road, combined with the width of an existing paved trail and presence of vertical curb will serve as an effective barrier. These completely restrict and redirect the flow of ground and surface water, and otherwise impair delivery of functions from upland sites located within the project area to Wetland B. Stormwater from the plant road is collected and directed to the Waterworks Gardens located north of the plant. Current buffer functions performed by the buffer area north of the existing plant road will not be altered by proposed project actions. South Plant Biogas and Heat Systems Improvement 11 ESA / 150513 Wetland Assessment May 2018 8.2 Project Impacts Reviewed Under RMC 4-3-090 - Shoreline Master Program Regulations Wetland B is physically disconnected from Springbrook Creek and is not within the 100-year floodplain of Springbrook Creek, and, therefore, would not be considered an associated shoreline of Springbrook Creek. However, if the City of Renton determines that the wetland is regulated as a shoreline, RMC 4-3- 090(D)(2)(d)(iv)(a) states that “Buffers shall not include areas that are functionally and effectively disconnected from the wetland by a permanent road or other substantially developed surface of sufficient width and with use characteristics such that buffer functions are not provided and that cannot be feasibly removed, relocated, or restored to provide buffer functions.” As described above, the buffer of Wetland B is separated by the intervening plant road and trail. The delivery of buffer functions from the subject upland site to Wetland B is prevented by these intervening improvements. As a result, shoreline jurisdiction would end at the north edge of the plant road and would not extend onto the project site. 9.0 CONCLUSIONS No wetlands were identified within the project area and one wetland was identified and delineated within 200 feet of the project area. Wetland B is north of the project site and its regulated buffer does not overlap the project site. Wetland B is a Category II wetland that requires a buffer of 150 feet for high-impact land uses. The proposed project has been designed to avoid impacts to wetland areas and associated buffers. No impacts are proposed to wetlands or wetland buffers as a result of this project. No fill will be placed in wetlands or other waters of the U.S. 10.0 LIMITATIONS Within the limitations of schedule, budget, scope-of-work, and seasonal constraints, we warrant that this study was conducted in accordance with generally accepted environmental science practices, including the technical guidelines and criteria in effect at the time this study was performed, as outlined in the Methods section. The results and conclusions of this report represent the authors’ best professional judgment, based on information provided by the project proponent in addition to that obtained during the course of this study. No other warranty, expressed or implied, is made. South Plant Biogas and Heat Systems Improvement 12 ESA / 150513 Wetland Assessment May 2018 11.0 REFERENCES City of Renton. 2017. Online Mapping Portal. Available: http://rp.rentonwa.gov/Html5Public/Index.html?viewer=CORMaps. Corps (U.S. Army Corps of Engineers). 2005. Regulatory Guidance Letter No. 05-05: Ordinary High Water Mark Identification. December 7, 2005. Corps (U.S. Army Corps of Engineers). 2010. Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region. Version 2. Wetlands Regulatory Assistance Program. May 2010. ERDC/EL TR-10-3. Available: https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1046494.pdf. Corps (U.S. Army Corps of Engineers). 2014. 2014 NWPL Home v3.2 - Home Page, National Wetland Plant List. Available: http://rsgisias.crrel.usace.army.mil/NWPL/.Environmental Laboratory. 1987. Corps of Engineers Wetlands Delineation Manual. Technical Report Y-87-1. U.S. Army Engineer Waterways Experiment Station, Vicksburg, Mississippi. Hruby, T. 2014. Washington State Wetland Rating System for Western Washington – Revised. October 2014. Ecology publication number 14-06-029. Olympia, WA. King County. 2017a. Map of WRIA 9. Green/Duwamish and Central Puget Sound Watershed. Available: http://www.govlink.org/watersheds/9/. Accessed November 2017. King County. 2017b. King County iMap, Interactive Mapping Tool. Available at: http://www.kingcounty.gov/services/gis/Maps/imap.aspx. Accessed November 2017.Munsell Color. 2000. Munsell Soil Color Charts. GretagMacbeth, New Windsor, New York. NRCS (Natural Resources Conservation Service). 1995. Hydric Soils List for Washington. Revised December 15, 1995.NRCS (Natural Resources Conservation Service). 2010. Field Indicators of Hydric Soils in the United States - A Guide for Identifying and Delineating Hydric Soils. Version 7.0, 2010. ftp://ftp-fc.sc.egov.usda.gov/NSSC/Hydric_Soils/FieldIndicators_v7.pdf. NCRS (Natural Resources Conservation Service). 2017. Online soils mapping. Available: http://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm. USFWS (U.S. Fish and Wildlife Service). 2017. National Wetlands Inventory – online wetlands mapping. Available: http://www.fws.gov/wetlands/Data/Mapper.html. Vepraskas, M.J. 1999. Redoximorphic Features for Identifying Aquic Conditions. Technical Bulletin 301. North Carolina Agricultural Research Service, North Carolina State University, Raleigh, North Carolina. WDFW (Washington Department of Fish and Wildlife). 2017. Priority habitats and species online mapping. Available: http://wdfw.wa.gov/mapping/phs/. WNHP (Washington Natural Heritage Program). 2017. Rare plant species and vegetation communities GIS mapping. South Plant Biogas and Heat Systems Improvement 13 ESA / 150513 Wetland Assessment May 2018 FIGURES AND PHOTOGRAPHS EXISTING SPOILS TO BE REMOVED FIGURE 1 - PROJECT LIMITS %&e( ^_ King County SouthTreatment Plant Project Site B la c k R iv e r DuwamishRiver GreenRiverWaterworks Gardens Spr i ngbr ookCr ee k 61stAveSSW 27th St MartinLutherKing Jun i o r W a y S S 143rd St Baker Blvd Tukwila Parkway RentonAveS Andover Park WS 133rd St Andover Park ESWSunset Blvd MonsterRdSWS 132nd St Southcenter Blvd SW 7th St Strander Blvd S Langston Rd SW 16th St LindAveSWI n t e r u r b a n Av e SSW Grady Way OakesdaleAveSW6 8 t h Av e S W Valley RdPath: U:\GIS\GIS\Projects\15xxxx\D150513_SouthPlantBioGas\03_MXDs_Projects\Fig01_Vicinity.mxd, anakae 1/11/2017SOURCE: City of Renton 2015; OSM 2015; ESA 2017 0 2,000 Feet South Plant Biogas and Heat Systems Improvements Figure 2 Vicinity Map N Project Site Wetland B Heating and Energy Recovery Building Thermal Oxidizer $$$$150-ft. Wetland Buffer buffer ends at r o a d e d g e $$Plant Road 12812 5 1 2 6 130129126128 127 DP-2 DP-1 DP-4 DP-3 Path: U:\GIS\GIS\Projects\15xxxx\D150513_SouthPlantBioGas\03_MXDs_Projects\Fig3_Wetlands_PDF.mxd, cstruthers 4/25/2018SOURCE: NAIP 2015 South Treatment Plant Biogas and Heat Systems Improvements Project Figure 3Wetland Delineation N 0 200 Feet Wetland Survey Points Wetland Grading Contours Project Area 150-ft. Wetland Buffer Study Area Photo 1. Proposed Thermal Oxidizer Site (November 2016). Photo 2. Proposed HERB construction site to the right. Northeast end of constructed swale in foreground (November 2016). Photo 3. One of the seasonally ponded areas of Wetland B, off-site to the north (September 2017). Photo 4. Outlet to Wetland B (September 2017). Photo 5. Looking west along Plant Road just north of the proposed HERB site. Wetland B is off-site to the right of photo (November 2016). Photo 6. Shallow ponding on compacted soil near DP3 (November 2016). Photo 7. Looking east at southwest end of constructed swale near DP4 (November 2016). Photo 8. Aerial image from 1990 showing proposed project area was open field. Photo 9. Aerial image from mid-1990 during South Treatment Plant’s upgrade to secondary treatment. Photo 10. Aerial image from 2002 showing new landscaping. Photo 11. Aerial image from 2017 showing approximate existing site conditions. South Plant Biogas and Heat Systems Improvement A-1 ESA / 150513 Wetland Assessment May 2018 APPENDIX A: WETLAND DEFINITION AND METHODOLOGY South Plant Biogas & Heat Systems Improvement A-3 ESA / 150513 Wetland Assessment May 2018 Wetland Definition Wetlands are formally defined by the U.S. Army Corps of Engineers (Corps) (Federal Register 1982), the Environmental Protection Agency (EPA) (Federal Register 1988), the Washington Shoreline Management Act (SMA) of 1971 and the Washington State Growth Management Act (GMA) as follows: … those areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas (Federal Register, 1982, 1986). In addition, the SMA and the GMA definitions add: Wetlands do not include those artificial wetlands intentionally created from non-wetland site, including, but not limited to, irrigation and drainage ditches, grass-lined swales, canals, detention facilities, wastewater treatment facilities, farm ponds, and landscape amenities, or those wetlands created after July 1, 1990 that were unintentionally created as a result of the construction of a road, street, or highway. Wetlands may include those artificially created wetlands intentionally created from non-wetland areas to mitigate the conversion of wetlands. Methods defined in the Western Mountains, Valleys, and Coast Regional Supplement (Corps, 2010) to the U.S. Army Corps of Engineers 1987 Wetlands Delineation Manual (Manual) were used to determine the presence and extent of wetlands on the subject property and within 200 feet. These methods are consistent with state requirements in WAC 173-22-035. The methodology outlined in the manuals is based upon three essential characteristics of wetlands: (1) hydrophytic vegetation; (2) hydric soils; and (3) wetland hydrology. Field indicators of these three characteristics must all be present in order to determine that an area is a wetland (unless problem areas or atypical situations are encountered). These characteristics are discussed below. Vegetation Plants must be specially adapted for life under saturated or anaerobic conditions to grow in wetlands. The Corps of Engineers has determined the estimated probability of each plant species’ occurrence in wetlands and has accordingly assigned a “wetland indicator status” (WIS) to each species (Corps, 2016). Plants are categorized as obligate (OBL), facultative wetland (FACW), facultative (FAC), facultative upland (FACU), upland (UPL), not listed (NL), or no indicator status (NI). Definitions for each indicator status are listed below. Species with an indicator status of OBL, FACW, or FAC are considered adapted for life in saturated or anaerobic soil conditions. Such species are referred to as “hydrophytic” vegetation. Key to Wetland Indicator Status codes: OBL Obligate: species that almost always occur wetlands under natural conditions (est. probability >99%). South Plant Biogas & Heat Systems Improvement A-4 ESA / 150513 Wetland Assessment May 2018 FACW Facultative wetland: species that usually occur in wetlands (est. probability 67 to 99%), but are occasionally found in non-wetlands. FAC Facultative: Species that are equally likely to occur in wetlands or non-wetlands (est. probability 34 to 66%). FACU Facultative upland: species that usually occur in non-wetlands (est. probability 67 to 99%), but are occasionally found in wetlands. UPL Upland: species that almost always occur in non-wetlands under normal conditions (est. probability >99%). NL Not listed: species that are not listed by USFWS (1988, 1993) and are presumed to be upland species. NI No indicator: species for which insufficient information is available to determine status, or which were not evaluated by USFWS. Areas of relatively homogeneous vegetative composition can be characterized by “dominant” species. The indicator status of the dominant species within each vegetative stratum is used to determine if the plant community may be characterized as hydrophytic. The vegetation of an area is considered to be hydrophytic if more than 50% of the dominant species have an indicator status of OBL, FACW, or FAC. The Regional Supplements provide additional tests for evaluating the presence of hydrophytic vegetation communities including the prevalence index, morphological adaptations, and wetland non- vascular plants. The Supplements also address difficult situations where hydrophytic vegetation indicators are not present but hydric soils and wetland hydrology are observed. Soils Hydric soils are indicative of wetlands. Hydric soils are defined as soils that are saturated, flooded, or ponded long enough during the growing season to develop anaerobic conditions in the upper part of the soil profile (Federal Register, 1994). The Natural Resources Conservation Service (NRCS), in cooperation with the National Technical Committee for Hydric Soils, has compiled lists of hydric soils (NRCS, 1995). These lists identify soil series mapped by the NRCS that meet hydric soil criteria. It is common, however, for a map unit of non-wetland (non-hydric) soil to have inclusions of hydric soil, and vice versa. Therefore, field examination of soil conditions is important to determine if hydric soil conditions exist. The NRCS has developed a guide for identifying field indicators of hydric soils (NRCS, 2010). This list of hydric soil indicators is considered to be dynamic; revisions are anticipated to occur on a regular basis as a result of ongoing studies of hydric soils. In general, anaerobic conditions create certain characteristics in hydric soils, collectively known as “redoximorphic features,” that can be observed in the field (Vepraskas, 1999). Redoximorphic features include high organic content, accumulation of sulfidic material (rotten egg odor), greenish- or bluish-gray color (gley formation), spots or blotches of different color interspersed with the dominant or matrix color (mottling), and dark soil colors (low soil chroma) (NRCS, 2010; Vepraskas, 1999). Soil colors are described both by common color name (for example, “dark brown”) and by a numerical description of their hue, value, and chroma (for example, 10YR 2/2) as South Plant Biogas & Heat Systems Improvement A-5 ESA / 150513 Wetland Assessment May 2018 identified on a Munsell soil color chart (Munsell Color, 2000). Soil color is determined from a moist soil sample. The Regional Supplements provide methods for difficult situations where hydric soil indicators are not observed, but indicators of hydrophytic vegetation and wetland hydrology are present. Hydrology Water must be present in order for wetlands to exist; however, it need not be present throughout the entire year. Wetland hydrology is considered to be present when there is permanent or periodic inundation or soil saturation at or near the soil surface for more than 14 consecutive days during the growing season at a minimum frequency of 5 years in 10 (Corps, 2010). Indicators of wetland hydrology include observation of ponding or soil saturation, water marks, drift lines, drainage patterns, sediment deposits, oxidized rhizospheres, water-stained leaves, and local soil survey data. Where positive indicators of wetland hydrology are observed, it is assumed that wetland hydrology occurs for a sufficient period of the growing season to meet the wetland criteria, as described by Corps (2010). The Regional Supplements provide methods for evaluating situations in wetlands that periodically lack indicators of wetland hydrology but where hydric soils and hydrophytic vegetation are present. South Plant Biogas Heat Systems Improvement B-1 ESA / 150513 Wetland Assessment May 2018 APPENDIX B: WETLAND DETERMINATION DATA SHEETS South Plant Biogas Heat Systems Improvement C-1 ESA / 150513 Wetland Assessment May 2018 APPENDIX C: WASHINGTON STATE WETLAND RATING SYSTEM AND RATING FORMS South Plant Biogas Heat Systems Improvement C-1 ESA / 150513 Wetland Assessment May 2018 Washington State Wetland Rating System The observed wetlands were rated using the Washington State Department of Ecology’s Wetland Rating System for Western Washington (Hruby, 2014). This system was developed by Ecology to differentiate wetlands based on their sensitivity to disturbance, their significance, their rarity, our ability to replace them, and the beneficial functions they provide to society. Wetlands are categorized using the Ecology rating system according to the following criteria: Category I wetlands represent a unique or rare wetland type; or are more sensitive to disturbance; or are relatively undisturbed and contain ecological attributes that are impossible to replace within a human lifetime. Category II wetlands are difficult, though not impossible, to replace, and provide high levels of some functions. Category III wetlands have a moderate level of function. They have been disturbed in some ways, and are often less diverse or more isolated from other natural resources in the landscape than Category II wetlands. Category IV wetlands have the lowest levels of functions and are often heavily disturbed. Wetland name or number Wetland B Name of wetland (or ID #):Date of site visit:9/7/2017 Rated by Trained by Ecology? Yes No Date of training Mar-15 HGM Class used for rating Wetland has multiple HGM classes? Yes No NOTE: Form is not complete with out the figures requested (figures can be combined ). Source of base aerial photo/map OVERALL WETLAND CATEGORY II (based on functions or special characteristics ) 1. Category of wetland based on FUNCTIONS Category I - Total score = 23 - 27 Score for each X Category II - Total score = 20 - 22 function based Category III - Total score = 16 - 19 on three Category IV - Total score = 9 - 15 ratings (order of ratings is not important ) M M 9 = H, H, H H L 8 = H, H, M H M Total 7 = H, H, L 7 = H, M, M 6 = H, M, L 6 = M, M, M 5 = H, L, L 5 = M, M, L 4 = M, L, L 3 = L, L, L 2. Category based on SPECIAL CHARACTERISTICS of wetland None of the above Coastal Lagoon Interdunal Value Score Based on Ratings 7 8 5 20 H CHARACTERISTIC Category Estuarine Wetland of High Conservation Value Bog Mature Forest Old Growth Forest Depressional & Flats RATING SUMMARY – Western Washington List appropriate rating (H, M, L) HydrologicImproving Water Quality MSite Potential Landscape Potential Habitat M FUNCTION Biogas Wetland B T. Story Wetland Rating System for Western WA: 2014 Update Rating Form - Effective January 1, 2015 1 WSDOT Adapted Form - March 2, 2015 Wetland name or number Wetland B Maps and Figures required to answer questions correctly for Western Washington Depressional Wetlands Map of: Figure # Cowardin plant classes Hydroperiods Location of outlet (can be added to map of hydroperiods ) Boundary of area within 150 ft of the wetland (can be added to another figure ) Map of the contributing basin 1 km Polygon: Area that extends 1 km from entire wetland edge - including polygons for accessible habitat and undisturbed habitat Screen capture of map of 303(d) listed waters in basin (from Ecology website) Screen capture of list of TMDLs for WRIA in which unit is found (from web) Riverine Wetlands Map of: Figure # Cowardin plant classes Hydroperiods Ponded depressions Boundary of area within 150 ft of the wetland (can be added to another figure ) Plant cover of trees, shrubs, and herbaceous plants Width of unit vs. width of stream (can be added to another figure ) Map of the contributing basin 1 km Polygon: Area that extends 1 km from entire wetland edge - including polygons for accessible habitat and undisturbed habitat Screen capture of map of 303(d) listed waters in basin (from Ecology website) Screen capture of list of TMDLs for WRIA in which unit is found (from web) Lake Fringe Wetlands Map of: Figure # Cowardin plant classes Plant cover of trees, shrubs, and herbaceous plants Boundary of area within 150 ft of the wetland (can be added to another figure ) 1 km Polygon: Area that extends 1 km from entire wetland edge - including polygons for accessible habitat and undisturbed habitat Screen capture of map of 303(d) listed waters in basin (from Ecology website) Screen capture of list of TMDLs for WRIA in which unit is found (from web) Slope Wetlands Map of: Figure # Cowardin plant classes Hydroperiods Plant cover of dense trees, shrubs, and herbaceous plants Plant cover of dense, rigid trees, shrubs, and herbaceous plants (can be added to another figure ) Boundary of area within 150 ft of the wetland (can be added to another figure ) 1 km Polygon: Area that extends 1 km from entire wetland edge - including polygons for accessible habitat and undisturbed habitat Screen capture of map of 303(d) listed waters in basin (from Ecology website) Screen capture of list of TMDLs for WRIA in which unit is found (from web) To answer questions: D 1.3, H 1.1, H 1.4 D 1.4, H 1.2 D 1.1, D 4.1 D 2.2, D 5.2 D 4.3, D 5.3 H 2.1, H 2.2, H 2.3 D 3.1, D 3.2 D 3.3 To answer questions: H 1.1, H 1.4 H 1.2 R 1.1 R 2.4 R 1.2, R 4.2 R 4.1 R 2.2, R 2.3, R 5.2 H 2.1, H 2.2, H 2.3 L 1.2 L 2.2 L 3.1, L 3.2 L 3.3 H 2.1, H 2.2, H 2.3 R 3.1 R 3.2, R 3.3 To answer questions: L 1.1, L 4.1, H 1.1, H 1.4 S 3.1, S 3.2 S 3.3 S 4.1 S 2.1, S 5.1 To answer questions: H 1.1, H 1.4 H 1.2 S 1.3 H 2.1, H 2.2, H 2.3 Wetland Rating System for Western WA: 2014 Update Rating Form - Effective January 1, 2015 2 WSDOT Adapted Form - March 2, 2015 Wetland name or number Wetland B For questions 1 -7, the criteria described must apply to the entire unit being rated. 1. Are the water levels in the entire unit usually controlled by tides except during floods? NO - go to 2 YES - the wetland class is Tidal Fringe - go to 1.1 1.1 Is the salinity of the water during periods of annual low flow below 0.5 ppt (parts per thousand)? NO - Saltwater Tidal Fringe (Estuarine)YES - Freshwater Tidal Fringe NO - go to 3 YES - The wetland class is Flats If your wetland can be classified as a Flats wetland, use the form for Depressional wetlands. 3. Does the entire wetland unit meet all of the following criteria? NO - go to 4 YES - The wetland class is Lake Fringe (Lacustrine Fringe) 4. Does the entire wetland unit meet all of the following criteria? The wetland is on a slope (slope can be very gradual ), The water leaves the wetland without being impounded. NO - go to 5 YES - The wetland class is Slope 5. Does the entire wetland unit meet all of the following criteria? The overbank flooding occurs at least once every 2 years. NO - go to 6 YES - The wetland class is Riverine NOTE: The Riverine unit can contain depressions that are filled with water when the river is not flooding. If hydrologic criteria listed in each question do not apply to the entire unit being rated, you probably have a unit with multiple HGM classes. In this case, identify which hydrologic criteria in questions 1 - 7 apply, and go to Question 8. At least 30% of the open water area is deeper than 6.6 ft (2 m). HGM Classification of Wetland in Western Washington If your wetland can be classified as a Freshwater Tidal Fringe use the forms for Riverine wetlands. If it is Saltwater Tidal Fringe it is an Estuarine wetland and is not scored. This method cannot be used to score functions for estuarine wetlands. The vegetated part of the wetland is on the shores of a body of permanent open water (without any plants on the surface at any time of the year) at least 20 ac (8 ha) in size; The water flows through the wetland in one direction (unidirectional) and usually comes from seeps. It may flow subsurface, as sheetflow, or in a swale without distinct banks. NOTE: Surface water does not pond in these type of wetlands except occasionally in very small and shallow depressions or behind hummocks (depressions are usually <3 ft diameter and less than 1 ft deep). The unit is in a valley, or stream channel, where it gets inundated by overbank flooding from that stream or river, 2. The entire wetland unit is flat and precipitation is the only source (>90%) of water to it. Groundwater and surface water runoff are NOT sources of water to the unit. Wetland Rating System for Western WA: 2014 Update Rating Form - Effective January 1, 2015 3 WSDOT Adapted Form - March 2, 2015 Wetland name or number Wetland B NO - go to 7 YES - The wetland class is Depressional NO - go to 8 YES - The wetland class is Depressional NOTES and FIELD OBSERVATIONS: 7. Is the entire wetland unit located in a very flat area with no obvious depression and no overbank flooding? The unit does not pond surface water more than a few inches. The unit seems to be maintained by high groundwater in the area. The wetland may be ditched, but has no obvious natural outlet. 8. Your wetland unit seems to be difficult to classify and probably contains several different HGM classes. For example, seeps at the base of a slope may grade into a riverine floodplain, or a small stream within a Depressional wetland has a zone of flooding along its sides. GO BACK AND IDENTIFY WHICH OF THE HYDROLOGIC REGIMES DESCRIBED IN QUESTIONS 1-7 APPLY TO DIFFERENT AREAS IN THE UNIT (make a rough sketch to help you decide). Use the following table to identify the appropriate class to use for the rating system if you have several HGM classes present within the wetland unit being scored. 6. Is the entire wetland unit in a topographic depression in which water ponds, or is saturated to the surface, at some time during the year? This means that any outlet, if present, is higher than the interior of the wetland. Riverine Treat as ESTUARINE Slope + Lake Fringe Depressional + Riverine along stream within boundary of depression Depressional + Lake Fringe Riverine + Lake Fringe NOTE: Use this table only if the class that is recommended in the second column represents 10% or more of the total area of the wetland unit being rated. If the area of the HGM class listed in column 2 is less than 10% of the unit; classify the wetland using the class that represents more than 90% of the total area. HGM classes within the wetland unit being rated Slope + Riverine Slope + Depressional Depressional Depressional If you are still unable to determine which of the above criteria apply to your wetland, or if you have more than 2 HGM classes within a wetland boundary, classify the wetland as Depressional for the rating. Salt Water Tidal Fringe and any other class of freshwater wetland HGM class to use in rating Riverine Depressional Lake Fringe Wetland Rating System for Western WA: 2014 Update Rating Form - Effective January 1, 2015 4 WSDOT Adapted Form - March 2, 2015 Wetland name or number Wetland B D 1.1. Characteristics of surface water outflows from the wetland: points = 3 points = 2 points = 1 points = 1 Yes = 4 No = 0 Wetland has persistent, ungrazed, plants > 95% of area points = 5 Wetland has persistent, ungrazed, plants > ½ of area points = 3 Wetland has persistent, ungrazed plants > 1/10 of area points = 1 Wetland has persistent, ungrazed plants < 1/10 of area points = 0 D 1.4. Characteristics of seasonal ponding or inundation: This is the area that is ponded for at least 2 months. See description in manual. Area seasonally ponded is > ½ total area of wetland points = 4 Area seasonally ponded is > ¼ total area of wetland points = 2 Area seasonally ponded is < ¼ total area of wetland points = 0 Total for D 1 Add the points in the boxes above 9 Rating of Site Potential If score is: 12 - 16 = H 6 - 11 = M 0 - 5 = L Record the rating on the first page D 2.1. Does the wetland unit receive stormwater discharges?Yes = 1 No = 0 1 Yes = 1 No = 0 D 2.3. Are there septic systems within 250 ft of the wetland?Yes = 1 No = 0 0 Source Yes = 1 No = 0 Total for D 2 Add the points in the boxes above 2 Rating of Landscape Potential If score is: 3 or 4 = H 1 or 2 = M 0 = L Record the rating on the first page Yes = 1 No = 0 Yes = 1 No = 0 Yes = 2 No = 0 Total for D 3 Add the points in the boxes above 4 Rating of Value If score is: 2 - 4 = H 1 = M 0 = L Record the rating on the first page D 3.3. Has the site been identified in a watershed or local plan as important for maintaining water quality (answer YES if there is a TMDL for the basin in which the unit is found )? D 1.2. The soil 2 in below the surface (or duff layer) is true clay or true organic (use NRCS definitions ). D 1.3. Characteristics and distribution of persistent plants (Emergent, Scrub-shrub, and/or Forested Cowardin classes): D 2.4. Are there other sources of pollutants coming into the wetland that are not listed in questions D 2.1 - D 2.3? D 3.1. Does the wetland discharge directly (i.e., within 1 mi) to a stream, river, lake, or marine water that is on the 303(d) list? D 2.2. Is > 10% of the area within 150 ft of the wetland in land uses that generate pollutants? D 3.2. Is the wetland in a basin or sub-basin where an aquatic resource is on the 303(d) list? D 3.0. Is the water quality improvement provided by the site valuable to society? 1 1 2 0 3 DEPRESSIONAL AND FLATS WETLANDS 1 0 Water Quality Functions - Indicators that the site functions to improve water quality D 1.0. Does the site have the potential to improve water quality? 2 Wetland has an unconstricted, or slightly constricted, surface outlet that is permanently flowing Wetland has an intermittently flowing stream or ditch, OR highly constricted permanently flowing outlet. Wetland is a depression or flat depression (QUESTION 7 on key) with no surface water leaving it (no outlet). Wetland is a flat depression (QUESTION 7 on key), whose outlet is a permanently flowing ditch. 4 D 2.0. Does the landscape have the potential to support the water quality function of the site? Wetland Rating System for Western WA: 2014 Update Rating Form - Effective January 1, 2015 5 WSDOT Adapted Form - March 2, 2015 Wetland name or number Wetland B D 4.1. Characteristics of surface water outflows from the wetland: points = 4 points = 2 points = 1 points = 0 Marks of ponding are 3 ft or more above the surface or bottom of outlet points = 7 Marks of ponding between 2 ft to < 3 ft from surface or bottom of outlet points = 5 Marks are at least 0.5 ft to < 2 ft from surface or bottom of outlet points = 3 The wetland is a “headwater” wetland points = 3 Wetland is flat but has small depressions on the surface that trap water points = 1 Marks of ponding less than 0.5 ft (6 in)points = 0 The area of the basin is less than 10 times the area of the unit points = 5 The area of the basin is 10 to 100 times the area of the unit points = 3 The area of the basin is more than 100 times the area of the unit points = 0 Entire wetland is in the Flats class points = 5 Total for D 4 Add the points in the boxes above 10 Rating of Site Potential If score is: 12 - 16 = H 6 - 11 = M 0 - 5 = L Record the rating on the first page D 5.1. Does the wetland unit receive stormwater discharges?Yes = 1 No = 0 1 D 5.2. Is > 10% of the area within 150 ft of the wetland in land uses that generate excess runoff? Yes = 1 No = 0 Yes = 1 No = 0 Total for D 5 Add the points in the boxes above 3 Rating of Landscape Potential If score is: 3 = H 1 or 2 = M 0 = L Record the rating on the first page points = 2 points = 1 Flooding from groundwater is an issue in the sub-basin.points = 1 points = 0 There are no problems with flooding downstream of the wetland.points = 0 Yes = 2 No = 0 Total for D 6 Add the points in the boxes above 2 Rating of Value If score is: 2 - 4 = H 1 = M 0 = L Record the rating on the first page 1 1 D 5.3. Is more than 25% of the contributing basin of the wetland covered with intensive human land uses (residential at >1 residence/ac, urban, commercial, agriculture, etc.)? The existing or potential outflow from the wetland is so constrained by human or natural conditions that the water stored by the wetland cannot reach areas that flood. Explain why 2 0 5 D 4.2. Depth of storage during wet periods: Estimate the height of ponding above the bottom of the outlet. For wetlands with no outlet, measure from the surface of permanent water or if dry, the deepest part. D 4.3. Contribution of the wetland to storage in the watershed: Estimate the ratio of the area of upstream basin contributing surface water to the wetland to the area of the wetland unit itself. D 6.1. The unit is in a landscape that has flooding problems. Choose the description that best matches conditions around the wetland unit being rated. Do not add points. Choose the highest score if more than one condition is met. D 6.2. Has the site been identified as important for flood storage or flood conveyance in a regional flood control plan? Hydrologic Functions - Indicators that the site functions to reduce flooding and stream degradation D 4.0. Does the site have the potential to reduce flooding and erosion? 2 Wetland is a depression or flat depression with no surface water leaving it (no outlet) Wetland has an unconstricted, or slightly constricted, surface outlet that is permanently flowing Wetland has an intermittently flowing stream or ditch, OR highly constricted permanently flowing outlet Wetland is a flat depression (QUESTION 7 on key), whose outlet is a permanently flowing ditch 3 D 5.0. Does the landscape have the potential to support hydrologic function of the site? D 6.0. Are the hydrologic functions provided by the site valuable to society? The wetland captures surface water that would otherwise flow down-gradient into areas where flooding has damaged human or natural resources (e.g., houses or salmon redds): Flooding occurs in a sub-basin that is immediately down- gradient of unit. Surface flooding problems are in a sub-basin farther down- gradient. DEPRESSIONAL AND FLATS WETLANDS Wetland Rating System for Western WA: 2014 Update Rating Form - Effective January 1, 2015 6 WSDOT Adapted Form - March 2, 2015 Wetland name or number Wetland B HABITAT FUNCTIONS - Indicators that site functions to provide important habitat H 1.0. Does the site have the potential to provide habitat? Aquatic bed 4 structures or more: points = 4 Emergent 3 structures: points = 2 Scrub-shrub (areas where shrubs have > 30% cover)2 structures: points - 1 Forested (areas where trees have > 30% cover)1 structure: points = 0 If the unit has a Forested class, check if : H 1.2. Hydroperiods Permanently flooded or inundated 4 or more types present: points = 3 Seasonally flooded or inundated 3 types present: points = 2 Occasionally flooded or inundated 2 types present: points = 1 Saturated only 1 types present: points = 0 Permanently flowing stream or river in, or adjacent to, the wetland Seasonally flowing stream in, or adjacent to, the wetland Lake Fringe wetland 2 points Freshwater tidal wetland 2 points H 1.3. Richness of plant species If you counted:> 19 species points = 2 5 - 19 species points = 1 < 5 species points = 0 H 1.4. Interspersion of habitats None = 0 points Low = 1 point Moderate = 2 points All three diagrams in this row are HIGH = 3 points 2 Check the types of water regimes (hydroperiods) present within the wetland. The water regime has to cover more than 10% of the wetland or ¼ ac to count (see text for descriptions of hydroperiods ). 2 Count the number of plant species in the wetland that cover at least 10 ft2.Different patches of the same species can be combined to meet the size threshold and you do not have to name the species. Do not include Eurasian milfoil, reed canarygrass, purple loosestrife, Canadian thistle 1 Decide from the diagrams below whether interspersion among Cowardin plants classes (described in H 1.1), or the classes and unvegetated areas (can include open water or mudflats) is high, moderate, low, or none. If you have four or more plant classes or three classes and open water, the rating is always high. These questions apply to wetlands of all HGM classes. The Forested class has 3 out of 5 strata (canopy, sub-canopy, shrubs, herbaceous, moss/ground-cover) that each cover 20% within the Forested polygon 2 H 1.1. Structure of plant community: Indicators are Cowardin classes and strata within the Forested class. Check the Cowardin plant classes in the wetland. Up to 10 patches may be combined for each class to meet the threshold of ¼ ac or more than 10% of the unit if it is smaller than 2.5 ac. Add the number of structures checked. Wetland Rating System for Western WA: 2014 Update Rating Form - Effective January 1, 2015 7 WSDOT Adapted Form - March 2, 2015 Wetland name or number Wetland B H 1.5. Special habitat features: Large, downed, woody debris within the wetland (> 4 in diameter and 6 ft long) Standing snags (dbh > 4 in) within the wetland Total for H 1 Add the points in the boxes above 10 Rating of Site Potential If Score is: 15 - 18 = H 7 - 14 = M 0 - 6 = L Record the rating on the first page H 2.0. Does the landscape have the potential to support the habitat function of the site? H 2.1 Accessible habitat (include only habitat that directly abuts wetland unit ). Calculate: 3 % undisturbed habitat + (5 % moderate & low intensity land uses / 2 ) = 5.5% If total accessible habitat is: > 1/3 (33.3%) of 1 km Polygon points = 3 20 - 33% of 1 km Polygon points = 2 10 - 19% of 1 km Polygon points = 1 < 10 % of 1 km Polygon points = 0 H 2.2. Undisturbed habitat in 1 km Polygon around the wetland. Calculate: 21 % undisturbed habitat + (5 % moderate & low intensity land uses / 2 ) = 23.5% Undisturbed habitat > 50% of Polygon points = 3 Undisturbed habitat 10 - 50% and in 1-3 patches points = 2 Undisturbed habitat 10 - 50% and > 3 patches points = 1 Undisturbed habitat < 10% of 1 km Polygon points = 0 H 2.3 Land use intensity in 1 km Polygon: If > 50% of 1 km Polygon is high intensity land use points = (-2) ≤ 50% of 1km Polygon is high intensity points = 0 Total for H 2 Add the points in the boxes above -1 Rating of Landscape Potential If Score is: 4 - 6 = H 1 - 3 = M < 1 = L Record the rating on the first page Site meets ANY of the following criteria:points = 2 It has 3 or more priority habitats within 100 m (see next page) It is mapped as a location for an individual WDFW priority species Site has 1 or 2 priority habitats (listed on next page) with in 100m points = 1 Site does not meet any of the criteria above points = 0 Rating of Value If Score is: 2 = H 1 = M 0 = L Record the rating on the first page Check the habitat features that are present in the wetland. The number of checks is the number of points. It has been categorized as an important habitat site in a local or regional comprehensive plan, in a Shoreline Master Plan, or in a watershed plan Undercut banks are present for at least 6.6 ft (2 m) and/or overhanging plants extends at least 3.3 ft (1 m) over a stream (or ditch) in, or contiguous with the wetland, for at least 33 ft (10 m) Stable steep banks of fine material that might be used by beaver or muskrat for denning (> 30 degree slope) OR signs of recent beaver activity are present (cut shrubs or trees that have not yet weathered where wood is exposed ) At least ¼ ac of thin-stemmed persistent plants or woody branches are present in areas that are permanently or seasonally inundated (structures for egg-laying by amphibians ) 3 It is a Wetland of High Conservation Value as determined by the Department of Natural Resources 1 Invasive plants cover less than 25% of the wetland area in every stratum of plants (see H 1.1 for list of strata ) 0 1 -2 H 3.0. Is the habitat provided by the site valuable to society? H 3.1. Does the site provide habitat for species valued in laws, regulations, or policies? Choose only the highest score that applies to the wetland being rated . It provides habitat for Threatened or Endangered species (any plant or animal on the state or federal lists) Wetland Rating System for Western WA: 2014 Update Rating Form - Effective January 1, 2015 8 WSDOT Adapted Form - March 2, 2015 Wetland name or number Wetland B Aspen Stands: Pure or mixed stands of aspen greater than 1 ac (0.4 ha). Herbaceous Balds: Variable size patches of grass and forbs on shallow soils over bedrock. Cliffs: Greater than 25 ft (7.6 m) high and occurring below 5000 ft elevation. Priority habitats listed by WDFW (see complete descriptions of WDFW priority habitats, and the counties in which they can be found, in: Washington Department of Fish and Wildlife. 2008. Priority Habitat and Species List. Olympia, Washington. 177 pp. Oregon White Oak: Woodland stands of pure oak or oak/conifer associations where canopy coverage of the oak component is important (full descriptions in WDFW PHS report p. 158 – see web link above ). Riparian: The area adjacent to aquatic systems with flowing water that contains elements of both aquatic and terrestrial ecosystems which mutually influence each other. Westside Prairies: Herbaceous, non-forested plant communities that can either take the form of a dry prairie or a wet prairie (full descriptions in WDFW PHS report p. 161 – see web link above ). Instream: The combination of physical, biological, and chemical processes and conditions that interact to provide functional life history requirements for instream fish and wildlife resources. Nearshore: Relatively undisturbed nearshore habitats. These include Coastal Nearshore, Open Coast Nearshore, and Puget Sound Nearshore. (full descriptions of habitats and the definition of relatively undisturbed are in WDFW report – see web link on previous page ). Snags and Logs: Trees are considered snags if they are dead or dying and exhibit sufficient decay characteristics to enable cavity excavation/use by wildlife. Priority snags have a diameter at breast height of > 20 in (51 cm) in western Washington and are > 6.5 ft (2 m) in height. Priority logs are > 12 in (30 cm) in diameter at the largest end, and > 20 ft (6 m) long. Talus: Homogenous areas of rock rubble ranging in average size 0.5 - 6.5 ft (0.15 - 2.0 m), composed of basalt, andesite, and/or sedimentary rock, including riprap slides and mine tailings. May be associated with cliffs. Caves: A naturally occurring cavity, recess, void, or system of interconnected passages under the earth in soils, rock, ice, or other geological formations and is large enough to contain a human. Note: All vegetated wetlands are by definition a priority habitat but are not included in this list because they are addressed elsewhere. WDFW Priority Habitats Count how many of the following priority habitats are within 330 ft (100 m) of the wetland unit: NOTE : This question is independent of the land use between the wetland unit and the priority habitat. Biodiversity Areas and Corridors: Areas of habitat that are relatively important to various species of native fish and wildlife (full descriptions in WDFW PHS report ). Old-growth/Mature forests: Old-growth west of Cascade crest – Stands of at least 2 tree species, forming a multi-layered canopy with occasional small openings; with at least 8 trees/ac (20 trees/ha) > 32 in (81 cm) dbh or > 200 years of age. Mature forests – Stands with average diameters exceeding 21 in (53 cm) dbh; crown cover may be less than 100%; decay, decadence, numbers of snags, and quantity of large downed material is generally less than that found in old-growth; 80-200 years old west of the Cascade crest. http://wdfw.wa.gov/publications/00165/wdfw00165.pdf or access the list from here: http://wdfw.wa.gov/conservation/phs/list/ Wetland Rating System for Western WA: 2014 Update Rating Form - Effective January 1, 2015 9 WSDOT Adapted Form - March 2, 2015 Wetland name or number Wetland B Wetland Type Category Check off any criteria that apply to the wetland. List the category when the appropriate criteria are met. SC 1.0. Estuarine Wetlands Does the wetland meet the following criteria for Estuarine wetlands? The dominant water regime is tidal, Vegetated, and With a salinity greater than 0.5 ppt Yes - Go to SC 1.1 No = Not an estuarine wetland SC 1.1. Yes = Category I No - Go to SC 1.2 SC 1.2.Is the wetland unit at least 1 ac in size and meets at least two of the following three conditions? Yes = Category I No = Category II SC 2.0. Wetlands of High Conservation Value (WHCV) SC 2.1. Yes - Go to SC 2.2 No - Go to SC 2.3 SC 2.2.Is the wetland listed on the WDNR database as a Wetland of High Conservation Value? Yes = Category I No = Not WHCV SC 2.3.Is the wetland in a Section/Township/Range that contains a Natural Heritage wetland? http://www1.dnr.wa.gov/nhp/refdesk/datasearch/wnhpwetlands.pdf Yes - Contact WNHP/WDNR and to SC 2.4 No = Not WHCV SC 2.4. Yes = Category I No = Not WHCV SC 3.0. Bogs SC 3.1. Yes - Go to SC 3.3 No - Go to SC 3.2 SC 3.2. Yes - Go to SC 3.3 No = Is not a bog SC 3.3. Yes = Is a Category I bog No - Go to SC 3.4 SC 3.4. Yes = Is a Category I bog No = Is not a bog NOTE: If you are uncertain about the extent of mosses in the understory, you may substitute that criterion by measuring the pH of the water that seeps into a hole dug at least 16 in deep. If the pH is less than 5.0 and the plant species in Table 4 are present, the wetland is a bog. Is an area with peats or mucks forested (> 30% cover) with Sitka spruce, subalpine fir, western red cedar, western hemlock, lodgepole pine, quaking aspen, Engelmann spruce, or western white pine, AND any of the species (or combination of species) listed in Table 4 provide more than 30% of the cover under the canopy? CATEGORIZATION BASED ON SPECIAL CHARACTERISTICS Is the wetland within a National Wildlife Refuge, National Park, National Estuary Reserve, Natural Area Preserve, State Park or Educational, Environmental, or Scientific Reserve designated under WAC 332-30-151? The wetland is relatively undisturbed (has no diking, ditching, filling, cultivation, grazing, and has less than 10% cover of non-native plant species. (If non-native species are Spartina , see page 25) At least ¾ of the landward edge of the wetland has a 100 ft buffer of shrub, forest, or un- grazed or un-mowed grassland. The wetland has at least two of the following features: tidal channels, depressions with open water, or contiguous freshwater wetlands. Has WDNR identified the wetland within the S/T/R as a Wetland of High Conservation Value and listed it on their website? Has the WA Department of Natural Resources updated their website to include the list of Wetlands of High Conservation Value? Does the wetland (or any part of the unit) meet both the criteria for soils and vegetation in bogs? Use the key below. If you answer YES you will still need to rate the wetland based on its functions . Does an area within the wetland unit have organic soil horizons, either peats or mucks, that compose 16 in or more of the first 32 in of the soil profile? Does an area within the wetland unit have organic soils, either peats or mucks, that are less than 16 in deep over bedrock, or an impermeable hardpan such as clay or volcanic ash, or that are floating on top of a lake or pond? Does an area with peats or mucks have more than 70% cover of mosses at ground level, AND at least a 30% cover of plant species listed in Table 4? Wetland Rating System for Western WA: 2014 Update Rating Form - Effective January 1, 2015 10 WSDOT Adapted Form - March 2, 2015 Wetland name or number Wetland B SC 4.0. Forested Wetlands Yes = Category I No = Not a forested wetland for this section SC 5.0. Wetlands in Coastal Lagoons Does the wetland meet all of the following criteria of a wetland in a coastal lagoon? Yes - Go to SC 5.1 No = Not a wetland in a coastal lagoon SC 5.1. Does the wetland meet all of the following three conditions? The wetland is larger than 1/10 ac (4350 ft2) Yes = Category I No = Category II SC 6.0. Interdunal Wetlands In practical terms that means the following geographic areas: Long Beach Peninsula: Lands west of SR 103 Grayland-Westport: Lands west of SR 105 Ocean Shores-Copalis: Lands west of SR 115 and SR 109 Yes - Go to SC 6.1 No = Not an interdunal wetland for rating SC 6.1. Yes = Category I No - Go to SC 6.2 SC 6.2.Is the wetland 1 ac or larger, or is it in a mosaic of wetlands that is 1 ac or larger? Yes = Category II No - Go to SC 6.3 SC 6.3. Yes = Category III No = Category IV Category of wetland based on Special Characteristics If you answered No for all types, enter “Not Applicable” on Summary Form The wetland is relatively undisturbed (has no diking, ditching, filling, cultivation, grazing), and has less than 20% cover of aggressive, opportunistic plant species (see list of species on p. 100). At least ¾ of the landward edge of the wetland has a 100 ft buffer of shrub, forest, or un- grazed or un-mowed grassland. Is the wetland west of the 1889 line (also called the Western Boundary of Upland Ownership or WBUO)? If you answer yes you will still need to rate the wetland based on its habitat functions. Is the wetland 1 ac or larger and scores an 8 or 9 for the habitat functions on the form (rates H,H,H or H,H,M for the three aspects of function)? Is the unit between 0.1 and 1 ac, or is it in a mosaic of wetlands that is between 0.1 and 1 ac? The wetland lies in a depression adjacent to marine waters that is wholly or partially separated from marine waters by sandbanks, gravel banks, shingle, or, less frequently, rocks The lagoon in which the wetland is located contains ponded water that is saline or brackish (> 0.5 ppt) during most of the year in at least a portion of the lagoon (needs to be measured near the bottom ) Does the wetland have at least 1 contiguous acre of forest that meets one of these criteria for the WA Department of Fish and Wildlife’s forests as priority habitats? If you answer YES you will still need to rate the wetland based on its functions. Old-growth forests (west of Cascade crest): Stands of at least two tree species, forming a multi-layered canopy with occasional small openings; with at least 8 trees/ac (20 trees/ha) that are at least 200 years of age OR have a diameter at breast height (dbh) of 32 in (81 cm) or more. Mature forests (west of the Cascade Crest): Stands where the largest trees are 80- 200 years old OR the species that make up the canopy have an average diameter (dbh) exceeding 21 in (53 cm). Wetland Rating System for Western WA: 2014 Update Rating Form - Effective January 1, 2015 11 WSDOT Adapted Form - March 2, 2015 I I I I I 4 I I I I 3 I I I I I I I I I I No. IRRIGATION LEGEND + + + + + + + A M • EXISTING (C3) EFFLUENT WATER MAIN (4") DUCTILE IRON UNLESS OTHERWISE NOrrD ON PLAN EXISTING (C4) RECLAIMED WATER MAIN DUCTILE IRON UNLESS OTHERWISE NOTED ON PLAN NEW RECLAIMED WATER MAIN 2" (UNLESS OTHERWISE NOTED ON PLANS) SCH. 80 PVC. TO BE INCLUDED IN THIS CONTRACT NEW (C3) EFFLUENT WATER MAIN 2" (UNLESS OTHERWISE NOTED) SCH. 80 PVC. TO BE INCLUDED IN THIS CONTRACT NEW (C4) IRRIGATION SLEEVE TO BE INCLUDED IN THIS CONTRACT NEW (C3) EFFLUENT IRRIGATION AREAS INSTALL POP-UP HEADS SIMILAR TO THE LAYOUT FOR IN DETAIL 2 SHEET 13. NEW RECLAIMED WATER IRRIGATION AREAS INSTALL 1" QUICK COUPLERS AS SHOWN ON PLANS. EXISTING (C4) RECLAIMED WATER IRRIGATION AREAS MAINTAIN EXISTING IRR. SYSTEM AND INSTALL 1" QUICK COUPLERS AS SHOWN ON PLANS. EXISTING (C3) EFFLUENT IRRIGATION AREAS CONTRACTOR SHALL ENSURE THESE AREA REMAIN IN FUNCTIONING ORDER. REWIRE VALVES WHERE INDICATED. "UTILITY GRADE" IRRIGATION 1" QUICK COUPLER BASED SYSTEM SPACE COUPLERS AS SHOWN ON PLANS. AREA OF EXISTING AND NEW IR~l~N EXISTING TO BE REWIRED TO~~,, \ CONTROLLER #1. INSTALL__>!' QUICK .\ COUPLERS AS SHOWN ON PLANS. \, GATE VALVE QUICK COUPLER VALVE 0 (1) EXISTING RAINBIRD-----._ IRRIGATION CONTROLLER EXISTING P.O.C. FOR C3 EFFLUENT WATER MAIN (4") EXISTING P.O.C. OR C4 RECLAIMED W TER MAIN (4") 2-1 /2" SCH. 80 PVC REVISION BY APP'D DA TE 8 ~ BI OWN AND CALDWELL C C \ t~, \ '.J ( \ I. ;-· / \',, --> r-- \ ,,; Designed By DanadJleva & Koen Jg Associates Plan,ieeo Urban Oo>1gnoco L•n~•c6po llrch,uc:, D CONTINUING ON DRAWING 12 DATUM NOTE: ~~'W, 1f!&.® j'S,.UAIS M&O:S:~1947) STATE OF WASHINGTON REGISTERED CH ~-----EXISTING P.O.C. FOR DES!llNED: \: \ RA, JH DRAWN: CHEO<Ell: JH AD, RA RECOMIIENDED, C3 EFFLUENT WATER MAIN (4") LIMIT OF PROJECT LINE. NEW IRRIGATION WORK TO BE WITHIN THIS BOUNDARY. REFERENCE PLANTING PLAN SHEETS L300-L323 TO ENSURE THAT ALL NEW PLANTING RECEIVES IRRIGATION. WHERE EXISTING IRRIGATION CROSSES OUTSIDE OF THIS BOUNDARY CONTRACTOR IS TO ENSURE THAT IRRIGATION SERVICE IS MAINTAINED TO THE EXISTING PLANTING OUTSIDE THE BOUNDARY DURING CONSTRUCTION AND IN WORKING CONDITION AFTER WORK HAS BEEN COMPLETED. '• (2) EXISTING RAINBIRD IRRIGATION CONTROLLERS King County Department of Natural Resources SOL"TH TREATMENT PLANT ENLARGEMENT Ill INTERNAL AND PERIMETER LANDSCAPING f.e==A.-DAN_AD_Jl_E_VA---ICON1RACT NO: APPROVED: IRRIGATION PLAN J. FERNANDES C93150C G H 5 4 3 2 DA'IE: MAY, 2000 FlLE ND: DRAWING NO! I 1 SHEET I I 5 I I EAST WALKWAY EDGE NECKLACE CURVE DATA CURVE PC PT NORTHING EASTING NORTHING EASTING RADIUS I C41 1811.61 1640.68 1887.85 1635.49 15.00' C43 1887.85 1635.49 1914.47 1635.94 31.50' C45 1921.56 1639.39 1935.65 1638.89 15.00' C47 1643.97 1634.07 1958.00 1630.44 27.00' C49 1958.00 1630.44 1961.64 1635.93 4.00' C51 1961.64 1635.93 1953.21 1643.37 12.50· C53 1945.87 1645.29 1933.77 1654.37 20.00· I 4 C55 1933.77 1654.37 1929.36 1656.80 5.00' C57 1918.20 1656.53 1899.65 1652.29 50.00' WEST WALKWAY EDGE NECKLACE CURVE DATA CURVE PC PT I NORTHING EASTING NORTHING EASTING RADIUS C44 1857.38 1626.07 1887.60 1624.81 C46 1887.60 1624.81 1910.93 1625.65 C48 1920.61 1630.96 1932.29 1629.47 C50 1936.05 1625.91 1962.41 1615.83 C52 1962.41 1615.83 1972.83 1633.20 I C54 1972.83 1633.20 1952.37 1649.81 C56 1947.51 1651.10 1941.35 1655.85 C58 1941.35 1655.85 1929.01 1662.96 C60 1926.14 1662.93 1921.30 1668.54 EAST WALKWAY EDGE NECKLACE LINE I LINE PC PT # NORTHING EASTING NORTHING EASTING L3 1914.47 1635.94 1921.56 1639.39 L5 1935.65 1638.89 1943.97 1634.07 L7 1953.21 1643.37 1945.87 1645.29 I L9 1929.36 1656.80 1918.20 1656.53 WEST WALKWAY EDGE I LINE PC # NORTHING EASTING L4 1910.93 1625.65 L6 1932.29 1629.47 LB 1952.37 1649.81 L10 1929.01 1662.96 I 2 I I I I BRUSH I I I No. REVISION BY APP'D DA TE BROWN AND CALDWELL Danadjteva & Koenig Associates Pla,.naro llrbanDaugno•• Land•o.apaArcn11oc,. Archnocto n DATUM NOTE: ~~Ii&!,'~ U.S.C. & O.S.(ADJusrm 1947} COORDINATES ARE BASED ON LOCAL. PLANT GRID WASTE GAS BURNER FACILITY DESIGNED: DRAWN: JH AD, JH, RA CHECKED: AO, RA 1"=20' RECOMMENDED: 1-:==A.=D-AN_AD_JJ_EV_A----fCONTRACT NO: APPROVED: \ J. FERNANDES C93150C 1938.59 1958.49 1977.60 1974.40 1978.02 1981.05 1981.91 1976.08 RADIUS 100.00' ARC LENGTH 16.28' 52.23' 22.21' 12.89' 35.26' 43.54' 49.90' ARC DELTA LENGTH 33.50° 58.47' .1· L36 • STONE WALKWAY© ATCH LINE~-- ~FSTONE WALKWAY TO TOP B.11.!(!)r.!' i!fttjSftURB ---~--'- ~--~~;~~ - King County Department of Natural Resources SOUTH TREATMENT PLANT ENLARGEMENT 11 I INTERNAL AND PERIMETER LANDSCAPING LAYOUT AND GRADING PLAN G H 4 3 2 ,. DATE: MAY, 2000 FILE NO: DRAIMNG NO: L2 SHEET I I I I I I I I I I I I I I I I I I I 5 4 2 ROAbv·"N" z 0 c., z 5 z r= z 0 () No. L36 " REVISION BY APP'D DA 1E BROWN AND CALDWELL C DanadJteva & Koentg Associates PJannaro Urbar> Doolgnor• Landocapa ArchlUCII ArcbLIIClo D DATUM NOTE: ~ JtON 100.00 EQUALS SEA LEVEL. 1929 • & G.S.(Al5JUsi>b 1947) COORDlNATES ARE BAS£D ON LOCAL Pl.ANT GRID E F DESIGNED, DRA'>N, DS AD, DM CHECKED: AD, RA RECOMMENDED: G H TW 123.75+/- BW 123.75+/- 6' STONE WALKWAY W ~ 1·~20· 0~::i.4 DEWATERING BUILDING King County Department of Natural Resources SOUTH TREATMENT PLANT ENLARGEMENT III .... _J ~ Cl z 0 c., z 5 z r= z 0 () INTERNAL AND PERIMETER LANDSCAPING 1--_A_. _oAN_AD_JIE_v_A---ICON CTN. APPROVE]}. LAYOUT AND GRADING PLAN J. FERNANDES C93150C F G H 4 3 DATE: MAY, 2000 FILE NO, DRAWING NO-. L3 SHEET I I I I I I I I I I I I I I I I I I I 5 4 3 2 A B ( I No. REVISION BY APP'D DA TE A 8 C I BR OWN AND CALDWELL C Designed By D ; t I j i l __ __/--....' )-" ii ~/// / / / I/ /71 I J I iJ DanadJleva & Koenig Associates I' !o.r>n a ro lirbo n D c 1111n~'" Lo nd ,co ~c A. r~ h l<CC I• Arch II cc I• D E DATUM NOTE: ~,t,~947) DESIGNED: G WASTE GAS BURNER FACILITY \ \ H ,) (22)PIAB , I C.:8 l 2S.2 l':, !i Ii I!; .1: I I 0 w~~efON AD, RA, OS King County Department of Natural Resources REGISTEAED ORA,.,., CHECKED: SCALE, SCALE 1 "=20' RECOMMENDED: . E ~ OS, JG AD, RA . ~O. b::.=A.=D_AN_AD_JIE_VA--fCONiRACT NO: APPR<MD: J. FERNANDES C93150C SOUTH TREATMENT PLANT ENLARGEMENT JJJ INTERNAL AND PERIMETER LANDSCAPING TREE PLANTING PLAN AREA 24 G H ,/~ / o- / ...J DATE, ~ Cl z 0 MAY, 2000 FILE NO: DRAIMNG NO: LIOI SHEET 5 4 3 2 I I 5 I I I I 4 I I I 3 I I I 2 I I I I I I I No. A {3)L1ST {6)PSME A B REVISION 8 STTTc_B_ o MH 125.6 ("", \ (11)1;!/AB \ {89)PIAB BY APP'D DA TE (6)ACRU BR OWN AND CALDWELL C u 5 LIST \., ____ __,__ ------------- ___,__ __ Designed By DATUM NOTE: fMYt'il lffl'!R!!l.'L" u.s.c. & ~Lmm 1947) DanadJleva & Koenig Associates Plannen U,ban Do"II""'" Lan<I"'""" A ,c:h'<o~O ..,.,c:hltoc:to D E I' ~.:::=--r=-~ ---l---------·i -_:. -::::-,cc :::c::-_-___ __J_ -----~ F """ .... ,,. CONTINUING ON DWG L105 DESIGNED: DRAWN: JH J AD, RA CHECKED: AD, RA DIGESTORS AND EQUIPMENT BUILDING Ci ---_____J ~ King County Department of Natural Resources SCALE: SOUTH TREATMENT PLANT ENLARGEMENT III SCALE 1"=20' / /Ao-ru,r .,,_-COMMENDED: 1-=~A.~DAN_A_D~_E_VA~CON1RACTNO: APPROVED: INTERNAL AND PERIMETER LANDSCAPING TREE PLANTING PLAN AREA 24 J. FERNANDES C93150C G H 5 4 3 2 DA'TE: MAY, 2000 FILE NO: DRA\10IG NO: Ll02 SHEET I I I I I I I I I I I I I I I I I I I 5 4 3 2 A '"'-..... ___ _ ---,,.,"--, \ No. A 8 OF.MS£ BRUSl-l \ REVISION BY APP'D DA TE 8 /-1 1' I 1/ l I I , I BR OWN AND CALDWBLL C Designed By DATUM NOTE: ~~ri .. 7) D ', ·, 1 ,,,,..., \ ( ! ~,,; DESGNED; H \ o MH 125 8 DATE: AD, RA King County Department. of Natural Resources MAY, 2000 SCALE: SCALE 1"=20' FILE NO: CHECKED: AD, RA SOUTH TREATMENT PLANT ENLARGEMENT III DRAWING NCJ: INTERNAL AND PERIMETER LANDSCAPING 1--,.,=_L_l_0_4_ TREE PLANTING PLAN SHEET A, DANADJIEVA CONTRACT NO: h,AP=PROVED="'",----, J. FERNANDES C9Jl 50C AREA 24 F G H 5 4 3 2 I I 5 I I I I 4 DENSE SR:.;':>-, -----_.-,----------- 4 ACRU I I I 3 I I I I I I I I I I No. REVISION A " IJi::.!~S::_ BY APP'D DA TE B BR OWN AND CALDWELL C Designed By Danadjleva & Koenig Associates Plonnoro lJrbon Jloo,1111oro La ~doeopo ArCJ:i!Loei, D DATUM NOTE: fl.W~ 1f/MO ~ O:S:c. " .:S:!A&,usmi , .. 7) E CONTINUING ON DWG L102 ,-! i L __ J ;, __ _ .rf:-------------' •.:,;~(: \, ,• --~ ------- CHECKED: AD, RA f r== ! I fR~-t,•=> --~~, I_ 0 _L,----~~------ 1 ALRH ----- King County Department of Natural Resources SCALE: SCALE 1"o20' C93150C SOUTH TREATME1'T PLANT ENLARGEMENT Ill INTERNAL AND PERIMETER LANDSCAPING TREE PLANTING PLAN AREA 24 G H DATE: MAY, 2000 Fil£ NO: DRAWING NO: LlOS SHEET 5 4 2 A B I I 5 I I I I 4 I I I 3 I I I 2 I I I I I I I No. REVISION A B BY APP'D DA TE C 0 1/. BR OWN AND CALDWELL C D I i Designed By 1, # /! I I I Danadjleva & Koenig Associates Pl•nnor, Urb•n Doo,gno,o l.and.ocopoArcb!ucu Atc-buoc,to D DATUM NOTE: l\l!i't~'l,'!'l /1&,00 f.911,AlS ilXc.&~1847) E E G WASTE GAS BURNER FACILITY (33)PSME NEW TURF 0 D ,;,· 0 0 " ,:,'0· ' C 0 ?i), King County Department of Natural Resources JH AD, RA SCALE 1"=20' RECOMMENDED, t-:==A.=D_A_N_AD_JJ_EV_A___..JCONlRACT NO: APPROVEO: J. FERNANDES C93150C F SOUTH TREATMENT PLANT ENLARGEMENT III INTERNAL AND PERIMETER LANDSCAPING OVERALL PLANTING PLAN AREA 24 G H 5 0 4 2 DAlE: MAY, 2000 Fil£ NO: DRAIIING NO: L301 SHEET I I I I I I 4 I I I 3 I I I 2 I I I I I I I 0 0 I') i 0 z 0 c., z 5 z F z 0 u No. A 0 0 3)ACRU 3)UST (6)PSME A REVISION B C 0 -~~-SALAL ,- ,f PLANT IN\, ALL NEW PLANTING AREAS °"' > AND IN AR.~S WHERE EXISTING VEGETATION. \ HAS 85EN ISTURBED BY CONSTRUCTION ,_ NORM OF R AD "N" EXCEPT UNDER CONIFERS. 0 )- ~,-------~.! - D 396 HEME (6)ACRU NEW TURF BR OWN AND CALDWELL BY APP'D DATE R C D 5 LIST 43)RHGL Designed By Danadjleva & Koenig Associates J>lannoro Urbnn Dcllgno,1 LnndlcDpc A,,cn11cct1 A,,chHccu D 0 ,., .. "'Jb.4 6 ACRU I ___ _j 1) "'--1,1 DATU~ NOTE: !Ml."'m 1~ f,Sf.8 U.S.C. & al:?,mzUSTED 1947) . I l1 I L __ ___J ~rL __ _ I .------L ____ _ o MH 125.J CLI 1250 J:k ~-------~-*'"c \ \ ......... .°""~~---C:~__,,, \_ J \_ L__,- \ CICE I i j I ;-1 / DIGESTORS AND EQUIPMENT BUILDING "''-,,,,,\ DESIGNED: \ \---~,----- \ : _ _i I G H (3)PINI AD, RA, JH King County Department of Natural Resources DRAWN: CHECKED: JH AD, RA SCALE 1"=20' b=A·=,...DA_N_A_DJJ_EV_A--;CONlRA T NO: APPROVED, J. FERNANDES C9 3l 50C F SOUTH TREATMENT PLANT ENLARGEMENT III INTERNAL AND PERIMETER LANDSCAPING OVERALL PLANTING PLAN AREA 24 G H DATE: I') 0 I') ~ 0 z 0 c., z 5 z F z 0 u MAY, 2000 FILE NO: DRAWING NI....302 SHEET 5 4 3 2 I I I I I I I I I I I I I I I I I I I 5 4 3 2 " 0 "1 ~ Cl z 0 t:) z 5 z i= z 0 (.) No, / I / DFN~; GRUSH A / / // // /// / / r I / ,/ INSTALL 1 1 /2" OF FIR BA!ifK IN ALL AREAS WHERE N, CONSTRUCTION HAS DISR P EXISTING WOOD MULCH ED / ,ti ) .1/ / 'CDA f REVISION BY APP'D DA TE B BR OWN AND CALDWELL C u F CONTINUING ON DWG 301 / CONTINUING ON DWG 308 Designed By DATUM NOTE: lnl~B47) CHECKED: AD, RA Danadjteva & Koenig Associates PI onno r • I,,~ 1 n [)a• It nor> Lon 4•c ope A re h """ to D E G H 1/l 0 "1 ~ Cl z 0 5 4 Cl 3 o MH 1:;;5.6 IN ALL AREAS EXCEPT UNDER CONIFERS WITHIN THIS BOUNDRY DATE: z 5 z i= z 0 (.) King County Department of Natural Resources MAY, 2000 SCALE: SCALE 1"=20' C93150C SOUTH TREATMENT PLANT ENLARGEMENT III INTERNAL AND PERIMETER LANDSCAPING OVERALL PLANT I NG PLAN AREA 24 G H FU NO: DRAWING NO: L304 SHEET 2 I I 5 I I I (11) ACRU I 4 DENSE BRUSH {4)ACRU I 6)ACSA I (4)ACSA I 3 I I I I I I I I I I No. RE\1SION SY APP'D DATE A 8 ' 3) LIST ---," ,,!;) / l,, ) "-, ,/ / / .I '\\ I __J '\ /i ,f // ,,/ ;/ // BROWN AND CALDWELL Designed By !1 ii I ii n d // ' /I / .;' II Ii CONTINUING ON DWG 309 DATUM NOTE: fM'!~lJl!.'j 11/8;,,DO '~ m .. .:s:~1 ... 7) DanadJJeva & Koenig Associates C D E I, L DESIGNED: " \ ' \ ' \ \ UNl'AVt.D PAR~'.if~G G. VD 00 \ ----=""=-= DA'IE: '° 0 r<) (!) == 0 z 0 (!) z s z F z 0 () AO, RA, JH King County Department of Natural Resources MAY, 2000 DRAWN: CHECKED: SCALE: JH AD, RA SCALE 1 "=20' RECOMMENDED: "'==A.=D_AN_A_D_J1_EV_A--1CON1RACT NO: APPRO'<ED: J, FERNANDES C93150C F SOUTH TREATMENT PLANT ENLARGEMENT I I I INTERNAL AND PERIMETER LANDSCAPING OVERALL PLANT I NG PLAN AREA 24 G H FU.E NO: DRAWING NO-L305 SHEET 5 4 3 2 Regional Wastewater Services Plan (RWSP) 2013 Comprehensive Review June 2014 King Street Center, KSC-NR-0512 201 South Jackson Street Seattle, WA 98104 http://dnr.metrokc.gov/wtd/ For comments or questions, contact: Pam Elardo, P.E., Division Director King County Wastewater Treatment Division 201 South Jackson Street KSC-NR-0512 Seattle, WA 98104-3856 206-477-4530 Pam.Elardo@kingcounty.gov This information is available in alternative formats on request at 206-477-5371 (voice) or 711 (TTY) Contents Executive Summary .................................................................................................................................. ES-1 Chapter 1 Introduction .............................................................................................................................. 1-1 King County’s Wastewater Treatment System ...................................................................................... 1-2 Regional Wastewater Services Plan ....................................................................................................... 1-4 Chapter 2 RWSP Achievements in 2007−2013 .......................................................................................... 2-1 RWSP Policies Implementation .............................................................................................................. 2-1 RWSP Capital Projects ............................................................................................................................ 2-2 Brightwater Treatment System .......................................................................................................... 2-3 Carnation Treatment Plant ................................................................................................................ 2-4 Conveyance System Improvement Projects ...................................................................................... 2-5 Reducing Infiltration and Inflow ........................................................................................................ 2-8 Protecting Our Waters Program ........................................................................................................ 2-9 Implementing the Sediment Management Plan .................................................................................. 2-14 Cleaning Up the Lower Duwamish Waterway Superfund Site ............................................................ 2-14 Creating Resources from Wastewater ................................................................................................. 2-15 Biosolids Recycling Program ............................................................................................................ 2-15 Energy Recovery and Efficiency Program ........................................................................................ 2-17 Reclaimed Water Program ............................................................................................................... 2-18 Protecting our Assets ........................................................................................................................... 2-20 Chapter 3 Financial Stewardship ............................................................................................................... 3-1 Establishing Annual Sewer Rate and Capacity Charge ........................................................................... 3-1 Residential Customer Equivalents ..................................................................................................... 3-2 Sewer Rate and Capacity Charge Projections .................................................................................... 3-4 Continuous Improvement Programs ..................................................................................................... 3-7 Productivity Initiative Pilot Program .................................................................................................. 3-7 Bright Ideas Program ......................................................................................................................... 3-8 Policy Guidance on Construction Fund and Emergency Reserves ......................................................... 3-8 Chapter 4 Forecasting Future Wastewater Treatment Plant Capacity Needs ........................................... 4-1 Summary ................................................................................................................................................ 4-1 Methodology .......................................................................................................................................... 4-2 Planning Assumptions ............................................................................................................................ 4-2 RWSP 2013 Comprehensive Review i Contents Population and Employment Forecasts ................................................................................................. 4-4 Average Wet Weather Flow Forecasts .................................................................................................. 4-7 Estimating Flow Factors for the Baseline Year ................................................................................... 4-7 Forecasting Future Flows ................................................................................................................... 4-8 Wasteload Forecasts ............................................................................................................................ 4-10 Estimating Loading Factors for the Baseline Year ............................................................................ 4-10 Forecasting Future Loadings ............................................................................................................ 4-10 Comparison of Future Flows, Loadings, and Capacities....................................................................... 4-12 Implications for Future Planning .......................................................................................................... 4-16 Chapter 5 Preparing for the Future ........................................................................................................... 5-1 Climate Change ...................................................................................................................................... 5-1 Regulatory Environment ........................................................................................................................ 5-2 Nutrient Removal ............................................................................................................................... 5-2 Source Control ................................................................................................................................... 5-3 Chemicals of Concern......................................................................................................................... 5-3 Other Topics ....................................................................................................................................... 5-3 Technology Trends ................................................................................................................................. 5-3 Decentralized Wastewater Systems .................................................................................................. 5-4 Nutrient Recovery .............................................................................................................................. 5-4 Energy Recovery ................................................................................................................................. 5-5 Indirect and Direct Potable Reuse ..................................................................................................... 5-5 Building Equity and Opportunity ........................................................................................................... 5-6 Chapter 6 Conclusions and Next Steps ...................................................................................................... 6-1 Conclusions ............................................................................................................................................ 6-1 Next Steps .............................................................................................................................................. 6-2 Appendix A. RWSP Policies Implementation in 2007−2013…………………………………………………………………A-1 Appendix B. Odor Prevention and Control Program……………………………………………………………………………B-1 Appendix C. Water Quality and Sediment Monitoring in 2013……………………………………………………………C-1 ii RWSP 2013 Comprehensive Review Contents Tables Table 3-1. Residential Customer Equivalents (1994–2013) ....................................................................... 3-3 Table 3-2. WTD Capacity Charge (2003−2014) .......................................................................................... 3-7 Table 4-1. Previous and Updated Planning Assumptions .......................................................................... 4-3 Table 4-2. Per-capita and Employee Flow Factors for 2010 ...................................................................... 4-8 Figures Figure 1-1. King County Wastewater Service Area and Facilities .............................................................. 1-3 Figure 1-2. Regional Wastewater Services Plan Projects and Service Areas (1999-2030) ........................ 1-5 Figure 2-1. Brightwater Treatment Plant ................................................................................................... 2-3 Figure 2-2. Brightwater Education and Community Center ...................................................................... 2-4 Figure 2-3. Carnation Treatment Plant ...................................................................................................... 2-5 Figure 2-4. Juanita Bay Pump Station ........................................................................................................ 2-6 Figure 2-5. Hidden Lake Pump Station ....................................................................................................... 2-6 Figure 2-6. Bellevue Pump Station ............................................................................................................. 2-6 Figure 2-7. Sources of Infiltration and Inflow ............................................................................................ 2-8 Figure 2-8. Location of the Puget Sound Beach CSO Control Projects .................................................... 2-11 Figure 2-9. King County’s Long-Term CSO Control Plan Projects ............................................................. 2-12 Figure 2-10. WTD’s 2012 Carbon Impact ................................................................................................. 2-17 Figure 3-1. Relationship Between the Monthly Sewer Rate and Capacity Charge .................................... 3-2 Figure 3-2. 2007 and 2013 Residential Customer Equivalent Forecasts (1993 to 2030) ........................... 3-4 Figure 3-3. Sewer Rate Projections with Inflation (2002–2014) ................................................................ 3-5 Figure 3-4. Sewer Rate Projections with Inflation (2002–2030) ................................................................ 3-5 Figure 3-5. Annual Capital Spending for the Wastewater Treatment Division (2000 to 2030) ................. 3-6 Figure 4-1. Previous and Current Population and Employment Projections for the WTD Service Area ... 4-4 Figure 4-2. King County’s Wastewater Treatment Service Areas .............................................................. 4-5 Figure 4-3. Previous (2004) and Current (2013) Population and Employment Forecasts For West Point Service Area ............................................................................................................................ 4-6 Figure 4-4. Previous (2004) and Current (2013) Population and Employment Forecasts For South Plant Service Area ............................................................................................................................ 4-6 Figure 4-5. Previous (2004) and Current (2013) Population and Employment Forecasts For Brightwater Service Area ............................................................................................................................ 4-7 Figure 4-6. Regional Water Purveyor Predicted Water Usage Reductions from Water Conservation ..... 4-9 Figure 4-7. Historical and Forecasted Average Wet Weather Flow at West Point, South, and Brightwater Treatment Plants, 1990−2060 .............................................................................................. 4-10 gure 4-8. Historical and Forecasted Average BOD load at Treatment Plants, 1990−2060 ...................... 4-11 Figure 4-9. Historical and Forecasted Average TSS load at Treatment Plants, 1990−2060 ..................... 4-12 Figure 4-10. Comparison of Actual and Forecast Solids Loadings with Systemwide Treatment Capacities, 1980−2060 ............................................................................................................................ 4-13 Figure 4-11. Actual and Forecast AWWF and Solids Loadings Compared to West Point Treatment Plant Capacities, 1990−2060 ......................................................................................................... 4-14 RWSP 2013 Comprehensive Review iii Contents Figure 4-12. Actual and Forecast AWWF and Solids Loadings Compared to South Treatment Plant Capacities, 1990−2060 ............................................................................................................................. 4-15 Figure 4-13. Actual and Forecast AWWF and Solids Loadings Compared to Brightwater Treatment Plant Capacities, 2010−2060 ............................................................................................................................. 4-16 Figure 4-14. Historical and Projected Systemwide Average Wet Weather Flow .................................... 4-17 iv RWSP 2013 Comprehensive Review Executive Summary The Regional Wastewater Services Plan (RWSP) outlines important projects, programs, and policies for King County to implement through 2030 to continue to protect public health and water quality and ensure sufficient wastewater capacity to meet future growth. In adopting the RWSP in 1999, the Metropolitan King County Council recognized the importance of reviewing implementation of the RWSP and adopted specific RWSP reporting policies that call for regular reviews and reports. The Wastewater Treatment Division (WTD) of the Department of Natural Resources and Parks (DNRP) has completed the RWSP 2013 Comprehensive Review as required by Ordinance 17232. The RWSP reporting policies were established through adoption of Ordinance 15384 and amended in 2012 through Ordinance 17480. A work plan for this review was approved by Motion 13758 in 2012. The review covers RWSP policy implementation from 2007 through 2013. This is the third comprehensive review report since adoption of the RWSP. Implementation of the RWSP protects the region’s water quality, environment, and economy by providing dependable, high-quality wastewater treatment. One of the RWSP’s primary objectives under the treatment plant policies was construction of a new Brightwater Treatment Plant in south Snohomish County. The Brightwater Plant, which uses membrane bioreactor (MBR) technology, started full operations in 2012. The Brightwater Plant produces high-quality effluent and Class A reclaimed water that is used for irrigation in the Sammamish Valley. In 2008, the Carnation Treatment Plant was completed. The Carnation Plant also uses MBR technology and is designed to treat all wastewater to Class A reclaimed water standards for discharge to an enhanced wetland in the Chinook Bend Natural Area in the Snoqualmie River basin. The RWSP 2013 comprehensive review included evaluating and updating future regional wastewater treatment capacity needs. The review confirmed the benefits of having a three-plant regional system (West, South and Brightwater treatment plants). Updated forecasts indicate that a full expansion at South Plant is unlikely to be needed in 2029 as previously projected, but may be needed in the 2030s. As the regional population has increased, treatment plant solids loadings have grown in proportion with population while average wet-weather flows decreased by 15 percent because of reduced water usage. These trends are likely to continue in the next few decades. WTD will conduct a study in 2015 to determine the most cost-effective methods to manage solids loading increases over time. Actual population growth and water use rates could be more or less than projected. Of the factors that affect treatment plant capacity, climate change is expected to have a significant impact on future peak flows at treatment plants. WTD will continue to track factors and trends that affect treatment plant capacity needs, including climate change impacts over time, monitor flow data, and work with local agencies as they implement their land use and sewer plans. In accordance with RWSP conveyance and infiltration/inflow (I/I) policies, WTD completed five conveyance system improvement (CSI) projects and one I/I reduction project between 2007 and 2013. These projects were designed to meet projected peak flow demands and the RWSP 20-year peak flow design standard. An update of the CSI plan, which will include a projection of future peak flows for the RWSP 2013 Comprehensive Review ES-1 Executive Summary treatment plants and future CSI projects, is scheduled for completion in 2015. Treatment plant capacity requirements may be adjusted when these projections are available. The RWSP policies provide guidance to maximize the beneficial reuse of byproducts from wastewater treatment. WTD makes use of biosolids and digester gas from the solids treatment process and reclaimed water from the liquids treatment process. In 2007−2013, 100 percent of biosolids were used as a fertilizer and soil amendment in agriculture and forestry or as an ingredient in compost, the Waste- to-Energy cogeneration system at West Point Plant was completed and is now operational, and reclaimed water was produced and distributed from the Carnation and Brightwater plants. WTD continues to produce and use reclaimed water for treatment processes and irrigation at the West and South plants and provides additional reclaimed water to the City of Tukwila from South Plant. WTD made significant progress from 2007 through 2013 to control combined sewer overflows (CSOs) to the Washington State standard of no more than one overflow per year on average at each CSO site. Construction began on four projects to control CSOs along Puget Sound beaches. Projects are under way or planned to control all remaining uncontrolled CSOs by 2030, under a consent decree with U.S. Department of Justice, U.S. Environmental Protection Agency, and Washington State Department of Ecology that was signed in 2013. CSO projects currently in design include the Georgetown Wet Weather Treatment Station, the Rainier Valley Wet Weather Storage project, and several green stormwater infrastructure projects that have the potential to reduce stormwater flows into the combined sewer system and reduce CSO project costs. King County is coordinating with the City of Seattle to identify cost savings and efficiencies and possible joint project opportunities to minimize impacts to communities and maximize water quality improvements. Maintaining the region’s wastewater assets is a high priority for WTD. The objectives of the Asset Management Program are to manage the lifecycle of a facility or asset; deliver a level of service that meets regulatory requirements and ratepayer expectations; and fulfill WTD’s mission to protect public health and enhance the environment by treating and reclaiming water, recycling solids, and generating energy. WTD’s Strategic Asset Management Plan (SAMP) will be updated in 2015 and will include action plans to improve asset management practices using data collected and analyzed under the program. WTD is committed to continuous improvement and strives to be a state-of the-art, energy-efficient, lean, continually improving agency. WTD completed a 10-year pilot Productivity Initiative Program in 2011 that generated nearly $84 million in savings for ratepayers. In 2011, WTD initiated a Bright Ideas Program that asks employees to identify efficiencies and cost saving measures in the division’s operations, which has generated over 550 ideas and is expected to save about $400,000 in 2014. RWSP comprehensive review reporting policies call for the review of the effectiveness of policy implementation. Based on results of this review, policy amendments are not recommended at this time. However, this report will serve as a foundation for upcoming policy discussions with the Metropolitan Water Pollution Abatement Advisory Committee, Regional Water Quality Committee, and County Council regarding future recommended policy revisions and changes to guide the future of the regional wastewater system. ES-2 RWSP 2013 Comprehensive Review Chapter 1 Introduction The Regional Wastewater Services Plan (RWSP) 2013 Comprehensive Review is presented in response to the RWSP reporting policies outlined in Ordinance 15384 and King County Code 28.86.165.1 Each chapter in this report describes a specific set of RWSP policies and how the policies were implemented in 2007–2013. The major topics of each chapter are as follows: • Chapter 2 summarizes RWSP implementation achievements made from 2007−2013. The chapter includes information on regional treatment and conveyance capital projects, infiltration and inflow (I/I), combined sewer overflow (CSO) control projects, and achievements made in implementing the County’s Sediment Management Plan, cleaning up the Lower Duwamish Waterway Superfund site, creating resources from wastewater, protecting the region’s wastewater assets, and implementing RWSP policies. • Chapter 3 describes how annual sewer rates and capacity charges are established, provides sewer rate and capacity charge projections through 2030, and compares them to projections in previous RWSP comprehensive review reports. The chapter also describes programs implemented in 2007−2013 to increase efficiency and policy guidance on construction fund and emergency reserves. • Chapter 4 summarizes future population and economic growth projections and the expected impact on the regional wastewater treatment system. It provides detail on the methodology and assumptions for developing projections and discusses the findings as they relate to future treatment plant capacity needs. • Chapter 5 summarizes WTD activities under way to address emerging issues and priorities such as climate change, chemicals of emerging concern, increased use and demand for the byproducts of wastewater treatment, sustainable building, technology trends, regulations that are more stringent, and equity and social justice. • Chapter 6 summarizes conclusions from the RWSP review and identifies next steps in continuing to implement the RWSP to protect the region’s water quality. The remainder of this chapter describes King County’s wastewater treatment system and the RWSP. 1 RWSP annual reports and comprehensive reviews are available on the Web at http://dnr.metrokc.gov/wtd/rwsp/library.htm. RWSP 2013 Comprehensive Review 1-1 Chapter 1. Introduction King County’s Wastewater Treatment System King County protects water quality and public health in the central Puget Sound region by providing high-quality and effective treatment to wastewater collected from 17 cities, 16 local sewer utilities, and 1 Indian Tribe. The County's Wastewater Treatment Division (WTD) serves about 1.5 million people, including most urban areas of King County and parts of south Snohomish County and northeast Pierce County. The wastewater system (Figure 1-1) includes three large regional treatment plants (the West Point Plant in the City of Seattle, the Brightwater Plant in south Snohomish County, and the South Plant in the City of Renton), one small treatment plant on Vashon Island, one community septic system (Beulah Park and Cove on Vashon Island), one reclaimed water treatment plant in the City of Carnation, four CSO treatment facilities (Alki, Carkeek, Mercer/Elliott West, and Henderson/Norfolk—all in the City of Seattle), over 360 miles of pipes, 19 regulator stations, 43 pump stations, and 38 CSO outfalls. Visit WTD’s website for more information on projects and programs: http://www.kingcounty.gov/environment/wtd.aspx. 1-2 RWSP 2013 Comprehensive Review Chapter1. Introduction Figure 1-1. King County Wastewater Service Area and Facilities RWSP 2013 Comprehensive Review 1-3 Chapter 1. Introduction RWSP Comprehensive Review Reporting Policies The policies below were established through adoption of Ordinance 15384, and amended in 2012 through Ordinance 17480. They guide the preparation of the RWSP comprehensive reviews. B.1. Comprehensive regional wastewater services plan review. The executive shall submit a written report to council and RWQC that provides a comprehensive review of the RWSP. The report will review the following: a. assumptions on the rate and location of growth, the rate of septic conversions and the effectiveness of water conservation efforts; b. phasing and size of facilities; c. effectiveness of RWSP policies implementation, for infiltration and inflow reduction, water reuse, biosolids, CSO abatement, water quality protection, environmental mitigation and public involvement; and d. policy guidance for the construction fund and the emergency capital reserves. 2. The next comprehensive regional wastewater services plan review is due in June 2014. Subsequent reports will be prepared every three to five years as established by the council and RWQC following their review of the current report. The specific due date will be based upon the availability of necessary information, the completion of key milestones, and the time needed to collect and analyze data. The executive may recommend policy changes based on the findings of the report and other information from changing regulations, new technologies or emerging or relevant factors. Regional Wastewater Services Plan In the 1990s, wastewater flow estimates based on projected population growth estimates in King County’s wastewater service area indicated that the regional wastewater treatment system would run out of capacity by 2010. To ensure the continuation of high-quality and effective wastewater treatment services in the future, the County carried out an intensive planning effort, involving numerous elected officials, representatives from local sewer agencies, organizations, and individuals from around the region. The RWSP resulted from this effort and was adopted by the Metropolitan King County Council in November 1999, by Ordinance 13680. The RWSP outlines a number of important projects, programs, and policies for King County to implement through 2030 (Figure 1-2). It called for building a new Brightwater Treatment Plant to accommodate growth in the northern portion of the wastewater service area. The plan also called for improvements to the County’s regional conveyance system to meet the 20-year peak flow design standard and accommodate increased flows; improvements to reduce existing and future levels of I/I (clean groundwater and stormwater) into local collection systems; and improvements to control CSOs so that an average of no more than one untreated discharge occurs per year at each CSO site by 2030.2 The RWSP also identified the need to expand South Plant by 2029 to handle projected increased wastewater flows in the southern and eastern portions of the the wastewater service area. 2 The Washington State Department of Ecology and the United States Environmental Protection Agency entered into a consent decree with King County in July 2013 to ensure control of King County CSOs to one event per year at each CSO location by 2030. 1-4 RWSP 2013 Comprehensive Review Chapter 1. Introduction Figure 1-2. Regional Wastewater Services Plan Projects and Service Areas (1999-2030) RWSP 2013 Comprehensive Review 1-5 Chapter 1. Introduction 1-6 RWSP 2013 Comprehensive Review Chapter 1. Introduction Ordinance 13680 was codified in the King County Code (KCC) as Chapter 28.86. Amendments to Ordinance 13680 and KCC Chapter 28.86 made during 2007−2013 are summarized below: • Ordinance 17587 was adopted by the King County Council in May 2013 to amend CSO control policies to ensure they are consistent with the 2012 amended long-term CSO control plan that the Council approved through Ordinance 17413 and the consent decree that was signed in 2013. • Ordinance 17492 was adopted by the King County Council in December 2012 to revise a financial policy addressing debt financing and borrowing. • Ordinance 17480 was approved by the King County Council in December 2012 to amend RWSP reporting policies regarding construction fund and emergency reserves in RWSP comprehensive review reports; provide guidance for completion of the RWSP comprehensive review in June 2014; and delete the requirement for Brightwater monthly reports. • Ordinance 16033 was approved by the King County Council in March 2008 to amend RWSP conveyance policies to provide guidance regarding field verifications and decennial flow monitoring; add a policy to update the CSI Program every five years; provide guidance on information to include in CSI Program updates; and added a policy to include evaluation of other demand management alternatives to meet identified conveyance needs Appendix A discusses how each RWSP policy was implemented in 2007−2013. This report does not recommend policy amendments at this time, but does serve as a foundation for upcoming discussions with MWPAAC, RWQC and the Council on any proposed policy changes for the years ahead. Visit the RWSP website for more information on this regional plan and to view the entire contents of the RWSP 2013 Comprehensive Review: http://www.kingcounty.gov/environment/wtd/Construction/planning/rwsp.aspx. RWSP 2013 Comprehensive Review 1-7 Chapter 1. Introduction 1-8 RWSP 2013 Comprehensive Review Chapter 2 RWSP Achievements in 2007−2013 This chapter summarizes RWSP implementation achievements made from 2007 through 2013. The chapter includes information on RWSP capital projects designed to provide needed regional treatment and conveyance capacity to meet population and employment growth, reduce infiltration and inflow (I/I), and meet the County’s commitment to control its combined sewer overflows (CSOs) by 2030. The chapter also summarizes achievements made in implementing the County’s Sediment Management Plan, cleaning up the Lower Duwamish Waterway Superfund site, creating resources from wastewater, protecting the region’s wastewater assets, and implementing RWSP policies. RWSP Policies Implementation The RWSP policies are part of the King County Code Chapter 28.86. Appendix A includes each policy and summary information on how the policy was implemented in 2007−2013. The policies provide guidance on the following areas: • Ensuring there is sufficient regional treatment and conveyance capacity to meet population and employment growth projections • Reducing I/I into the regional conveyance system • Achieving control of all the County’s CSOs by 2030 • Creating resources from the wastewater treatment process • Protecting and monitoring water quality of the region’s water bodies • Providing wastewater services in a cost-effective and environmentally responsible manner • Planning comprehensively • Being a good neighbor through controlling nuisance odors, engaging the public, and providing mitigation measures for environmental impacts from the construction and operation of wastewater facilities • Financing, including setting sewer rates and capacity charges for the regional wastewater system • Reporting on the progress of RWSP implementation RWSP comprehensive review reporting policies call for the inclusion of information on the effectiveness of policy implementation and note that the County Executive may recommend policy changes based on the findings of the report and other information from changing regulations, new technologies, or emerging or relevant factors. Appendix A discusses how each policy was implemented in 2007−2013, and as a next step in the RWSP comprehensive review process, WTD will be working with MWPAAC’s RWSP 2013 Comprehensive Review 2-1 Chapter 2. RWSP Achievements in 2007−2013 Engineering and Planning Subcommittee and the County Council’s Regional Water Quality Committee (RWQC) to discuss policy implementation and effectiveness and any recommendations for policy amendments. This report does not recommend policy amendments at this time, but does serve as a foundation for the upcoming discussions with MWPAAC and RWQC. Several policy amendments were made during 2007−2013. They are summarized below and noted in Appendix A. • Amendments to RWSP CSO control policies. In May 2013, the County Council approved Ordinance 17587, amending CSO control policies. The amendments ensure the policies are consistent with the 2012 amended long-term CSO control plan that the County Council approved through Ordinance 17413 and the Consent Decree that was signed in 2013. • Amendments to RWSP financial policies. In December 2012, the County Council approved Ordinance 17492, revising a financial policy addressing debt financing and borrowing. • Amendments to RWSP reporting policies. In December 2012, the County Council approved Ordinance 17480, amending RWSP reporting policies. The amendments included the following: o Adding information on policy guidance for construction fund and emergency reserves in RWSP comprehensive review reports o Providing guidance for the next RWSP comprehensive review to be completed in June 2014 o Deleting requirement for Brightwater monthly reports • Amendments to RWSP conveyance policies. In March 2008, the County Council approved Ordinance 16033, amending RWSP conveyance policies. The amendments included the following: o Added policy guidance to confirm assumptions and needs (field verifications, decennial flow monitoring) o Added a policy to update the CSI Program every five years and provided guidance on information to include in CSI Program updates o Added a policy to include evaluation of other demand management alternatives to meet identified conveyance needs RWSP Capital Projects RWSP policies call for the County to ensure there is sufficient treatment plant and conveyance system capacity to meet population and employment growth through 2030. The policies provide guidance for facility sizing to accommodate population growth. 2-2 RWSP 2013 Comprehensive Review Chapter 2. RWSP Achievements in 2007−2013 RWSP policies also call for the County to carry out projects to reduce the impact of I/I on the regional system’s capacity and to control CSOs to the Washington State standard of one untreated overflow from each CSO location per year based on a 20-year moving average. This section provides information on the treatment plant, conveyance, I/I, and CSO control projects that were under way or completed in 2007−2013. Brightwater Treatment System A major achievement was the completion and startup of the Brightwater Treatment System. The new facilities include a state-of-the-art treatment plant (Figure 2-1), 13 miles of conveyance, including the pipes and pumps taking wastewater to and from the plant, and a marine outfall. The Brightwater system began full operations in fall 2012, and its completion marks the region’s largest clean-water project of the last half century. Brightwater’s membrane bioreactor (MBR) technology produces effluent that is 70 percent cleaner than that produced by conventional wastewater technologies. Figure 2-1. Brightwater Treatment Plant The RWSP also provides guidance for the County’s wastewater facilities to be a good neighbor and to meet or exceed its regulatory requirements. A commitment during the design of Brightwater was to ensure there are no detectable odors at the treatment plant’s property boundary and beyond. To date, no odor complaints have been attributed to the Brightwater Plant. More information on the Brightwater Treatment System is available at http://www.kingcounty.gov/environment/wtd/Construction/North/Brightwater.aspx. RWSP 2013 Comprehensive Review 2-3 Chapter 2. RWSP Achievements in 2007−2013 Brightwater Education and Community Center The Brightwater Education and Community Center (Figure 2-2) opened in September 2011. The center features: • 70 acres of public open space with three miles of walking trails and 40 acres of natural habitat • A community center with meeting rooms available for public rental • A clean water learning space featuring both indoor and outdoor settings Figure 2-2. Brightwater Education and Community Center During the Brightwater siting process, the public asked King County to include the center as part of treatment plant design to provide an asset to the host community. In the first year of operation, the center served approximately 4,000 4th-8th graders in school programs, 300 participants in family programs, and 150 teachers in professional development workshops. More information on the Brightwater Education and Community Center is available at http://www.kingcounty.gov/environment/brightwater-center.aspx. Carnation Treatment Plant In 2002, the King County Council amended the Comprehensive Water Pollution Abatement Plan and added the City of Carnation to the County’s wastewater service area. The City of Carnation decided to replace on-site septic systems with a new wastewater treatment facility and collection system to better protect public health and the environment, achieve the City’s comprehensive plan goals, and maintain and enhance community livability. The City designed and built the local wastewater collection system and contracted with King County to design, build, operate, and maintain a new treatment plant and associated discharge facilities. The Carnation Treatment Plant (Figure 2-3) was completed in 2008. The plant uses MBR technology and is designed to treat wastewater to Class A reclaimed water standards. In March 2009, the plant started discharging its Class A reclaimed water to enhance a wetland in the Chinook Bend Natural Area. The plant has a dual discharge system. In addition to the wetland, an outfall discharges to the Snoqualmie 2-4 RWSP 2013 Comprehensive Review Chapter 2. RWSP Achievements in 2007−2013 River only when required by a regulatory agency (such as when necessary to augment flows in the Snoqualmie River), in case of plant upset or failure of ultraviolet disinfection system, or during periods of scheduled maintenance. More information on the Carnation Treatment Plant is available at http://www.kingcounty.gov/environment/wtd/About/System/Carnation.aspx. Figure 2-3. Carnation Treatment Plant Conveyance System Improvement Projects In accordance with RWSP policies, the Conveyance System Improvement (CSI) Program works to provide sufficient capacity in areas of the separated conveyance system to meet projected demands and the RWSP 20-year peak flow design standard. The 20-year peak flow design standard was adopted by the King County Council to serve as an objective measure for designing and building conveyance facilities intended to meet National Pollutant Discharge Elimination System (NPDES) permit requirements. A 20- year peak flow consists of both storm flow (I/I) and base flow (wastewater from homes and businesses). In setting this standard, the King County Executive and King County Council recognized that it is one of the most stringent standards in the nation and would require time to upgrade the conveyance system to meet this standard. RWSP CSI Projects Completed in 2007-2013 The RWSP CSI projects that were completed during 2007 through 2013 are as follows: • Juanita Bay Pump Station Replacement project (Figure 2-4). Construction of this project was completed in 2008. It replaced the aging 14.2-mgd (million gallons per day) Juanita Bay Pump Station with a 30.6-mgd pump station. • Hidden Lake Pump Station and Sewer Improvement project (Figure 2-5). Construction of this project was completed in 2009.The project included building a new Hidden Lake Pump Station in the City of Shoreline, replacing approximately 12,000 feet of the Boeing Creek Trunk, and RWSP 2013 Comprehensive Review 2-5 Chapter 2. RWSP Achievements in 2007−2013 building a 500,000-gallon underground storage facility in Boeing Creek Park. The new pump station has a pumping capacity of 6.8 mgd, an increase of 2.5 mgd over the replaced pump station’s capacity. • Bellevue Pump Station Upgrade and Force Main Installation project (Figure 2-6). Construction of this project was completed in 2010. The project included construction of a new force main and replacement of an 8-mgd pump station. The refurbished pump station’s capacity is able to convey more than 13 mgd of wastewater from west and central Bellevue to the South Treatment Plant. • Bellevue Influent Trunk Improvement project. Construction of this project was completed in 2012. The project included constructing a pipeline that parallels the Bellevue Influent Trunk to serve the rapidly growing downtown Bellevue area. • Kent-Auburn Conveyance System Improvements project (Phase A). Construction on this project was completed in early 2014. The project included construction of two new pipelines, the Kent East Hill Diversion in Kent and the Stuck River Trunk in Auburn. Figure 2-4. Juanita Bay Pump Station Figure 2-5. Hidden Lake Pump Station Figure 2-6. Bellevue Pump Station 2-6 RWSP 2013 Comprehensive Review Chapter 2. RWSP Achievements in 2007−2013 RWSP CSI Projects in Development in 2007-2013 CSI projects that are currently being developed are as follows: • Sunset and Heathfield Pump Stations and Force Main Upgrade project. This project began predesign in 2013. The project will update the undersized Sunset and Heathfield pump stations and associated sewer force main in Bellevue. Originally constructed in 1965 (with upgrades in 1987), the pump stations have a system capacity of 18 mgd. The upgraded system will convey a peak flow of 30 mgd and will improve odor control. Construction is expected to begin in 2016. More information on the project is available at http://www.kingcounty.gov/environment/wtd/Construction/East/SunsetHeathfield.aspx. • North Creek Interceptor project. This project will replace a main wastewater conveyance pipeline that serves parts of Bothell and unincorporated Snohomish County. The project includes construction of approximately 10,000 feet of new sewer line and connecting it to previously constructed pipe. This new pipeline ranges from 30 to 48 inches in diameter. Construction will take place in both the City of Bothell and unincorporated Snohomish County. Construction is expected to begin in 2014. More information on the project is available at http://www.kingcounty.gov/environment/wtd/Construction/North/NCI.aspx. • North Lake Sammamish Flow Diversion project. Alternatives analysis is under way for this project. The project will divert wastewater flows from the North Lake Sammamish Basin to the Brightwater Treatment Plant to free up capacity in the East Side Interceptor. Construction is expected to begin in 2017. More information on the project is available at http://www.kingcounty.gov/environment/wtd/Construction/East/NLkSamFlowDiversion.aspx. • North Mercer Island Interceptor and Enatai Interceptor Upgrade project. This project is just beginning; work on alternatives analysis is expected to begin in 2014. The project will increase the capacity of the existing North Mercer Island Interceptor and Enatai Interceptor to meet the RWSP design standard. The North Mercer Island and Enatai Interceptors serve areas in North Mercer Island, the southwest portion of Bellevue, and the Town of Beaux Arts Village. Construction is expected to begin in 2019. More information on the project is available at http://www.kingcounty.gov/environment/wtd/Construction/East/NMIEnatai.aspx. • Lake Hills and Northwest Lake Sammamish Interceptor Upgrade project. This project will replace the existing Lake Hills Trunk and upgrade the Northwest Lake Sammamish Interceptor to meet the RWSP conveyance design standard. The existing gravity pipelines are about 4.5 miles long and are located in the City of Redmond. This project is just beginning; work on alternatives analysis is expected to begin in 2014. Decennial Flow Monitoring As part of the CSI Program, the Decennial Flow Monitoring project began in 2009 and was completed in 2011. The project was carried out according to RWSP conveyance policies, which call for the Wastewater Treatment Division to conduct systemwide flow monitoring in the separated conveyance system every 10 years to correspond with the federal census. The project collected flow data over two wet seasons. RWSP 2013 Comprehensive Review 2-7 Chapter 2. RWSP Achievements in 2007−2013 Data collected from 235 flow meter locations will inform the CSI Program update that is under way and is also available to local agencies for use in planning and designing their systems. 2015 CSI Program Update Work on the 2015 CSI Program update began in 2013. The last update was completed in 2007. RWSP policies call for regular program updates to verify, make adjustments to, or identify new conveyance system needs. WTD will continue working with the Engineering and Planning Subcommittee of the Metropolitan Water Pollution Abatement Advisory Committee (MWPAAC) and individual agencies to complete the program update. Activities to complete the update include the following: • Analyzing and applying new flow data and population forecasts to produce an updated list of capacity needs and priorities • Developing conceptual projects and planning-level cost estimates to meet capacity needs • Prioritizing conceptual projects More information on the CSI Program is available at http://www.kingcounty.gov/environment/wastewater/CSI.aspx. Reducing Infiltration and Inflow I/I is water that enters the sewer system through cracked pipes, leaky manholes, or improperly connected storm drains, downspouts, and sump pumps (Figure 2-7). Most inflow comes from stormwater and most infiltration comes from groundwater. About 75 percent of the peak flow in the County’s separated conveyance system is from I/I; 95 percent originates in local systems, primarily from side sewers on private property. Figure 2-7. Sources of Infiltration and Inflow 2-8 RWSP 2013 Comprehensive Review Chapter 2. RWSP Achievements in 2007−2013 In 2007−2013, WTD continued to implement the Executive’s Recommended I/I Control Program that was approved by the King County Council through Motion 12292 in May 2006. Implementation focused on completing an initial I/I reduction project in the Skyway Water and Sewer District. The project reached substantial completion in March 2012. It included replacing side sewers serving 302 residential properties, over 90 manholes, and approximately 19,000 linear feet of 8-inch-diameter sewer main. The purpose of the project was to determine whether and how it is possible to cost-effectively remove enough I/I from the regional conveyance system to delay, reduce, or eliminate a planned CSI project. The definition of cost-effectiveness focuses on regional benefit in terms of capital project costs. The project was developed in consultation with MWPAAC’s Engineering and Planning Subcommittee during the discussions that led to development of the recommended I/I Control Program. One season of post-construction flow monitoring has been completed. Preliminary results indicate that the project resulted in reducing peak flow by about 19 percent, which is less than anticipated. Reasons for this result include the following: (1) properties may have had more sump pumps than anticipated, (2) fewer parcels than planned underwent complete rehabilitation because of increasingly difficult field conditions as work progressed into the wet season and more hardscape features than anticipated were present on individual properties, and (3) the area that contributes I/I to the sewer basin appears to have been larger than originally delineated. However, the Skyway initial I/I reduction project did provide benefits including delaying the need for storage. WTD intends to conduct another wet-season of post- construction flow monitoring to confirm or update the results of the project. In accordance with the approved I/I Control Program, WTD will work with the Engineering and Planning Subcommittee of MWPAAC in 2015 to develop recommendations for long-term I/I reduction and control. More information on the I/I Control Program is available at http://www.kingcounty.gov/environment/wastewater/II.aspx. Protecting Our Waters Program WTD made significant progress in 2007−2013 to implement the County’s CSO Control Program, called Protecting Our Waters. CSOs are discharges of wastewater and stormwater from combined sewers into water bodies during heavy rainstorms when sewers are full. Combined sewers, which carry both wastewater and stormwater, exist in many parts of older cities across the nation, including Seattle. To protect treatment plants and avoid sewer backups into homes, businesses, and streets, combined sewers in Seattle sometimes overflow into nearby water bodies. Although the wastewater in CSOs is greatly diluted by stormwater, CSOs may be harmful to public health and aquatic life because they can carry chemicals and disease-causing pathogens. The County began its CSO control efforts in the late 1970s. The County is committed to controlling all its CSO sites by 2030. About one-half of its 38 CSO sites are controlled. Projects are under way or planned to control the remaining uncontrolled CSOs. A summary of the Protecting Our Waters Program’s achievements in 2007−2013 follows. RWSP 2013 Comprehensive Review 2-9 Chapter 2. RWSP Achievements in 2007−2013 Control of Ballard CSO Control of the Ballard CSO was incorporated into the Ballard Siphon Replacement project’s design and construction. The project achieved substantial completion in 2013. The project included building a new 85-inch-diameter siphon pipe under Salmon Bay between the Ballard and Interbay areas of Seattle. The new pipe replaced two 36-inch-diameter wooden stave pipes that have served the Ballard community since the 1930s. The project may also result in reducing overflows at the 11th Ave NW CSO site. Projects to Control CSOs along Puget Sound Beaches Construction began on four projects to control CSOs along Puget Sound Beaches (Figure 2-8): • The North Beach CSO control project is building an underground storage tank in the rights-of- way in Northwest Blue Ridge Drive and Triton Drive Northwest in Seattle. The facility will store excess flows during large storms when the North Beach Pump Station reaches maximum capacity. Construction is expected to be complete in 2015. More information on the project is available at http://www.kingcounty.gov/environment/wtd/Construction/Seattle/NBeachCSOStorage.aspx. • The South Magnolia CSO control project is building an underground storage tank adjacent to Smith Cove Park, south of the Magnolia Bridge in Seattle. The facility will store peak flows when the South Magnolia Trunk reaches maximum capacity. Construction is expected to be complete in 2015. More information on the project is available at http://www.kingcounty.gov/environment/wtd/Construction/Seattle/SMagnoliaCSOStorage.aspx • The Murray CSO control project is building an underground storage tank beneath property across the street from Seattle’s Lowman Beach Park. The facility will store peak flows when the Murray Pump Station reaches maximum capacity. Construction is expected to complete in 2016. More information on the project is available at http://www.kingcounty.gov/environment/wtd/Construction/Seattle/MurrayCSOStorage.aspx. • The Barton CSO control project is constructing roadside rain gardens, a type of green stormwater infrastructure (GSI) in the City of Seattle’s planting strips in the Sunrise Heights and Westwood neighborhoods. Street runoff will be diverted away from storm drains and into the vegetated swales. Once in the swales, the water will filter through soil to an underdrain, which will take the water to a deep well for slow infiltration underground. Construction is expected to be complete in 2015. More information on the project is available at http://www.kingcounty.gov/environment/wtd/Construction/Seattle/BartonCSO-GSI.aspx. 2-10 RWSP 2013 Comprehensive Review Chapter 2. RWSP Achievements in 2007−2013 Figure 2-8. Location of the Puget Sound Beach CSO Control Projects CSO Control Program Review and Plan Update In accordance with RWSP policies, the CSO Control Program review and plan update was completed in 2012. As a result, in September 2012, the County Council approved an amendment to the County’s long- term CSO control plan through Ordinance 17413. The plan includes nine projects to control the remaining 14 uncontrolled CSOs by 2030 (Figure 2-9). The U.S. Environmental Protection Agency (EPA) also approved the amended plan in 2013, and the plan is incorporated into the consent decree that the County entered into with the U.S. Department of Justice, EPA, and Washington State Department of Ecology (Ecology) in 2013. To date, the County is on schedule to meet all the milestones outlined in the consent decree. RWSP 2013 Comprehensive Review 2-11 Chapter 2. RWSP Achievements in 2007−2013 Figure 2-9. King County’s Long-Term CSO Control Plan Projects 2-12 RWSP 2013 Comprehensive Review Chapter 2. RWSP Achievements in 2007−2013 Work began on three projects outlined in the Council-approved CSO control plan: Georgetown Wet Weather Station to control the Brandon and South Michigan CSOs; Rainier Valley Wet Weather Storage to control the Hanford #1 CSO, and the Highland Park and South Park green stormwater infrastructure (GSI )project to help control the West Michigan and Terminal 115 CSOs. • The Georgetown Wet Weather Treatment Station includes construction of a CSO wet-weather treatment station between the Brandon Street and South Michigan Street Regulator Stations, conveyance pipeline, and a new outfall structure to release the treated water into the Duwamish Waterway. When constructed, the station will have the capacity to treat up to 66 million gallons of combined rain and wastewater a day that would otherwise have discharged directly to the Duwamish without treatment during storm events. Construction is expected to begin in 2017. More information on the project is available at http://www.kingcounty.gov/environment/wtd/Construction/Seattle/BrandonMichiganCSO.aspx. • The Rainier Valley Wet Weather Storage project will install a new sewer pipeline near the intersection of Rainier Avenue South and Martin Luther King Boulevard South in Seattle to divert flows to an existing pipe with extra capacity. Any excess flows from this area will be routed to a new storage tank at the intersection of South Hanford Street and South 27th Avenue. Construction is expected to begin in 2015. More information on the project is available at http://www.kingcounty.gov/environment/wtd/Construction/Seattle/HanfordCSO.aspx. • The Highland Park and South Park GSI project is exploring the feasibility of reducing West Michigan and Terminal 115 CSOs using GSI or a combination of GSI and storage for sewer overflows. Based on street layouts and results of soils and groundwater testing, King County will discuss options for GSI with the community. GSI construction is expected to begin in 2016, and if needed, work on the storage pipe portion of the project would begin in 2019. More information on the project is available at http://www.kingcounty.gov/environment/wtd/Construction/Seattle/WMichT115CSO.aspx. RainWise Rebate Program Rain gardens and cisterns can help control stormwater that enters the combined sewer system. Through a memorandum of agreement (MOA) with Seattle Public Utilities (SPU), WTD began offering opportunities for residents to participate in the RainWise Rebate Program where there are potential benefits to the County’s CSO control projects. The program pays for rain gardens and cisterns on private property in some parts of the city and was started by SPU in 2010. Since then, over 250 rain gardens and cisterns are now helping to control stormwater runoff and preventing CSOs. The MOA outlines the cost- sharing and other responsibilities of each agency. More information on the RainWise program is available at http://www.kingcounty.gov/environment/wastewater/CSO/BeRainwise.aspx. Water Quality Assessment and Monitoring Study Work began in 2013 on the Water Quality Assessment and Monitoring Study (assessment) that was called for in Ordinance 17413. The purpose of the study is to examine how upcoming Protecting Our Waters projects can be sequenced and integrated to optimize the investment being made in these RWSP 2013 Comprehensive Review 2-13 Chapter 2. RWSP Achievements in 2007−2013 projects. In September 2013, the County Council approved the study’s scope of work through Motion 13966. The assessment will examine local water quality issues near King County CSOs in Elliott Bay, Lake Union/Ship Canal, and the Duwamish River. Results from the assessment will be used to inform the next CSO Control Program review and plan update, which is due to regulators in 2018. The goals of the assessment are as follows: • Provide information on how CSO control can work in conjunction with other water quality projects to maximize water quality improvements • Identify opportunities to lower the cost of CSO control • Identify technologies that could potentially improve water quality such as GSI • Establish baseline conditions for mandatory post-construction monitoring of CSO control projects More information on the assessment is available at http://www.kingcounty.gov/environment/wastewater/CSO/WQstudy.aspx. Implementing the Sediment Management Plan As a part of RWSP implementation, WTD is carrying out a Sediment Management Plan (SMP) to remediate contaminated sediments near CSO outfalls. Most of the contamination occurred in the early to mid-1900s. The SMP addresses sediment contamination cleanups that are required under federal Comprehensive Environmental Response, Compensation, and Liability Act (Superfund) and state Model Toxic Control Act regulations. The SMP’s objectives are to repair potential environmental damage through a timely, efficient, and economical process. The following activities were carried out as part of implementing the SMP during 2007–2013: • Completed cleanup of the former Denny Way CSO site off of Myrtle Edwards Park in Seattle and, in 2008, began monitoring sediment quality (to be completed in 2018) • Improved modeling to predict deposition of contaminants around CSO outfalls • Completed post-construction monitoring of the Diagonal/Duwamish cleanup site • Conducted sampling of sediments in the East Duwamish Waterway Superfund site and as part of the East Waterway Group finalized the East Duwamish Waterway remedial investigation and completed a draft feasibility study. The East Waterway Group is a partnership between the City of Seattle, King County, and the Port of Seattle. More information on the SMP is available at http://www.kingcounty.gov/environment/wastewater/SedimentManagement.aspx . Cleaning Up the Lower Duwamish Waterway Superfund Site King County continues to work to improve water quality in the Lower Duwamish Waterway Superfund site through actions such as controlling CSOs, restoring habitat, capping and removing sediments, and controlling toxicants from industries and stormwater runoff. Since the 1960s, regional source control 2-14 RWSP 2013 Comprehensive Review Chapter 2. RWSP Achievements in 2007−2013 efforts have reduced flows of industrial waste and sewage into the Lower Duwamish by 98 percent, or 27 billion gallons per year. The County is also partnering with the City of Seattle, the Port of Seattle, and the Boeing Company as part of the Lower Duwamish Waterway Group (LDWG). The LDWG has been working with EPA and Ecology since 2001 to study contamination and determine the best and most effective alternatives to clean up the Lower Duwamish Waterway. During the 2007–2013 timeframe, the LDWG completed a remedial investigation and feasibility study for the Lower Duwamish Waterway Superfund Site and started a study to better understand who is eating contaminated seafood from the Duwamish River. In 2013, EPA issued the Proposed Plan for the Lower Duwamish Waterway Superfund Site, which presents a Preferred Alternative to clean up contamination in the in-waterway portion of the Lower Duwamish Waterway Superfund site. EPA is expected to issue a Record of Decision in third quarter of 2014 to direct cleanup actions and long-term monitoring. The County, in partnership with the LDWG, carried out engagement and outreach activities with interested industries, businesses, residents, and environmental and community groups throughout the efforts to develop the remedial investigation, the feasibility study, and on EPA’s proposed cleanup plan. The process to allocate cleanup costs among potentially responsible parties, including King County, is under way. In addition, WTD’s Lower Duwamish Waterway Green Grants Program began providing grant funding in 2011 for air or water quality improvement projects, environmental education, and community outreach efforts within the Duwamish River Valley. The funding supports projects that reduce air pollution, prevent CSOs, and prevent pollution from going into the Duwamish River. Past projects have included roadside rain gardens, outreach to businesses on how to implement best management practices to stop stormwater pollution, an art installation that measures air quality, and wetland restoration. More information on the County’s efforts to clean up the Lower Duwamish Waterway is available at http://www.kingcounty.gov/environment/wastewater/Duwamish-waterway.aspx. Creating Resources from Wastewater RWSP policies provide guidance on beneficial uses for byproducts from wastewater treatment— biosolids and digester gas from the solids treatment process and reclaimed water from the liquids treatment process. This section provides information on achievements made in 2007−2013 through WTD’s Biosolids Recycling Program, Energy Recovery and Efficiency Program, and Reclaimed Water Program. Biosolids Recycling Program Biosolids are the nutrient-rich organic material produced by treating wastewater solids. After being processed and treated, biosolids are beneficially used as a fertilizer and soil amendment in agriculture and forestry or as an ingredient in compost. In 2007−2013, King County recycled 100 percent of its biosolids for these uses; the description of uses for 2007−2012 is provided in each year’s RWSP annual reports. RWSP 2013 Comprehensive Review 2-15 Chapter 2. RWSP Achievements in 2007−2013 WTD launched the County’s biosolids brand, Loop®, in 2012. The development of the Loop brand is part of a long-term strategic goal to increase public support and strengthen demand for biosolids. More information on the benefits and uses of Loop is available at http://www.loopforyoursoil.com/. In 2013, 115,801 wet tons of Loop biosolids were produced at the West Point, South, and Brightwater treatment plants, all of which were recycled and used beneficially as a nutrient-rich soil amendment for forestry and agricultural applications or was used to make compost. The sale of biosolids generated over $188,000 in fertilizer revenue from customers. The biosolids were used as a fertilizer andsoil amendment for a variety of applications: • About 6,800 acres of dryland wheat in Douglas County as part of the Boulder Park Soil Improvement Project • About 2,600 acres of hops, orchards, and wheat at Natural Selection Farms in the Yakima Valley • Over 600 acres of Douglas fir plantations on state forestlands and on Hancock’s Snoqualmie Forest as part of the Mountains to Sound Greenway Biosolids Forestry Program Highlights of other achievements for the Biosolids Recycling Program in 2007−2013 are as follows: • Construction of the West Point Digestion Improvement project was completed. The project will enhance the reliability of the West Point plant’s solids digestion system and reduce the risk of digester upsets under current and future solids loading conditions. • Progress was made on a project at the West Point Plant to upgrade and replace the screening equipment that filters out trash and other debris. The project will meet the state’s biosolids management rule requiring significant removal of manufactured inerts (trash and plastics) from biosolids. Construction of the screening project is expected to be complete in late 2014. • An analysis of alternative uses and market opportunities for biosolids was completed in 2009. The analysis provided cost-benefit information for land application, composting, and alternative energy production. The process confirmed that land application and composting of biosolids are the most cost-effective and reliable options at this time. The report on the alternative uses and market opportunities is available at http://www.kingcounty.gov/environment/wastewater/Biosolids/DocumentsLinks.aspx. • GroCo compost, which is made with Loop is now “Declare” certified, which meets Living Building Challenge (LBC) standards. Declare offers LBC project teams a materials guide for product specification. LBC is the built environment's most rigorous sustainability performance standard. More information on the Declare label is available at http://www.declareproducts.com/. Several research studies were conducted. Highlights from the studies are listed below. • In 2008, WTD participated in a study through the Northwest Biosolids Management Association to quantify the carbon sequestration benefits of using biosolids and other organic residuals as a 2-16 RWSP 2013 Comprehensive Review Chapter 2. RWSP Achievements in 2007−2013 soil amendment for land application. Results showed a significant increase in carbon stored in agricultural soils, indicating that use of biosolids as a soil amendment has the potential to reduce the carbon footprint while helping secure the sustainability of agriculture in the state. For example, the benefit of using Loop in 2012 offset over 42,000 tons of carbon dioxide equivalents, which is similar to taking 8,000 cars off the road that year (Figure 2-10). The results are similar for 2013. Because of investments in energy conservation, renewable energy production and carbon and nutrient recycling, the WTD is 70 percent of the way to being carbon-neutral in its operations. Figure 2-10. WTD’s 2012 Carbon Impact • In summer 2009, the County began collaborating on a carbon-sequestration demonstration project in a borrow pit at Island Center Forest on Vashon Island.3 Researchers are evaluating the ability of composted organic residuals (biosolids, food waste, and woody debris) to recover soil quality by capturing and storing carbon, improving soil health, and enhancing vegetation growth on this degraded site. Long-term monitoring in under way. • In 2009, a biosolids research and demonstration garden was installed at South Treatment Plant. University of Washington scientists studied the safety of vegetables grown in a sandy loam soil mix and a biosolids compost soil mix. The research team noted that vegetables grown in the biosolids compost mix were deemed safe and the growth was considered lush. More information on the County’s Biosolids Recycling Program is available at http://www.kingcounty.gov/environment/wastewater/Biosolids.aspx. Energy Recovery and Efficiency Program RWSP policies call for the County to use digester gas, an energy-rich methane gas naturally produced as a byproduct of solids treatment, for energy and other beneficial purposes when it is cost-effective to do so. In addition, the County’s Strategic Climate Action Plan includes energy goals to implement energy efficiencies and increase renewable energy production. 3 A borrow pit is an area where material (usually soil, gravel or sand) has been dug for use at another location. RWSP 2013 Comprehensive Review 2-17 Chapter 2. RWSP Achievements in 2007−2013 The South, West Point, and Brightwater treatment plants use digester gas to produce heat, electricity, and natural gas. At South Plant, digester gas that is not used for in-plant purposes is “scrubbed” to the quality required for pipeline natural gas and then sold to Puget Sound Energy. A major achievement during 2007−2013 is the completion and startup of the Waste-to-Energy cogeneration system at the West Point Plant. The cogeneration system creates electricity from the facility’s digester gas and captures the heat generated from the influent pump engines. The system reduces West Point’s demand for electricity supplied from the power grid, and will provide a significant portion of West Point’s heat demand for most of the year. The cogeneration system, scheduled to be online in 2014, will produce about 18,000 megawatt hours (MWh) of “green” electricity each year. Seattle City Light will purchase power produced by the engines, including renewable energy credits. This partnership will help Seattle City Light achieve its 15 percent renewable energy goal by 2020 in accordance with Washington Initiative 937. The facility is expected to generate $1.4 million in annual revenue to WTD from the sale of green electricity. Other achievements during 2007−2013 include: • Replacement of blowers at the West Point and South plants with more efficient blowers. • WTD’s energy team conducts energy audits on facilities that consume over 5,000 million British Thermal Units (MBtu) of annual energy. Results of the audits will inform future energy-efficiency capital projects. • In 2012, a request for information was advertised inviting local developers and commercial owners to submit ideas for privately owned district energy systems that could extract and recover heat from WTD’s conveyance system. More information on WTD’s energy program is available at http://www.kingcounty.gov/environment/wastewater/ResourceRecovery/Energy.aspx. Reclaimed Water Program RWSP water reuse policies provide guidance to King County on the development and implementation of its Reclaimed Water Program. WTD has been safely producing and using reclaimed water since 1997. Two major achievements in the Reclaimed Water Program occurred during 2007−2013 with the completion and startup of the Carnation and Brightwater treatment plants. Both facilities produce and distribute reclaimed water. Reclaimed Water Planning Studies WTD participated in several reclaimed water planning studies during this timeframe. In 2007, WTD completed a preliminary analysis of reclaimed water options in the Green River Valley to answer questions raised by the Cities of Auburn, Covington, Kent, Renton, and Tukwila. Information from the study was incorporated into the reclaimed water comprehensive planning process that occurred in 2009–2012. 2-18 RWSP 2013 Comprehensive Review Chapter 2. RWSP Achievements in 2007−2013 King County and the Covington Water District signed a memorandum of agreement in 2007 to jointly fund and pursue a phased approach to explore opportunities for reclaimed water development in the district’s service area. Results from this effort were incorporated into the reclaimed water comprehensive planning process, described below. In 2008–2009, WTD worked with the SPU on Seattle’s economic analysis of the potential for providing reclaimed water from the Brightwater Treatment Plant to large irrigators and other potential users of nonpotable water in north Seattle. Information from this analysis was incorporated into the reclaimed water comprehensive planning process. In 2009−2012, WTD initiated a reclaimed water comprehensive planning process to determine whether and how King County should expand its existing Reclaimed Water Program over the next 30 years. WTD worked closely with local water and sewer utilities throughout the process, and a database was developed on potential reclaimed water uses in the region. WTD developed and analyzed three conceptual strategies for reclaimed water satellite or skimming facilities to serve potential reclaimed water uses. Reclaimed Water Production and Use in 2013 As part of RWSP annual reports, information is provided on reclaimed water used each year for in-plant or off-site purposes. Information for 2013 follows. South Treatment Plant South Plant produced 81.7 million gallons (MG) of reclaimed water in 2013. The majority of the water was used at the plant for process water and landscape irrigation. If the reclaimed water were not available for these uses, WTD would have to use potable water, which would have increased the facility’s operational costs by $155,380 in 2013. About 2.94 MG of reclaimed water was distributed and used off site by reclaimed water customers, including the City of Tukwila. The city uses reclaimed water for irrigation of the Starfire Sports Complex and wetland plants nursery, and for city public works uses such as street sweeping and sewer flushing. West Point Treatment Plant The West Point Plant produced 189.2 MG of reclaimed water in 2013. All of the reclaimed water produced was used at the plant site for process water. If the reclaimed water were not available for these uses, WTD would have to use potable water for such applications, which would have increased the facility’s operational costs by $1,242,411 in 2013. Carnation Treatment Plant In 2013, the Carnation Plant discharged 31.93 MG of reclaimed water to enhance a wetland in the County's Chinook Bend Natural Area. Brightwater Treatment Plant About 30.2 MG of reclaimed water from the Brightwater Plant was distributed to the Brightwater Education and Community Center and the Willows Run Golf Course in 2013. The water was used for irrigation, toilets/urinals, and public art. In addition, 336 MG of reclaimed water was produced and used RWSP 2013 Comprehensive Review 2-19 Chapter 2. RWSP Achievements in 2007−2013 for process water at the plant. If the reclaimed water were not available for these uses, WTD would have had to use potable water, which would have increased the facility’s operational costs by $1,802,235 in 2013. Protecting our Assets It would cost more than $20 billion to build King County’s wastewater system from the ground up today, and the value of existing facilities is estimated at about $6 billion. RWSP policies provide guidance for an asset management program to maintain and repair equipment and facilities and to develop an asset management plan. In addition, the Council-approved scope of work (Motion 13758) for the 2013 RWSP comprehensive review report included adding information on assumptions regarding asset management and replacement. Maintaining the region’s wastewater assets is a high priority for WTD. The division’s Asset Management Program oversees inspection of the regional treatment facilities and conveyance system, repairing and replacing aging facilities, and developing plans to address ongoing system issues. The primary objectives of the program are to manage the whole lifecycle of assets in a manner that minimizes the total costs of owning, maintaining, and operating them; deliver a level of service that meets regulatory requirements and ratepayer expectations; and fulfill WTD’s mission to protect public health and enhance the environment by treating and reclaiming water, recycling solids, and generating energy. WTD continues to update its asset management plans and practices. The assumptions, or principles, that guide WTD’s Asset Management Program are as follows: • Applying the principle that proper management of the region’s wastewater assets is essential for public and environmental health and safety. • Using Enterprise Asset Management (EAM) to standardize the management of assets across sections, facilities, business units, and geographical locations. EAM integrates techniques for control and optimization throughout asset lifecycles, including design, commissioning, operations, and replacement. Effective EAM allows WTD to do the following: o Maximize return on assets o Balance costs and risks o Improve asset decision making o Comply with required regulations o Increase asset service responses and enhance efficiency o Lower total cost of ownership • Maintaining an accurate asset inventory is essential for a successful asset management program. 2-20 RWSP 2013 Comprehensive Review Chapter 2. RWSP Achievements in 2007−2013 • Understanding criticality (the likelihood of failure [asset condition] and consequence of failure) is key to managing risk and fulfilling WTD’s mission. • Continually assessing and confirming criticality of an asset to ensure efficient allocation of resources is of utmost importance and is an ongoing process. • Ensuring good records management and ongoing tracking of asset performance provides for condition-based maintenance and better decision making about the needs and life of an asset • Employing “Maintenance Best Practices” leads to better outcomes for facility operations and ratepayers: o Improved asset utilization and performance o Reduced capital cost o Reduced asset-related operating costs o Extended life of asset These principles form the basis of WTD’s Strategic Asset Management Plan (SAMP) that was updated in 2010. Because asset management tools evolve over time and lessons learned on optimizing asset use is an ongoing process, WTD continues to update its SAMP; the next update is scheduled to be complete by the end of 2015. WTD’s facilities inspection team performs regularly scheduled condition assessments on the conveyance system and facility structures. Results of the assessments and any rehabilitation recommendations are reported in a Facilities Inspection Annual Work Plan. As of 2012, WTD’s closed-circuit television (CCTV) crew has inspected a million lineal feet of pipe over 10 years. In 2008, WTD completed a study on the vulnerability of major wastewater facilities to flooding from sea- level rise. As effects of climate change continue to grow, it is important to assess the potential for flooding at WTD’s facilities that are adjacent to tidally influenced water bodies. The study identified these facilities and their potential for flooding, considering the effects of both sea-level rise and storm surges, and then recommended the next steps in planning for this change. The study is available at http://www.kingcounty.gov/environment/wastewater/CSI/Library/SeaLevelRise.aspx. Ongoing and future activities to continually improve how WTD protects its assets include the following: • Develop a tracking system in the computerized maintenance management system (CMMS) to compile energy efficiency data to support asset refurbishment and replacement projects. • Continue work to produce long-term capital restoration and replacement forecasts. • Conduct a best practices assessment. WTD is reviewing other agencies’ best practices. RWSP 2013 Comprehensive Review 2-21 Chapter 2. RWSP Achievements in 2007−2013 • Implement a resiliency and recovery. The program includes conducting a susceptibility review of the region’s wastewater facilities with respect to their vulnerability to damage in the event of a disaster, the potential extent of such damage, and ways to improve recoverability of affected facilities immediately after a disaster. • Complete the SAMP update. More information on WTD’s asset management activities are available at http://www.kingcounty.gov/environment/wtd/Construction/Assets.aspx. 2-22 RWSP 2013 Comprehensive Review Chapter 3 Financial Stewardship The RWSP financial policies guide the County on the long-term financing. The policies provide direction for establishing annual sewer rates and capacity charges, and for allocating wastewater system costs between existing and new customers. Appendix A provides information on how the RWSP financial policies were implemented in 2007−2013. This chapter describes how annual sewer rates and capacity charges are established, gives sewer rate and capacity charge projections through 2030, and compares them to projections in previous RWSP comprehensive review reports. The chapter also describes programs implemented in 2007−2013 to increase efficiency and policy guidance on construction fund and emergency reserves. Establishing Annual Sewer Rate and Capacity Charge The RWSP calls for existing customers to pay a monthly sewer rate to cover the portion of the existing and expanded system that serves them. New customers pay costs associated with the portion of the existing system that serves them and costs associated with expanding the system to serve future customers, in accordance with a fundamental principle of the RWSP that “growth pays for growth.” The charges for new customers are collected through a combination of the monthly sewer rate and the capacity charge. The capacity charge is designed to provide a means by which the growth customers (new connections to the system) pay their equitable share of the cost of their service. The basic approach is to identify (allocate) the costs of serving each customer group and then design rates and the capacity charge so that each pay their equitable share. At the request of the County Council’s Regional Water Quality Committee (RWQC), a Financial Policies Work Group (FPWG) was formed in 2009 to review the RWSP financial policies. The FPWG was comprised of staff representing MWPAAC, sewer districts, City of Seattle, City of Bellevue, the King County Executive, and the King County Council. The FPWG reviewed the capacity charge methodology in depth. Although the FPWG had lengthy discussions regarding how certain costs associated with growth are allocated either to existing customers or current growth customers (those connecting between 2003 and 2030), there was no consensus on changing any of the allocations used to calculate the capacity charge. The RWQC was briefed on the work of the FPWG during summer 2013. Based on the briefing, the capacity charge discussion at RWQC has been tabled for now. Factors that affect the sewer rate and capacity charge include the number of Residential Customer Equivalents (RCEs), wastewater operating expenditures, capital program expenses, number of new connections, and debt financing. In addition, these charges are affected by the allocation of capital program costs between customers establishing new connections to the system and those with existing connections. Figure 3-1 illustrates the relationship between the monthly rate and the capacity charge. 3-1 RWSP 2013 Comprehensive Review Chapter 3. Financial Stewardship Figure 3-1. Relationship Between the Monthly Sewer Rate and Capacity Charge Residential Customer Equivalents King County uses an RCE as the basic unit for charging local agencies for wastewater services. Agencies are charged one RCE for each single detached housing unit, regardless of size or water consumption. For multifamily dwellings and commercial and industrial establishments, agencies are charged on the basis of water consumption. For each 750 cubic feet of water per month consumed, the agency is charged for one RCE. Local agencies employ a variety of means of allocating these costs to their customers. For example, in the City of Seattle, the charge for all customers—single-family, multifamily, commercial, and industrial— is based on water consumption. Other agencies charge per RCE. Table 3-1 shows RCEs by category for 1994 to 2013. During this period, total RCEs increased by a little over 59,000 relative to 1994 levels or an average annual percentage growth of 0.45 percent. This aggregate change masks the underlying differences among the categories of customers. For example, from 1994 to 2013, single-family residential RCEs increased by 90,354, which was partially offset by a decline in commercial and multifamily RCEs of approximately 31,000. In addition, the recent recession dampened RCE growth during the 2009 to 2012 period, with a 0.4 percent decrease in 2009. The 2013 growth of 1.3 percent is seen as a bounce back from the recession-induced low growth period of 2009 through 2012. Figure 3-2 shows the comparison of RCE forecasts for 2007 and for 2013. It is assumed that RCEs will continue to grow beyond 2013 levels, increasing at approximately 0.43 percent annually through 2030. The County continually monitors for changes in underlying assumptions and will adjust these projections accordingly. The long-term forecast of RCEs is a trend projection intended to provide a conservative financial forecast (relatively low, steady growth) for the County’s wastewater utility to avoid underestimating sewer rates, especially in the near term. As such, it does not attempt to reflect swings in the business cycle or reflect 3-2 RWSP 2013 Comprehensive Review Chapter 3. Financial Stewardship the basis of capacity needs and timing. As recently shown, RCEs can be affected by short-term swings as the result of the economic climate. Table 3-1. Residential Customer Equivalents (1994–2013) Year Single Family Residential % Change Commercial & Multifamily % Change Total % Change 1994 296,757 1.3% 362,300 -0.4% 659,057 0.4% 1995 299,963 1.1% 367,828 1.5% 667,791 1.3% 1996 303,292 1.1% 367,894 0.0% 671,186 0.5% 1997 307,340 1.3% 371,514 1.0% 678,854 1.1% 1998 310,878 1.2% 376,426 1.3% 687,304 1.2% 1999 315,878 1.6% 378,219 0.5% 694,097 1.0% 2000 320,117 1.3% 376,705 -0.4% 696,822 0.4% 2001 325,125 1.6% 377,235 0.1% 702,360 0.8% 2002 329,265 1.3% 355,830 -5.7% 685,095 -2.5% 2003 334,555 1.6% 350,578 -1.5% 685,133 0.0% 2004 342,582 2.4% 345,327 -1.5% 687,909 0.4% 2005 349,535 2.0% 340,282 -1.5% 689,817 0.3% 2006 357,115 2.2% 333,819 -1.9% 690,934 0.2% 2007 364,044 1.9% 338,902 1.5% 702,946 1.7% 2008 370,621 1.8% 336,225 -0.8% 706,846 0.6% 2009 375,513 1.3% 328,282 -2.4% 703,795 -0.4% 2010 378,148 0.7% 326,243 -0.6% 704,391 0.1% 2011 381,031 0.8% 326,247 0.0% 707,278 0.4% 2012 383,903 0.8% 324,991 -0.4% 708,894 0.2% 2013 387,111 0.8% 331,049 1.9% 718,160 1.3% RWSP 2013 Comprehensive Review 3-3 Chapter 3. Financial Stewardship Figure 3-2. 2007 and 2013 Residential Customer Equivalent Forecasts (1993 to 2030) Sewer Rate and Capacity Charge Projections Sewer Rate Long-term projections of the monthly sewer rate are not strictly comparable to those presented each year in the annual rate process. The rates presented during the annual rate process incorporate the most up-to-date data and the assumption that not all of the capital improvement program (CIP) budget will be expended during the year. Historically, in a given year, actual capital spending is 10 to 25 percent less than budgeted for the entire program. This is largely because projects are delayed for a variety of reasons, including permitting issues, unknown geotechnical conditions, and unforeseen construction delays. Accounting for this actual spending lowers the proposed rate. However, long-term planning assumes that 100 percent of the costs are incurred by completion. Consequently, the long-run rate projections reflect an assumption that 100 percent of the annual CIP budget is expended each year. Figure 3-3 presents the most current mid-term view of the original 1998 RWSP rate projections, the rate projections from the RWSP 2006 Comprehensive Review, and the actual rates through 2014 (all rates include inflation). Figure 3-4 presents long-term sewer rate projections from the RWSP 2006 Comprehensive Review and updated RWSP sewer rate projections with inflation (2002–2030) and compares them with the 2013 long-term projections. 3-4 RWSP 2013 Comprehensive Review Chapter 3. Financial Stewardship Figure 3-3. Sewer Rate Projections with Inflation (2002–2014) Figure 3-4. Sewer Rate Projections with Inflation (2002–2030) $0.00 $10.00 $20.00 $30.00 $40.00 $50.00 $60.00 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 Original RWSP Forecast 2006 RWSP Update Forecast 2013 Adopted Rate Comparison of Monthly Wastewater Rate Projections 1998 Original RWSP, 2006 RWSP Update and 2013 Adopted Rate (monthly rates with inflation) Actual rates through $39.79 2014 rate ` RWSP 2013 Comprehensive Review 3-5 Chapter 3. Financial Stewardship Actual monthly sewer rates have closely tracked the long-run projections associated with the 2006 update through 2014. The main determinant of the pattern of monthly rates is the annual capital spending patterns, as shown in Figure 3-5. This chart shows capital spending for the wastewater program from 2000 to 2030. It highlights the relatively high amount of spending for the Brightwater Treatment System during the 2003 to 2010 period, with peak capital expenditure in 2009 and 2010. After completion of Brightwater construction, capital spending returned to a more normal long-run level of approximately $175 to $200 million in 2013 dollars. Figure 3-5. Annual Capital Spending for the Wastewater Treatment Division (2000 to 2030) Capacity Charge The increases in capital costs associated with new capacity have a direct and significant effect on the capacity charge. This effect is shown in Table 3-2, which presents the 2003 to 2014 capacity charge for both lump sum and monthly payments. The largest component of change in the capacity charge during this period was in the capital cost of Brightwater. As Brightwater progressed and cost estimates stabilized, increases in the capacity charge largely reflect the rate of inflation. Because Brightwater is allocated exclusively as a growth cost, the impact to the capacity charge is direct. 0 50 100 150 200 250 300 $0 $100,000,000 $200,000,000 $300,000,000 $400,000,000 $500,000,000 $600,000,000 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 Total Capital Spending without inflation in 2013 $ 3-6 RWSP 2013 Comprehensive Review Chapter 3. Financial Stewardship Table 3-2. WTD Capacity Charge (2003−2014) Year Monthly Charge Total Lump-Sum Paymenta Total When Paid Monthly 2003 $17.60 $2,197 $3,168 2004 $18.00 $2,247 $3,240 2005 $34.05 $4,251 $6,129 2006 $34.05 $4,251 $6,129 2007 $42.00 $5,196 $7,560 2008 $46.25 $5,721 $8,325 2009 $47.64 $5,893 $8,575 2010 $49.07 $6,070 $8,833 2011 $50.45 $6,241 $9,081 2012 $51.95 $6,427 $9,351 2013 $53.50 $6,618 $9,630 2014 $55.35 $6,847 $9,963 a.Current policy discounts lump sum payments at 3.2% percent. Although total RCEs (new plus existing) have grown at a relatively slow rate recently, the number of newly connecting customers has equaled or surpassed originally expected levels. While new connections averaged more than 9,500 RCEs per year since the beginning of the capacity charge program in 1990, they averaged approximately 10,000 per year between 2000 and 2013. This average masks some volatility in that period, especially during the economic downturn of 2008 to 2013 when the average was closer to 7,500 new connections per year. The forecast begins with a conservative assumption on a recovery to 9,500 new connections in 2014 before moving to approximately 10,000 a year for 2015 to 2020, a level supported by longer-term demographic and employment trends for the County’s wastewater service area. The projections decrease to approximately 9,600 per year after 2020, reflecting a slowing in projected population growth. Continuous Improvement Programs Productivity Initiative Pilot Program WTD’s Productivity Initiative Pilot Program was developed to identify and implement ways to increase efficiency. This 10-year incentive program applied certain private-sector business practices, including the establishment of an incentive-based cash payment to employees in the wastewater program, to reduce RWSP 2013 Comprehensive Review 3-7 Chapter 3. Financial Stewardship operating costs, increase productivity, and continue a high level of service and environmental protection for WTD’s customers. The pilot program ended in April 2011. The program generated nearly $84 million in savings for ratepayers over its 10-year lifespan. More information on the Productivity Initiative Pilot Program, including the comprehensive review report of the program, is available at http://www.kingcounty.gov/environment/wtd/About/Finances/PI.aspx. Bright Ideas Program WTD is committed to continuous improvement. As a follow-up to the Productivity Initiative, WTD established an employee-initiated program called Bright Ideas. The program encourages creative problem-solving throughout the organization and uses employees’ ideas to improve how WTD does business. Since Bright Ideas was launched in September 2012, WTD employees have submitted more than 550 ideas. It is expected that the program will result in over $400,000 in savings in 2014. Policy Guidance on Construction Fund and Emergency Reserves The King County Council adopted Ordinance 17480 in December 2012, amending the RWSP comprehensive review reporting policies. The ordinance calls for including information related to policy guidance on WTD’s construction fund and emergency reserves in RWSP comprehensive reviews. Policy guidance on the construction fund and emergency reserves is provided in Motion 13798, which was adopted by the County Council in December 2012. The development of the motion resulted from the work conducted by the FPWG in its review of RWSP financial policies. The direction provided in the motion continues to make sense and serve WTD’s ratepayers well. WTD will continue to review this guidance as directed in the motion. In regards to the construction fund and emergency reserves, the motion states: 2. Reserves in the Wastewater Treatment Division operating and capital budgets. a. The current practice of maintaining a liquidity reserve of at least ten percent of operating expenses plus five million dollars in the construction fund has been viewed favorably by rating agencies and has improved bond ratings, and should therefore continue. b. The proposed financial plan for each fiscal year should include a minimum cash balance, to be utilized for reserves, at the beginning of the year equal to or greater than ten percent of operating expenses plus five million dollars in the construction fund. c. If the cash balance or reserve has been utilized in the current or preceding year, the financial plan will show how and when it will be restored to the minimum. d. In addition to this minimum cash balance, the financial plan should include an emergency capital reserve at the beginning of year with a minimum of fifteen million 3-8 RWSP 2013 Comprehensive Review Chapter 3. Financial Stewardship dollars to be used for unanticipated system repairs or equipment replacement in the event of a natural disaster or some unforeseen system failure. e. Interest earnings on the emergency capital reserve shall be available for operations. f. If the emergency capital reserve has been utilized in the current or preceding year, the financial plan will show how the capital reserve will be replenished to fifteen million within five years. g. As a part of each Regional Wastewater Services Plan review and update, the dollar amounts for reserves stipulated in this motion should be reviewed to ensure they are appropriate in future years. RWSP 2013 Comprehensive Review 3-9 Chapter 3. Financial Stewardship 3-10 RWSP 2013 Comprehensive Review Chapter 4 Forecasting Future Wastewater Treatment Plant Capacity Needs A major component of the RWSP 2013 comprehensive review included evaluating and updating future regional wastewater treatment capacity needs. This chapter summarizes this analysis, provides more detail on methodology and findings, and discusses the findings as they relate to future treatment plant capacity needs. Summary In general, WTD updates its treatment plant forecasts every 10 years using updated population and employment forecasts provided by the Puget Sound Regional Council (PSRC). WTD also evaluates and updates other key planning assumptions, such as water use, water conservation, and the service area growth rate. The last major forecasting update occurred as part of the RWSP 2004 update and used PSRC’s 2003 forecast. The results found that the difference in overall change between population forecasts over the planning period and change in planning assumptions was insignificant with respect to the wastewater system’s treatment capacity needs and confirmed the need and timing for the Brightwater Treatment Plant and the anticipated expansion of South Treatment Plant in 2029. For this review, WTD used PSRC’s 2013 Land Use Forecast as input for population and employment numbers and worked closely with the Metropolitan Water Pollution Abatement Advisory Committee’s (MWPAAC) Engineering and Planning Subcommittee (E&P Subcommittee) in May through December 2013 to update RWSP planning assumptions. WTD also met with individual agencies and consulted the water and sewer comprehensive plans of several local agencies. This information along with operational data from the treatment plants over the past several years was used to forecast treatment plant capacity needs through 2060. Key findings from the analysis are as follows: • Regional population continues to increase. • Treatment plant solids loadings will continue to grow in proportion with population growth. • There was a 15 percent reduction in average wet-weather flow (AWWF) over the last decade, which aligns with reduction in water use seen from 2000 to 2010. Because of this and projected future water use and conservation, the AWWF capacity needs are less than forecast previously. • Projections of future peak flows for the treatment plants are being developed as part of the 2015 Conveyance System Improvement Program update. Capacity requirements will be reevaluated when these projections become available. The analysis confirmed the benefits of having a three-plant regional system. Findings indicate that with the Brightwater Plant, there is sufficient treatment plant capacity until the 2030s. Current forecasts indicate that solids loadings capacity will be needed sooner than AWWF capacity at all three plants, which could require additional equipment and digesters to handle the solids capacity needs. The forecasts indicate that a full expansion at South Treatment Plant is unlikely to be needed in 2029 as RWSP 2013 Comprehensive Review 4-1 Chapter 4. Forecasting Future Wastewater Treatment Plant Capacity Needs previously projected. WTD will continue to monitor the factors and trends that affect treatment plant capacity needs. Methodology WTD’s population and employment forecasts generally coincide with the most recent federal census data. For this forecast, the current baseline year is 2010; the previous baseline year was 2000. A 50-year planning horizon was used for this current forecasting effort. The method used to forecast wastewater treatment plant flows and solids loadings (wasteloads) is to multiply the population and employment forecasts by flow and wasteload factors representing average volumes generated per person: • AWWF has historically been used as the main indicator of treatment plant capacity needs. The South Plant and Brightwater Plant service areas are served by separated sewer systems. AWWF for these service areas is defined as the average of all flows during November through April. For the West Point Plant, the AWWF is defined as the average of all non-storm flows during November through April because the service area includes combined sewers and the plant has wet weather treatment capacity above its secondary treatment capacity. • Solids must be treated to ensure compliance with National Pollution Discharge Elimination System (NPDES) permit limitations. Biological oxygen demand (BOD) and total suspended solids (TSS) entering the plants are measured daily. Biosolids (Loop) leaving the plants are also measured. The measurements are used in estimating future solids loading. Peak flows to the treatment plants are also important in evaluating capacity needs. Peak flows represent the highest combination of base flow and infiltration/inflow (I/I) expected to enter a wastewater system during wet weather over a set time period (for example, 30-minute increments). The information needed to forecast the peak flows is being generated as part of the 2015 Conveyance System Improvement (CSI) Program update; therefore, peak flow forecasts for the treatment plants will be generated following completion of the update. Planning Assumptions The planning assumptions used during this update compared to those used for the 2000 baseline forecasts are shown in Table 4-1. WTD worked with MWPAAC’s E&P Subcommittee from May through December 2013 to update these planning assumptions. In addition, WTD had discussions with individual agencies, reviewed agency water and sewer comprehensive plans, and used flow monitoring and treatment plant data to inform the update of the planning assumptions. 4-2 RWSP 2013 Comprehensive Review Chapter 4. Forecasting Future Wastewater Treatment Plant Capacity Needs Table 4-1. Previous and Updated Planning Assumptions Category Previous Assumption Updated Assumption Planning horizon 2050 50-year planning horizon (2060) Extent of eventual service area Potentially sewerable areas in Urban Growth Areas of King County’s wastewater service area Same Future population 2003 Puget Sound Regional Council (PSRC) forecast 2013 PSRC forecast Water use Base Year 2000 Seattle residential: 55 gpcd Other residential: 66 gpcd Commercial: 33 gped Industrial: 55 gped Base Year 2010 Inside Seattlea Residential: 46 gpcd Commercial: 30 gped Industrial: 61−68 gped Outside Seattle Residential: 54 gpcd Commercial: 18 gped Industrial: 45−56 gped Water conservation A 10% reduction in per-capita and per employee water consumption between 2000 and 2010 and no additional reduction after 2010 A 10% reduction in per-capita and per-employee water consumption between 2010 and 2030 and no additional reduction after 2030 Sewered area growth rate 90% of unsewered sewerable area in 2000 is sewered by 2030, 100% by 2050 100% of unsewered sewerable area in 2010 is sewered by 2060, at a rate of 20% per decade starting in 2010 Average wet weather I/I degradation (treatment plants) Increase of 7% per decade up to a maximum of 28% No degradation Design flow (separated conveyance system) 20-year peak flow Same Degradation of peak I/I (separated conveyance system) Model basin peak I/I in year 2000 with assumed increase of 7% per decade up to a maximum of 28% (over 4 decades) Model basin peak I/I in year 2010 with assumed increase of 7% per decade through the planning horizon New system I/I (separated conveyance system) 1,500 gpad with 7% degradation per decade increase to approximately 2,000 gpad over 4 decades 2,000 gpad plus assumed I/I degradation (7% per decade) through the planning horizon gpcd = gallons per-capita per day; gped = gallons per employee per day; gpad = gallons per acre per day. a Because of the large difference between industrial and commercial water usage inside and outside Seattle, the analysis used separate employment usage factors for Seattle. b The data did could not determine any apparent trend for AWWF I/I degradation rate. RWSP 2013 Comprehensive Review 4-3 Chapter 4. Forecasting Future Wastewater Treatment Plant Capacity Needs Population and Employment Forecasts WTD relies on population and employment forecasts from the Puget Sound Regional Council (PSRC) to project flows in sewer model basins, which are delineations of the WTD service area. Model basins are aggregated to forecast flows in treatment plant service areas. For its latest flow projections, WTD is using the PSRC 2013 Land Use Forecast as input for population and employment numbers. The 2013 Land Use Forecast was developed using PSRC’s new UrbanSim model. The model forecasts growth for each year out to 2040 for residential populations and several employment categories. Figure 4-1 shows previous and current population projections for the whole WTD service area. Actual population growth in sewered areas through 2010 is very close to the growth forecast as part of the RWSP 2004 Update. The total residential population served by sewers is now projected to grow by 49 percent from 2010 to 2050 using the 2013 forecast compared to 45 percent for the same period using the 2004 forecast. This population is predicted to grow by 8.6 percent between 2050 and 2060. Commercial and industrial employment dropped slightly between 2000 and 2010; PSRC projects a recovery in employment levels by 2020, with employment rising slightly above the 2004 forecast by 2040. Commercial employment is extrapolated to 2060 with an increase of 12 percent per decade, and industrial employment is extrapolated with an increase of 3 percent per decade. Figure 4-1. Previous and Current Population and Employment Projections for the WTD Service Area Figure 4-2 shows the West Point, South, and Brightwater service areas. It was assumed in this analysis that the service areas would remain the same throughout the planning period. Figures 4.3, 4-4, and 4-5 compare the previous and current population forecasts for each treatment plant service area. Projections of sewered residential population are generated for each model basin using the assumed 4-4 RWSP 2013 Comprehensive Review Chapter 4. Forecasting Future Wastewater Treatment Plant Capacity Needs sewered area growth rate shown in Table 4-1. All existing and future commercial and industrial employees were assumed to be served by sewers. Figure 4-2. King County’s Wastewater Treatment Service Areas RWSP 2013 Comprehensive Review 4-5 Chapter 4. Forecasting Future Wastewater Treatment Plant Capacity Needs Figure 4-3. Previous (2004) and Current (2013) Population and Employment Forecasts For West Point Service Area Figure 4-4. Previous (2004) and Current (2013) Population and Employment Forecasts For South Plant Service Area 4-6 RWSP 2013 Comprehensive Review Chapter 4. Forecasting Future Wastewater Treatment Plant Capacity Needs Figure 4-5. Previous (2004) and Current (2013) Population and Employment Forecasts For Brightwater Service Area Average Wet Weather Flow Forecasts Estimating Flow Factors for the Baseline Year The process to forecast AWWF for each treatment plant begins with determining both the AWWF and the average dry weather flow (ADWF) for the baseline year of 2010. Flow meters in the conveyance system were used to estimate Brightwater flows prior to its startup. The next step is to determine the portion of the flows attributable to base wastewater flow and to infiltration and inflow (I/I). Base flow is estimated based on wet weather water usage. WTD obtained winter water usage data from water purveyors in its service area. Actual residential gallons per-capita per day (gpcd) of winter water usage for the years 2008 through 2012 were averaged for each purveyor and further apportioned to each treatment plant basin using PSRC population data for the period. Daily consumption rates were estimated for residential, commercial, and industrial populations inside and outside Seattle because recent history shows that residential consumption is lower and commercial/industrial consumption is higher in Seattle than in other areas. Because water purveyors generally combine commercial and industrial per-employee daily usage (gped), WTD used King County Industrial Waste Program records to estimate per-employee industrial water use (process waste discharge plus the per-employee commercial daily usage). Flow factors are the per-capita or per-employee daily flow to the wastewater system, estimated as the daily consumption rates discussed previously. The updated flow factors are shown in Table 4-2. The flow RWSP 2013 Comprehensive Review 4-7 Chapter 4. Forecasting Future Wastewater Treatment Plant Capacity Needs factors for residential, commercial, and industrial water use and the 2010 population and employment data were used to estimate base flow to the plants; the remaining measured flow is assumed to be I/I. Table 4-2. Per-capita and Employee Flow Factors for 2010 Forecasting Future Flows Most regional purveyors anticipate further reductions in per-capita water usage, as shown in Figure 4-6. In addition, during discussions with the E&P Subcommittee, the Alderwood Water and Sewer District indicated that it is updating its data and anticipates more water conservation than shown in Figure 4-6. To accommodate these predictions, future base flow to the plants was forecast by multiplying the 2010 flow factors by the PRSC population forecasts assuming all flow factors would decrease by 10 percent between 2010 and 2030 as the result of water conservation. The lower water consumption reduces the amount of AWWF entering the plants. Average wet weather I/I is forecast to be the same as in 2010 for the entire 50-year planning period because there was not any apparent trend in the data collected. Figure 4-7 shows historical and projected AWWF from 1990 through 2060 for each treatment plant. AWWF at West Point and South plants declined about 15 percent between 2000 and 2010−2011, despite increased population. (The figure shows that some flows from West Point were temporarily diverted to South Plant through the North Creek Pump Station until Brightwater came online.) This decline was due in part to water conservation and in part to Brightwater beginning operations. The AWWF is expected to slowly increase, even with increased water conservation, because of population growth. South Plant AWWF is forecast to increase at a faster rate, which reflects the higher population growth rate forecast for its service area. West Point South Plant Brightwater Inside Seattle Outside Seattle Inside Seattle Outside Seattle Outside Seattle Residential (gpcd) 46 54 46 54 54 Commercial (gped) 30 18 30 18 18 Industrial (gped) 61 49 68 56 45 Notes: gpcd = gallons per-capita per day; gped = gallons per employee per day; gpad = gallons per acre per day. 4-8 RWSP 2013 Comprehensive Review Chapter 4. Forecasting Future Wastewater Treatment Plant Capacity Needs Figure 4-6. Regional Water Purveyor Predicted Water Usage Reductions from Water Conservation RWSP 2013 Comprehensive Review 4-9 Chapter 4. Forecasting Future Wastewater Treatment Plant Capacity Needs Figure 4-7. Historical and Forecasted Average Wet Weather Flow at West Point, South, and Brightwater Treatment Plants, 1990−2060 Wasteload Forecasts Estimating Loading Factors for the Baseline Year Solids loading to the treatment plants is directly related to population and employment. Biological oxygen demand (BOD) and total suspended solids (TSS) are measured daily at each treatment plant. To estimate existing (2010) wasteloads, the influent BOD and TSS measurements from 2007 through 2012 for each plant were averaged and adjusted for flow transfers to or from Brightwater. South Plant loads included septage from septage haulers, solids from the Vashon and Carnation Treatment Plants, and loadings from the SeaTac Airport deicing facility. West Point loadings included street washoff that enters through the combined system. Forecasting Future Loadings Residential, commercial, and industrial loading factors (pounds per person per day) were determined for BOD and TSS based on population forecasts and the 2010 wasteload averages. The daily per-employee industrial loading factor was based on the Industrial Waste Program’s discharge and monitoring data Flows from West Point were temporarily diverted to South Plant through the North Creek Pump Station when the station came online in 2000. When Brightwater came online, flows treated at South Plant and West Point that are a part of Brightwater’s service area were sent to Brightwater. 4-10 RWSP 2013 Comprehensive Review Chapter 4. Forecasting Future Wastewater Treatment Plant Capacity Needs from 2008 through 2012. The loading factors were multiplied by population and employment forecasts by decade through 2060. Separate daily loading factors (pounds per day) were determined for other loads (septage, deicing, and street washoff). The future loading factor for septage was based on 2011 and 2012 daily loads (increased from the 2010 load because one septage receiver left the market in 2009). Figures 4-8 and 4-9 show actual and projected BOD and TSS loads for each treatment plant from 1990 through 2060. As population increases, the loadings to the treatments plants are forecast to increase proportionately. Figure 4-8. Historical and Forecasted Average BOD load at Treatment Plants, 1990−2060 RWSP 2013 Comprehensive Review 4-11 Chapter 4. Forecasting Future Wastewater Treatment Plant Capacity Needs Figure 4-9. Historical and Forecasted Average TSS load at Treatment Plants, 1990−2060 Comparison of Future Flows, Loadings, and Capacities WTD compared the AWWF and wasteload forecasts to treatment plant capacities to determine if capacity could be exceeded in the 50-year planning period. Solids loadings appear to be a greater determinant of capacity requirements than AWWF. Historically, AWWF has been used as a proxy for treatment plant capacity. The nominal plant capacity based on AWWF no longer reflects the capacity limitations of the treatment plants, mainly because of reduced water usage. Loadings continue to rise with population growth, whereas AWWF may either decrease or rise more slowly because of the effects of water conservation and commercial/industrial usage. This finding is consistent with trends in other wastewater utilities throughout the country. Figure 4-10 shows the actual and forecast wasteloads from 1985 through 2060 and the systemwide capacities to treat BOD and TSS, both with and without the South Plant expansion around 2000 and the start of Brightwater operation in 2011. 4-12 RWSP 2013 Comprehensive Review Chapter 4. Forecasting Future Wastewater Treatment Plant Capacity Needs Figure 4-10. Comparison of Actual and Forecast Solids Loadings with Systemwide Treatment Capacities, 1980−2060 Comparison of forecast AWWF and solids loadings with capacity at the three treatments plants indicates the benefits of a three-plant system and that the plants will have sufficient treatment capacity until at least the 2030s: • West Point Plant. Figure 4-11 shows that AWWF will not exceed design capacity at West Point through 2060, whereas capacity to treat TSS may be exceeded by around 2030 and to treat BOD about 10 years later. • South Plant. Figure 4-12 shows that AWWF may be at capacity at South Plant in 2060 and that the capacity to treat TSS will be exceeded by around 2035 and to treat BOD about 10 years later. • Brightwater Plant. Figure 4-13 shows that AWWF may come close to reaching capacity at Brightwater past 2060 and that BOD and TSS treatment capacities may be exceeded in the late 2030s with the addition of membrane cassettes and other associated equipment planned for 2020. RWSP 2013 Comprehensive Review 4-13 Chapter 4. Forecasting Future Wastewater Treatment Plant Capacity Needs Figure 4-11. Actual and Forecast AWWF and Solids Loadings Compared to West Point Treatment Plant Capacities, 1990−2060 4-14 RWSP 2013 Comprehensive Review Chapter 4. Forecasting Future Wastewater Treatment Plant Capacity Needs Figure 4-12. Actual and Forecast AWWF and Solids Loadings Compared to South Treatment Plant Capacities, 1990−2060 RWSP 2013 Comprehensive Review 4-15 Chapter 4. Forecasting Future Wastewater Treatment Plant Capacity Needs Figure 4-13. Actual and Forecast AWWF and Solids Loadings Compared to Brightwater Treatment Plant Capacities, 2010−2060 Implications for Future Planning Actual population growth and water use rates could be more or less than projected. Factors such as the economy and natural or manmade events such as climate change could affect projections. Regulatory requirements could change; for example, nutrient removal requirements would likely require treatment plant upgrades that could affect treatment capacity. WTD will continue its evaluations and will revise forecasts as appropriate. The analysis shows that with the addition of Brightwater, capacity at the three regional plants is sufficient until the 2030s. The forecasts indicate that additional capacity may be needed in the 2030s to meet the projected solids loadings. The required upgrades to expand the solids handling capacity may be less extensive than a full treatment plant upgrade and may include the need for additional digester capacity. WTD plans to conduct a study in 2015/2016 to explore options to meet future solids loadings needs. 4-16 RWSP 2013 Comprehensive Review Chapter 4. Forecasting Future Wastewater Treatment Plant Capacity Needs Although system-wide AWWF has remained fairly stable since 1990 and per-capita water use is expected to continue to decrease in the near future, growth in population is expected to result in increased AWWF through 2060 (Figure 4-14). The analysis shows that capacity at the three regional plants is expected to be sufficient to accommodate the increased AWWF for the next 40 years. Projections of future peak flows for the treatment plants are being developed as part of the 2015 CSI Program update. Capacity requirements will be reevaluated when these forecasts become available. Of the factors that affect treatment plant capacity, peak flows are expected to have the greatest sensitivity to future climate change. Current scientific knowledge and projections on how climate change is expected to affect peak flows will be incorporated into a sensitivity evaluation as part of the peak flow projections. The 2015 CSI program update may identify flow transfers that may be needed based on future conveyance capacity needs. WTD will reassess treatment plant flow forecasts if projects are identified that will lead to flow transfers not accounted for in the 2013 forecasts. Recently a septage hauler applied for an operating permit to treat waste at its facility rather than at South Plant. Based on its hauling record, this could reduce septage loads at South Plant by a third, thus reducing TSS loading by 4,700 pounds per day and BOD by 1,500 pounds per day. This represents about 2.5 percent of the solids loading at South Plant and would delay the need for additional solids loading capacity at South Plant by about two years. Figure 4-14. Historical and Projected Systemwide Average Wet Weather Flow RWSP 2013 Comprehensive Review 4-17 Chapter 4. Forecasting Future Wastewater Treatment Plant Capacity Needs 4-18 RWSP 2013 Comprehensive Review Chapter 5 Preparing for the Future The RWSP was approved in 1999 and set a course for meeting the region’s wastewater needs through 2030. The timing of this RWSP comprehensive review represents the midway point of RWSP implementation. To date, the RWSP has been implemented as planned and amended to adjust to changing conditions or new information. The RWSP continues to protect water quality and the environment and ensures sufficient wastewater treatment and conveyance capacity to keep pace with population and employment growth. Since adoption of the RWSP, several new trends and issues have emerged that influence wastewater management. These include climate change, new information about chemicals of concern, increased use and demand for the byproducts of wastewater treatment, sustainable building practices, technology trends, and more stringent regulations. In addition, county initiatives and priorities have evolved over time. For, example, the County adopted its first strategic plan in 2010. The plan established the following priorities for all county departments: • Improve customer service • Build lasting regional partnerships • Stabilize county finances • Build a culture of performance and empower employees to work together as “One King County” Other key county priorities include responding to the challenges of climate change and integrating equity and social justice considerations into the County’s decisions and policies, practices, and methods for engaging communities. This chapter summarizes WTD activities under way to address these emerging issues and priorities. Climate Change Improving energy efficiency and reducing greenhouse gas emissions are important elements in addressing climate change. WTD has an active energy program both to conserve and to generate energy. The use of Loop® biosolids also helps reduce greenhouse gas emissions. Chapter 2 provides more information on WTD’s energy and biosolids recycling program. WTD incorporates sustainable building practices into new facilities. The division considers energy costs and energy efficiencies in the planning, design, construction, and operation of its facilities. WTD has started to use the Institute for Sustainable Infrastructure’s EnvisionTM certification criteria during project design. Use of this assessment tool helps the project design team assess costs and benefits over the project lifecycle, evaluate environmental benefits, use outcome-based objectives, and achieve higher levels of sustainability. The tool is designed specifically for civil infrastructure projects such as roads, airports, dams, and water and wastewater systems. RWSP 2013 Comprehensive Review 5-1 Chapter 5. Preparing for the Future Incorporating roadside rain gardens and other green stormwater infrastructure (GSI) into projects not only helps reduce combined sewer overflows (CSOs) and the amount of untreated stormwater that finds its way to surface water, it also facilitates natural processes that recharge groundwater, preserve base flow in streams, moderate impacts to water and air temperature, and protect hydrologic and hydraulic stability. WTD is committed to using GSI where technically feasible and cost-effective. See Chapter 2 for more information on how GSI is being incorporated into the County’s Protecting Our Waters program. WTD continues to implement the recommendations resulting from the study on the vulnerability of major wastewater facilities to flooding from sea-level rise. Work includes incorporating projected rises in sea level into the planning process for upgrades or rehabilitation of facilities located in areas affected by tides and storm surges. Estimates of sea-level rise continue to evolve. WTD regularly reviews new data and information to keep its projections current. As the effects of climate change (hotter temperatures, more frequent droughts, and other effects) become more noticeable across the country, there is concern that populations may shift to milder climates. WTD is including the potential for climate migration in its planning for the future. Regulatory Environment RWSP policies provide guidance for the County’s participation in the development of water quality laws and standards. The County regularly participates in the development of effective and reasonable regulations. The County participates on committees associated with the Washington State Department of Ecology (Ecology) water quality related rulemaking processes and efforts to update water quality standards. For example, the County is a member of Ecology’s “Delegate’s Table” that was formed in 2012 to provide advice and perspective on the water quality standards rule-making process that is under way. In addition, the County has been working closely with Ecology and the U.S. Environmental Protection Agency in developing and evaluating Lower Duwamish Superfund cleanup options. Nutrient Removal One emerging area of concern for Ecology is algal growth, stimulated by nitrogen loadings to Puget Sound. The loadings may be contributing to depression of dissolved oxygen (DO) levels in near-bottom regions. In 2006, Ecology began a major study to determine the extent of low DO and how nitrogen from a variety of sources affects DO levels. Wastewater treatment plants around the nation are under growing pressure to remove nutrients. While it is not clear how Ecology will use the results of its studies to establish future regulatory limits, WTD conducted two studies to evaluate the impacts of a range of potential nitrogen limits on capital and operating costs at the South and West Point treatment plants. The studies evaluated a variety of nitrogen removal technologies and used existing treatment plant data and computer modeling to develop capital costs, operation and maintenance costs, and greenhouse gas emissions for each regulatory scenario. Results of the studies show that the costs of upgrading South Plant would range from approximately $0.5 billion to $1 billion with an associated operating cost increase of $10 million to $33 million per year. The estimated costs of upgrading the West Point Plant would be about $1 billion with an operating cost 5-2 RWSP 2013 Comprehensive Review Chapter 5. Preparing for the Future of $30 million per year. However, because of lack of available space, upgrading the West Point Plant to remove nitrogen would most likely substantially reduce its treatment capacity. Source Control Source control is one of the most effective ways to keep pollutants from entering the wastewater system and being discharged to water bodies. The King County Industrial Waste Program (KCIW) regulates industrial wastewater discharged into the County wastewater system. KCIW works cooperatively with more than 1,500 companies and facilities to protect surface water and biosolids quality, the environment, public health, and the wastewater system. The program provides technical assistance and ensures that industrial facilities treat wastewater for harmful substances before discharging the wastewater to sanitary sewers. Since 2007, KCIW has worked with other agencies to conduct pollution source control inspections at Lower Duwamish Waterway businesses as part of an Ecology interagency coordination effort. More information on the County’s Industrial Waste Program is available at http://www.kingcounty.gov/environment/wastewater/IndustrialWaste.aspx. Chemicals of Concern WTD continues to follow the emerging science and technology investigations of chemicals of concern thought to be reaching the environment through wastewater or stormwater discharges. These include (1) chemicals found in personal care products and pharmaceuticals that are suspected to be endocrine disruptors or have other unintended effects on humans and/or wildlife and (2) other commonly used chemicals such as plasticizers, flame-retardants, and surface coatings like Gor-Tex and Teflon. Other Topics The following are other issues that are important to WTD: • Relabeling or banning of “disposable wipes” because they cause significant maintenance issues in wastewater systems. • Product stewardship efforts to reduce pollutants in wastewater and stormwater. • Drug take-back programs by local governments or pharmaceutical companies to reduce contamination of wastewater with unused and expired drugs. In 2013, King County’s Board of Health passed a Rule & Regulation to create a drug take-back system for King County residents. The program promotes the safe disposal of unused prescription and over-the-counter medicines. It will be funded and operated by the drug manufacturers who produce the medications. Under the new program, residents may dispose of unwanted medicines at pharmacies and other secure locations across the county for no charge. The new law creates one of only two such systems in the country. Technology Trends Certain technology trends are emerging in the industry, including decentralized systems, nutrient recovery, energy recovery, and indirect and direct potable water reuse. WTD continues to monitor technology trends and to consider pilot projects as appropriate. Information on these trends follows. RWSP 2013 Comprehensive Review 5-3 Chapter 5. Preparing for the Future Decentralized Wastewater Systems The use of decentralized wastewater treatment systems is increasing. For some areas, decentralized systems are the most sustainable and cost-effective solutions. Examples of decentralization are as follows: • Consolidated Utility District (CUD) of Rutherford County, Tennessee. The utility provides sewer service to many of its outlying customers through an innovative system, often referred to as a septic tank effluent pumping (STEP) system. Approximately 50 subdivisions contain a STEP system, a recirculating sand filter, and a large effluent drip dispersal system, all of which are owned and managed by the CUD. The system allows for high-density development (subdivisions) in areas where city sewer service is not available or soil types are not conducive to conventional septic tank and drain field lines. The 1,500-gallon septic tank is equipped with a pump and control panel located at each residence for controlled discharge of wastewater to a centralized wastewater collection system. For more information, see http://www.cudrc.com/Departments/Waste-Water.aspx. • Loudoun Water, in Loudoun County, Virginia. Loudon Water has adopted an integrated approach to wastewater management that includes purchased capacity from a centralized plant, a satellite water reclamation facility, and several small community cluster systems. The approach has allowed Loudoun County to maintain its rural character and create a system in which growth pays for growth. Developers design and construct cluster wastewater facilities to Loudoun Water standards at their own cost and transfer ownership of the system to Loudoun Water for continued maintenance. For more information, see http://www.loudounwater.org/. • The Bullitt Center in Seattle, Washington. World Architecture News honored the Bullitt Center as the “greenest commercial building in the world.” The Bullitt Center was built to achieve the goals of the Living Building Challenge and demonstrate 365 continuous days of performance that meet net zero energy and water. The center has a water and sewage processing system that provides some waste product processing on site and uses hauling to avoid discharge to the municipal sewage system. WTD supports the Bullitt Center’s efforts to achieve the Living Building certification by taking the building’s liquid waste stream to the Carnation Treatment Plant. At the Carnation Plant, the waste stream is treated and discharged to enhance a wetland in the Chinook Bend Natural Area rather than being discharged to a water body. WTD also takes the building’s solids from the composting toilets to make the GroCo commercial compost product. GroCo compost obtained “Declare” certification through the partnership with the Bullitt Center. For more information, see http://www.bullittcenter.org/. Nutrient Recovery Clean Water Services in Hillsboro, Oregon, opened the world’s largest municipal nutrient recovery facility in 2012. The project is a public-private partnership with Ostara Nutrient Recovery Technologies of Vancouver, Canada. The facility captures phosphorus in wastewater to produce 1,200 tons a year of Crystal Green, a high value, slow-release fertilizer. The Ostara process is also being used in several wastewater plants in Canada. More information is available at 5-4 RWSP 2013 Comprehensive Review Chapter 5. Preparing for the Future http://www.cleanwaterservices.org/AboutUs/WastewaterAndStormwater/TreatmentFacilities/RockCre ekNutrientRecovery.aspx. Energy Recovery WTD continues to investigate means to improve and expand its ability to produce energy from wastewater treatment. Two promising opportunities area as follows: • WTD is assessing the potential of adding organic wastes (such as food waste) to the sewage solids that are processed in anaerobic digesters at the South Treatment Plant. Recent WTD studies of what is known as “grease co-digestion” have investigated the costs and potential revenues associated with establishing a waste restaurant grease (brown grease) receiving facility. Brown grease is typically processed in rendering facilities and/or disposed of in landfills because there is a shortage of facilities that can cost-effectively convert the grease to energy. When restaurant grease is mixed into anaerobic digesters, it can substantially increase the production of valuable biogas that can be used to produce renewable energy. Numerous wastewater treatment facilities have successfully implemented brown grease co-digestion programs. In addition to continuing to assess the benefits of a facility at South Plant, WTD is working with private entrepreneurs to determine if the private sector might be able to cost- effectively convert this waste product into renewable energy. • The South Plant biogas scrubber system currently processes biogas produced by the treatment plant solids digestion system to convert it into high-quality bio-methane (natural gas). This bio- methane is then injected into the nearby natural gas pipeline and sold to Puget Sound Energy. However, elements of the gas management system are aging and will require replacement in the near future. A study was conducted to assess the existing system of biogas recovery and energy production to determine if it still provides the “best and highest” use the biogas. Results from the study are expected in 2014. Indirect and Direct Potable Reuse Advances in water treatment technology allow for production of high-quality drinking water for indirect and direct potable use. Two examples are as follows: • In Texas, the Colorado River Municipal Water District is developing a direct potable reuse project. The project will reclaim wastewater effluent from the City of Big Spring and process it using advanced treatment technology. Approximately 1.8 million gallons per day of water from the facility will be blended with other water from surface water reservoirs. More information on this project is available at http://twri.tamu.edu/publications/txh2o/summer-2013/reclaiming-a- valuable-clean-resource/. • In California, the Orange County Water District and the Orange County Sanitation District jointly funded the Groundwater Replenishment System (GWRS). The GWRS takes highly treated wastewater that would have previously been discharged into the Pacific Ocean and purifies it using a three-step advanced treatment process consisting of microfiltration, reverse osmosis, and ultraviolet light with hydrogen peroxide. The purified water is injected into a seawater RWSP 2013 Comprehensive Review 5-5 Chapter 5. Preparing for the Future barrier and pumped to recharge basins where it naturally percolates into the groundwater basin. More information on this system is available at http://www.gwrsystem.com/. Building Equity and Opportunity WTD strives to further the goals of the County’s Equity and Social Justice Initiative in all its work—from planning through facility operations. In 2011, WTD conducted an analysis to compare historical capital project cost data with King County demographic data (to determine whether demographics (race, ethnicity, social status) affect project costs and schedule performance. The analysis used GIS (geographic information systems) to map 133 historical capital projects to see how they related to minority and income demographic conditions. When considering capital improvement, outreach, or planning decisions, these maps help assess the potential impacts of new actions as they relate to current service levels and spatial demographics. This analysis verified that the location of WTD facilities had no discernable correlation to the race, ethnicity, or economic status of the host community. It further confirms that facility locations are driven by hydraulics and topography–not any community-based factors. WTD has also reviewed how its facilities are assets in the neighborhoods where they are located in comparison to neighborhood demographics. The information from this work is being used to improve facilities in residential areas where any discrepancies in screening or other neighborhood enhancements have been identified. In addition, the WTD community outreach team shares information in multiple languages and uses other techniques to reach people who might not have traditionally participated in these processes. WTD provides career training and opportunities consistent with the Equity and Social Justice Initiative. In order to continue to introduce youth to wastewater careers, the division has developed more contracts with higher education organizations to provide work-study placements for students with financial aid awards and to provide job-training opportunities to disadvantaged youth through King County Worksource’s Work-to-Hire program. 5-6 RWSP 2013 Comprehensive Review Chapter 6 Conclusions and Next Steps This chapter summarizes conclusions from the review of RWSP implementation in 2007 through 2013 and next steps in continuing to implement the RWSP and protect the region’s water quality. Conclusions • Overall, implementation of the RWSP continues to protect the region’s water quality, environment, and economy by providing dependable and high-quality wastewater treatment. • The RWSP’s primary objective, completion of the Brightwater Treatment Plant, has been achieved. The Brightwater Plant began operation in 2011 and is producing effluent, whose quality exceeds conventional secondary treatment, and reclaimed water that is used for irrigation in the Sammamish Valley. • A major component of the RWSP 2013 comprehensive review included evaluating and updating future regional wastewater treatment capacity needs. The review confirmed the benefits of having a three-plant regional system. Findings indicate that with construction of the Brightwater Plant, there is sufficient treatment plant capacity until the 2030s. Updated forecasts indicate that a full expansion at South Treatment Plant is unlikely to be needed in 2029 as previously projected. WTD will continue to monitor the factors and trends that affect treatment plant capacity needs. • Actual population growth and water use rates could be more or less than projected. Of the factors that affect treatment plant capacity, climate change is expected to have a significant impact on future peak flows at treatment plants. WTD will track trends and climate change impacts and projections over time. • In accordance with RWSP conveyance and infiltration/inflow (I/I) policies, WTD completed five conveyance system improvement (CSI) projects and one I/I reduction project between 2007 and 2013. • RWSP policies provide guidance to find beneficial uses for byproducts from wastewater treatment. WTD continues to create resources from the wastewater it treats in the form of biosolids and digester gas from the solids treatment process and reclaimed water from the liquids treatment process. • WTD made significant progress in 2007−2013 to implement combined sewer overflow (CSO) control projects under the Protecting Our Waters Program to control all its CSO sites by 2030. About one-half of its 38 CSO sites are controlled to the Washington State standard of no more than one overflow per year on average. Projects are under way or planned to control the remaining uncontrolled CSOs by 2030. RWSP 2013 Comprehensive Review 6-1 Chapter 6. Conclusions and Next Steps • It would cost well over $20 billion to build King County’s wastewater system from the ground up today, and the current value of existing facilities is about $6 billion. The primary objectives of the Asset Management Program are to manage the whole lifecycle of a facility or asset; deliver a level of service that meets regulatory requirements and ratepayer expectations; and fulfill WTD’s mission to protect public health and enhance the environment by treating and reclaiming water, recycling solids, and generating energy. • WTD is committed to continuous improvement. It completed a 10-year pilot Productivity Initiative Program in 2011 aimed at increasing efficiency. The program generated nearly $84 million in savings for ratepayers over its lifespan. Under WTD’s new Bright Ideas Program, WTD employees have submitted more than 550 ideas to improve efficiencies that are expected to result in over $400,000 in savings in 2014. • RWSP comprehensive review reporting policies call for the inclusion of information on the effectiveness of policy implementation. This information is provided in Appendix A. Next Steps • WTD will continue to implement the Protecting Our Waters Program to control the County’s' remaining uncontrolled CSOs. • WTD will conduct a study in 2015−2016 to explore options to meet future solids loadings needs that might improve treatment plant efficiency and reduce the cost of improvements needed to handle increased loadings over time. • The CSI Program, which details capital projects necessary to meet the 20-year peak flow standard, was last updated in 2007. Based on updated population and employment projections released by the Puget Sound Regional Council in 2013, WTD will work to complete a CSI Program update in 2015. Projections of future peak flows for the treatment plants will also be developed as part of the update and capacity requirements will be reevaluated. • In order to maintain accurate forecasts of wastewater system capacity needs, WTD will track trends and climate change impacts over time and will continue to monitor flow data and work with local agencies as they implement their land use and sewer plans in order to track actual population growth and water use rates in relation to current projections. • WTD’s first I/I reduction project intended to reduce or eliminate the need for a CSI project was completed in 2013. The project followed recommendations contained in the I/I Control Program approved by the Council in 2006. In accordance with the program, WTD will be working with MWPAAC in 2015 to develop recommendations for long-term I/I reduction and control. • WTD will be working with MWPAAC’s Engineering and Planning Subcommittee and the RWQC to discuss policy implementation and effectiveness and any recommendations for policy amendments. These discussions will help to inform the County Executive, who may recommend policy changes in 2015. 6-2 RWSP 2013 Comprehensive Review Chapter 6. Conclusions and Next Steps • WTD’s Strategic Asset Management Plan (SAMP) was last updated in 2010. Optimizing asset management practices is an ongoing process, and WTD will update the SAMP in December 2015. • WTD will continue its efforts to be a state-of the-art, energy-efficient, lean, continually improving agency. A cornerstone of this effort will be the ongoing Bright Ideas Program that provides a means for employees to identify and seek approval for implementing efficiencies and cost saving measures in the Division’s operations. • WTD will continue to expand its ability to create resources from wastewater through facilities at the West, South, and Brightwater plants by using digester gas to produce heat, electricity, and natural gas; recycling 100 percent of biosolids produced through the treatment process; and finding new customers and uses for reclaimed water. RWSP 2013 Comprehensive Review 6-3 Chapter 6. Conclusions and Next Steps 6-4 RWSP 2013 Comprehensive Review Appendix A RWSP Policies Implementation in 2007−2013 Appendix A. RWSP Policies Implementation in 2007−2013 Introduction This appendix provides information on how RWSP policies were implemented in 2007−2013. The appendix is in a similar format to the two previous RWSP comprehensive reviews.4 RWSP policies are part of King County Code Chapter 28.86. There are 13 sets of RWSP policies: • Treatment Plant Policies (TPP) • Conveyance Policies (CP) • Infiltration and Inflow Policies (I/IP) • Combined Sewer Overflow Control Policies (CSOCP) • Biosolids Policies (BP) • Water Reuse Policies (WRP) • Wastewater Services Policies (WWSP) • Water Quality Protection Policies (WQPP) • Wastewater Planning Policies (WWPP) • Environmental Mitigation Policies (EMP) • Public Involvement Policies (PIP) • Financial Policies (FP) • Reporting Policies The introductory material for each policy set and the column that states each policy are written exactly as written in the King County Code, including punctuation and capitalization. The reader may notice certain words that are not capitalized that are usually capitalized or vice versa. The King County Code has its own style guide, and the policies reflect that guide. Any changes in policy made during 2007−2013 are noted in italics after either the introductory material or the policy. The second column summarizes how each policy was implemented in 2007−2013. The information reflects WTD’s review of each policy. 4 Previous RWSP comprehensive reviews are available at http://www.kingcounty.gov/environment/wtd/Construction/planning/rwsp/Library/CompReview.aspx. A-2 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 RWSP Treatment Plant Policies A. Explanatory material. The treatment plant policies are intended to guide the county in providing treatment at its existing plants and in expanding treatment capacity through the year 2030. The policies direct that secondary treatment will be provided to all base sanitary flows. The county will investigate possible tertiary treatment with a freshwater outfall to facilitate water reuse. The policies also direct how the county will provide the expanded treatment capacity necessary to handle the projected increases in wastewater flows resulting from population and employment growth. The policies provide for the construction of a new treatment plant (the Brightwater treatment plant) to handle flows in a new north service area, expansion of the south treatment plant to handle additional south and east King County flows and the reservation of capacity at the west treatment plant to handle Seattle flows and CSOs. The potential for expansion at the west and south treatment plants will be retained for unanticipated circumstances such as changes in regulations. The policies address goals for odor control at treatment plants and direct that water reuse is to continue and potentially expand at treatment plants. Treatment Plant Policies How implemented in 2007−2013 TPP-1: King County shall provide secondary treatment to all base sanitary flow delivered to its treatment plants. Treatment beyond the secondary level may be provided to meet water quality standards and achieve other goals such as furthering the water reuse program or benefiting species listed under the ESA. The County operates three regional treatment plants—West Point, South, and Brightwater Treatment Plants, two local treatment plants—Vashon and Carnation Treatment Plants, and one large on-site septic system (Beulah Cove/Park). The processes used at all of the County’s treatment plants provide secondary treatment. The West Point and South Plants treat wastewater to secondary treatment using an activated sludge biological process. The Vashon Treatment Plant uses an oxidation ditch system. The Brightwater and Carnation Plants use membrane bioreactor technology. The Beulah Cove/Park uses a septic tank/trickling filter. Reclaimed water is produced at the South, West Point, Carnation, and Brightwater Plants. (See TPP-9 for information on the uses of reclaimed water produced from these plants.) TPP-2: King County shall provide additional wastewater treatment capacity to serve growing wastewater needs by constructing the Brightwater treatment plant at the Route 9 site north of the city of Woodinville and then expanding the treatment capacity at the south treatment plant. The west treatment plant shall be maintained at its rated capacity of one hundred thirty-three mgd. The south treatment plant capacity shall be limited to that needed to serve the eastside and south King County, except for flows from the North Creek Diversion project and the planned six-million-gallon storage tank, or minor rerating to facilitate Construction of the Brightwater Treatment System is complete, and the system began full operations on October 29, 2012. The work to complete the RWSP 2013 comprehensive review included updating key planning assumptions and using updated population and employment forecasts developed by the Puget Sound Regional Council to forecast treatment plant average wet- weather flow (AWWF) and solids loadings capacity through 2060. Findings indicate that there is sufficient AWWF and loadings capacity systemwide into the 2030s. WTD will continue to examine assumptions and trends RWSP 2013 Comprehensive Review A-3 Appendix A. RWSP Policies Implementation in 2007−2013 Treatment Plant Policies How implemented in 2007−2013 south or east county growth. The potential for expansion at the west treatment plant and south treatment plant should be retained for unexpected circumstances which shall include, but not be limited to, higher than anticipated population growth, new facilities to implement the CSO reduction program or new regulatory requirements. that could affect treatment plant capacity needs to ensure optimal timing for any future capacity-related capital investments. (See Chapter 4 for more information on the process to forecast treatment plant flows and loadings.) TPP-3: Any changes in facilities of the west treatment plant shall comply with the terms of the West Point settlement agreement. The County continues to be in compliance with the terms of the 1991 West Point Settlement Agreement. TPP-4: King County’s goal is to prevent and control nuisance odor occurrences at all treatment plants and associated conveyance facilities and will carry out an odor prevention program that goes beyond traditional odor control. To achieve these goals, the following policies shall be implemented: 1. Existing treatment facilities shall be retrofit in a phased manner up to the High/Existing Plant Retrofit odor prevention level as defined in Table 1 of Attachment A to Ordinance 14712, the odor prevention policy recommendations dated March 18, 2003. This level reflects what is currently defined as the best in the country for retrofit treatment facilities of a similar size. Odor prevention systems will be employed as required to meet the goal of preventing and controlling nuisance odor occurrences; 2. Existing conveyance facilities that pose nuisance odor problems shall be retrofitted with odor prevention systems as soon as such odors occur, subject to technical and financial feasibility. All other existing conveyance facilities shall be retrofitted with odor control systems during the next facility upgrade; 3. The executive shall phase odor prevention systems implementing the tasks that generate the greatest improvements first, balancing benefit gained with cost, and report to the council on the status of the odor prevention program in the annual RWSP report as outlined in K.C.C. 28.86.165; 4. New regional treatment facilities shall be constructed with odor control systems that are designed to meet the High/New Plant odor prevention level as defined in Table 1 of Attachment A to Ordinance 14712, the odor prevention policy recommendations dated March 18, 2003. This level reflects what is currently defined as the best in the country for TPP-4.1 Work associated with phased odor control retrofits in 2007−2013 included the following: • West Point Plant. Completed modifications to the odor scrubber system. Operational activities, such as cleaning process tanks more frequently, were also implemented to complement and improve the results of the phased retrofits. • South Plant. Completed installation of covers for each first pass of the four aeration basins and for the return activated sludge (RAS) channel and added a new odor scrubber to control emissions from the aeration basins and the RAS channel. Operational activities, such as more frequent inspections of the odor scrubber system, were implemented to complement and improve the results of the phased retrofits. In addition, a formal environmental management system (EMS) was implemented for air emission sources including odor control. The retrofits and operational changes have served to reduce nuisance odors at both West Point and South Plants. WTD continues to evaluate the results of these efforts to determine if any further actions are needed. TPP-4.2: When odors are attributed to existing conveyance facilities, measures are taken to control and prevent those odors. These measures include sealing manhole covers, adjusting chemicals, and repairing or replacing odor control equipment. Conveyance system improvement projects include upgrades to odor control facilities as appropriate. For example, odor control equipment was included as part of the Hidden Lake Pump Station and Sewer Replacement project that was completed in spring 2009 and as part of the Bellevue Pump Station upgrade that was completed in 2011. TPP-4.3: The schedule for phased improvements follows the direction provided in this policy. RWSP A-4 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 Treatment Plant Policies How implemented in 2007−2013 new treatment facilities of a similar size; 5. New conveyance facilities serving these new regional treatment facilities shall also be constructed with odor control systems as an integral part of their design; 6. Design standards will be developed and maintained for odor control systems to meet the county’s odor prevention and control goals; 7. A comprehensive odor control and prevention monitoring program for the county’s wastewater treatment and conveyance facilities will be developed. This program shall include the use of near facility neighbor surveys and tracking of odor complaints and responses to complaints and shall consider development of an odor prevention benchmarking and audit program with peer utilities; and 8. New odor prevention and measurement technologies will be assessed and methods for pilot testing new technologies identified when determined by the executive to be necessary and appropriate for achieving the goals of this policy. annual reports include a status of the odor prevention program. TPP-4.4: The Brightwater Plant’s odor control system was designed to meet the “best in the country for new facilities” level, described in Attachment A to Ordinance 14712. There have been no odors attributed to the Brightwater Treatment Plant since it began operating. TPP-4.5: Odor control was incorporated into the Brightwater conveyance system. There have been no sewage-related odors attributed to Brightwater conveyance facilities since they began operating. There was one complaint in 2013 related to diesel odors that emanated from the Brightwater Influent Pump Station during testing of the pump station’s generators in 2013. To resolve the situation, a project is under way to install diesel oxidation catalyst units on each generator exhaust system. TPP-4.6: WTD continues to use the design standards for the County’s odor control systems. TPP-4.7: Surveys of businesses and residents that are near-neighbors of the County’s regional treatment plants are carried out every two years. The findings provide feedback on odor sources and process improvements that have reduced odor impacts. Information on the surveys is available at http://www.kingcounty.gov/environment/wtd/About/Sys tem/NearNeighborSurvey.aspx. In addition, WTD has procedures in place to log, investigate, and track all odor complaints. WTD’s goal is to respond to each complaint within two hours after receiving a complaint. WTD consults with peer utilities on odor control technologies, lessons learned, and other related information. TPP-4.8: WTD keeps informed on new technologies through participation in professional organizations and technical conferences. No assessments or pilot studies were conducted during 2007−2013. TPP-5: King County shall undertake studies to determine whether it is economically and environmentally feasible to discharge reclaimed water to systems such as the Lake Washington and Lake Sammamish watersheds including the Ballard Locks. WTD developed and analyzed conceptual strategies for discharging reclaimed water into Lake Washington and additional reclaimed water uses in the Lake Sammamish watershed as part of the reclaimed water comprehensive planning process that took place in 2009–2012. WTD will continue to monitor any changing conditions or future opportunities for reclaimed water uses in these watersheds. RWSP 2013 Comprehensive Review A-5 Appendix A. RWSP Policies Implementation in 2007−2013 Treatment Plant Policies How implemented in 2007−2013 TPP-6: The county shall evaluate opportunities in collaboration with adjacent utilities regarding the transfer of flows between the county's treatment facilities and treatment facilities owned and operated by other wastewater utilities in the region. The evaluation shall include, but not be limited to, cost environmental and community impacts, liability, engineering feasibility, flexibility, impacts to contractual and regulatory obligations and consistency with the level of service provided at the county owned and operated facilities. King County and the City of Edmonds continued to transfer wastewater flows between systems in accordance with their interlocal agreement. The agreement stipulates that an equivalent amount of flow is transferred through the Lake Ballinger Pump Station from Edmonds to King County’s West Point system as is transferred to Edmonds from King County’s Richmond Beach area. The transfers occurred during the dry season. An additional agreement was followed that sent the first 6 mgd of the Lake Ballinger Pump Station flows to Edmonds during the wet season until Brightwater came fully online in 2012. This arrangement made use of extra Edmonds treatment capacity and minimized the risk of overflows into Lake Washington during large storm events. TPP-7: King County may explore the possibility of constructing one or more satellite treatment plants in order to produce reclaimed water. The county may build these plants in cooperation with a local community and provide the community with reclaimed water through a regional water supply agency. In order to ensure integrated water resource planning, in the interim period prior to the development of a regional water supply plan, King County shall consult and coordinate with regional water suppliers to ensure that water reuse decisions are consistent with regional water supply plans. To ensure costs and benefits are shared equally throughout the region, all reclaimed water used in the community shall be distributed through a municipal water supply or regional water supply agency consistent with a regional water supply plan. In 2007, WTD completed a preliminary analysis of reclaimed water options in the Green River Valley to answer questions raised by the Cities of Auburn, Covington, Kent, Renton, and Tukwila. Information from the study was incorporated into the reclaimed water comprehensive planning process that occurred in 2009–2012. King County and the Covington Water District signed a Memorandum of Agreement in 2007 to jointly fund and pursue a phased approach to explore opportunities for reclaimed water development in the district’s service area. Information from this effort was incorporated into the reclaimed water comprehensive planning process. In 2008–2009, WTD worked with the Seattle Public Utilities (SPU) on SPU’s economic analysis of the potential for providing reclaimed water from the Brightwater Treatment Plant to large irrigators and other potential users of nonpotable water in north Seattle. Information from this effort was incorporated into the reclaimed water comprehensive planning process. WTD developed and analyzed three conceptual strategies for reclaimed water satellite or skimming facilities as part of the reclaimed water comprehensive planning process. WTD will continue to monitor changing conditions or future opportunities that could result in further exploration of such facilities. WTD worked closely with water utilities during the reclaimed water comprehensive planning process and will continue to coordinate with water utilities on future opportunities. TPP-8: King County shall continue water reuse and explore opportunities for expanded use at existing plants, and shall explore water reuse WTD has been producing and using reclaimed water since 1997 at the South and West Point plants. South Plant uses its reclaimed water at the plant for process A-6 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 Treatment Plant Policies How implemented in 2007−2013 opportunities at all new treatment facilities. water and landscape irrigation. Some of the the reclaimed water is distributed and used offsite for irrigation or public works uses, such as sewer flushing and street sweeping. All of the reclaimed water produced at the West Point Plant is used at the plant site for process water and landscape irrigation. The Carnation Treatment Plant began operating in 2008. The facility produces and discharges reclaimed water to enhance a wetland in the County's Chinook Bend Natural Area. The Brightwater Treatment System began full operations in 2012. Brightwater produces reclaimed water for use at the Brightwater Environmental and Education Center for non-drinking purposes such as toilet flushing and landscape irrigation. In summer 2013, Brightwater began distributing some of its reclaimed water offsite for irrigation uses. RWSP 2013 Comprehensive Review A-7 Appendix A. RWSP Policies Implementation in 2007−2013 RWSP Conveyance Policies A. Explanatory material. The conveyance policies are intended to guide how major improvements to the wastewater conveyance system, including building and upgrading the pipes and pump stations needed to convey wastewater to the Brightwater treatment plant and building the outfall pipe from the Brightwater treatment plant, will be accomplished. The policies also include guidance for other major and minor conveyance improvements to accommodate increased flows in other parts of the service area and to prevent improper discharges from the sanitary system. Conveyance Policies How implemented in 2007–2013 CP-1: To protect public health and water quality, King County shall plan, design and construct county wastewater facilities to avoid sanitary sewer overflows. 1. The twenty-year peak flow storm shall be used as the design standard for the county’s separated wastewater system. 2. Parameters developed by the wastewater treatment division in consultation with the metropolitan water pollution abatement advisory committee shall be used to guide project scheduling and prioritization for separated wastewater system projects. 3. The south treatment plant effluent transfer system shall be designed with a five-year design storm standard. When effluent volumes exceed the five-year design standard and exceed the capacity of the south treatment plant effluent transfer system, secondary treated effluent from the south treatment plant will be discharged to the Green/Duwamish river until the flow subsides such that the flow can be discharged through the south treatment plant effluent transfer system. CP-1.1: The 20-year peak flow storm is used as the design standard for the County’s separated wastewater system. All of the conveyance system improvement (CSI) capital projects that were implemented during the 2007−2013 period used this standard as the basis for design of the project. CP-1.2: The parameters developed with the Metropolitan Water Pollution Abatement Advisory Committee (MWPAAC) during the process to complete the 2007 CSI Program Update continue to guide CSI project scheduling and prioritization. CP-1.3: Effluent volumes did not exceed the capacity of the of the South Plant’s effluent transfer system during 2007–2013. CP-2: King County shall construct the necessary wastewater conveyance facilities, including, but not limited to pipelines, pumps and regulators, to convey wastewater from component agencies to the treatment plants for treatment and to convey treated effluent to water bodies for discharge. Conveyance facilities shall be constructed during the planning period of this plan to ensure that all treatment plants can ultimately operate at their rated capacities. No parallel eastside interceptor shall be constructed. No parallel Kenmore Interceptor shall be constructed. Conveyance projects in 2007–2013 were implemented following the prioritization that was included in the 2007 CSI Program update. The prioritization process was developed by WTD and MWPAAC. The goal of the process is to phase implementation of CSI projects to meet the most pressing needs and continue to protect public health, the environment, and ratepayers. The completion of the Brightwater Treatment System eliminates any need to parallel the Eastside Interceptor or the Kenmore Lakeline. A-8 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 Conveyance Policies How implemented in 2007–2013 CP-3: King County shall periodically evaluate population and employment growth assumptions and development pattern assumptions used to size conveyance facilities to allow for flexibility to convey future flows that may differ from previous estimates. The following activities shall take place to confirm assumptions and conveyance improvement needs: 1. Field verification of wastewater flows and conveyance component conditions prior to implementation of regional conveyance capital projects that are intended to expand capacity of the system; and 2. Decennial flow monitoring to correspond with the Federal Census conducted every ten years. (Ordinance 16033, approved in March 2008, amended this policy to provide direction on the activities to undertake to confirm assumptions and needs.) WTD uses population and employment growth projections from the Puget Sound Regional Council (PSRC), along with other RWSP key planning assumptions (see Chapter 4) in its efforts to forecast flows and determine sizing and timing of capital investments to meet conveyance or treatment capacity needs. CP-3.1: WTD completed field verification prior to implementing CSI projects during the 2007−2013 period. CP-3.2: The Decennial Flow Monitoring (DFM) project was completed in 2011. Data was collected from 235 flow meters in the separated portion of the regional wastewater service area. The data is being used to prepare the 2015 CSI Program update and will inform the prioritization, timing, and sizing of future CSI projects. The data is also available to local agencies for use in planning and designing their systems. CP-4: The executive shall update the conveyance system improvement program every five years beginning in 2013 to ensure the program remains current. The program updates shall provide information on growth patterns, rate of growth and flow projections and report on how this information affects previously identified conveyance needs. The program updates shall also provide information on changed or new conveyance needs identified since the previous update. (This policy was added through Ordinance 16033.) WTD began work in 2013 to update the CSI program, and the program update is expected to be complete in 2015. WTD is using PSRC’s 2013 population and employment forecast data, WTD’s updated planning assumptions (see Chapter 3), data from the DFM project, and information from local agencies to verify or update future needs for the separated conveyance system. CP-5: King County shall apply uniform criteria throughout its service area for the financing, development, ownership, operation, maintenance, repair and replacement of all conveyance facilities. The criteria shall include: 1. County ownership and operation of permanent conveyance facilities that serve natural drainage areas of greater than one thousand acres; 2. Conformance to the county's comprehensive water pollution abatement plan and the Regional Wastewater Service Plan as precondition of county ownership; and 3. A financial feasibility threshold governing limitations of the county's financial contribution to: development of a new interceptor or trunk sewer; or acquisition of an interceptor or trunk sewer constructed by a local agency. The The acquisition of the Central Plateau Interceptor from the City of Renton was the only acquisition that took place in 2007–2013 in accordance with this policy. RWSP 2013 Comprehensive Review A-9 Appendix A. RWSP Policies Implementation in 2007−2013 Conveyance Policies How implemented in 2007–2013 threshold, as specified in K.C.C. 28.84.080, shall consider the capital costs that can be supported by the existing customers in the natural drainage area that would be served by the new facility. (This policy used to be CP-4. Ordinance 16033 moved it to CP-5; no other changes were made to this policy.) CP-6: King County shall closely integrate water reuse planning and I/I study results with planning for wastewater conveyance and treatment facilities. King County shall consider water conservation and demand management assumptions developed by local utilities for wastewater facility planning. (This policy used to be CP-5. Ordinance 16033 moved it to CP-6; no other changes were made to this policy.) WTD implemented this policy in 2007−2013 through the following activities: • Assessed the effects of conceptual reclaimed water strategies on planned conveyance system projects in 2012 as part of the reclaimed water comprehesnive planning process. Findings indicated that the strategies would not affect any planned conveyance system improvements. • Implemented the Skyway initial infiltration and inflow (I/I) reduction project. Post-project flow monitoring is under way, and results will be incorporated into conveyance system planning as appropriate. • Updated the water conservation and water use assumptions based on winter water use data and the projections of future use from local water utilites (see Chapter 4). WTD worked closely with MWPAAC on the update of the RWSP key planning assumptions. The updated assumptions will be used to verify or udpate the sizing and timing of any future conveyance capacity needs. CP-7: King County shall evaluate other demand management alternatives to meet identified conveyance needs, such as infiltration and inflow (I/I) reduction, water conservation, and reclaimed water facilities. Factors such as operational, environmental and financial impacts, costs and benefits, and the net present value of alternatives shall be included in the evaluation of all feasible alternatives identified by the county. (This policy was added through Ordinance 16033.) The process to determine how best to meet an identified conveyance need occurs during project planning and predesign and includes consideration of the alternatives and factors listed in this policy. A-10 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 RWSP Infiltration and Inflow Policies A. Explanatory material. The I/I policies are intended to guide the county in working cooperatively with component agencies to reduce the amount of I/I that flows into component agencies’ local collection systems, thereby reducing the impact of I/I on the regional system’s capacity. This cooperative process will assess levels of I/I in local conveyance systems and construct pilot projects and will evaluate the cost-effectiveness and environmental costs and benefits of local collection system rehabilitation. The executive will develop and recommend long-term measures to reduce existing and future levels of I/I into local collection systems. Incentives for component agencies to meet the adopted target for I/I reduction may include a surcharge. Infiltration and Inflow (I/I) Policies How Implemented in 2007–2013 I/IP-1: King County is committed to controlling I/I within its regional conveyance system and shall rehabilitate portions of its regional conveyance system to reduce I/I whenever the cost of rehabilitation is less than the costs of conveying and treating that flow or when rehabilitation provides significant environmental benefits to water quantity, water quality, stream flows, wetlands or habitat for species listed under the ESA. The County’s Regional I/I Control Program was approved by the King County Council in 2006 through Motion 12292. The program calls for WTD to carry out initial I/I reduction projects to test the cost- effectiveness of I/I reduction on a larger scale than the pilot projects that were completed in 2004. WTD worked closely with MWPAAC to identfiy potential initial I/I reduction project areas for further analysis. As a result of the analysis, design efforts, and budget limitations, WTD selected the Skyway Initial I/I reduction project for implementation. The project was managed and funded by King County in partnership with the Skyway Water and Sewer District. Construction was completed in 2013. Analysis of the project’s results are under way. WTD will be working closely with MWPAAC to develop recommendations on the next steps regarding the County’s I/I control program and policy updates. I/IP-2: King County shall work cooperatively with component agencies to reduce I/I in local conveyance systems utilizing and evaluating I/I pilot rehabilitation projects, and developing draft local conveyance systems' design guidelines, procedures and policies, including inspection and enforcement standards. Evaluations of the pilot rehabilitation projects and a regional needs assessment of the conveyance system and assessments of I/I levels in each of the local sewer systems will form the basis for identifying and reporting on the options and the associated cost of removing I/I and preventing future increases. The executive shall submit to the council a report on the options, capital costs and environmental costs and benefits including but not limited to those related to water quality, groundwater inception, stream flows and wetlands, and habitat of species listed under the ESA. No later than December 31, 2005, This policy was written to provide guidance to the I/I reduction pilot program, which was completed in 2004. As a result of the 10 pilot projects, the Executive’s recommended I/I control program was developed in coordination with MWPAAC and approved by the County Council through Motion 12292 in 2006. RWSP 2013 Comprehensive Review A-11 Appendix A. RWSP Policies Implementation in 2007−2013 Infiltration and Inflow (I/I) Policies How Implemented in 2007–2013 utilizing the prior assessments and reports the executive shall recommend target levels for I/I reduction in local collection systems and propose long-term measures to meet the targets. These measures shall include, but not be limited to, establishing new local conveyance systems design standards, implementing an enforcement program, developing an incentive based cost sharing program and establishing a surcharge program. The overall goal for peak I/I reduction in the service area should be thirty percent from the peak twenty-year level identified in the report. The county shall pay one hundred percent of the cost of the assessments and pilot projects. I/IP-3: King County shall consider an I/I surcharge, no later than June 30, 2006, on component agencies that do not meet the adopted target levels for I/I reduction in local collection systems. The I/I surcharge should be specifically designed to ensure the component agencies’ compliance with the adopted target levels. King County shall pursue changes to component agency contracts if necessary or implement other strategies in order to levy an I/I surcharge. One of the recommendations included in the 2006 I/I control program was to not implement a surcharge on local agencies. As noted in I/IP-1, WTD will be working with MWPAAC to develop recommendations on the next steps regarding the County’s I/I program and policy updates. A-12 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 RWSP Combined Sewer Overflow Control Policies A. Explanatory material. The CSO control policies are intended to guide the county in controlling CSO discharges. Highest priority for controlling CSO discharges is directed at those that pose the greatest risk to human health, particularly at bathing beaches, and environmental health, particularly those that threaten species listed under ESA. The county will continue to work with federal, state and local jurisdictions on regulations, permits and programs related to CSOs and stormwater. The county will also continue its development of CSO programs and projects based on assessments of water quality and contaminated sediments. Note: In May 2013, the King County Council approved Ordinance 17587, which amended several of the CSO control policies to ensure the policies are consistent with the 2012 Council-approved long-term CSO Control Plan and consent decree that was negotiated in 2013 with the U.S. Environmental Protection Agency (EPA) and the Washington State Department of Ecology (Ecology). Combined Sewer Overflow Control Policies How Implemented in 2007–2013 CSOCP-1: King County shall plan to control its CSO discharges by the end of 2030 to meet: 1. The state's CSO control standard of an average of one untreated discharge per CSO outfall per year based on a twenty-year moving average, and 2. Conditions of National Pollutant Discharge Elimination System permit requirements; 3. conditions of the Environmental Protection Agency/Washington state Department of Ecology Consent Decree. (Ordinance 17587 amended this policy to include 2030 as the completion date to achieve CSO control; define the state’s CSO control standard; and reconfirm the County’s commitment to meet permit requirements and the conditions of the consent decree.) The King County Council approved the County’s amended long-term CSO control plan through Ordinance 17413 in September 2012. The plan includes a schedule to complete nine CSO control projects by the end of 2030. EPA subsequently approved the plan in March 2013. The project schedule is also included in the consent decree that was negotiated with EPA and Ecology in 2013. CSOCP-2: King County shall continue to work with state and federal agencies to develop cost-effective regulations that protect water quality. King County shall meet the requirements of state and federal regulations and agreements. (This policy was amended by Ordinance 17587. The language in this policy had previously been included as part of CSOCP-1. The Engineering and Planning Subcommittee of MWPAAC [E&P] recommended making this The County continues to work with state and federal agencies on regulations related to protecting water quality. For example, the County is a member of Ecology’s “Delegate’s Table” that was formed in 2012 to provide advice and perspective to Ecology on the water quality standards rule-making process that is under way. In addition, the County has been working closely with Ecology and EPA in developing and evaluating Lower Duwamish Superfund cleanup options. The County continues to meet all of its state and RWSP 2013 Comprehensive Review A-13 Appendix A. RWSP Policies Implementation in 2007−2013 Combined Sewer Overflow Control Policies How Implemented in 2007–2013 a separate policy.) federal regulations and agreements. CSOCP-3: Consistent with the Environmental Protection Agency/Washington state Department of Ecology Consent Decree and the county's long-term CSO control plan as approved through Ordinance 17413, King County shall give the highest priority for control of CSO discharges that have the highest potential to impact: 1. Human health through contact with CSO flows or fish consumption; or 2. Environmental health, such as in areas where sediment remediation is under way or anticipated or where there is potential to impact species listed under ESA. (Previously, this policy was CSOCP-2. Ordinance 17587 amended this policy to add language to be consistent with the approved amendment to the County’s long-term CSO plan and to better define “highest priority”.) The CSO control project schedule that was approved by the Council and EPA and included in the consent decree reflects the priorities outlined in this policy. CSOCP-4: Consistent with its legal authority, if King County constructs new projects that would separate stormwater from its combined system that result in separated stormwater discharges to waterways, the county shall coordinate with the city of Seattle in the city's municipal stormwater National Pollutant Discharge Elimination System permit (MS4) process as appropriate. (Previously, this policy was CSOCP-3. Ordinance 17587 amended this policy to clarify that the policy provides guidance for new projects.) There were no new projects constructed in 2007– 2013 that corresponded to this policy. CSOCP-5: King County's wastewater conveyance and treatment facilities shall not be designed to intercept, collect and treat new sources of stormwater. However, King County may evaluate benefits and impacts to the county system from accepting stormwater from the city of Seattle that is not currently in the combined system and shall consider factors including, but not limited to existing capacity, benefits and costs to ratepayers and the regional system, operational impacts, payment to county for value of the use of available capacity and for the costs of conveyance and treatment of new sources of stormwater and compliance with state and federal regulations and commitments. (Previously, this policy was CSOCP-4. Ordinance 17587 amended the policy to clarify The County’s facilities are not designed to intercept, collect, or treat new sources of stormwater. During the 2007–2013 timeframe, there were no proposals from the City of Seattle regarding additional stormwater to WTD’s system. A-14 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 Combined Sewer Overflow Control Policies How Implemented in 2007–2013 that King County’s facilities shall not be designed for new sources of stormwater and to require the County to consider the benefits, costs and impacts of accepting new sources of stormwater from Seattle if such a request were to occur.) CSOCP-6: In accordance with King County's industrial waste rules and regulations, including K.C.C. 28.84.050.K.1 and 28.84.060, the county shall accept contaminated stormwater runoff from industrial sources and shall establish a fee to capture the cost of transporting and treating this stormwater. Specific authorization for such discharge is required. (Previously, this policy was CSOCP-5. Ordinance 17587 amended the policy to ensure it is consistent with King County Code’s definition of industrial waste and to acknowledge that the policy is in accordance with industrial waste rules and regulations.) WTD’s Industrial Waste Program continues to coordinate the approvals of and cost recovery for industrial discharges. CSOCP-7: King County shall consider implementing green stormwater infrastructure projects to control CSOs when results of technical, engineering, and benefit/cost analyses and modeling demonstrate it is a viable and cost-effective CSO control method. (Ordinance 17587 added this policy to assure that the use of green stormwater infrastructure to control CSOs would be based on analytical results and modeling.) The Barton CSO control project that is under way in Seattle is a green stormwater infrastructure (GSI) project. The project includes constructing bioretention swales in the planter strips in the city right-of-way on up to 15 blocks in the Sunrise Heights and Westwood neighborhoods in West Seattle. The decision to use GSI for this project was based on the results of analyses listed in this policy. The project is expected be complete by the end of 2015. Four of the nine CSO control projects that were approved through Ordinance 17413 have been identified as projects that could benefit from GSI: West Michigan/Terminal 115, University, Montlake, and 11th Ave NW CSO control projects. The analyses listed in this policy will be conducted prior to implementing specific GSI projects. CSOCP-8: King County shall consider implementing joint CSO control projects with the city of Seattle when it is cost-effective, is within county legal authorities and can be accomplished within the schedule outlined in the Environmental Protection Agency/Washington state Department of Ecology Consent Decree and the county's approved long-term CSO control plan. (Previously, this policy was CSOCP-6 Ordinance 17587 amended the policy to incorporate information on potential joint projects with Seattle, consistent with the consent decree and Council-approved Three of the nine CSO control projects that were approved through Ordinance 17413 are identified as potential joint projects with Seattle to control both agencies’ CSOs in the 3rd Ave W, University, and Montlake CSO basins. Five small transfers of flows from Seattle projects to the King County system have also been identified; the City would reimburse the County for any operation and maintenance (O&M) costs associated with these flows. The County and City continue to discuss the potential for these joint projects. The City is expected to finalize and submit its long-term CSO control plan to EPA and Ecology in 2015. RWSP 2013 Comprehensive Review A-15 Appendix A. RWSP Policies Implementation in 2007−2013 Combined Sewer Overflow Control Policies How Implemented in 2007–2013 amendment to the long-term CSO control plan.) CSOCP-9: King County shall implement its long-range sediment management strategy to address its portion of responsibility for contaminated sediment locations associated with county CSOs and other facilities and properties. Where applicable, the county shall implement and cost share sediment remediation activities in partnership with other public and private parties, including the county's current agreement with the Lower Duwamish Waterway Group, the Department of Ecology and the Environmental Protection Agency, under the federal Comprehensive Environmental Response, Compensation and Liability Act. (Previously, this policy was CSOCP-7, Ordinance 17587 moved the policy to CSOCP- 9.) The County continues to work to improve water quality in the Lower Duwamish Waterway through actions such as reducing CSOs, restoring habitats, capping or removing sediments, and controlling toxicants from industries and stormwater runoff. WTD continued to carry out its Sediment Management Plan (SMP) to remediate contaminated sediments near CSO outfalls. The following activities were carried out as part of implementing the SMP during 2007–2013: • Completed cleanup of the former Denny Way CSO site off of Myrtle Edwards Park in Seattle; monitoring of sediment quality began in 2008 and will continue through 2018 • Developed a model to better predict deposition of contaminants around CSO outfalls • Completed post-construction monitoring of the Diagonal/Duwamish cleanup site • Conducted sampling of sediments in the East Duwamish Waterway Superfund site, finalized the East Duwamish Waterway remedial investigation, and completed a draft feasibility study The Lower Duwamish Waterway Group (LDWG) consists of King County, the City of Seattle, the Port of Seattle, and the Boeing Company. The LDWG has been working with EPA and Ecology since 2001 to study the contamination and determine the best and most effective alternatives to clean up the Lower Duwamish Waterway (LDW). During the 2007–2013 timeframe, the LDWG completed a remedial investigation and feasibility study for the LDW Superfund site and started a study to better understand who is eating contaminated seafood from the Duwamish River. In 2013, EPA issued the Proposed Plan for the Lower Duwamish Waterway Superfund Site, which presents a preferred alternative to clean up contamination in the in-waterway portion of the LDW Superfund site. EPA is expected to issue a Record of Decision in third quarter 2014 to direct cleanup actions and long-term monitoring. The County, in partnership with the LDWG, carried out engagement and outreach activities with interested industries, businesses, residents, and environmental and community groups throughout development of the remedial investigation, feasibility study, and EPA’s proposed cleanup plan. A-16 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 Combined Sewer Overflow Control Policies How Implemented in 2007–2013 The process to allocate cleanup costs among potential responsible parties (PRPs) is under way. CSOCP-10: Consistent with the Environmental Protection Agency/Washington state Department of Ecology Consent Decree, King County shall assess CSO control projects, priorities and opportunities using the most current studies and information available, for each CSO Control Plan Amendment as required by the Department of Ecology in the National Pollutant Discharge Elimination System permit renewal process. (Previously, this policy was CSOCP-8. Ordinance 17587 added language to be consistent with the Council-approved long- range CSO control plan and the consent decree. In addition, the policy was split into two policies – see CSOCP-11.) For the 2012 CSO Control Program review and plan amendment, WTD assessed available scientific studies to identify information that could shape the program. Studies relating to the LDW Superfund cleanup efforts and to salmon health and recovery informed the recommendation and schedule to complete CSO control projects in LDW sooner than planned in the 1999 RWSP CSO control schedule. CSOCP-11: Before completion of an National Pollutant Discharge Elimination System required CSO Control Plan Amendment, the executive shall submit a CSO program review report to the council and RWQC. The purpose of the review is to evaluate, at a minimum, changes to regulations, new technologies, existing CSO control performance, and human and environmental health priorities that may affect implementation of the CSO Control Plan. Based on its consideration of the CSO program review, RWQC may make recommendations to the council for modifying or amending the CSO program, including changing the sequencing of CSO projects. Any future updates or amendments to the county's long-term CSO control plan are subject to Environmental Protection Agency and Washington state Department of Ecology approvals. (Ordinance 17587 moved this portion of the previous CSOCP-8, and added language to indicate that EPA and Ecology must approve any future CSO Control Plan Amendment.) The County Executive submitted the 2012 CSO Control Program review to the County Council in June 2012. The Council approved the program review and schedule for the amended long-term CSO control plan in September 2012. As required, the County’s 2012 long-term CSO control plan amendment was submitted to Ecology and EPA in October 2012. The next program review is scheduled to be submitted to the County Council in 2017. CSCOP-12: King County shall implement its CSO control projects in accordance with the Environmental Protection Agency/Washington state Department of Ecology Consent Decree and the schedule outlined in the county's approved long-term CSO control plan. (Ordinance 17587 added this policy to be consistent with the Council-approved long-term CSO control plan and Consent Decree.) Compliance with the consent decree is a top priority for the County. All the CSO control projects outlined in the consent decree are on schedule to achieve their critical milestones. CSOCP-13: King County shall prepare a water Work on the Water Quality Assessment And RWSP 2013 Comprehensive Review A-17 Appendix A. RWSP Policies Implementation in 2007−2013 Combined Sewer Overflow Control Policies How Implemented in 2007–2013 quality assessment and monitoring study, consistent with the guidance provided in Ordinance 17413 and other applicable legal requirements, to inform the next combined sewer overflow control program review in 2018. (Ordinance 17587 added this policy to be consistent with Ordinance 17413, which directs the County Executive to conduct a water quality assessment and monitoring study.) Monitoring Study is under way. The scope of work for the assessment and study was approved by the County Council in September 2013. More information is available at http://www.kingcounty.gov/environment/wastewater/C SO/WQstudy.aspx. A-18 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 RWSP Biosolids Policies A. Explanatory material. The biosolids policies are intended to guide the county to continue to produce and market class B biosolids. The county will also continue to evaluate alternative technologies so as to produce the highest quality marketable biosolids. This would include technologies that produce class A biosolids. Biosolids Policies How Implemented in 2007–2013 BP-1: King County shall strive to achieve beneficial use of wastewater solids. A beneficial use can be any use that proves to be environmentally safe, economically sound and utilizes the advantageous qualities of the material. One hundred percent of King County’s Loop® biosolids were used beneficially as a soil amendment and fertilizer in agriculture and forestry or as an ingredient in compost. Loop production began at the Brightwater Treatment Plant in late 2011. BP-2: Biosolids-derived products should be used as a soil amendment in landscaping projects funded by King County. Specifications for the Loop compost (GroCo) have been added to King County’s standard procurement documents for use in bids and contracts. GroCo was used in landscaping at the Brightwater Treatment Plant. BP-3: King County shall consider new and innovative technologies for wastewater solids processing, energy recovery, and beneficial uses brought forward by public or private interests. King County shall seek to advance the beneficial use of wastewater solids, effluent, and methane gas through research and demonstration projects. Examples of efforts to meet this policy during 2007– 2013 are as follows: • Through the Northwest Biosolids Management Association (NBMA), WTD participates in biosolids-related research studies. In 2008, a research project was conducted to quantify the carbon sequestration benefits of using biosolids and other organic residuals as a soil amendment for land application. Results showed a significant increase in carbon stored in agricultural soils, indicating that use of biosolids as a soil amendment has the potential to reduce the carbon footprint while helping secure the sustainability of agriculture in the state. By sequestering carbon and avoiding synthetic fertilizers, the use of Loop offset over 42,000 tons of carbon dioxide equivalents in 2012, which is similar to taking 8,000 cars off the road. • WTD issued a Request for Information in 2008 to learn about options for supplementing, strengthening, or diversifying the County’s biosolids program. Findings showed that generally no changes are needed at this time. The current program captures energy by producing biogas from digestion, helps reduce atmospheric carbon by storing it in the soil, provides fertilizer for crops, and is less expensive than other options. • In summer 2009, the County began collaborating on a carbon-sequestration demonstration project in a borrow pit at Island Center Forest on Vashon Island. Researchers are evaluating the ability of composted organic residuals (biosolids, food waste, and woody debris) to recover soil quality RWSP 2013 Comprehensive Review A-19 Appendix A. RWSP Policies Implementation in 2007−2013 Biosolids Policies How Implemented in 2007–2013 by capturing and storing carbon, improving soil health, and enhancing vegetation growth. • In 2009, a Loop research and demonstration garden was installed at South Treatment Plant. University of Washington scientists studied the safety of vegetables grown in a sandy loam soil mix and a biosolids compost soil mix. The vegetables grown in the biosolids compost mix were deemed safe and the growth was considered lush. • A request for information was submitted in 2012 inviting local developers and commerical owners to submit ideas for privately owned district energy systems that could extract and recover heat from WTD’s conveyance system. The goal was to gauge interest in the private sector about investing in new technologies that would make heat energy and possibly other forms of energy in the wastewater system more widely available.WTD is working with real estate developers to demonstrate how their projects can tap into this thermal energy asset. BP-4: King County shall seek to maximize program reliability and minimize risk by one or more of the following: 1. maintaining reserve capacity to manage approximately one hundred fifty percent of projected volume of biosolids; 2. considering diverse technologies, end products, and beneficial uses; or 3. pursuing contractual protections including interlocal agreements, where appropriate. WTD recycles 100 percent of its biosolids for use in forestry and on irrigated and dryland crops, and to make compost. In accordance with this policy, the biosolids program has permitted land, primarily in Douglas County, to maintain site capacity for 150 percent of annual volume. This additional capacity has allowed King County to recycle 100 percent of its biosolids even when one or more of its projects have temporarily reduced capacity. In addition, WTD has an agreement with the City of Everett for temporary storage for the County’s biosolids at the City’s treatment plant, which mitigates the effects of winter pass closures. When the passes reopen, the stored bisolids would be taken to Douglas County. The County continues to evaluate markets that would provide additional site capacity and environmental benefits and to investigate technologies that have the potential to cost-effectively produce Class A biosolids. Two requests for proposals were issued for composting services. While no new facilities were available, a new lower-cost, multi-year contract was awarded to the County’s long-term contractor for GroCo. More information on how the County continues to implement this policy is available in the Biosolids Strategic Plan 2012–2016, which is available at http://www.kingcounty.gov/environment/wastewater/Bi osolids/DocumentsLinks.aspx. BP-5: King County shall produce and use biosolids in accordance with federal, state and local regulations. WTD continues to meet all regulatory requirements for production and beneficial use of biosolids. In accordance with an amendment to the state’s biosolids management rule (WAC 173-308-205), A-20 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 Biosolids Policies How Implemented in 2007–2013 construction began in 2013 on the influent screenings project at the West Point Treatment Plant and will be completed in third quarter 2014. The project meets the rule’s requirement for “significant removal” of manufactured inerts (trash and plastics) from biosolids. The amendment rule requires treatment plants to screen these objects from the wastewater stream with 3/8-inch or finer bar screens. The West Point Plant currently has 5/8-inch screens. BP-6: King County shall strive to produce the highest quality biosolids economically and practically achievable and shall continue efforts to reduce trace metals in biosolids consistent with 40 C.F.R. Part 503 pollutant concentration levels (exceptional quality) for individual metals. The county shall continue to provide class B biosolids and also to explore technologies that may enable the county to generate class A biosolids cost-effectively or because they have better marketability. Future decisions about technology, transportation and distribution shall be based on marketability of biosolids products. WTD’s biosolids are routinely monitored for metals, conventional constituents (phosphorous, potassium, and pH), microbes, and organic compounds. The metal concentrations are well below the most restrictive federal and state standards. Industrial source control and pretreatment have reduced the amount of metals in biosolids by 70–90 percent since the 1980s. WTD participated in studies on the fate and degradation of trace organic compounds after land application of biosolids. Compounds include nonylphenol (a surfactant), ibubprofen, triclosan (an antibacterial), and estrogens. These are found in household cleaning products, personal care products, and pharmaceuticals. All compounds degraded quickly, and no movement in soil, leaching, or plant uptake was observed. WTD launched the County’s biosolids brand, Loop, in 2012. The development of the Loop brand is part of a long-term strategic goal to increase public support and strengthen demand for biosolids. More information on the benefits and uses of Loop is available at http://www.loopforyoursoil.com/. WTD developed an inventory of organic residuals and degraded lands managed by the County, with the objective of partnering with other county agencies to improve soils, sequester carbon, and reduce costs of managing residuals. The demonstration project at the Island Center Forest is a result of these efforts (see BP-3). BP-7: When biosolids derived products are distributed outside the wastewater service area, the county shall require that local sponsors using the products secure any permits required by the local government body. The local sponsors outside of the County’s wastewater service area who use biosolids are responsible for securing local support and any applicable permits relating to the use of biosolids. BP-8: King County shall work cooperatively with statewide organizations on biosolids issues. King County participates in local organizations and is a founding member of the NBMA, whose purpose is to share technical knowledge about biosolids management between members and to provide opportunities to work with university scientists; local, state, and federal regulators; and the general public. Through the NBMA, WTD works cooperatively with RWSP 2013 Comprehensive Review A-21 Appendix A. RWSP Policies Implementation in 2007−2013 Biosolids Policies How Implemented in 2007–2013 regulatory officials, scientists, and other biosolids managers on regulatory issues, education and training, public information, and research and demonstration. BP-9: King County shall seek to minimize the noise and odor impact associated with processing, transporting and applying of biosolids, consistent with constraints of economic and environmental considerations and giving due regard to neighboring communities. In 2011, a new 10-year hauling contract was awarded. The new contract required an onboard tracking system, in advance of federal requirements to monitor both trucks and drivers. During 2011 and 2012, the biosolids program began replacing its fleet of haul trucks. The trucks are quieter and meet new EPA 2010 nitrous oxide (N2O) emission standards, lowering the N2O emissions to less than 1 percent of the emissions of the previous fleet. Construction of the West Point Treatment Plant Digestion System Improvements project was completed in 2013. The project will enhance the reliability of the West Point Plant’s solids digestion system and reduce the risk of digester upsets under current and future solids loading conditions. In addition to affecting the quality of the biosolids, these upsets could increase odor at the plant. The project also included modifications to the blending storage tank (Digester 6) to enable its use as an emergency digester if needed. WTD has procedures in place to log, investigate, and track all odor complaints. WTD’s goal is to respond to each complaint within two hours after receiving a complaint. (See TPP-4 for more information on the County’s odor goals.) BP-10: Where cost-effective, King County shall beneficially use methane produced at the treatment plants for energy and other purposes. The South, West Point, and Brightwater Treatment Plants use digester gas (methane) to produce heat, electricity, and natural gas. At the South Treatment Plant, digester gas that is not used for in-plant purposes is “scrubbed” to the quality required for pipeline natural gas and then sold to Puget Sound Energy. The new Waste-to-Energy cogeneration system that came online at the West Point Plant in 2013 will supply a source of green energy for plant operations and for sale to Seattle City Light per an agreement that was signed in 2009. The system will produce about 18,000 megawatt hours of electricity per year, which is the same amount of power used by 1,100 typical Pacific Northwest homes. A-22 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 RWSP Water Reuse Policies A. Explanatory material. The water reuse policies are intended to guide the county in continuing to develop its program to produce reclaimed water. The county will coordinate its program with regional water supply plans and work with state agencies and local jurisdictions on opportunities for water reuse. The county will implement pilot and demonstration projects. Additional projects shall be implemented subject to economic and financial feasibility assessments, including assessing environmental benefits and costs. The water reuse policies, as in the treatment plant policies, intend that the county continue producing reclaimed water at its treatment plants. The treatment plant policies also address the potential construction of one or more satellite plants. These small plants would provide reclaimed water, with the solids being transferred to the regional plants for processing. Water Reuse Policies How Implemented in 2007–2013 WRP-1: King County shall actively pursue the use of reclaimed water while protecting the public health and safety and the environment. The county shall facilitate the development of a water reuse program to help meet the goals of the county to preserve water supplies within the region and to ensure that any reclaimed water reintroduced into the environment will protect the water quality of the receiving water body and the aquatic environment. WTD has been safely using reclaimed water since 1997 at the South and West Point treatment plants. Some of the reclaimed water produced at the South Plant is distributed and used off-site by reclaimed water customers, including the City of Tukwila. Starfire Sports uses reclaimed water for irrigation, and the City uses it for street sweeping, sewer flushing, and other public works uses. In March 2009, the Carnation Treatment Plant started discharging its Class A reclaimed water to enhance a wetland in the Chinook Bend Natural Area. The Brightwater Treatment Plant began producing reclaimed water in 2012. Reclaimed water is used at the Brightwater Environmental and Education Center for non-drinking purposes, such as toilet flushing and landscape irrigation. It is also used for in-plant uses. In June 2013, reclaimed water from Brightwater was distributed to Willows Run Golf Course for irrigation purposes. The County’s Reclaimed Water Program includes customer support and and development, permit compliance, and planning associated with reclaimed water use from South, Carnation, and Brightwater Plants. The County carried out two studies during this timeframe—a turf irrigation study and an ornamental plant and food crop irrigation study—in partnership with University of Washington researchers to develop local, independent, best-available science about the public health and environmental impacts of using reclaimed water. Results of both studies confirmed that that reclaimed water uses are safe for people and the environment. More information on the reclaimed water studies are available at http://www.kingcounty.gov/environment/wastewater/R RWSP 2013 Comprehensive Review A-23 Appendix A. RWSP Policies Implementation in 2007−2013 Water Reuse Policies How Implemented in 2007–2013 esourceRecovery/ReWater/WaterResearch.aspx. Also, the County carried out a joint feasibility study with the City of Bothell, which was completed in 2013. The City has requested more information from the County on customer interests and funding options. WTD carried out a reclaimed water comprehensive planning process during this timeframe. The County worked with local jurisdictions, water supply agencies, and interested parties in the effort. The planning effort gathered informaton on potential uses for reclaimed water now and over the next 30 years and the different ways that that the County’s reclaimed water program could serve potential uses for reclaimed water. WRP-2: By December 2007, the King County executive shall prepare for review by council a reclaimed water feasibility study as part of a regional water supply plan which will include a comprehensive financial business plan including tasks and schedule for the development of a water reuse program and a process to coordinate with affected tribal and local governments, the state and area citizens. The reclaimed water feasibility study shall be reviewed by the RWQC. At a minimum the feasibility study shall comply with chapter 90.46 RCW and include: 1. Review of new technologies for feasibility and cost effectiveness, that may be applicable for future wastewater planning; 2. Review of revenue sources other than the wastewater rate for distribution of reused water; 3. Detailed review and an update of a regional market analysis for reused water; 4. Review of possible environmental benefits of reused water; and 5. Review of regional benefits of reused water. This policy has been fully implemented. The reclaimed water feasibility study was issued in March 2008 and reviewed by the Regional Water Quality Committee in April 2008; the study is available at http://www.kingcounty.gov/environment/wastewater/R WCompPlan/Library/Feasibility.aspx. WRP-3: Recycling and reusing reclaimed water shall be investigated as a possible future significant new source of water to enhance or maintain fish runs, supply additional water for the region’s nonpotable uses, preserve environmental and aesthetic values and defer the need to develop new potable water supply projects. The reclaimed water planning process collected information on potential nonpotable consumptive and environmental enhancement uses. Conceptual strategies to provide reclaimed water for some of these uses were developed and evaluated as a part of the effort. The information gathered in the planning effort will help inform any future reclaimed water opportunities that may arise. Documentation from the planning effort is available at http://www.kingcounty.gov/environment/wastewater/R WCompPlan/Library.aspx. WRP-4: King County’s water reuse program WTD coordinated with water supply agencies during A-24 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 Water Reuse Policies How Implemented in 2007–2013 and projects shall be coordinated with the regional water supply plans and regional basin plans, in accordance with state and federal standards. The coordination shall be done with the affected water supply purveyors. Water reuse must be coordinated with water supply/resource purveyors to ensure that resources are developed in a manner complementary with each other to allow the most effective management of resources in the county. the reclaimed water planning process. Although a regional water supply plan has not been developed, the County remains committed to coordinating with water supply agencies on reclaimed water projects and related issues. WRP-5: King County shall implement nonpotable projects on a case-by-case basis. To evaluate nonpotable projects, King County shall develop criteria which will include, but are not limited to: capital, operation and maintenance costs; cost recovery; potential and proposed uses; rate and capacity charge impacts; environmental benefits; fisheries habitat maintenance and enhancement potential; community and social benefits and impacts; public education opportunities; risk and liability; demonstration of new technologies; and enhancing economic development. A detailed financial analysis of the overall costs and benefits of a water reuse project shall include cost estimates for the capital and operations associated with a project, the anticipated or existing contracts for purchases of reused water, including agricultural and other potential uses, anticipated costs for potable water when the project becomes operational; and estimates regarding recovery of capital costs from new reused water customers versus costs to be assumed by existing ratepayers and new customers paying the capacity charge. Water reuse projects that require major capital funding shall be reviewed by RWQC and approved by the council. There were no new major projects implemented during this timeframe. As opportunities arise, WTD will evaluate potential reclaimed water projects using the criteria in this policy prior to implementing any new major reclaimed water projects. WRP-6: King County shall work with local water purveyors, including when the local purveyors update their water comprehensive plans, to evaluate the opportunities for water reuse within their local service area. WTD participates in discussions with individual water agencies, jurisdictions, MWPAAC, and other entities concerning reclaimed water opportunities. In addition, King County Code 13.24.010 calls for water comprehensive plans to include an evaluation of reclaimed water opportunities, as required by RCW 90.46.120, and calls for sewer comprehensive plans to discuss opportunities for reclaimed water, as required under RCW 90.48.112 and 90.48.495. King County’s Utilities and Technical Review Committee (UTRC) serves as the technical review body for water and sewer utilities' comprehensive plans and works RWSP 2013 Comprehensive Review A-25 Appendix A. RWSP Policies Implementation in 2007−2013 Water Reuse Policies How Implemented in 2007–2013 with the utilities during review of their plans. WRP-7: King County shall develop an active water reuse public education and involvement program to correspond with the development of the water reuse program and be coordinated with other water conservation education programs. Information on water conservation and reclaimed water is incorporated into WTD’s education programs, including the display at the Brightwater Education and Community Center. WTD’s education programs include treatment plant open houses, treatment plant tours for schools and interested groups, and information shared at public meetings, on websites, and through social media. As part of its education efforts, WTD reaches out to other education programs, local wastewater and water supply agencies, and community, environmental, and business groups. The information on how WTD implemented its Public Involvement Policies in 2007–2013 provides more information on WTD’s education and outreach programs. WRP-8: King County shall utilize a forum or multiple forums to provide opportunities for coordination and communication with the Washington state Departments of Health and Ecology, which have the principal state regulatory roles in the planning, design and construction of reuse facilities. The county shall involve other parties on these forums, including but not limited to, the Corps of Engineers, Washington state Department of Fish and Wildlife, National Marine Fisheries Service, United States Fish and Wildlife Service, regional water suppliers, tribal governments, local water and wastewater districts, cities, local health departments, watershed forums and environmental and community groups. This process is an ongoing element of the County’s reclaimed water program. Agencies cited in WRP-8 are regular participants, along with the County, in multiple processes and committees related to water supply and environmental and public health issues. Examples of WTD’s specific efforts during this timeframe are as follows: • Participated in Ecology’s effort on reclaimed water rule making. The County was an active member of Ecology’s Reclaimed Water Rule Advisory Committee. The rule-making process was suspended in 2010. The governor directed state agencies to review all current and anticipated rule-making and decide what could be delayed. • Worked closely with the groups listed in this policy during the reclaimed water comprehensive planning effort. • Helped establish and is a board member of the WaterReuse Association’s Pacific Northwest Section. The new section will focus on local legislative and regulatory issues in Washington, Oregon, Idaho, and Alaska—and is the first WateReuse section to include multiple states. WRP-9: King County shall work, on a case-by- case basis, with the Washington state Departments of Health and Ecology on water reuse projects including, but not limited to, those that are not specifically cited in the 1997 Department of Health and Ecology Water Reclamation and Reuse Standards. King County works closely with the Washington State Departments of Health and Ecology on the County’s reclaimed water program, including the reclaimed water permitting processes for South, Brightwater, and Carnation treatment plants. South Plant’s reclaimed water permit was renewed in 2009, Carnation’s reclaimed water permit became effective in 2009 and was renewed in 2013, and Brightwater’s reclaimed water permit became effective in 2011. A-26 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 Water Reuse Policies How Implemented in 2007–2013 WRP-10: King County shall hold and maintain the exclusive right to any reclaimed water generated by the wastewater treatment plants of King County. The County continues to be in compliance with this policy. The policy is in accordance with RCW 90.46.120, which states “The owner of a wastewater treatment facility that is reclaiming water with a permit issued under this chapter has the exclusive right to any reclaimed water generated by the wastewater treatment facility.” WRP-11: King County’s water reuse program projects shall not impair any existing water rights unless compensation or mitigation for such impairment is agreed to by the holder of the affected water rights. The County continues to be in compliance with this policy. The policy is in accordance with RCW 90.46.130, which states “…facilities that reclaim water under this chapter shall not impair any existing water right downstream from any freshwater discharge points of such facilities unless compensation or mitigation for such impairment is agreed to by the holder of the affected water right.” WRP-12: King County shall retain the flexibility to produce and distribute reclaimed water at all treatment plants including retaining options to add additional levels of treatment. The County continues to look to expand customer opportunities for distributing reclaimed water from South and Brightwater treatment plants. All of the reclaimed water from the Carnation Plant is used to enhance a wetland at the Chinook Bend Natural Area. Reclaimed water produced at Brightwater, South, and West Point Plants is used for irrigation at the plant sites and for in-plant purposes. WRP-13: King County shall continue to evaluate potential funding of pilot-scale and water reuse projects, in whole or in part, from the wastewater utility rate base. The Reclaimed Water Feasibility Study included a review of revenue sources for reclaimed water distribution, and the reclaimed water comprehensive planning process included discussions on ways to fund future reclaimed water projects. The County’s reclaimed water projects are currently funded through the wastewater rate and reclaimed water customers. WRP-14: King County shall complete an economic and financial feasibility assessment, including environmental benefits, of its water reuse program. The assessment shall include the analysis of marginal costs including stranded costs and benefits to estimate equitable cost splits between participating governmental agencies and utilities. The assessment shall also include a review of existing and planned water and wastewater facilities in an approved plan to ensure that water reuse facilities are justified when any resulting redundant capacity as well as other factors are taken into account. The feasibility study that was completed per WRP-2 addressed this policy. In addition, the reclaimed water comprehensive planning process included an economic and financial feasibility assessment and an analysis of environmental benefits of the conceptual strategies that were developed as part of the process. WRP-15: King County should pursue development of a water reuse program to discharge reclaimed water to reduce freshwater consumption used in the operation of the Ballard Locks as a priority water reuse project. This policy is similar to the guidance in TPP-5. WTD developed and analyzed conceptual strategies for discharging reclaimed water into Lake Washington and additional reclaimed water uses in the Lake Sammamish watershed as part of the reclaimed water comprehensive planning process that took place in 2009–2012. Based on the analysis, it was determined RWSP 2013 Comprehensive Review A-27 Appendix A. RWSP Policies Implementation in 2007−2013 Water Reuse Policies How Implemented in 2007–2013 to not pursue any of the strategies at this time. WTD will continue to monitor changing conditions or future opportunities that could result in additional reclaimed water uses in these watersheds A-28 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 RWSP Wastewater Service Policies A. Explanatory material. The wastewater services policies guide the county in both providing wastewater services to its customers and maintaining the wastewater system in a cost-effective, environmentally responsible manner. These policies shall also guide King County’s development and operation of community treatment systems. King County provides wholesale wastewater treatment and disposal service to component agencies. The county’s wastewater service area boundary generally coincides with the boundaries of these component agencies, including certain areas in Snohomish county and Pierce county. The county is to provide wastewater services to areas within the respective urban growth boundaries and in rural areas only to protect public health and safety, in conformance with state provisions and local growth management act policies and regulations. Wastewater Services Policies How Implemented in 2007–2013 WWSP-1: King County shall provide wastewater services to fulfill the contractual commitments to its component agency customers in a manner that promotes environmental stewardship, recognizes the value of wastewater in the regional water resource system and reflects a wise use of public funds. King County has long-term agreements to provide sewage disposal and treatment services with 33 local governments and one Indian Tribe. Environmental stewardship is an important component of the County’s wastewater treatment service; WTD’s mission is to protect public health and enhance the environment by treating and reclaiming water, recycling solids, and generating energy. WTD’s vision of creating resources from wastewater is carried out in recognition of the overall value of wastewater. WTD provides high-quality wastewater treatment in as cost-effective manner as possible. The division regularly evaluates projects in the planning and design phases to identify potential cost-savings. WTD bonds are highly rated and receive low interest rates. WWSP-2: King County shall continue to foster tribal relations as appropriate to structure processes for joint water quality stewardship. WTD regularly works with affected Tribal Governments on its plans and projects. Activities with the Tribal Governments during the 2007 to 2013 timeframe include the following: • Participating in workshops on environmental priorities and CSO control technologies during the 2012 CSO Control Program review • Holding meetings and discussions with staff from area tribal governments during the reclaimed water comprehensive planning process • Working with the Puyallup Tribal Government to address shellfish contamination of the Quartermaster Harbor area of Vashon-Maury Island and in other closed or restricted areas in the Vashon-Maury Island area • Working with the Suquamish and Tulalip Tribal Governments to implement a shellfish program enhancement effort in the Richmond Beach area of north King County as part of the Brightwater RWSP 2013 Comprehensive Review A-29 Appendix A. RWSP Policies Implementation in 2007−2013 Wastewater Services Policies How Implemented in 2007–2013 mitigation program • Working with the Muckleshoot Indian and Suquamish Indian Governments in the decision process for cleaning up Duwamish River sediments and on improving equity and social justice determinants • Working with Muckleshoot Indian Tribe regarding water or sewer plan reviews and approvals within areas of interest to the tribe. WWSP-3: King County shall not accept additional wastewater directly from private facilities within the boundaries of a component agency without the prior written consent of such component agency. WTD has received no such requests from private facilities since the adoption of the RWSP. WWSP-4: King County’s wastewater service area generally has been developed along those boundaries adopted in the original metropolitan Seattle sewerage and drainage survey, substantive portions of which were adopted as the county's comprehensive water pollution abatement plan and amended. King County's wastewater service area consists of the service areas of the component agencies with which a sewage disposal agreement has been established (agreement for sewage disposal, section 2) and the county's service area boundary is the perimeter of these areas. The service area boundary for sewer service provided to Snohomish county and Pierce county shall not exceed each county’s urban growth boundary. The service area boundary within King County shall be consistent with countywide planning policy CO-14 and the King County Comprehensive Plan which permit sewer expansion in rural areas and resource lands where needed to address specific health and safety problems. To protect public health and safety, the county may assume in accordance with state procedures, the ownership of existing sewer treatment and conveyance facilities that have been constructed by a sewer district organized under state law. The County’s wastewater service area boundary remains consistent with this policy. WWSP-5: Extensions of existing conveyance facilities or construction of new conveyance facilities must be consistent with King County’s land use plans and policies, and certified by potentially affected land use jurisdictions as consistent with their adopted land use plans and policies. WTD evaluates its projects during the planning process to ensure consistency with the County’s land use plans and policies. WTD maintains and reviews up-to-date local capital improvement plans for jurisdictions and sewer districts in the County’s wastewater service area and works closely with local jurisdictions through all phases of a WTD project that is planned within their jurisdiction. A-30 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 Wastewater Services Policies How Implemented in 2007–2013 WWSP-6: King County shall operate and maintain its facilities to protect public health and the environment, comply with regulations and improve services in a fiscally responsible manner. WTD’s mission is to protect public health and enhance the environment by treating and reclaiming water, recycling solids, and generating energy. Extensive resources have been committed to maintaining the integrity of the wastewater system and preventing sanitary sewer overflows. The Industrial Waste and Local Hazardous Waste Management programs work to control pollutants at their sources and prevent those pollutants from reaching the County’s treatment plants. The King County Council’s review of WTD’s programs, priorities, and costs during the annual rate setting process and Council’s budget process provides additional assurance that WTD is carrying out its programs in a fiscally responsible manner. WWSP-7: King County shall plan, design and construct wastewater facilities in accordance with standards established by regulatory agencies and manuals of practice for engineering. WTD designs and constructs wastewater treatment facilities to ensure that they fully comply or exceed regulatory and permit requirements. WTD applies science and engineering to planning, design, and construction of facilities and follows industry-recognized standards. As a result, the County’s wastewater system exceeds the reliability standards of most major metropolitan systems and has been able to absorb record storm events in recent years with little effect on public health and safety. WTD participates in national organizations and associations that address issues such as pumping standards, treatment and odor control standards and technologies, and predictive modeling tools. In addition, WTD follows the guidelines in the Criteria for Sewage Works Design manual. Ecology prepares this manual, also known as the “Orange Book.” It serves as a guide for the design of wastewater collection, treatment, and reclamation systems and addresses requirements that will lead to approvable plans. WAC 173-240-040 requires that sewer plans and specifications are reasonably consistent with the Orange Book. WWSP-8: King County shall construct, operate and maintain facilities to prevent raw sewage overflows and to contain overflows in the combined collection system. In the event of a raw sewage overflow, the county shall initiate a rapid and coordinated response including notification of public health agencies, the media, the public and the affected jurisdiction. Preserving public health and water quality shall be the highest priority, to be implemented by immediately initiating repairs or constructing temporary diversion systems that return flow back to the wastewater system. Implementation of the RWSP ensures that adequate wastewater capacity will be available when needed. The various sections and work units of WTD coordinate to assess needs and prioritize projects to prevent overflows. WTD’s forecasting and demand-modeling capabilities, in-field flow monitoring, and ongoing facility inspections provide essential information to identify and address capacity, operational, and maintenance needs. WTD has established emergency response procedures in the event of sewage overflows. WWSP-9: To ensure the region’s multibillion-WTD’s formal and detailed Strategic Asset RWSP 2013 Comprehensive Review A-31 Appendix A. RWSP Policies Implementation in 2007−2013 Wastewater Services Policies How Implemented in 2007–2013 dollar investment in wastewater facilities, an asset management program shall be established that provides for appropriate ongoing maintenance and repair of equipment and facilities. The wastewater maintenance budget, staffing levels and priorities shall be developed to reflect the long-term useful life of wastewater facilities as identified by the asset management program. Management Plan (SAMP) that was developed in 2006 was updated in 2010. The next update is scheduled for 2014. The focus of the SAMP is to balance lifecycle costs and risks at the asset level. To optimize stewardship of ratepayer dollars, minimize risk of asset failure and comply with regulations WTD’s Asset Management Program (AMP) is sustained at all levels of the division through the Asset Management Steering Committee (AMSC), Maintenance Best Practices Steering Committee (MBPSC), Technical Standards Committee (TSC) and the Computerized Maintenance Management System (CMMS) Users Group. WTD’s AMP strives to apply the whole life (cradle to grave) approach to its assets. The focus is holistic, starting with the development of technical standards and predesign (what we build), project management and engineering (how we build it), O&M (how we operate and maintain it from commissioning through decommissioning and disposal), and finance (how we pay for it). The ability to measure and improve each step of the asset management process is the function of the Key Performance Indicator (KPI) Program, which is currently being updated. Another important element is tracking, scheduling, and assessing asset management and performance over the life of the asset. A high priority for WTD is to ensure this essential information is kept current in its CMMS. WWSP-10: The asset management program shall establish a wastewater facilities assets management plan, updated annually, establishing replacement of worn, inefficient and/or depreciated capital assets to ensure continued reliability of the wastewater infrastructure. Regularly scheduled condition assessments are performed on the conveyance system and facility structures. Findings and rehabilitation recommendations are reported in a facilities inspection annual work plan and are tracked in CMMS. The lifecycle of process equipment, facility structures, and the conveyance system is managed under the SAMP. WWSP-11: King County shall design, construct, operate and maintain its facilities to meet or exceed regulatory requirements for air, water and solids emissions as well as to ensure worker, public and system safety. WTD’s treatment plants continue to meet and. in most cases, exceed permit requirements. In 2013, all of the County’s treatment plants operated without any violation of their NPDES permit effluent limits. The Industrial Waste Program permits discharges into the sewer that are not hazardous to workers and cause no environmental harm. For emergencies, WTD has procedures in place to ensure worker, public, and system safety. A-32 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 Wastewater Services Policies How Implemented in 2007–2013 WWSP-12: King County shall accept sewage, septage and biosolids from outside its service area provided that it is consistent with the King County Comprehensive Plan or the comprehensive plan of the source jurisdiction, capacity is available and no operating difficulties are created. The county shall establish a rate to recover costs from accepting sewage, septage and biosolids from outside its service area. Services are monitored for consistency with applicable plans and to ensure they cause no adverse impact to the wastewater system. A separate rate, based on solids content, has been established to cover the costs of processing deliveries of septage and biosolids at the South Treatment Plant. WWSP-13: King County shall identify the potential for “liability protection” for component agencies for unexpected costs associated with water quality requirements. This policy was developed in 1999, soon after Chinook salmon was listed as a threatened species under the Endangered Species Act. There was discussion that if the County were to do a Habitat Conservation Plan (HCP) for the entire wastewater service area, there might be a way for the local agencies to achieve “liability protection” under WTD’s HCP. WTD discontinued the work on the HCP in April 2005 after the first phase was completed. WWSP-14: King County shall continue its long- standing commitment to research and development funding relating to water quality and technologies for the wastewater system. Examples of studies undertaken in this timeframe include: • Nitrogen Removal Study. WTD conducted two studies to evaluate the impacts of a range of potential nitrogen limits on capital and operating costs at the South Treatment Plant and West Point Treatment Plant. The studies evaluated a variety of nitrogen removal technologies and used existing treatment plant data and computer modeling to develop capital costs, O&M costs and greenhouse gas (GHG) emissions for each regulatory scenario. Results of the studies show that the costs of upgrading the South Treatment Plant would range from approximately $0.5 billion to $1 billion with an associated operating cost increase of $10 to $33 million per year. The estimated costs of upgrading the West Point Treatment Plant is $1 billion with an operating cost of $30 million per year. Upgrading the West Point Plant to remove nitrogen would substantially reduce its treatment capacitybecause of lack of available space and would therefore require construction of one or more new treatment plants with a total design capacity of 75–150 mgd. • South Plant Biogas Utilization. The South Plant biogas scrubber system currently processes biogas produced by the solids digestion system to convert it into high-quality bio-methane (natural gas). This gas is then injected into the nearby natural gas pipeline and sold to Puget Sound Energy. Critical elements of the biogas recovery and RWSP 2013 Comprehensive Review A-33 Appendix A. RWSP Policies Implementation in 2007−2013 Wastewater Services Policies How Implemented in 2007–2013 energy production system are aging and will require replacement in the near future. A study was conducted to assess the system to determine if it still provides the best and highest use the biogas. The study concluded that replacing the gas scrubbing system with new technology and upgrading the plant heating systems would resolve substantial issues at a similar capital cost but significantly lower lifecycle cost when compared to the status quo alternative or other alternatives evaluated (including internal combustion engine generators). • Grease Co-Digestion at South Plant. WTD has been investigating the potential of adding organic wastes (such as food waste) to the sewage solids that are processed in anaerobic digesters (“co- digestion”) at the South Plant. Recent WTD studies have investigated the costs and potential revenues associated with establishing a waste restaurant grease (“brown grease”) receiving facility. Brown grease is typically processed in rendering facilities and/or disposed of in landfills. There is a shortage of facilities that can cost- effectively convert the grease to energy. When restaurant grease is mixed into anaerobic digesters, it can substantially increase the production of valuable biogas that can be used to produce renewable energy. Numerous wastewater treatment facilities have successfully implemented brown grease co-digestion programs. In addition to continuing to assess the benefits of a facility at South Plant, WTD is actively working with private entrepreneurs to determine if the private sector could cost-effectively convert this waste product into renewable energy. WWSP-15: King County will consider development and operation of community treatment systems under the following circumstances: 1. The systems are necessary to alleviate existing documented public health hazards or water quality impairment; 2. Connections to public sewers tributary to conventional wastewater treatment facilities are not technically or economically feasible; 3. Installation of on-site septic systems is not technically feasible; 4. Properties to be served by said systems are within the jurisdiction and service area of a local government authority authorized to provide sewer service; 5. The local sewer service provider agrees to own and operate the collection system tributary The County continues to own and operate the Beulah Park/Cove Treatment Facility on Vashon Island in accordance with this policy. A-34 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 Wastewater Services Policies How Implemented in 2007–2013 to the community treatment system; 6. Development of the community systems and provision of sewer service are consistent with all applicable utility and land use plans; and Public sewer extensions shall be in compliance with King County Comprehensive Plan Policy F-313 as in effect on March 11, 1999. RWSP 2013 Comprehensive Review A-35 Appendix A. RWSP Policies Implementation in 2007−2013 RWSP Water Quality Protection Policies A. Explanatory materials. The water quality protection policies are intended to guide King County in identifying and resolving regional water quality issues, protecting public and environmental health and protecting the public’s investment in wastewater facilities and water resource management. Research and analysis are required and will be used to evaluate water quality in county streams and other bodies of water within the service district. Water Quality Protection Policies How Implemented in 2007–2013 WQPP-1: King County shall participate in identifying and resolving water quality issues pertaining to public health and ecosystem protection in the region to ensure that the public's investment in wastewater facilities and water resource management programs is protected. King County monitors the waters and sediments near treatment plant and CSO outfalls to ensure compliance with water quality regulations and to quickly identify and resolve water quality issues. King County’s Trouble Call Program responds to water quality emergencies in King County. The primary role of this program is to support WTD. The program also investigates activities such as illegal spills, dump sites, construction erosion and sediment control problems, unknown discharges from outfalls, algal blooms, and fish kills. The program’s mission is to respond, investigate, and work cooperatively with agencies on water quality complaints and emergency environmental situations within the greater King County region. More information on the program is available at http://www.kingcounty.gov/environment/wlr/sections- programs/environmental-lab/trouble-call.aspx. WQPP-2: King County shall evaluate the impacts and benefits of actions that affect the quality of the region’s waters and identify measures to meet and maintain water quality standards. WTD builds, operates, and maintains wastewater facilities to ensure the County meets or exceeds water quality regulations and standards, such as NPDES discharge limitations. In 2007 through 2012, West Point and South treatment plants received the National Association of Clean Water Agencies (NACWA) Platinum Peak Performance Award each year for operating multiple consecutive years of compliance with NPDES permit effluent limits. The Vashon Treatment Plant received NACWA’s Silver Peak Performance Award in 2010 and the Gold Award in 2011 and 2012. NACWA’s Silver Awards are presented to facilities with no more than five NPDES violations in a year and Gold Awards are presented to facilities with no NPDES permit effluent limit violations in a year. In 2011, the Vashon Plant had one effluent limit violation because of a pH exceedance that occurred on December 12, and in 2012, the plant earned Ecology’s “Outstanding Performance Award” for meeting all the conditions of its NPDES permit with no violations of any kind. The Vashon Plant met its NPDES permit effluent requirements in 2007 through 2009. The Carnation Treatment Plant received NACWA’s Gold Award in 2010 and 2012, and the Silver Award in 2011. In 2011, the plant exceeded its reclaimed water A-36 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 Water Quality Protection Policies How Implemented in 2007–2013 permit instantaneous maximum turbidity limits on two days in March. All of the County’s treatment plants met their NPDES permit effluent limits in 2013. At the time of publication of this report, NACWA had not awarded its peak performance awards for 2013. The County’s CSO Control Program, Protecting Our Waters, and amended long-term CSO control plan is designed to protect water quality in the water bodies where the County’s CSOs discharge. The County is on schedule to meet all the milestones associated with its CSO Control Program and consent decree to ensure all the County’s CSOs are controlled by 2030. About one- half of the County’s CSOs are controlled to the state standard of one untreated overflow from each location per year on average. Construction is under way on four CSO control projects along Puget Sound beaches, and work has begun on two CSO control projects in the Lower Duwamish Waterway that were approved by the County Council in 2012 as part of the County’s amended long-term CSO control plan. WQPP-3: King County shall forecast future aquatic resource conditions that may affect wastewater treatment decisions and work cooperatively to identify cost-effective alternatives to mitigate water quality problems and enhance regional water quality. King County routinely monitors and models the condition of County water resources and uses information from these efforts and from other programs in the region to identify trends. The Water Quality Assessment And Monitoring Study that is under way and was approved through Ordinance 17413 aligns with this policy. The assessment is examining local water quality concerns near King County CSOs in Elliott Bay, Lake Union/Ship Canal, and the Duwamish River. WQPP-4: King County shall participate with its regional partners to identify methods, plans and programs to enhance water quality and water resources in the region. King County works with other entities in the region on water quality monitoring and protection programs, including cities, Tribes, and state and federal agencies. The County monitoring data is routinely used by Ecology when they present monitoring results in the Puget Sound region. The County continues to work with Ecology and local jurisdictions on developing and implementing Total Maximum Daily Loads for impaired surface waters and to develop a more coordinated ambient monitoring program. Since 2008, multiple agencies and organizations, including the County, are participating in a regional stormwater monitoring coordination effort to ensure cost efficiencies and avoid duplication in the monitoring programs. The regional monitoring recommendations have been incorporated into stormwater NPDES permits for jurisdictions. The County also participates on coordination committees regarding toxic chemical monitoring, marine water quality monitoring, and RWSP 2013 Comprehensive Review A-37 Appendix A. RWSP Policies Implementation in 2007−2013 Water Quality Protection Policies How Implemented in 2007–2013 freshwater monitoring. The County continues to provide technical assistance to the Puget Sound Partnership (PSP). The County also participates in the South Central Caucus Group, which is the local integrating organization (LIO), for PSP’s South Central Puget Sound Action Area and the Snohomish-Stillaguamish LIO, which is one of the LIOs for the PSP’s Whidbey Action Area. WQPP-5: The King County executive shall implement a comprehensive water quality monitoring program of streams and water bodies that are or could be impacted by influent, effluent, sanitary system overflows or CSOs. The range of data to be gathered should be based on water pollutants and elements that scientific literature identifies as variables of concern, what is needed to substantiate the benefits of abating combined sewer overflows and what is required by state and federal agencies. The executive shall submit summary reports and comprehensive reviews of this information to the King County council as outlined in K.C.C. 28.86.165. A summary report on the County’s comprehensive water quality monitoring program is provided in the RWSP annual reports. Monitoring results are also provided annually in the environmental indicator tab of the County’s Department of Natural Resources and Parks KingStat website at http://your.kingcounty.gov/dnrp/measures/. WQPP-6: King County shall implement and maintain water quality, monitoring, evaluating and reporting programs to support the national pollutant discharge elimination system for wastewater and other permit applications, and ensure permit compliance. King County has ongoing monitoring programs that assess discharge quality for permit compliance. Ambient water and sediment quality monitoring provides background information and assists in identifying any adverse impacts from wastewater facilities. The specific programs that were under way in this timeframe and support the regional wastewater treatment system’s needs are as follows: • Marine water quality monitoring, including routine offshore and nearshore water quality, continuous water quality, and sediment quality in King County’s marine waters • Lake Union, Lake Washington, and Lake Sammamish water quality monitoring, including routine water quality and continuous water quality • Stream water quality monitoring in Water Resource Inventory Areas (WRIAs) 8 (greater Lake Washington watershed) and 9 (Green/Duwamish watershed) and on Vashon Island, including routine water quality, stream benthos (bottom-dwelling organisms), and pollution source identification • Streamflow and temperature monitoring in WRIAs 8 and 9 • Freshwater swimming beach monitoring in WRIAs 8 and 9 • Toxics and contaminant assessment in fish tissue in Lake Washington and addressing new and emerging A-38 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 Water Quality Protection Policies How Implemented in 2007–2013 contaminants of concern • Watershed impact assessment/management support affecting the WTD service area. In response to a proviso in the 2012 King County Budget, a report on King County’s water quality monitoring was provided to the King County Council in April 2012. The report is available at http://green.kingcounty.gov/WLR/Waterres/StreamsDat a/pdf/King-County-WTD-Proviso-Final-4-18-12.pdf. WQPP-7: King County shall actively participate in the development of water quality laws, standards and program development to ensure cost-effective maintenance or enhancement of environmental and public health. The County regularly participates in the development of effective and reasonable regulations, both on its own and through professional organizations such as NACWA, Water Environment Federation, Water Reuse Association, and Pacific Northwest Clean Water Association. The County participates in advisory groups, contributes technical information, and reviews and comments on proposals. County staff has also been participating in nationwide discussions on emerging chemicals of concerns. The County participates on committees associated with Ecology’s water quality related rule-making processes and efforts to update water quality standards. For example, the County is a member of Ecology’s “Delegate’s Table” that was formed in 2012 to provide advice and perspective to Ecology on the water quality standards rule-making process that is under way. The County also participated in Ecology’s reclaimed water rule-making process, which was suspended in 2010. In addition, the County has been working closely with Ecology and the U.S. Environmental Protection Agency (EPA) in developing and evaluating Lower Duwamish Superfund cleanup options. WQPP-8: King County shall assess the risk to human health and the environment from wastewater treatment and conveyance activities, and use this information in evaluating water pollution abatement control options. Results of the water quality monitoring activities described in WQPP-6 help to inform WTD of any risks to public health and environment from its facilities. WTD operates and maintains its facilities to ensure they are operating well and meet or exceed permit and other requirements that are designed to protect public health and the environment. In addition, during design and construction of wastewater facilities, WTD works with the affected communities and regulatory agencies to ensure measures are taken to minimize adverse impacts to the public or the environment during construction or operations. RWSP 2013 Comprehensive Review A-39 Appendix A. RWSP Policies Implementation in 2007−2013 RWSP Wastewater Planning Policies A. Explanatory material. The wastewater planning policies are intended to guide the county in its long- term comprehensive planning for design and construction of facilities that meet the wastewater needs of customers within the service area. Recognizing that the RWSP is a complex and dynamic comprehensive development guide that will regularly need to be updated, the county will conduct annual reviews of plan implementation and its consistency with policies, and of scientific, economic and technical information as well as periodic comprehensive reviews of the assumptions on which the RWSP is based. These policies also express the intent of the council to request that the RWQC continue review of the conditions and assumptions that guide the implementation of the RWSP. Wastewater Planning Policies How Implemented in 2007–2013 WWPP-1: King County shall plan comprehensively to provide for the design and construction of facilities that meet the wastewater system needs of the service area and shall coordinate with other local jurisdictions to ensure that construction-related disruption to neighborhoods is minimized. WTD considers several factors to ensure comprehensive wastewater planning. Flow monitoring and facilities inspections provide key information related to capacity, maintenance, and asset replacement needs. WTD reviews population and employment forecasts, water conservation and water use assumptions, and rainfall data and then incorporates updated information into its planning of facilities. In addition, WTD reviews the comprehensive plans of its local agencies and meets with representatives of those agencies to confirm planning assumptions as well as to coordinate construction related activities. WTD regularly works with permitting agencies, local jurisdictions, and affected neighbors during the planning, design, and construction of projects to minimize construction related disruptions. Agreements related to hours of construction, parking for construction workers, noise control, and traffic control measures often result from these efforts. WWPP-2: In planning future wastewater systems, King County shall make a long-term assessment of wastewater system needs. To protect public health and water quality, it is essential to plan wastewater facilities before they are needed. Current planning takes into account a 50- year planning horizon from the base year 2010. This means that 2060 represents the year that WTD assumes that all the sewerable portions of the County’s service area will be sewered. However, WTD expects the population in its service area to continue to increase after 2060. To ensure that existing and planned facilities will meet future needs, the County monitors population and employment forecasts, comprehensive plans of the local agencies, the potential for new regulations, new technologies, and information relating to climate change. WWPP-3: In planning for facilities, King County shall work collaboratively with other jurisdictions and look for opportunities to WTD coordinates with local jurisdictions and agencies during planning and implementation of projects. Examples during the 2007−2013 timeframe are as A-40 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 Wastewater Planning Policies How Implemented in 2007–2013 achieve cost-savings. follows: • Update of RWSP planning assumptions. WTD coordinated closely with the Engineering and Planning Subcommittee of MWPAAC and individual local agencies during the review and update of the RWSP planning assumptions for the RWSP 2013 comprehensive review. • Skyway initial I/I reduction project. This project was managed and funded by King County in partnership with the Skyway Water and Sewer District. As part of the cost-share agreement, the project rehabilitated mains and manholes in the project basin at the District's cost. • Bellevue Influent Trunk project. This project was completed in 2012. It included design and construction of a new portion of the City of Bellevue’s West Central Business District (CBD) Trunk. Under a cost-share agreement, the City of Bellevue covered the costs associated with the improvements to the CBD Trunk and shared a portion of the design, construction, and staff labor costs. • Ballard Siphon Replacement project. Coordination within WTD also provides opportunities for cost-savings. Control of the Ballard CSO was incorporated into this project, which was completed in 2013. • Long-term CSO control plan. The County worked closely with the City of Seattle during development of the County’s amended long-term CSO control plan, which was approved by the County Council in September 2012. Three of the nine CSO control projects that were approved are identified as potential joint projects with Seattle to control both agencies’ CSOs in the 3rd Ave W, University, and Montlake CSO basins. Five small transfers of flows from Seattle projects to the King County system have also been identified; the City would reimburse the County for any O&M costs associated with these flows. The County and City continue to discuss the potential for these joint projects. • RainWise. Over 250 rain gardens and cisterns are now helping to control stormwater runoff and preventing CSOs as part of the RainWise Program in Seattle. Seattle Public Utilities (SPU) started the successful program in 2010 to pay for rain gardens and cisterns on private property in some parts of the city. WTD is now also offering the RainWise Program to homeowners through a memorandum of agreement with the SPU; the RWSP 2013 Comprehensive Review A-41 Appendix A. RWSP Policies Implementation in 2007−2013 Wastewater Planning Policies How Implemented in 2007–2013 agreement outlines the cost-sharing and other responsibilities of each agency. • Lower Duwamish Waterway Superfund cleanup. The County is an active participant in the Lower Duwamish Waterway Group (LDWG), which consists of King County, the City of Seattle, the Port of Seattle, and the Boeing Company. The LDWG has been working with EPA and Ecology since 2001 to study contamination and determine the best and most effective alternatives to clean up the LDW. WWPP-4: Facility sizing shall take into account the need to accommodate build-out population. As noted in WWPP-2, current planning considers needs over a 50-year planning horizon, through 2060. The year 2060 represents when potentially sewerable portions of the County’s service area are expected to be sewered. WTD evaluated regional treatment plant capacity needs through 2060 as part of the process to complete the RWSP 2013 comprehensive review. The 2015 CSI program update will evaluate and identify separated conveyance system capacity needs over a 50-year planning horizon, through 2060. WWPP-5: RWSP review processes. King County shall monitor the implementation of the RWSP and conduct reviews of the RWSP as outlined in K.C.C. 28.86.165. During 2007−2013, RWSP annual reports were submitted in accordance with the reporting policies outlined in K.C.C. 28.86.165. The RWSP 2013 comprehensive review has been completed following the guidance provided in K.C.C. 28.86.165. A-42 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 RWSP Environmental Mitigation Policies A. Explanatory material. The environmental mitigation policies are intended to guide King County in working with communities to develop mitigation measures for environmental impacts from the construction and operation of wastewater facilities. These policies also ensure that the siting and mitigation processes for wastewater facilities are consistent with the Growth Management Act and the state Environmental Policy Act. Environmental Mitigation Policies How Implemented in 2007–2013 EMP-1: King County shall work with affected communities to develop mitigation measures for environmental impacts created by the construction, operation, maintenance, expansion or replacement of regional wastewater facilities. These mitigation measures shall: 1. Address the adverse environmental impacts caused by the project; 2. Address the adverse environmental impacts identified in the county’s environmental documents; and 3. Be reasonable in terms of cost and magnitude as measured against severity and duration of impact. During the planning, design and construction of projects, WTD works with permitting and regulatory agencies, local jurisdictions, tribes, and affected businesses and residents to identify measures to avoid and minimize environmental impacts that could result from the construction, operation, maintenance, and expansion or replacement of regional wastewater facilities. Adverse environmental impacts and associated mitigation are typically identified during project review under the State Environmental Policy Act and consultations or reviews required by local, state and federal regulations (such as Endangered Species Act and National Historic Preservation Act). Examples of mitigation related activities that occurred in 2007–2013 are as follows: • Barton Pump Station Upgrade project. Construction impacts associated with this project include temporary closure of a Fauntleroy Ferry Terminal toll collection lane and the release of odorous air when the pump station wetwell was exposed. To address these impacts, the County worked with Washington State Ferries to develop an operational strategy (such as closing the ferry lane only during non-peak use times) and agreed on traffic control plans to minimize impacts to ferry traffic. To minimize odor impacts during construction, an aboveground temporary odor control unit will be located at the project site to treat foul air from the wetwell. Following construction, part of the site will be restored for use as a street-end park containing a community- maintained garden and artwork and providing beach access. The County incorporated community input into the landscaping plan for the site and measures for protecting and replacing artwork. • Barton CSO Control project. The County proposed construction rain of gardens, a low impact development approach, for controlling CSOs in the Barton basin rather than constructing a large tank that would have had a higher potential for adverse environmental impacts. The County responded to community RWSP 2013 Comprehensive Review A-43 Appendix A. RWSP Policies Implementation in 2007−2013 Environmental Mitigation Policies How Implemented in 2007–2013 concerns by reducing the number of proposed curb extensions and locating rain gardens on one side of the street instead of both to preserve mature trees. The County is minimizing impacts by phasing construction. • Murray CSO Control project. Based on community feedback received during predesign, the County decided to locate the CSO storage facility on private properties occupied by residential buildings rather than in a public park. Mitigation included compensation to property owners for fair market value of the properties and relocation benefits to eligible tenants. Project design elements were developed by a professional artist and landscape architect with input by community members to address concerns about potential aesthetic impacts. Design elements include the provision of public access to portions of the project site, maintenance of Puget Sound views from publicly accessible areas, finishes and landscaping that have a more park-like than industrial feel, and redesign of Beach Drive to discourage through- traffic. • North Beach CSO Control project. Based on community feedback received during predesign and design, the County located the CSO storage facility below an existing street and configured it so as to minimize impacts to residential and park access during construction. A new permanent aboveground ancillary equipment facility was situated on the project site and designed so that it would not block views of Puget Sound from nearby residences. The County worked with the City of Seattle on a street restoration plan to ensure that the design addressed community’s concerns. The City proposed new street lights, but did not require them after the County conveyed the community’s concerns about light pollution in the residential area that currently has unobstructed views of Puget Sound. The street restoration plan also included reconfiguration of the intersection in which the storage facility is located to increase pedestrian and vehicle safety. • Kent/Auburn Conveyance System Improvement project. The County developed traffic control plans for this trenched pipeline installation project. The plans included traffic and pedestrian detour routes, flaggers, notice to businesses, residences, and a school of times when construction would be nearby. The County minimized the impact of trenching through a school playground by performing the work during A-44 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 Environmental Mitigation Policies How Implemented in 2007–2013 the summer. A professional archaeologist monitored activities in culturally sensitive project areas. EMP-2: Mitigation measures identified through the state Environmental Policy Act process shall be incorporated into design plans and construction contracts to ensure full compliance. This policy is implemented for every project that undergoes the SEPA review process. WTD environmental planners prepare checklists and review construction plans and specifications to make sure mitigation measures are included in these documents. Typical mitigation measures included in SEPA checklists for WTD projects include the following: • Temporary erosion and sedimentation control measures during project construction • Measures to minimize noise, such as mufflers or sound barriers • Landscaping and architectural features to help a facility blend into the surrounding area • Actions to minimize light and glare • Construction traffic routing and parking plans EMP-3: The siting process and mitigation for new facilities shall be consistent with the Growth Management Act and the state Environmental Policy Act, as well as the lawful requirements and conditions established by the jurisdictions governing the permitting process. Wastewater treatment facilities are considered essential public facilities under the Growth Management Act. WTD plans new facilities or upgrades to existing facilities to ensure capacity is available when needed. Environmental, community, cost, right-of-way, and regulatory considerations are included in the process to site new wastewater facilities. WTD staff works with permitting agencies and local jurisdictions to ensure projects and facilities comply with applicable requirements and conditions. EMP-4: King County shall mitigate the long- term and short-term impacts for wastewater facilities in the communities in which they are located. The county’s goal will be to construct regional wastewater facilities that enhance the quality of life in the region and in the local community, and are not detrimental to the quality of life in their vicinity. King County is committed to being a good neighbor with its wastewater facilities. The examples provided in EMP-1 align with this policy. RWSP 2013 Comprehensive Review A-45 Appendix A. RWSP Policies Implementation in 2007−2013 Environmental Mitigation Policies How Implemented in 2007–2013 EMP-5: King County shall enter into a negotiated mitigation agreement with any community that is adversely impacted by the expansion or addition of major regional wastewater conveyance and treatment facilities. Such agreements shall be executed in conjunction with the project permit review. Mitigation shall be designed and implemented in coordination with the local community, and shall be at least ten percent of the costs associated with the new facilities. For the south treatment plant and for the new north treatment plant, a target for mitigation shall be at least ten percent of individual project costs, or a cumulative total of ten million dollars for each plant, whichever is greater, provided that mitigation funded through wastewater revenues is consistent with: chapter 35.58 RCW; Section 230.10.10 of the King County Charter; agreements for sewage disposal entered into between King County and component agencies; and other applicable county ordinance and state law restrictions. This policy was written with the construction of a new third regional treatment system (now known as the Brightwater Treatment System) and the anticipated full future expansion of the South Plant in mind. The Brightwater systemwide mitigation package that has been implemented complied with this policy. A-46 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 RWSP Public Involvement Policies A. Explanatory material. The public involvement policies are intended to guide the county in maintaining public information and education programs and to engage the public and component agencies in planning, designing and operating decisions that affect them. Public Involvement Policies How Implemented in 2007−2013 PIP-1: King County shall maintain public information/education programs and engage the public and component agencies of local sewer service in the planning, designing and operating decisions affecting them. WTD holds monthly meetings MWPAAC to share information with local agencies on programs and projects that are at various stages of planning and implementation. WTD routinely engages public officials and residents in the planning and decision-making process for its projects and programs. Here are some examples of how the public influenced WTD decisions: • With the help of a group of educators who raised more than $1 million, the Brightwater Center achieved platinum LEED status. The Brightwater Center is an environmental education and community center built to replace a grange hall on the Brightwater site. • 53rd Avenue Pump Station improvements were designed to expand the facility underground in order to maintain neighborhood views. • As part of the Ravenna Creek Pipe Extension, WTD removed invasive weeds and replaced native plants in some areas around the Ravenna Creek Daylighting Project in the south end of Ravenna Park. • Neighbors of the Murray Pump Station worked with WTD designers to minimize the “industrial facility” feel, encourage views of Puget Sound, discourage through-traffic on Beach Drive, and enhance continuous space between Lowman Beach Park and the facility site. • WTD responded to a West Seattle community’s concerns by minimizing the number of blocks and the number of parking spaces required for a GSI project. Neighbors have input on street trees and many want a rain garden on their own property. • MWPAAC participated in the process to amend the CSO control plan in 2012. Members also provided significant input on the proposed CSO control policy updates that were developed to be consistent with the CSO control plan and the CSO consent decree. These CSO control policies were approved by the King County Council in May 2013. • Industrial waste customers provided advice on policies, procedures, and program priorities RWSP 2013 Comprehensive Review A-47 Appendix A. RWSP Policies Implementation in 2007−2013 Public Involvement Policies How Implemented in 2007−2013 through an advisory committee, customer survey, and program workshops. PIP-2: King County shall develop public information and education programs to support county wastewater programs and shall lay the groundwork for public understanding of and involvement in specific programs. WTD places high importance on educating the public regarding the wastewater system, projects and services. Innovations in 2007−2013 include the following: • WTD’s website transitioned to a new domain www.kingcounty.gov in 2007−2008 and was improved to make it more user-friendly and informative. The website includes information on the county’s wastewater system and process, programs planned for the future, projects in design and construction, and the sewer rate and the capacity charge. • The status of King County and Seattle CSOs is now on the web in real time. King County worked with Seattle in 2011 to bring its overflow information into the County’s website in order to streamline the public’s access to the information. http://www.kingcounty.gov/environment/wastewat er/CSOstatus.aspx • The King County Equity and Social Justice Ordinance (launched as in initiative in 2008) has shaped the way WTD implements the public involvement policies. Information is being provided in multiple languages, and other techniques are being used to reach people who might not have traditionally participated in these processes. • WTD has been expanding its use of social media tools to include Facebook, Twitter, U-tube, Vimeo, and Flickr. Ongoing activities from 2007−2013 include the following: • Public information and outreach: web pages, open houses, information booths, displays, speakers bureau, wastewater treatment facility tours, and education partnerships. • Two-way dialogue: briefings, 24-hour hotlines, advisory groups, public meetings, canvassing neighborhoods with fliers, newsletters, mailings, response to inquiries, on-line forms. • Response to odor complaints within two hours. • Response to over 15,000 customer calls every year from ratepayers about the monthly sewer and capacity charge rates. • Outreach to industrial businesses regarding federal and King County pretreatment regulations, policies, and procedures: meetings, A-48 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 Public Involvement Policies How Implemented in 2007−2013 newsletters, fact sheets and web page with easy access to tools and forms. • Media relations to keep local news media informed about WTD projects and programs that affect the neighborhoods they serve and provide general information on the wastewater system. See PIP-5 for more information on WTD’s educational programs. PIP-3: King County shall involve public officials and citizens of affected jurisdictions early and actively in the planning and decision-making process for capital projects. A public involvement initial needs assessment is conducted at the beginning of every WTD capital project to assess opportunities for early and active involvement. The assessment is used to tailor public involvement plans for specific projects. Examples of how early, active involvement shaped capital projects are as follows: • Public officials and the public had many opportunities to comment on and shape the 2012 CSO Control Program review. Information was available through briefings, presentations, and workshops; in public libraries; and on the W eb. Materials were available in five languages. http://www.kingcounty.gov/environment/wastewat er/CSO/ProgramReview.aspx • Our Duwamish is a website designed to provide one location for information on all the services King County provides in the Duwamish area and links to opportunities to comment on EPA’s Superfund cleanup plan. http://www.kingcounty.gov/environment/watershe ds/green-river/OurDuwamish.aspx • In 2013, outreach was under way in the Duwamish area, where WTD has large CSO control projects (Brandon-Michigan, Hanford) planned over the next several years. While continuing to maintain existing relationships, WTD is also reaching out to diverse community leaders, offering treatment plant tours to area schools, and developing multi-lingual tools to help implement these projects. PIP-4: King County shall inform affected residents and businesses in advance of capital construction projects. WTD construction teams include community relations experts to inform affected residents and businesses in advance of capital construction projects and respond to questions and concerns. Typical activities include pre-construction meetings, fliers, web updates, signs, direct on-the-ground contact, and 24-hour project hotlines. Procedures are in place to document and track questions, concerns, or complaints, and ensure prompt response. Lessons-learned evaluations are conducted to identify what has worked and to apply the lessons to other projects. RWSP 2013 Comprehensive Review A-49 Appendix A. RWSP Policies Implementation in 2007−2013 Public Involvement Policies How Implemented in 2007−2013 This website explains how WTD works with the public throughout the stages of a capital project from planning to construction to operation. http://www.kingcounty.gov/environment/wtd/Constructi on/phases.aspx WTD provides construction information in multiple languages to reach everyone in affected neighborhoods. For example, construction information was provided in Russian and English during the Bellevue Influent Trunk project (completed in 2012). http://www.kingcounty.gov/environment/wtd/Constructi on/Completed/BellevueInfluentTrunk.aspx In 2012, routine construction specifications were updated so that solutions to some typical community impacts are automatically included when a contract is bid. This ensures all communities have the same level of consideration and improves service for everyone, including communities who may have linguistic or other challenges communicating with the County. PIP-5: King County shall disseminate information and provide education to the general public, private sector and governmental agencies regarding the status, needs and potential future of the region's water resources. WTD reached significant information and education milestones between 2007−2013: • A new partnership with Cascadia Community College began in 2012 to provide training for future treatment plant operators. http://www.cascadia.edu/programs/degrees/water quality.aspx • In 2011, WTD celebrated the Brightwater Grand opening. More than 2000 people (general public; private sector and governmental agencies) attended the event and learned about the status and potential future of the region’s water resources. • In 2011, the Brightwater Center opened and began offering significant programming about water resources through educational partnerships with IslandW ood and other organizations. The center includes an interactive display hall. In the first year of operation the center reached approximately 4,000 4th−8th graders in school programs, 300 participants in family programs, and 150 teachers in professional development workshops. • King County’s new biosolids brand Loop® was introduced to the public at the 2012 Flower and Garden Show. King County biosolids have been a key ingredient in compost available at the show for decades. • Since 2010, King County, Seattle University and the Salvation Army Renton Food Bank have partnered on a five-year community farm project A-50 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 Public Involvement Policies How Implemented in 2007−2013 located on an acre of the South Treatment Plant, demonstrating the use of GroCo compost made with Loop biosolids and increasing public understanding of the benefits of nutrient recycling. http://www.kingcounty.gov/environment/wtd/Educ ation/SouthPlant/RRdemoprojects.aspx Continuing programs include the following: • Treatment plant tours. Over 3,000 students and hundreds of other interested parties annually learn the importance of water conservation and the process of wastewater treatment by touring a treatment plant. • Treatment plant open houses. Members of the public are invited to tour the Brightwater Treatment Plant one Saturday every month. Tours at other treatment plants are scheduled each year in conjunction with World Water Day (March) and World Toilet Day (November) and upon request. All of these events feature water conservation, water quality, and wastewater treatment information. Key educational materials include the following: • Let’s Talk Trash brochures and posters. These materials, designed to prevent trash in the wastewater system, are available in six languages. http://www.kingcounty.gov/environment/wtd/Educ ation/ThingsYouCanDo/TalkTrash.aspx • Ratepayer report. This is a detailed report for the general public about the services WTD provides. It is updated each time the rate is changed. http://www.kingcounty.gov/environment/wtd/Abou t/Finances/RatePayerReport.aspx • New materials describing the quality and effectiveness of Loop biosolids are available at http://www.loopforyoursoil.com/. PIP-6: King County shall actively solicit and incorporate public opinions throughout the implementation of its comprehensive plan. The activities described in PIP-1 through PIP-5 illustrate how WTD keeps people informed and involved in the projects and programs associated with implementing the RWSP. WTD solicits public feedback and opinion in its the bi- annual water quality surveys, bi-annual surveys of near neighbors of the regional treatment plants, capital project surveys, public meetings, open houses, and informational booths. Opportunities for public comment are also provided via WTD project websites, emails, letters, and phone calls. RWSP 2013 Comprehensive Review A-51 Appendix A. RWSP Policies Implementation in 2007−2013 Public Involvement Policies How Implemented in 2007−2013 PIP-7: Beginning January 1, 2001, King County shall implement a public awareness and education program regarding the environmental impacts and costs to wastewater rate payers of I/I in the local and regional conveyance systems. WTD’s I/I website provides detailed information on I/I, how it is found and fixed, and what people can do to help. http://www.kingcounty.gov/environment/wastewater/II. aspx WTD serves as a clearinghouse regarding information on technologies related to I/I reduction; this information is made available to MWPAAC members. From 2007−2012, members of the Skyway community participated in intensive public involvement associated with construction of a pilot I/I project. http://www.kingcounty.gov/environment/wastewater/II/ InitialProjects/Skyway.aspx . Meetings, newsletters, door-to-door fliers, and response to complaints and inquiries included education about the impacts of I/I on the wastewater system. Community members in Bellevue and Issaquah received significant I/I information until Skyway was selected for the pilot project. A post-construction survey of Skyway residents illustrated a high level of understanding of the I/I problem. The survey showed that 61 of 63 respondents (97 percent) recalled getting information about the project before it began, and 62 of the 63 respondents (98.5 percent) understood the purpose of the project and the benefit to the area. PIP-8: King County shall support regional water supply agencies and water purveyors in their public education campaign on the need and ways to conserve water. King County should promote pilot projects that support homeowner water conservation in coordination with water suppliers and purveyors, emphasizing strategies and technologies that reduce wastewater. Water conservation is a key theme for all of WTD’s outreach and education efforts, including Brightwater Center activities, open houses, informational booths, public meetings, and school outreach. It is embedded in a number of the “things you can do” to protect the environment featured on the web site. http://www.kingcounty.gov/environment/wtd/Education /ThingsYouCanDo.aspx Water conservation is a major theme in the Brightwater Center displays, including signs informing visitors about the use of reclaimed water on site. Because Brightwater is in its service area, Cross Valley Water District had input on the displays developed for the center. A-52 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 RWSP Financial Policies A. Under the provisions of the King County Charter and RCW 35.58.200, these financial policies are hereby adopted and declared to be the principal financial policies of the comprehensive water pollution abatement plan for King County, adopted by the Municipality of Metropolitan Seattle (Metro) in Resolution No. 23, as amended, and the RWSP, a supplement to the plan. B. Explanatory material. 1. Financial forecast and budget. Policies FP-1 through FP-10 are intended to guide the county in the areas of prudent financial forecasting and budget planning and are included to ensure the financial security and bonding capacity for the wastewater system. This set of policies also addresses the county’s legal and contractual commitments regarding the use of sewer revenues to pay for sewer expenses. 2. Debt financing and borrowing. Policies FP-11 through FP-14 are intended to guide the county in financing the wastewater system capital program. These policies direct that capital costs be spread over time to keep rates more stable for ratepayers by the county issuing bonds. A smaller share of annual capital costs will be funded directly from sewer rates and sewer revenues and capacity charges. 3. Collecting revenue. Policies FP-15 through FP-17 are intended to guide King County in establishing annual sewer rates and approving wastewater system capital improvement and operating budgets. Monthly sewer rates, which are the primary source of revenue for the county’s regional wastewater system, are to be uniformly assessed on all customers. Customers with new connections to the wastewater system will pay an additional capacity charge. The amount of that charge is set by the council, within the constraints of state law. 4. Community treatment systems. Policy FP-18 is intended to guide the county in the financial management of community treatment systems. Financial Policies How Implemented in 2007–2013 FP-1: The county shall maintain for the wastewater system a multiyear financial forecast and cash-flow projection of six years or more, estimating service growth, operating expenses, capital needs, reserves and debt service. The financial forecast shall be submitted by the executive with the annual sewer rate ordinance. A six-year financial plan is submitted each year with the WTD sewer rate proposal and again with the annual budget proposal. The financial plan is also updated for each new bond issue or bond refunding. FP-2: If the operations component of the proposed annual wastewater system budget increases by more than the reasonable cost of the addition of new facilities, increased flows, new programs authorized by the council, and inflation, or if revenues decline below the financial forecast estimate, a feasible alternative spending plan shall be presented, at the next quarterly budget report, to the council by the executive identifying steps to reduce cost increases. There were no occurrences of the situation described in FP-2 in 2007–2013, nor are any anticipated for the near-term. If such a situation were to occur, this policy would be implemented. RWSP 2013 Comprehensive Review A-53 Appendix A. RWSP Policies Implementation in 2007−2013 Financial Policies How Implemented in 2007–2013 FP-3: The executive shall maintain an ongoing program of reviewing business practices and potential cost-effective technologies and strategies for savings and efficiencies; the results shall be reported in the annual budget submittal and in an annual report to the RWQC. Results of WTD’s Productivity Initiative Pilot Program, a 10-year incentive program, was reported annually in RWSP annual reports. In addition, an annual report was submitted to the King County Council. The pilot program ended in April 2011. The program generated nearly $84 million in savings for ratepayers. As part of WTD’s continuous improvement efforts and the Executive’s Efficiency Initiative, WTD has implemented a Bright Ideas program, which encourages creative problem-solving throughout the organization and uses employees’ ideas to improve how WTD does business. Information on this program is included as part of the annual sewer rate submittal to the King County Council. FP-4: New technologies or changes in practice that differ significantly from existing technologies or practices shall be reported to the council and RWQC with projected costs prior to implementation and shall also be summarized in the RWSP annual report. No major changes in wastewater technologies or practices were implemented during this timeframe. FP-5: Significant new capital and operational initiatives proposed by the Executive that are not within the scope of the current RWSP nor included in the RWSP, or are required by new state or federal regulations will be reviewed by the RWQC and approved by the council to ensure due diligence review of potential impacts to major capital projects' schedules, including Brightwater, the bond rating or the sewer rate and capacity charge. All capital and operational costs are reviewed as part of the annual budget adoption process. No initiatives of this type were included in either the capital or operating budget requests in this timeframe. Brightwater began full operations on October 29, 2012. FP-6: The county shall maintain for the wastewater system a prudent minimum cash balance for reserves, including but not limited to, cash flow and potential future liabilities. The cash balance shall be approved by the council in the annual sewer rate ordinance. Since 2007, the bond ratings of the wastewater system have been upgraded. The rating from Moody’s has been upgraded twice from A1 to Aa2 and the rating from Standard’s and Poor’s has been upgraded once from AA to AA+. FP-7: Unless otherwise directed by the council by motion, the King County department of natural resources and parks or its successor agency shall charge a fee that recovers all direct and indirect costs for any services related to the wastewater system provided to other public or private organizations. All work performed by WTD for other public or private organizations has required the recovery of all direct and indirect costs. FP-8: Water quality improvement activities, programs and projects, in addition to those that are functions of sewage treatment, may be eligible for funding assistance from sewer rate revenues after consideration of criteria and limitations suggested by the metropolitan water pollution abatement advisory committee, and, if The 1.5 percent of annual operating budget limit on “Culver” funds had been strictly adhered to when such funding was approved in the annual rate process. This funding was eliminated from the 2011, 2012, 2013, and 2014 rate submittals. As part of the 2015 rate submittal, the County Executive has proposed the start-up of “Our Waters” A-54 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 Financial Policies How Implemented in 2007–2013 deemed eligible, shall be limited to one and one half percent of the annual wastewater system operating budget. An annual report on activities, programs and projects funded will be made to the RWQC. Alternative methods of providing a similar level of funding assistance for water quality improvement activities shall be transmitted to the RWQC and the council within seven months of policy adoption. program, which, if approved and implemented, would adhere to this policy. FP-9: The calculation of general government overhead to be charged to the wastewater system shall be based on a methodology that provides for the equitable distribution of overhead costs throughout county government. Estimated overhead charges shall be calculated in a fair and consistent manner, utilizing a methodology that best matches the estimated cost of the services provided to the actual overhead charge. The overall allocation formula and any subsequent modifications will be reported to the RWQC. Overhead costs of King County general government are allocated by the Executive budget office to all parts of the County on a consistent basis. FP-10: The assets of the wastewater system are pledged to be used for the exclusive benefit of the wastewater system including operating expenses, debt service payments, asset assignment and the capital program associated therewith. The system shall be fully reimbursed for the value associated with any use or transfer of such assets for other county government purposes. The executive shall provide reports to the RWQC pertaining to any significant transfers of assets for other county government purposes in advance of and subsequent to any such transfers. No assets were transferred outside of WTD in 2007– 2013. FP-11: The county shall structure bond covenants to ensure a prudent budget standard. Bond covenants are strictly followed, monitored, and revised to maintain prudent and conservative standards. Outstanding bonds are constantly monitored for refunding opportunities to lower interest rates/debt service. See FP-6 regarding the upgrading of WTD’s bond ratings since 2007. FP-12: King County should structure the term of its borrowings to match the expected useful life of the assets to be funded. In 2007, WTD increased the term of bonds issued to 40 years. In addition to moderating the impact to current sewer rates, this provides a better match between the life of the facilities and the debt financing their construction. FP-13: The wastewater system’s capital program shall be financed predominantly by annual staged issues of long-term general obligation or sewer revenue bonds, provided WTD capital expenditures are predominantly funded by the issuance of Sewer Revenue Bonds. Between 2007 and 2013, County General Obligation Bonds have not been a significant portion of new debt RWSP 2013 Comprehensive Review A-55 Appendix A. RWSP Policies Implementation in 2007−2013 Financial Policies How Implemented in 2007–2013 that: All available sources of grants are utilized to offset targeted program costs; Funds available after operations and reserves are provided for shall be used for the capital program; excess funds accumulated in reserves may also be used for capital; Consideration is given to competing demands for use of the county’s overall general obligation debt capacity; and Consideration is given to the overall level of debt financing that can be sustained over the long term given the size of the future capital programs, potential impacts on credit ratings, and other relevant factors such as intergenerational rate equity and the types of projects appropriately financed with long-term debt. issuances. Significant bond refundings occurred between 2011 and 2012. All refinanced revenue bonds have been refunded with new revenue bonds with the same term and at least a present value savings of 5 percent. In some cases, refinanced general obligation bonds have been refunded with new revenue bonds with the same term and at least a present value savings of 5 percent. FP-14: To achieve a better maturity matching of assets and liabilities, thereby reducing interest rate risk, short-term, variable rate borrowing shall be used to fund a portion of the capital program, provided that: Outstanding short-term, variable rate debt comprises no more than twenty percent of total outstanding revenue bonds and general obligation bonds; and Appropriate liquidity is available to protect the day-to-day operations of the system. (Ordinance 17492, approved in December 2012, amended this policy to add the words “variable rate”, and changed the percent amount of allowable outstanding short term, variable debt to comprise twenty [previously it was fifteen] percent of total outstanding revenue bonds and general obligation bonds.) Short-term variable (junior lien) debt is targeted for no more than approximately 20 percent of the total debt issued. Year-end liquidity reserves are targeted at 10 percent of the year’s operating expense total plus $5 million. FP-15: King County shall charge its customers sewer rates and capacity charges sufficient to cover the costs of constructing and operating its wastewater system. Revenues shall be sufficient to maintain capital assets in sound working condition, providing for maintenance and rehabilitation of facilities so that total system costs are minimized while continuing to provide reliable, high quality service and maintaining high water quality standards. 1. Existing and new sewer customers shall each contribute to the cost of the King County maintains a uniform monthly sewer rate in accordance with this policy. The sewer rate is set on an annual basis such that, given projections of other revenues and costs, the revenue requirements for providing wastewater services are met. The rate stabilization reserve allows for excess revenues generated in an earlier year to be treated as operating revenues for the subsequent year. These revenues therefore can be applied directly to debt coverage requirements in the subsequent year, allowing for a reduction of the sewer rate in that subsequent year. The use and planned use of the rate stablization funds are included in annual the rate A-56 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 Financial Policies How Implemented in 2007–2013 wastewater system as follows: a. Existing customers shall pay through the monthly sewer rate for the portion of the existing and expanded conveyance and treatment system that serves existing customers. b. New customers shall pay costs associated with the portion of the existing wastewater conveyance and treatment system that serves new customers and costs associated with expanding the system to serve new customers. New customers shall pay these costs through a combination of the monthly sewer rate and the capacity charge. Such rates and charges shall be designated to have growth pay for growth. 2. Sewer rate. King County shall maintain a uniform monthly sewer rate expressed as charges per residential customer equivalent for all customers. a. Sewer rates shall be designed to generate revenue sufficient to cover, at a minimum, all costs of system operation and maintenance and all capital costs incurred to serve existing customers. b. King County should attempt to adopt a multiyear sewer rate to provide stable costs to sewer customers. If a multiyear rate is established and when permitted upon the retirement by the county of certain outstanding sewer revenue bonds, a rate stabilization reserve account shall be created to ensure that adequate funds are available to sustain the rate through completion of the rate cycle. An annual report on the use of funds from this rate stabilization account shall be provided annually to the RWQC. c. The executive, in consultation with the RWQC, shall propose for council adoption policies to ensure that adequate debt service coverage and emergency reserves are established and periodically reviewed. 3. Capacity charge. The amount of the capacity charge shall be a uniform charge, shall be approved annually and shall not exceed the transmittal financial plan and the annual budget financial plan as required by Governmental Accounting Standards Board (GASB) accounting standards. Information on the rate stabilization account is included in the annual sewer rate briefing to the Regional Water Quality Committee. The debt service coverage minimum is based on meeting two ratios, 1.25 on parity debt (revenue and general obligation bonds) and a target of 1.15 on all debt. The capacity charge is based on the methodology listed in this policy. RWSP 2013 Comprehensive Review A-57 Appendix A. RWSP Policies Implementation in 2007−2013 Financial Policies How Implemented in 2007–2013 cost of capital facilities necessary to serve new customers. The methodology that shall be applied to set the capacity charge is set forth in FP-15.3.a. a. The capacity charge shall be based on allocating the total cost of the wastewater system (net of grants and other non rate revenues) to existing and new customers as prescribed in this subsection. The total system cost includes the costs to operate, maintain, and expand the wastewater system over the life of the RWSP. Total estimated revenues from the uniform monthly rate from all customers and capacity charge payments from new customers, together with estimated non rate revenues, shall equal the estimated total system costs. The capacity charge calculation is represented as follows: Capacity = [Total system costs — rate revenue Charge from existing customers] — Rate revenue from new customers _________________________________ Number of new customers where: (1) total system costs (net of grants and other non rate revenues) minus rate revenue from existing customers equals costs allocated to new customers. (2) costs allocated to new customers minus rate revenue from new customers equals the total revenue to be recovered through the capacity charge. (3) total capacity charge revenue requirements divided by the total number of new customers equals the amount of the capacity charge to be paid by each new customer. b. The capacity charge may be paid by new customers in a single payment or as a monthly charge at the rate established by the council. The county shall establish a monthly capacity charge by dividing that amount by one hundred eighty (twelve monthly payments per A-58 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 Financial Policies How Implemented in 2007–2013 year for fifteen years). The executive shall transmit for council adoption an ordinance to adjust the discount rate for lump sum payment. The executive shall also transmit for council adoption an ordinance to adjust the monthly capacity charge to reflect the county's average cost of money if the capacity charge is paid over time. c. King County shall pursue changes in state law to enable the county to require payment of the capacity charge in a single payment. d. The capacity charge shall be set such that each new customer shall pay an equal share of the costs of facilities allocated to new customers, regardless of what year the customer connects to the system. The capacity charge shall be based upon the costs, customer growth and related financial assumptions used for the Regional Wastewater Services Plan adopted by Ordinance 13680 as such assumptions may be updated. Customer growth and projected costs, including inflation, shall be updated every three years beginning in 2003. e. The county should periodically review the capacity charge to ensure that the actual costs of system expansion to serve new customers are reflected in the charge. All reasonable steps should be taken to coordinate the imposition, collection of and accounting for rates and charges with component agencies to reduce redundant program overhead costs. f. Existing customers shall pay the monthly capacity charge established at the time they connected to the system as currently enacted by K.C.C. 28.84.055. New customers shall pay the capacity charge established at the time they connect to the system. g. To ensure that the capacity charge will not exceed the costs of facilities needed to serve new customers, costs assigned and allocated to new customers shall be at a minimum ninety five percent of the projected capital costs of new and existing treatment, conveyance and biosolids capacity needed to serve new customers. RWSP 2013 Comprehensive Review A-59 Appendix A. RWSP Policies Implementation in 2007−2013 Financial Policies How Implemented in 2007–2013 h. Costs assigned and allocated to existing customers shall include the capital cost of existing and future treatment, conveyance and biosolids capacity used by existing customers, and the capital costs of assessing and reducing infiltration and inflow related to the use of the existing conveyance and treatment capacity. i. Capital costs of combined sewer overflow control shall be paid by existing and new customers based on their average proportionate share of total customers over the life of the RWSP. j. Operations and maintenance costs shall be paid by existing and new customers in the uniform monthly rate based on their annual proportionate share of total customers. k. Any costs not allocated in FP-15.3 f., g., h., i. and j. shall be paid by existing and new customers in the sewer rate. l. Upon implementation of these explicit policies, the Seattle combined sewer overflow benefit charge shall be discontinued. 4. Based on an analysis of residential water consumption, as of December 13, 1999, King County uses a factor of seven hundred fifty cubic feet per month to convert water consumption of volume-based customers to residential customer equivalents for billing purposes. King County shall periodically review the appropriateness of this factor to ensure that all accounts pay their fair share of the cost of the wastewater system. FP-16: The executive shall prepare and submit to the council a report in support of the proposed monthly sewer rates for the next year, including the following information: Key assumptions: key financial assumptions such as inflation, bond interest rates, investment income, size and timing of bond issues, and the considerations underlying the projection of future growth in residential customer equivalents; Significant financial projections: all key projections, including the annual projection of operating and capital costs, debt service All key assumptions, significant financial projections, historical results, and policy options are provided as part of the annual sewer rate submittal letter and attachments. A-60 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 Financial Policies How Implemented in 2007–2013 coverage, cash balances, revenue requirements, revenue projections and a discussion of significant factors that impact the degree of uncertainty associated with the projections; Historical data: a discussion of the accuracy of the projections of costs and revenues from previous recent budgets, and Policy options: calculations or analyses, or both, of the effect of certain policy options on the overall revenue requirement. These options should include alternative capital program accomplishment percentages (including a ninety percent, a ninety-five percent and a one hundred percent accomplishment rate), and the rate shall be selected that most accurately matches historical performance in accomplishing the capital program and that shall not negatively impair the bond rating. FP-17: Expenditures from the wastewater revenues to correct water pollution problems caused by septic systems shall occur only if such expenditures financially benefit wastewater system current customers when the additional monthly sewer rate revenues from these added customers are considered. No expenditures from the wastewater revenue were used for these purposes in 2007−2013. FP-18: The cost of community treatment systems developed and operated in accordance with WWSP-15 would not be subsidized by the remaining ratepayers of the county’s wastewater treatment system. This policy has been adhered to since the adoption of the RWSP. RWSP 2013 Comprehensive Review A-61 Appendix A. RWSP Policies Implementation in 2007−2013 RWSP Reporting Policies A. The executive shall review the implementation of the RWSP on a regular basis and submit the following reports to council and the RWQC: Reporting Policies How Implemented in 2004–2006 A. Regional wastewater services plan annual report. The executive shall submit a written report to the council and RWQC in September each year until the facilities identified in the RWSP are operational. This report, covering the previous year's implementation, will provide the following: 1. A summary of activities for each major component of the RWSP, including treatment, conveyance, infiltration and inflow, combined sewer overflows, water reuse, biosolids and highlights of research and development projects underway and proposed for the coming year; 2. Details on each active RWSP project in the capital budget, including a project summary, project highlights, project issues, upcoming activities, schedules, an expenditures summary including staff labor and miscellaneous services, a description of adjustments to costs and schedule and a status of the projects contracts; 3. A status of the odor prevention program, including a listing and summary of odor complaints received and progress on implementing odor prevention policies and projects; 4. A summary of the previous year's results for the comprehensive water quality monitoring program; 5. A review of the plan elements, including water pollution abatement, water quality, water reclamation, Endangered Species Act compliance, biosolids management and variability of quality over time, wastewater public health problems, compliance with other agency regulations and agreements, to ensure it reflects current conditions; and 6. An update of anticipated RWSP program costs through the year 2030 The RWSP annual reports are submitted to the King County Council in September to cover the previous year’s implementation and include information on the items listed in 1 through 6 of this policy. The King County Executive has transmitted an annual report to the King County Council every year since 2000. B.1. Comprehensive regional wastewater services plan review. The executive shall submit a written report to council and RWQC that provides a comprehensive review of the RWSP. The report will review the following: The RWSP 2013 Comprehensive Review is the third RWSP comprehensive review and covers implementation of the RWSP from 2007 through 2013. The report has been prepared following the guidance in this policy. A-62 RWSP 2013 Comprehensive Review Appendix A. RWSP Policies Implementation in 2007−2013 Reporting Policies How Implemented in 2004–2006 a. assumptions on the rate and location of growth, the rate of septic conversions and the effectiveness of water conservation efforts; b. phasing and size of facilities; and c. effectiveness of RWSP policies implementation, for infiltration and inflow reduction, water reuse, biosolids, CSO abatement, water quality protection, environmental mitigation and public involvement; d. policy guidance for the construction fund and the emergency capital reserves 2. The next comprehensive regional wastewater services plan review is due in June 2014. Subsequent reports will be prepared every three to five years as established by the council and RWQC following their review of the current report. The specific due date will be based upon the availability of necessary information, the completion of key milestones, and the time needed to collect and analyze data. The executive may recommend policy changes based on the findings of the report and other information from changing regulations, new technologies or emerging or relevant factors; 3. The comprehensive regional wastewater services plan review will include all elements of the RWSP annual report, replacing it for that year. (Ordinance 17480, which was approved in December 2012, amended this policy to include “policy guidance for the construction fund and the emergency capital reserves” in RWSP comprehensive reviews, and established the due date for this Comprehensive Review Report.) C. Operational master plan. The RWSP Operational Master Plan that was adopted by council in December 1999 shall be updated on a regular basis in conjunction with policy revisions to the RWSP. In accordance with Motion 13758, the King County Executive submitted to the County Council a report on options to provide summary information on WTD’s long-range capital program. The report was submitted in August 2013. RWSP 2013 Comprehensive Review A-63 Appendix B Odor Prevention and Control Program Appendix B. Odor Prevention and Control Program Odor Prevention and Control Program RWSP policies provide direction on implementing an Odor Prevention and Control Program at all wastewater treatment plants and associated conveyance facilities that goes beyond traditional odor control. RWSP policies also call for including a summary of odor complaints in annual reports. WTD received and investigated 49 odor complaints in 2013. When investigating an odor complaint, the source is not always identifiable. For example, some complaints received are in areas where there are no WTD facilities. Of the 56 complaints received, 25 were determined to be attributable to WTD facilities. The breakdown is shown in Table 1. No odor complaints were attributed to the Brightwater, South, Vashon, and Carnation treatment plants. Complaints attributable to WTD facilities were resolved through replacing carbon in odor control facilities, using chemical solutions, sealing manhole covers, replacing equipment such as fan belts, and restoring power after a power outage. Table1. Odor Complaints in 2013 Location Complaints Received Complaints Attributed to WTD Facilities South Treatment Plant 3 0 South Plant conveyance facilities 25 19 West Point Treatment Plant 10 1 West Point conveyance facilities 14 4 Brightwater Treatment Plant 1 0 Brightwater conveyance facilities 3 1a Vashon Treatment Plant 0 0 Carnation Treatment Plant 0 0 Total 56 25 a There were no sewage-related odors attributed to Brightwater conveyance facilities since they began operating. This complaint was related to diesel odors that emanated from the Brightwater Influent Pump Station during testing of the pump station’s generators in 2013. To resolve the situation, a project is under way to install diesel oxidation catalyst units on each generator exhaust system. Odor complaints in 2007−2012 can be found in the RWSP annual reports at http://www.kingcounty.gov/environment/wtd/Construction/planning/rwsp/Library/AnnualReport.aspx. More information on the Odor Prevention and Control Program is available at http://www.kingcounty.gov/environment/wtd/Response/OdorControl/GoodNeighbor.aspx. B-2 RWSP 2013 Comprehensive Review Appendix C Water Quality and Sediment Monitoring in 2013 Appendix B. Odor Prevention and Control Program Water Quality and Sediment Monitoring in 2013 To protect public health and King County’s significant investment in water quality improvements, the County regularly monitors treatment plant effluent, marine water, fresh water, and sediments. The parameters used to assess a water body’s health under Washington State Water Quality Standards are fecal coliform bacteria, dissolved oxygen, temperature, pH, nutrients, turbidity, and a variety of chemical compounds. Monitoring results for the previous year are presented as environmental indicators on the County’s Department of Natural Resources and Parks KingStat website at http://your.kingcounty.gov/dnrp/measures/. Overall water and sediment quality conditions observed in 2013 were largely consistent with those observed in 2012 and in previous years. Key findings in 2013 include the following: • Treatment plant effluent consistently met permit requirements. • Waters in most urban streams are frequently warmer than Washington State temperature standards allow, have more bacteria than the standards allow, and occasionally do not have as much oxygen as required by state standards. • The health of streams, as measured by the diversity and abundance of the community of organisms that live on the stream bottom, is generally not as good in urban areas. • Two beaches in Lake Sammamish and six beaches in Lake Washington had incidents of high bacteria that did not meet state standards. These events were brief and did not result in beach closures. • With the exception of two stations in Quartermaster Harbor, marine water quality throughout the Puget Sound Central Basin was at a low level of concern in 2013. Level of concern rankings in Quartermaster Harbor were moderate and high due to low dissolved oxygen and dissolved inorganic nitrogen values during the late summer and early fall months. • There were no exceedances of the standards for fecal coliform bacteria levels at the County’s treatment plant marine outfalls in 2013. In addition, investigations to locate sources of bacteria in Juanita Creek, Thornton Creek, Boise Creek and the stormwater drainage infrastructure in White Center continued in 2013. When sources are identified, staff works with other entities, such as county and local stormwater programs, local sewer districts, and Public Health−Seattle & King County, to ensure identified sources are controlled. Data and reports are available at the Water and Land Resources Division’s Science and Technical Support Section website at http://www.kingcounty.gov/environment/wlr/sections-programs/science- section/doing-science.aspx. Water quality and sediment monitoring reports for 2007−2012 can be found in the RWSP annual reports at http://www.kingcounty.gov/environment/wtd/Construction/planning/rwsp/Library/AnnualReport.aspx. C-2 RWSP 2013 Comprehensive Review June 29, 2010 - FINAL i pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/TOC.docx KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT (SOUTH PLANT NITROGEN REMOVAL STUDY) TABLE OF CONTENTS EXECUTIVE SUMMARY Page No. ES.1 INTRODUCTION ............................................................................................... ES-1 ES.2 SOUTH PLANT NITROGEN REMOVAL - CURRENT CONFIGURATION ......... ES-1 ES.3 SOUTH PLANT NITROGEN REMOVAL SCENARIOS ...................................... ES-2 ES.4 SOUTH PLANT NITROGEN REMOVAL EFFECT ON RECLAIMED WATER PRODUCTION ................................................................................................... ES-7 ES.5 FINDINGS AND CONCLUSIONS .................................................................... ES-10 CHAPTER 1 SOUTH PLANT NITROGEN REMOVAL - CURRENT CONFIGURATION 1.1 INTRODUCTION .................................................................................................. 1-1 1.2 BACKGROUND .................................................................................................... 1-2 1.2.1 Description of Existing Plant ...................................................................... 1-2 1.2.2 Summary of Current NPDES Permit .......................................................... 1-5 1.3 NITROGEN LIMIT SCENARIOS ........................................................................... 1-6 1.4 FLOW AND LOAD BASIS ..................................................................................... 1-6 1.5 NITROGEN REMOVAL CAPACITY ANALYSIS .................................................... 1-7 1.5.1 Data Analysis ............................................................................................ 1-9 1.5.2 Model Calibration .................................................................................... 1-18 1.5.3 Modeling Results TIN 8 ........................................................................... 1-18 1.5.4 Modeling Results TIN 3 ........................................................................... 1-21 1.6 CONCLUSIONS.................................................................................................. 1-23 CHAPTER 2 SOUTH PLANT NITROGEN REMOVAL SCENARIOS 2.1 INTRODUCTION .................................................................................................. 2-1 2.2 ALTERNATIVES SCREENING ............................................................................. 2-1 2.2.1 Nitrogen Removal Alternatives .................................................................. 2-1 2.2.2 Initial Alternatives Screening Results ....................................................... 2-14 2.2.3 Nitrogen Removal Alternatives Analysis .................................................. 2-14 2.3 ALTERNATIVES EVALUATION .......................................................................... 2-28 2.4 ALTERNATIVES SUBJECT TO MORE DETAILED ANALYSIS .......................... 2-31 2.4.1 Necessary Equipment ............................................................................. 2-31 2.4.2 Site layout ............................................................................................... 2-34 2.4.3 Cost .................................................................................................... 2-34 2.4.4 Sensitivity Analysis .................................................................................. 2-37 2.5 GREENHOUSE GAS COMPARISON ................................................................. 2-45 2.5.1 Overview ................................................................................................. 2-45 2.5.2 Background ............................................................................................. 2-47 June 29, 2010 - FINAL ii pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/TOC.docx 2.5.3 Methodology ............................................................................................ 2-47 2.5.4 Categories and Sources of GHG Emissions ............................................ 2-48 2.5.5 Estimate of GHG Emissions in Terms of “CO2 Equivalents” .................... 2-48 2.5.6 Description of GHG Emissions Estimates ................................................ 2-49 2.5.7 Direct GHG Emissions ............................................................................. 2-49 2.5.8 Indirect GHG Emissions .......................................................................... 2-51 2.5.9 Summary of GHG Emissions Estimates .................................................. 2-52 2.6 FINDINGS AND CONCLUSIONS ....................................................................... 2-55 CHAPTER 3 SOUTH PLANT NITROGEN REMOVAL EFFECT ON RECLAIMED WATER PRODUCTION 3.1 INTRODUCTION .................................................................................................. 3-1 3.2 SUMMARY OF RECLAIMED WATER STANDARDS ........................................... 3-1 3.3 RECLAIMED WATER EVALUATION .................................................................... 3-4 3.3.1 Reclaimed Water Effects ........................................................................... 3-4 3.3.2 Reclaimed Water Options Costs ................................................................ 3-7 3.3.3 Other Effects ............................................................................................. 3-8 3.4 CONCLUSIONS.................................................................................................... 3-8 LIST OF APPENDICES APPENDIX A - Evaluation Criteria APPENDIX B - Cost Assumptions and Summaries LIST OF TABLES Table ES.1 8 mg/L TIN (Summer-only) Alternative Footprint Analysis ...................... ES-3 Table ES.2 3 mg/L TIN (Year-round) Alternative Foot Print Analysis ........................ ES-3 Table ES.3 8 mg/L TIN (Summer-only) Scoring Matrix .............................................. ES-4 Table ES.4 3 mg/L TIN (Year-round) Scoring Matrix ................................................. ES-5 Table ES.5 Estimate Summary for 8 mg/L TIN (Summer-only) Permit Level Upgrade to the STP ................................................................................ ES-6 Table ES.6 Estimate Summary for 3 mg/L TIN (Year-round) Permit Level Upgrade to the STP .............................................................................................. ES-6 Table ES.7 Summary of Relative Reclaimed Water Cost Effects ............................ ES-10 Table 1.1 Current NPDES Permit Summary .............................................................. 1-5 Table 1.2 Design Influent Flow and Loads ................................................................ 1-7 Table 1.3 Current Configuration – TIN 8 mg/L Scenario Modeling Results .............. 1-20 Table 1.4 Current Configuration – TIN 3 mg/L Scenario Modeling Results .............. 1-23 Table 2.1 Nitrogen Removal Alternatives .................................................................. 2-2 Table 2.2 8 mg/L TIN (Summer-only) Alternative Footprint Analysis ....................... 2-21 Table 2.3 3 mg/L TIN (Year-round) Alternative Foot Print Analysis ......................... 2-28 Table 2.4 8 mg/L TIN (Summer-only) Scoring Matrix ............................................... 2-30 Table 2.5 3 mg/L TIN (Year-round) Scoring Matrix .................................................. 2-31 Table 2.6 Estimate Summary for 8 mg/L TIN (Summer-only) Permit Level Upgrade to the STP ................................................................................. 2-36 Table 2.7 Estimate Summary for 3 mg/L TIN (Year-round) Permit Level Upgrade to the STP ............................................................................................... 2-36 June 29, 2010 - FINAL iii pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/TOC.docx Table 2.8 Greenhouse Gases and Global Warming Potentials ................................ 2-49 Table 2.9 Estimated Annual Total Metric Tons of Carbon Dioxide Equivalent Emission.................................................................................................. 2-53 Table 3.1 Definitions of Reclaimed Water ................................................................. 3-2 Table 3.2 Summary of Reclaimed Water Uses Requiring Nitrogen Removal............. 3-3 Table 3.3 Summary of Relative Reclaimed Water Costs Effects ............................... 3-7 Table 3.4 Summary of Other Relative Reclaimed Water Effects................................ 3-8 LIST OF FIGURES Figure ES.1 GHG Comparison ................................................................................... ES-8 Figure 1.1 STP Process Flow Schematic ................................................................... 1-3 Figure 1.2 STP Arial Photograph ................................................................................ 1-4 Figure 1.3 Process Schematic for STP BioWin Model ................................................ 1-8 Figure 1.4 Raw Sewage Flow for the Period from 2005 to 2009 ............................... 1-10 Figure 1.5 Raw Sewage Loading Data for the Period from 2005 to 2009 ................. 1-11 Figure 1.6 SVI Data for the Period from 2007 to 2009 .............................................. 1-12 Figure 1.7 Settleability Data from 2003 Tests Compared to Standard SVI-Based Formulas ................................................................................................. 1-13 Figure 1.8 Temperature Data for the Period from 2005 to 2009 ............................... 1-15 Figure 1.9 SRT Data for the Period from 2005 to 2009 ............................................. 1-16 Figure 1.10 Washout Aerobic SRT Values for Nitrifier Organisms .............................. 1-17 Figure 1.11 MLE Schematic ....................................................................................... 1-19 Figure 1.12 Bardenpho Schematic ............................................................................. 1-22 Figure 2.1 MLE Schematic ......................................................................................... 2-4 Figure 2.2 Bardenpho Schematic ............................................................................... 2-6 Figure 2.3 Step Feed Schematic ................................................................................ 2-7 Figure 2.4 BAF/DNF Schematic ................................................................................. 2-9 Figure 2.5 Examples of Media Used in MBBR and IFAS Processes ......................... 2-10 Figure 2.6 MLE IFAS Schematic .............................................................................. 2-11 Figure 2.7 Centrate Reaeration Schematic ............................................................... 2-13 Figure 2.8 MLE Footprint 8 mg/L TIN (Summer only) ............................................... 2-16 Figure 2.9 MLE – MBR 8 mg/L TIN (Summer only) Footprint ................................... 2-17 Figure 2.10 MLE – IFAS 8 mg/L TIN (Summer only) Footprint (Conservative Sizing) ..................................................................................................... 2-18 Figure 2.11 MLE – IFAS 8 mg/L TIN (Summer only) Footprint (Aggressive Sizing) .... 2-19 Figure 2.12 BAF/DNF 8 mg/L TIN (Summer only) Footprint ....................................... 2-20 Figure 2.13 Bardenpho 3 mg/L TIN (Year round) Footprint......................................... 2-22 Figure 2.14 Bardenpho-MBR 3 mg/L TIN (Year round) Footprint ............................... 2-23 Figure 2.15 Bardenpho-IFAS 3 mg/L TIN (Year round) Footprint Conservative Sizing ...................................................................................................... 2-25 Figure 2.16 Bardenpho-IFAS 3 mg/L TIN (Year round) Footprint Aggressive Sizing .. 2-26 Figure 2.17 BAF/DNF 3 mg/L TIN (Year round) Footprint ........................................... 2-27 Figure 2.18 BioWin Schematic – 8 mg/L Permit Level ................................................ 2-38 Figure 2.19 BioWin Schematic – 3 mg/L (Year round) Permit Level ........................... 2-39 Figure 2.20 Dynamic Influent Flow and Concentration 8 mg/L TIN (Summer only) Permit Level ............................................................................................ 2-41 June 29, 2010 - FINAL iv pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/TOC.docx Figure 2.21 Dynamic Influent Flow and Concentration 3 mg/L TIN (Year round) Permit Level ............................................................................................ 2-42 Figure 2.22 Dynamic Effluent Flow and Concentration 8 mg/L TIN (Summer only) Permit Level ............................................................................................ 2-43 Figure 2.23 Dynamic Effluent Flow and Concentration 3 mg/L TIN (Year round) Permit Level ............................................................................................ 2-44 Figure 2.24 State Point Diagram for Bardenpho BNR................................................. 2-46 Figure 2.25 GHG Comparison .................................................................................... 2-54 Figure 3.1 Site Requirements for 98 mgd of Conventional Filtration ........................... 3-5 Figure 3.2 Site Requirements for 36 mgd of Conventional Filtration ........................... 3-6 June 29, 2010 - FINAL v pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/TOC.docx ABBREVIATIONS AACE Association for the Advancement of Civil Engineering AB32 Assembly Bill 32 BAF Biological Aerated Filter BNR Biological Nitrogen Removal BOD5 Biochemical Oxygen Demand (5-day) C Celsius CARB California Air Resources Board CAS Conventional Activated Sludge CCAR GRP California Climate Action Registry General Reporting Protocol cfm Cubic Feet per Minute CH4 Methane County King County CO2 Carbon Dioxide CO2e Equivalent CO2 DAFT Dissolved Air Flotation Thickener DIN Dissolved Inorganic Nitrogen DNF Denitrifying Filter DO Dissolved Oxygen Ecology Department of Ecology EPA Environmental Protection Agency fbf Filterable BOD5 Fraction fvu Non-biodegradable Volatile Fraction GHG Greenhouse Gas gpd Gallons per Day gpd/sf Gallons per Day per Square Foot GWP Global Warming Potential HOCI Hypochlorite IFAS Integrated Fixed Film Activated Sludge IPCC International Panel on Climate Change LOTT Lacey, Olympia, Tumwater, Thurston County MBBR Moving Bed Bioreactor MBR Membrane Bioreactor MG Million Gallons June 29, 2010 - FINAL vi pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/TOC.docx mg/L Milligrams per Liter mgd Million Gallons per Day mL/g Milliliter per Gram MLE Modified Ludzak-Ettinger MCLG Maximum Containment Limit Goal MLR Mixed Liquor Return MLSS Mixed Liquor Suspended Solids N Nitrogen N2O Nitrous Oxide NH4+ Ammonium Ion NDN Nitrification/Denitrification NH4MgPO4 6H2O Ammonium Magnesium Phosphate NO3- Nitrate Ion NPDES National Pollutant Discharge Elimination System NR Nitrogen Removal O&M Operation and Maintenance POTW Publically Owned Treatment Works ppd Pounds per Day ppd/kcf Pounds per Day per Thousand Cubic Feet ppd/sf Pounds per Day per Square Foot RAS Return Activated Sludge SF Square Foot SRT Solids Residence Time STP South Treatment Plant SVI Sludge Volume Index TIN Total Inorganic Nitrogen TKN Total Kjeldahl Nitrogen TSS Total Suspended Solids U.S. United States WAS Waste Activated Sludge WERF Water Environment Research Foundation WWTP Wastewater Treatment Plant June 29, 2010 - FINAL ES-1 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/ES.docx Executive Summary ES.1 INTRODUCTION According to the Washington State Department of Ecology (Ecology 2008b), portions of South Puget Sound do not meet Washington State water quality standards for dissolved oxygen (DO). Ecology is concerned that algal growth stimulated by nitrogen loadings to Puget Sound is causing DO depression in near-bottom regions. In 2006 Ecology began a major study to determine the extent of low DO and how nitrogen from a variety of sources affects DO levels. While it is not clear how Ecology will use the results of its studies to establish future regulatory limits, King County (County) has undertaken this project to evaluate potential effects of future nitrogen removal requirements for the King County South Treatment Plant (STP). This report is divided into three chapters. Chapter 1 describes project assumptions and evaluates how much flow the existing STP could process if required to comply with a summer seasonal limit of 8-milligrams per liter (mg/L) TIN (Total Inorganic Nitrogen) or an annual limit of 3-mg/L TIN and what modifications would be required for nitrogen removal. Chapter 2 evaluates the potential effects (e.g., tankage, footprint, cost, greenhouse gas emissions) to the STP if it were required to meet the assumed seasonal or year-round limit while maintaining its current rated capacity (144-million gallons per day (mgd) max month year-round and 98-mgd max month during summer). Chapter 3 evaluates the effects that implementing nitrogen removal would have on reclaimed water production at the STP. ES.2 SOUTH PLANT NITROGEN REMOVAL - CURRENT CONFIGURATION A project team was assembled to evaluate the effects of potential future nitrogen limits on the capacity of the STP. A full-plant model was developed and calibrated to operating data collected at the plant. The project team decided upon two effluent nitrogen scenarios representing potential permitting scenarios: (1) a summer effluent limit of 8 mg/L TIN and (2) a year-round effluent limit of 3 mg/L TIN. As part of a project workshop, the project team also decided that the capacity rating of the current plant to meet the two target nitrogen effluent scenarios would be determined with one aeration basin and one secondary clarifier out of service. Based on these assumptions, the modeled capacity of the current STP to meet the summer effluent limit of 8 mg/L TIN is 36 mgd. This capacity rating was based on operating the existing aeration basins in a Modified Ludzak-Ettinger (MLE) configuration. To meet this effluent limit, minor modifications would be needed at the current plant including the addition of baffle walls, mixed liquor return (MLR) pumps and a chemical delivery system. However, major construction would be needed (onsite or offsite) to meet the current maximum summer month flow of 98 mgd and replace the 62 mgd of capacity lost as a result of the nitrogen removal modifications. June 29, 2010 - FINAL ES-2 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/ES.docx Based on the assumptions established in the first workshop, the modeled capacity of the current STP to meet the year-round effluent limit of 3 mg/L TIN was determined to be 30 mgd. This capacity rating was based on operating the existing aeration basins in a Bardenpho configuration. To meet this effluent limit, minor modifications would be needed at the current plant including the addition of baffle walls, MLR pumps and a chemical delivery system. However, construction would be needed (onsite or offsite) to meet the current maximum month flow of 144 mgd and replace the 114 mgd of capacity lost as a result of the nitrogen removal modifications. ES.3 SOUTH PLANT NITROGEN REMOVAL SCENARIOS There are four general classes of nitrogen removal alternatives: • Land-based • Aquatic • Chemical • Biological At the first workshop on October 1, 2009, a variety of potential alternatives within each of the classes was considered and four biological nitrogen removal alternatives were selected for further evaluation for each nitrogen removal scenario. These selected alternatives represent a range of biological alternatives including suspended growth, attached growth and hybrid processes. For the 8 mg/L TIN (summer-only) scenario, the selected processes were: 1) MLE, 2) MLE – membrane bioreactor (MBR), 3) MLE – integrated fixed-film activated sludge (IFAS) and 4) biological aerated filter (BAF) / denitrifying filter (DNF). For the 3 mg/L TIN (year-round) scenario, the selected processes were: 1) Bardenpho, 2) Bardenpho – MBR, 3) Bardenpho – IFAS, and 4) BAF/DNF. For each representative alternative, side stream treatment was evaluated to determine whether additional treatment could reduce the footprint and cost of the alternative. The four selected alternatives for each nitrogen limit scenario were evaluated to determine a relative cost and footprint for each alternative. Tables ES.1 and ES.2 summarize the footprint effects of each alternative for the effluent limit scenario of 8 mg/L TIN during the summer and 3 mg/L TIN year round, respectively. Footprint estimates are primarily for comparative purposes, and do not currently account for other features that can consume land area such as roads, odor control, and ancillary equipment. The MLE alternative requires the greatest footprint and provides very little space for the plant to expand to treat future flows or to respond to future changes in effluent quality requirements while the BAF-DNF and MLE-MBR alternatives provide the most available space for future expansion. The MLE-IFAS alternative could be very attractive from a footprint standpoint if the most aggressive of the manufacturer’s performance and design criteria could be confirmed. June 29, 2010 - FINAL ES-3 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/ES.docx The Bardenpho alternative requires the greatest footprint and does not fit on the site while the BAF-DNF and Bardenpho-MBR alternatives provide the most available space for future expansion. The Bardenpho-IFAS alternative could be very attractive from a footprint standpoint if the aggressive version of manufacturer’s claims and assumed packing densities could be confirmed. Table ES.1 8 mg/L TIN (Summer-only) Alternative Footprint Analysis South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division MLE MLE-MBR MLE-IFAS (A)(1) MLE-IFAS (C)(2) BAF / DNF Total added basins, sf(3) 359,900 107,700 39,900 191,600 100,700 Full buildout capacity assuming no expansion on the biosolids site, mgd(1) 144 270 360 210 270 (1) IFAS A stands for the aggressive sizing of IFAS. Notes: (2) IFAS C stands for the conservative sizing of IFAS. (3) Capacity ratings are based on maximum month flows during the summer months. The maximum month flow capacity of the current plant for summer flows is 98 mgd. The assumed density of aeration basins is based on the proposed STP site buildout layout provided by the County. No extra allowances were made for roads or ancillary facilities. Table ES.2 3 mg/L TIN (Year-round) Alternative Foot Print Analysis South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division Bardenpho Bardenpho - MBR Bardenpho - IFAS (A)(1) Bardenpho - IFAS (C)(2) BAF / DNF Total added basins, sf 1,009,100 293,700 80,300 505,900 183,300 Full buildout capacity assuming no expansion on the biosolids site, mgd(3) TL(4) 170 300 TL(4) 240 (1) IFAS A stands for the aggressive sizing of IFAS. Notes: (2) IFAS C stands for the conservative sizing of IFAS. (3) Capacity ratings are based on maximum month flows. The maximum month flow capacity of the current plant is 144 mgd. The assumed density of aeration basins is based on the proposed STP site buildout layout provided by the County. No extra allowances were made for roads or ancillary facilities. (4) TL = estimated foot print is too large and does not fit on the site. Based on team input from the first workshop, the four alternatives for each nutrient limit scenario were evaluated based on the following cost and non-cost criteria: (1) onsite capital costs, (2) operation and maintenance (O&M) costs, (3) risk, (4) future flexibility, (5) footprint, (6) energy, (7) odor, (8) compatibility with existing processes, (9) biosolids quality, and (10) reclaimed water quality/quantity. Each of these criteria was scored from 1 (low) to 3 (high). The weighting for each criterion was established by the team at the second workshop on June 29, 2010 - FINAL ES-4 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/ES.docx December 15, 2009. Tables ES.3 and ES.4 present the weighted results for each effluent limit scenario. Based on this analysis, the two leading alternatives for both effluent limit scenarios were the MBR and BAF/DNF. The County decided to select the MBR system as the representative alternative for both effluent limit scenarios. The team concluded that the BAF/DNF system should also be considered in more detail at a facility planning or pre- design level. Since aggressive IFAS sizing potentially offers a very competitive alternative, the County may want to consider pilot testing to determine the optimum kinetic parameters and packing densities. Table ES.3 8 mg/L TIN (Summer-only) Scoring Matrix South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division Score Criteria Weight MLE MBR IFAS A(1) IFAS C(2) BAF Onsite Capital Cost 1 3 2 3 1 3 O&M Cost 1 3 1 2 2 2 Risk 2 3 3 0(3) 1 2 Future Flexibility 2 1 3 3 1 3 Footprint 3 1 3 3 2 3 Energy 2 3 2 3 1 2 Odor 1 2 2 2 2 2 Compatibility with existing processes 1 3 3 3 3 3 Biosolids Quality 1 2 2 2 2 2 Reclaimed Water Quality/Quantity 1 1 3 2 2 2 Un-weighted Total 22 24 F(4) 17 24 Weighted Total 31 38 F(4) 24 37 (1) IFAS A stands for the aggressive sizing of IFAS. Notes: (2) IFAS C stands for the conservative sizing of IFAS. (3) The aggressive IFAS sizing was determined to be too risky based on the manufacturer’s lack of sufficiently demonstrated approach to tank sizing. The County may want to consider pilot testing to further support this consideration. (4) A score of a “0” on any of the criteria results in a failure of that alternative. June 29, 2010 - FINAL ES-5 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/ES.docx Table ES.4 3 mg/L TIN (Year-round) Scoring Matrix South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division Score Criteria Weight MBR IFAS A(1) IFAS C(2) BAF Onsite Capital Cost 1 2 3 3 2 O&M Cost 1 1 1 3 2 Risk 2 3 0(3) 1 2 Footprint 3 2 3 0(4) 2 Energy 2 1 3 2 2 Odor 1 2 2 2 2 Compatibility with existing processes 1 3 3 3 3 Biosolids Quality 1 2 2 2 2 Reclaimed Water Quality/Quantity 1 3 2 1 2 Un-weighted Total 19 F(5) F(5) 19 Weighted Total 27 F(5) F(5) 27 (1) IFAS A stands for the aggressive sizing of IFAS. Notes: (2) IFAS C stands for the conservative sizing of IFAS. (3) The aggressive IFAS sizing was deemed to be too risky based on the manufacturer’s lack of an adequate explanation for tank sizing. This alternative should be pilot tested before further consideration. (4) The conservative sizing of IFAS was given a “0” for footprint since this alternative did not fit on the site. (5) A score of a “0” on any of the criteria results in a failure of that alternative. Tables ES.5 and ES.6 present summaries of estimated costs for upgrade of the STP to provide for nitrogen removal for the two potential permit levels. The estimates include the cost of odor control covers and equipment for the reactor tanks. The cost estimates were based on a preliminary quantity estimate for excavation and concrete for new tanks and estimated cost for new equipment. To these direct costs were added allowances for piping and miscellaneous mechanical equipment, electrical equipment, instrumentation, site work, contingency, general conditions, contractor overhead, and profit, sales tax, allied costs (planning, design, construction management, permits, etc.). O&M costs were estimated based on an Environmental Protection Agency (EPA) database for unit process labor, estimated power requirements and chemical consumption, and allowances for structural and equipment maintenance. Costs were indexed to estimated unit prices for March 15, 2010. The expected accuracy range for this type of estimate is defined by the Association for the Advancement of Cost Engineering (AACE) as a Level - 5 Order of Magnitude Estimate and has an expected accuracy range of +50 to -30 percent. The tables present summaries of costs for major project elements in five columns: 1. Costs for conventional activated sludge (CAS) operation June 29, 2010 - FINAL ES-6 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/ES.docx Table ES.5 Estimate Summary for 8 mg/L TIN (Summer-only) Permit Level Upgrade to the STP South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division Treatment Element CAS MLE Upgrade MLE MBR Total BNR Upgrade Difference Present Worth Cost, $ Million Capital Cost(1) $0 $105 $425 $530 $530 Operation and Maintenance(2) $25 $46 $129 $176 $149 Total Present Worth $25 $151 $554 $706 $679 (1) Capital cost includes construction cost, contingency (40%), tax, and allied costs (costs of planning, engineering, construction management, permitting, legal and other associated costs (45%)). All costs are in March 2010 dollars. Notes: (2) Present worth O&M values were calculated assuming a 3% discount rate over a 20-year period on calculated current yearly O&M costs. Table ES.6 Estimate Summary for 3 mg/L TIN (Year-round) Permit Level Upgrade to the STP South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division Treatment Element CAS Bardenpho Upgrade Bardenpho MBR Total BNR Upgrade Difference Present Worth Cost, $ Million Capital Cost (1) $0 $188 $779 $967 $959 Operation and Maintenance(2) $25 $128 $394 $522 $475 Total Present Worth $25 $316 $1,173 $1,489 $1,434 (1) Capital cost includes construction cost, contingency (40%), tax, and allied costs (costs of planning, engineering, construction management, permitting, legal and other associated costs (45%)). All costs are in March 2010 dollars. Notes: (2) Present worth O&M values were calculated assuming a 3% discount rate over a 20-year period on calculated current yearly O&M costs. June 30, 2010 - FINAL ES-7 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/ES.docx 2. Upgrade of the existing CAS to provide for biological nitrogen removal (BNR) 3. New Parallel MBR BNR facilities 4. The total estimated cost for the BNR upgrade 5. The difference in cost between the BNR upgrade and the cost of operation of the existing CAS The greenhouse gas (GHG) emissions of the representative alternative for each permit scenario were compared against the current mode of operation at the STP. A summary of the results of the GHG analysis for the project is presented in Figure ES.1. This figure presents a bar chart representing the total estimated annual production of carbon dioxide (CO2) equivalents for the three process alternatives: 1. CAS 2. BNR with an effluent permit goal of 8 mg/L TIN for the six summer months of the year by conversion of the existing aeration tanks to an MLE process with treatment of the remaining flow by MLE MBR. Operation in CAS the remainder of the year. 3. BNR with an effluent permit goal of 3 mg/L TIN (year-round) by conversion of the existing aeration tanks to a Bardenpho process with treatment of the remaining flow by Bardenpho MBR. The results indicate that the effect of a summer-only effluent permit level of 8 mg/L TIN would be approximately two thirds more GHG emissions compared to secondary treatment at the STP. Imposition of a 3 mg/L TIN year-round limit would result in approximately three times more emissions of equivalent GHGs. The primary sources of increased GHG emissions are process nitrous oxide (N2O) and purchased electricity. ES.4 SOUTH PLANT NITROGEN REMOVAL EFFECT ON RECLAIMED WATER PRODUCTION The STP currently provides secondary treatment for up to 144 mgd of flow on a maximum month basis for discharge to Puget Sound. Substantial removal of ammonia is not achieved. Reclaimed water filtration facilities for up to 1.5 mgd of secondary effluent are available using coagulation, flocculation, sand filtration, and disinfection. Implementation of BNR at the STP could have a significant effect on reclaimed water availability, potential customers, and quality, depending on the technology selected. The current flow of the STP during the summer season when reclaimed water could be potentially useful for irrigation is approximately 98 mgd. Coagulation, flocculation, and filtration would be required to implement production of 98 mgd of reclaimed water from the current non-nitrified secondary effluent. Assuming typical detention times and loading ratios, approximately 38,000 square foot (sf) of coagulation, flocculation, and filtration facilities would be required. In calculating effects, current capacity of 1.5 mgd was ignored. pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig ES.1.docx GHG COMPARISON FIGURE ES.1 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT June 29, 2010 - FINAL ES-9 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/ES.docx The MLE – MBR alternative for operation for an 8 mg/L TIN permit level during the summer would produce up to 62 mgd of MBR effluent water during the summer that would substantially meet the requirements for Class A reclaimed water. To produce reclaimed water equaling the full current dry weather flow of 98 mgd, sand filtration of 36 mgd from the existing secondary clarifiers would be needed resulting in a requirement of approximately 13,000 sf of coagulation, flocculation, and filtration facilities. The Bardenpho – MBR upgrade strategy would produce up to 114 mgd of MBR effluent year round that would substantially meet the requirements of Class A reclaimed water. This means that during the summer season, the STP could treat the full summer flow through the MBRs, if BNR were implemented. Table ES.7 compares the costs of reclaimed water production for the full 98 mgd summer flow for the current non-nitrified secondary effluent to the requirements for additional filtration assuming nitrogen removal upgrade by a parallel MBR process for either the 8 mg/L (summer only) or the 3 mg/L (year-round) TIN permit level. As shown in Table ES.7, there would be no additional cost to implement reclaimed water production for the full summer flow of 98 mgd if the 3 mg/L (year-round) TIN permit limit project is implemented. Table ES.7 shows that the cost of implementing reclaimed water by conventional filtration is approximately $104 million in present worth capital and operating and maintenance costs. If a 3 mg/L (year-round) TIN permit limit project using parallel MBR were implemented, this cost would be avoided. The relative present worth cost of implementing 36 mgd of reclaimed water production for non-nitrified effluent would be approximately $45 million. This would represent a savings of approximately $45 million over providing full summer reclaimed water production today from non-nitrified STP effluent. This relative savings in reclaimed water production would be realized if the 8 mg/L (summer-only) parallel MBR project were implemented. June 29, 2010 - FINAL ES-10 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/ES.docx Table ES.7 Summary of Relative Reclaimed Water Cost Effects South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division Treatment Process Current Approach. Non-nitrified Secondary Effluent. No new facilities. Summer only. 8 mg/l TIN Summer Limit Parallel MLE-MBR Processes 3 mg/l TIN All-year Limit Add’l Sand Filtration Req’d 98 mgd sand filters MLE Effluent 36 mgd sand filters MBR Effluent 62 mgd - no sand filters MBR Effluent 114 mgd – no sand filters Capital Cost $57M $23M $0 $0 Annual O&M Cost $3.1M/yr $1.4M/yr $0 $0 Disinfection Assumed equal cost for all alternatives. Present Worth O&M(1) $47M $22M $0 Total Present Worth $104M $45M $0 (1) Present worth O&M values calculated assuming a 3% discount rate over a 20-year period on calculated current yearly O&M costs. Notes: ES.5 FINDINGS AND CONCLUSIONS The principle findings and conclusions of this report are the following: 1. At a project workshop two potential nitrogen removal permit requirements were determined to bracket potential permit limits that could be applied by the Department of Ecology in response to South Puget Sound water quality studies: 1) a “least stringent” potential effluent limit of 8 mg/L TIN for the summer months only and 2) a “most stringent” potential limit of 3 mg/L TIN year-round. 2. Based on assumptions developed at project workshops, the modeled capacity of the current STP, with minor modifications, to meet the “least stringent” summer effluent limit was 36 mgd. Major modifications that would be needed would be construction of a new treatment plant to treat the remainder of the summer flow (approximately 62 mgd). 3. The modeled capacity of the current STP to meet, with minor modifications, the “most stringent” year-round effluent limit was 30 mgd. Major modifications that would be needed would be construction of a new treatment plant to treat the remainder of the flow (approximately 114 mgd). 4. A large number of potential nitrogen removal alternatives were considered for each potential permit scenario and reduced to four for each permit scenario. Potential effects of each of these upgrade strategies were estimated using a series of criteria June 29, 2010 - FINAL ES-11 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/ES.docx including capital cost, O&M cost, risk, flexibility, footprint, energy, odor generation potential, compatibility with existing processes, effect on biosolids quantity, and the amount and quality of reclaimed water produced. Each of these criteria were scored from 1 (low) to 3 (high) and tallied to determine the ranking. The final ranking indicated that for the 8 mg/L TIN (summer-only) permit level, the most promising upgrade strategy would be to upgrade the existing CAS process at the STP to provide for anoxic and aerobic treatment in two stages by a MLE process and to construct a parallel nitrogen removing MBR process to treat the remainder of the flow. For the 3 mg/L TIN (year-round) discharge alternative a similar strategy was selected, but using a four-stage anoxic and aerobic process (the Bardenpho process). It was concluded that two other processes, BAF/DNF and IFAS processes, were potentially cost-effective and have similar enough other effects that they should be considered for pilot testing in the future. 5. The incremental present worth cost for upgrade of the STP to meet an 8 mg/L TIN permit level during the summer months is estimated at approximately $680 million more than continuing operation of secondary treatment over the next twenty years. The estimated incremental present worth cost for upgrade of the STP to meet a 3 mg/L TIN (year-round) permit level is approximately $1,430 million more than the cost of continuing with secondary treatment. 6. It was concluded that meeting an 8 mg/L TIN summer permit level would result in nearly two thirds more GHG emissions from the STP compared to the currently-used CAS process and that a 3 mg/L TIN year-round permit level would result in approximately three times more GHG emissions compared to continuing with secondary treatment at the STP. 7. If BNR were implemented at the STP, between 36 and 98 mgd of effluent would be made available that would be suitable for reclaimed water use. Assuming that the costs of production of this water were required for BNR in any case, this water would be available for reclaimed use at a relative savings over the costs of production of the water using conventional gravity sand filtration. Cost savings would be in the range of $45 to $104 million, depending on the level of nitrogen removal implemented. There would also be a savings in land area of between one quarter and one acre and a savings of a small amount in electricity consumption and GHG emissions, compared to production of the same amount of reclaimed water using media filtration if BNR treatment facilities were not available. June 29, 2010 - FINAL 1-1 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch01.docx Chapter 1 SOUTH PLANT NITROGEN REMOVAL - CURRENT CONFIGURATION 1.1 INTRODUCTION According to the Washington State Department of Ecology (Ecology 2008b), portions of South Puget Sound do not meet Washington State water quality standards for dissolved oxygen (DO). Ecology is concerned that algal growth stimulated by nitrogen loadings to Puget Sound is causing DO depressions in near-bottom regions. The form of nitrogen of greatest interest to Ecology is dissolved inorganic nitrogen (DIN), which is the sum of nitrate, nitrite, and ammonium. In 2006 Ecology began a major study to determine the extent of low DO and how nitrogen from a variety of sources affects DO levels. The primary concern was with South Puget Sound below the Tacoma Narrows, but because it was thought that circulation of nitrogen from the north could cause low DO effects, the Central Puget Sound area north of the Tacoma Narrows and south of Edmonds was included in the study. All of King County’s wastewater treatment plants (WWTP) discharge to the Central Puget Sound. The scope of work for the Ecology study includes data collection, developing hydrodynamic and water quality models, and simulating alternative management scenarios. To date Ecology has completed data collection and hydrodynamic modeling. The last elements of Ecology’s scope of work are being completed in 2010. Ecology produced two significant conclusions from its data collection effort (Ecology, 2008a): • Nitrogen is the main pollutant that causes low dissolved oxygen levels. • In September 2007, wastewater treatment plants contributed 80 percent of the watershed DIN load to South Puget Sound (nitrogen loads in late summer are particularly important because this is when DO levels are the lowest). Because of the greater population density in the Central Puget Sound study area, the sum of WWTP DIN loadings from the combined Central and South Puget Sound area contributed over 90 percent of the watershed DIN load to the combined Central and South Puget Sound. Results of the hydrodynamic modeling are available as an external review draft (Ecology, 2009). These results conclude that “Based on predicted dilution levels derived from water column maximum dye concentrations during September 16-30, 2007, dye from South and Central Puget Sound exchanges through the Tacoma Narrows (Figure ES-7). Therefore, we cannot rule out the influence of Central Puget Sound sources on South Puget Sound water quality. However, the results are not sufficient to rule in an influence either given the complexity of nutrient transport and transformation within marine environments. The water quality model is needed to quantify the link between sources and water quality impairments.” Results of the water quality transport modeling are expected in 2010. June 30, 2010 - FINAL 1-2 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch01.docx With this background King County (the County) undertook the current project to “determine the effectiveness and costs of a range of treatment scenarios designed to reduce nitrogen discharged by the South Treatment Plant (STP)” (from scope of work for King County Contract E00025E07). An initial project team workshop was conducted on October 1, 2009 where the project assumptions were established. Three memoranda were produced as part of this project. The first memorandum evaluated how much flow the existing STP could process if required to comply with two different levels of nitrogen removal and what modifications would be required for each. The second memorandum evaluated the potential effects on the STP (in terms of additional tankage, footprint, cost, and greenhouse gas emissions) if it were required to meet the assumed seasonal or year-round limit while maintaining its current rated capacity (144-million gallons per day (mgd) max month year-round and 98-mgd max month during summer). The third memorandum evaluated effects on the reclaimed water program for the County. These three memoranda have been incorporated, respectively, into Chapters 1, 2, and 3 of this report. The purpose of this first chapter is to describe the process used to determine target effluent nitrogen limits and the re-rated capacity of the current STP to meet these target nitrogen limits. 1.2 BACKGROUND 1.2.1 Description of Existing Plant The STP was built in 1965 on a 94 acre site in Renton, Washington. The plant has been modified several times since 1965; a schematic of the current plant and an aerial overview are shown in Figures 1.1 and 1.2. Wastewater enters the plant through the Eastside and South Interceptors. Rags and paper are removed through coarse bar screens and grit is removed in pre-aerated grit tanks. Screened, degritted wastewater flows to 12 primary clarifiers, where approximately 60 percent of total suspended solids (TSS) are removed. Primary clarifier effluent flows by gravity to four aeration basins. The aeration basins are operated in a plug flow mode and wastewater, mixed with return activated sludge (RAS) flows through the basin in a serpentine manner. The first one-eighth of each basin is not aerated and acts as selector, limiting growth of filamentous bacteria. Mixed liquor suspended solids (MLSS) are clarified in 24 secondary clarifiers. Secondary effluent is disinfected in chlorine contact channels using a hypochlorite solution prior to discharge in the Puget Sound. pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 1.1.docx STP PROCESS FLOW SCHEMATIC FIGURE 1.1 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 1.2.docx STP AERIAL PHOTOGRAPH FIGURE 1.2 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT June 29, 2010 - FINAL 1-5 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch01.docx 1.2.2 Summary of Current NPDES Permit The STP’s current National Pollution Discharge Elimination System (NPDES) permit was issued in 2009 and expires in 2014. The permit is summarized in Table 1.1 for the plant’s main Puget Sound outfall. The current STP permit does not regulate effluent nitrogen but it does require the plant to monitor the final effluent for total ammonia (concentration and load), nitrate-nitrite, and total Kjeldahl nitrogen (TKN) concentration, monthly. Table 1.1 Current NPDES Permit Summary South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division Parameter Average Monthly(1) Average Weekly(2) BOD5 30 mg/L, 36,000 ppd, 85% removal of influent BOD5 45 mg/L 54,000 ppd TSS 30 mg/L, 36,000 ppd, 85% removal of influent TSS 45 mg/L, 54,000 ppd Fecal Coliform Bacteria(3) 200/100 mL 400/100 mL pH(4) Daily minimum is equal to or greater than 6.0 and the daily maximum is less than or equal to 9.0 Parameter Average Monthly(1) Maximum Daily(5) Total Residual Chlorine 0.5 mg/L 0.75 mg/L Notes: (1) Average monthly effluent limit means the highest allowable average of daily discharges over a calendar month. To calculate the discharge value to compare to the limit, you add the value of each daily discharge measured during a calendar month and divide this sum by the total number of daily discharge measured. See footnote 3 for fecal coliform calculations. (2) Average weekly discharge limitation means the highest allowable average of “daily discharges” over a calendar week, calculated as the sum of all “daily discharges” measured during a calendar week divided by the number of “daily discharges” measured during that week. See footnote 3 for fecal coliform calculations. (3) To calculate the average monthly and average weekly values for fecal coliforms, you must use the geometric mean. Ecology gives directions to calculate this value in publication No. 04-10- 020, Information Manual for Treatment Plant Operators. (4) Indicates the range of permitted values. The Permittee must report the instantaneous maximum and minimum pH monthly. Do not average pH values. (5) Maximum daily effluent limit means the highest allowable daily discharge. The daily discharge means the discharge of a pollutant measured during a calendar day. The daily discharge is the average measurement of the pollutant over the day. This does not apply to pH. The current permit lists plant flows and loads: • Maximum month design flow of 144 mgd • Peak instantaneous design flow of 325 mgd • Maximum month five day biochemical oxygen demand (BOD5) loading of 251,000 pounds per day (ppd) • Maximum month TSS loading of 235,000 ppd June 29, 2010 - FINAL 1-6 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch01.docx 1.3 NITROGEN LIMIT SCENARIOS This section describes the process used to determine target nitrogen limits for use in project nitrogen removal scenarios. The nitrogen concentration in WWTP effluent is regulated to either protect human health or the environment. Since nitrate in drinking water can be responsible for the “blue baby syndrome”, the Environmental Protection Agency (EPA) has set a maximum contaminant limit goal (MCLG) of 10 milligrams per liter (mg/L) for nitrate (measured as nitrogen) in public drinking water supplies. From the perspective of effects on the human environment: since nitrogen can limit algal growth, decreasing effluent nitrogen concentration can improve the quality of the receiving water. The Lacey, Olympia, Tumwater, Thurston County (LOTT) Budd Inlet Treatment Plant in Olympia was the first large treatment plant discharging to Puget Sound to be given a nitrogen limit. This plant is limited to an average summer (for two periods from April through October) total inorganic nitrogen (TIN) concentration of 3 mg/L. TIN is defined as is the sum of ammonia, nitrate, and nitrite (TIN and DIN are the same). Several plants in Florida are now facing potential total nitrogen limits of less than 1 mg/L. A summer season permit limit would be less stringent, in the sense that the limit could be met with smaller tank volumes and fewer other effects, than a maximum month limit (or even a maximum day limit) that was enforced year-round. This is because biological nitrification, typically a key step in nitrogen removal, is slower in cold temperatures. The extreme range of possible limits for total inorganic nitrogen based on this background would be from 1 mg/L (most stringent) to 10 mg/L TIN (least stringent) in terms of numerical value. From a compliance period perspective: a limit imposed as an average over the entire year would be least stringent and a maximum month (or even maximum day) limit imposed in the coldest months of the year would be the most stringent. Based on these considerations, two permit scenarios were selected at the first project workshop on October 1, 2009 (Carollo Engineers, 2009a). The two permit scenarios given below represent the least and most stringent permit scenarios that workshop participants felt could reasonably be requested by Ecology, respectively: 1. Summer-season (May 1 through October 31) limit of 8 mg/L TIN 2. Year-round limit of 3 mg/L TIN imposed in the coldest month 1.4 FLOW AND LOAD BASIS The work documented in this report evaluated the capacity of the existing STP treatment system and modifications to the existing system necessary to provide nitrogen removal for the design maximum month flow of 144 mgd. This corresponds to the rated maximum month flow from the current NPDES permit. The BOD5, TSS, and ammonia loads that correspond to this flow were taken from Brown and Caldwell (2004) and from STP plant records for the year 2007. These are summarized in Table 1.2. June 29, 2010 - FINAL 1-7 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch01.docx The design year-round maximum month flow and loads from Brown and Caldwell (2004) were used to evaluate the permit scenario of a year-round limit of 3 mg/L TIN. To evaluate the 8 mg/L (summer-only) TIN limit scenario maximum summer month flows and loads during the design year were determined from the Brown and Caldwell (2004) values using peak factors from the STP record for the years 2006 through 2008. These values are also summarized in Table 1.2. Table 1.2 Design Influent Flow and Loads South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division Description Current Annual Average Design Summer Maximum Month Design Year-round Maximum Month(1) Flow, mgd 85 98 144 BOD5, ppd 164,000 231,000 251,000 TSS, ppd 168,000 221,000 235,000 NH4-N, ppd 16,300 26,200 23,600 Notes: (1) Brown and Caldwell (2004) 1.5 NITROGEN REMOVAL CAPACITY ANALYSIS Treatment plant models were developed by Carollo for this report and calibrated to existing plant data to evaluate the capacity of the existing plant to meet the two effluent permit scenarios defined above. As part of the work, Carollo prepared two models; a steady state model using Biotran, a proprietary Carollo spreadsheet model, and BioWin, commercial process analysis software from Envirosim. Both models included primary treatment, activated sludge reactors, secondary sedimentation tanks, solids thickening, digestion, and dewatering unit process and return flows. Figure 1.3 presents a schematic of the model developed in BioWin. These calibrated models were used to define the capacity of the current treatment plant (with minor modifications) to meet the summer season limit of 8 mg/L of TIN and the year round limit of 3 mg/L of TIN. The analysis of the current treatment plant described in this report was based on maximum month flows and loads. For our analysis we assumed that one aeration basin and one secondary clarifier was out of service. This was a decision of the October 1, 2009 workshop. The analysis assumed that 23 out of the 24 clarifiers would be in service, even at the reduced flows required to meet the more stringent effluent limits. This assumption allows operation at higher MLSS concentrations while still maintaining the current solids loading rates on the clarifiers. This section describes the analysis of the STP data, the model calibration process, and the model results for the two effluent scenarios. pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 1.3.doc PROCESS SCHEMATIC FOR STP BIOWIN MODEL FIGURE 1.3 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT Anaerobic Pass 1 Aerobic Pass 2 Aerobic Pass 3 Aerobic Pass 4 Aerobic Pass 1 Effluent Digesters 1- 4 Storage Digester Sludge Disposal Cl2 Contact Screened Sewage June 29, 2010 - FINAL 1-9 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch01.docx 1.5.1 Data Analysis In preparation for the model analysis, operating data for the period from 2005 through 2009 were reviewed. Figure 1.4 presents a time-series graph of influent flow at the STP for the period. A full year of data for 2007 was taken as representative of the period and was used for calibration of the Biotran model. The average and maximum month flows for 2007 were 76.5 mgd and approximately 120 mgd, respectively. Influent BOD5 loadings in 2007 averaged approximately 165,000 ppd with a maximum month average of approximately 195,000 ppd. The maximum month TSS load has historically been approximately the same as the maximum month BOD5 load. Daily influent loadings for the entire period are shown in Figure 1.5. Three key parameters are especially important for successful activated sludge operation and model calibration: sludge settleability, temperature, and solids residence time (SRT). The data analysis for these three parameters is summarized in the sections below. 1.5.1.1 Sludge Settleability The sludge volume index (SVI) gives an indication of sludge settling rates, which are important for solids capture in the secondary sedimentation tanks. SVI values for STP have mostly been below 150 milliliter per gram (mL/g) with several excursions as high as 250 mL/g in the last two years. Figure 1.6 shows a time-series plot of SVI data since 2007. Solids settling capacity can be calculated based on settling tests, or estimated from a statistically-derived formula. Brown and Caldwell (2004) included settling velocity data from tests in March and August of 2003. These data are compared in Figure 1.7 to data calculated using the Daigger and Pitman equations (Daigger, 1995 and Pittman, 1985) and using the default settling parameters from BioWin. The graph shows the calculated solids flux capacity in pounds of solids per square foot of clarifier cross-section per day (ppd/sf). The solids flux rate based on the Daigger equation lies between the two values measured in 2003. For the initial modeling, the BioWin default values were used, but the effect of settleability on performance was considered in a sensitivity evaluation presented in the Chapter 2. 1.5.1.2 Temperature Temperature affects biological growth and sludge settling. In general, for higher temperatures, growth rates and oxygen consumption in the activated sludge process increase, and settling rates may also increase as a result of lower fluid viscosity. At lower temperatures biological growth slows. pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 1.4.doc RAW SEWAGE FLOW FOR THE PERIOD FROM 2005 TO 2009 FIGURE 1.4 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 1.5.doc RAW SEWAGE LOADING DATA FOR THE PERIOD FROM 2005 TO 2009 FIGURE 1.5 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 1.6.doc SVI DATA FOR THE PERIOD FROM 2007 TO 2009 FIGURE 1.6 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 1.7.doc SETTLEABILITY DATA FROM 2003 TESTS COMPARED TO STANDARD SVI-BASED FORMULAS FIGURE 1.7 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT June 29, 2010 - FINAL 1-14 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch01.docx Influent temperature data from 2005 through 2009 provided by the County were evaluated to determine the minimum 30-day running average summer (May 1 through October 31) temperature and the minimum 30-day running average year-round temperature. These data are shown in Figure 1.8. Based on the four years of data a minimum month summer temperature of 13.9 degrees Celsius (C) and a minimum month year-round temperature of 11.4 C were selected for use in the project. 1.5.1.3 Solids Residence Time The SRT of the activated sludge system is a key parameter for model calibration as it determines bacterial growth rates, which in turn determine oxygen consumption and sludge production for the system. Figure 1.9 presents data for aeration basin total SRT provided by the County. The SRT varied from a minimum of 2.1 days to a maximum of 5.8 days over the period of the data. The models used for this study were calibrated to the average total SRT during the 2007 calibration time period of 3.5 days. A key group of organisms for this evaluation are the nitrifiers. These organisms are sensitive to temperature as is illustrated in Figure 1.10. This graph shows the washout, or minimum, SRT for the nitrifiers as predicted by Jenkins, et al. 2004. At the minimum summer temperature of approximately 14 C, nitrifying organisms are washed out of the system when the aerobic SRT is less that approximately 6 days. At the minimum year- round temperature of approximately 11 C, the nitrifying organisms are washed out of the system when the aerobic SRT is less than approximately 12 days. With one-eighth of the existing aeration tanks operated anaerobically, only seven-eighths of the total SRT count towards aerobic SRT. In other words, for the total average SRT of 3.5 days maintained in the STP during 2007 the aerobic SRT would have been approximately 3.1 days. The summer nitrification temperature estimate presented in Figure 1.8 can be compared to the STP’s full-scale nitrification testing experience. During the summer of 2000 the STP was operated at a 10 to 14 day total SRT with one-eighth of the basin unaerated (resulting in an aerobic SRT of 9 to 12 days) and the RAS rate at maximum flow. During this period the plant was able to operate with good nitrification and secondary effluent ammonia concentrations less than 1 mg/L and reasonably good denitrification; with secondary effluent nitrate concentrations in the range of 10 to 15 mg/L. Based on this full-scale experience, modeling in BioWin and Biotran, and the minimum SRTs listed in Figure 1.6, the target aerobic SRT for the summer effluent scenario of 8 mg/L TIN was 9 days and the target aerobic SRT of the year-round effluent scenario of 3 mg/L TIN was 13 days. pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 1.8.doc TEMPERATURE DATA FOR THE PERIOD FROM 2005 TO 2009 FIGURE 1.8 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 1.9.doc SRT DATA FOR THE PERIOD FROM 2005 TO 2009 FIGURE 1.9 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT pw:\\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 1.10.doc WASHOUT AEROBIC SRT VALUES FOR NITRIFIER ORGANISMS FIGURE 1.10 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT June 29, 2010 - FINAL 1-18 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch01.docx 1.5.2 Model Calibration The “South Plant Peak Flow Management Report” (Carollo Engineers, 2010) described three different approaches to the BioW in model calibration as summarized below: 1. The default values from BioWin for raw sewage 2. The values from Biotran calibrated to 2007 STP data 3. Values assumed in the 2000 Brown and Caldwell evaluation The Peak Flow Management Report found little difference between the three different calibration approaches. Based on this finding, the second calibration approach, using 2007 STP data, was used to calibrate the model for this study. Data received from the County for the year 2007 was used to match primary organics removal, the amount of solids produced in waste activated sludge (WAS), and the recorded solids residence time for the average mixed liquor suspended solids for the period. Two primary parameters were used to produce the calibration: the apparent filterable BOD5 fraction (filterable BOD5 fraction (fbf) = 0.415) and the non-biodegradable volatile suspended solids (non-biodegradable volatile fraction (fvu) = 0.15). These values were used to produce wastewater characteristic ratios for the raw wastewater. These characteristic ratios were in turn used as input to a BioWin model of the entire STP. 1.5.3 Modeling Results TIN 8 Based on the calibrated BioWin model and an assumed aerobic SRT of 9 days, the secondary effluent scenario of 8 mg/L TIN can be met with a reduced maximum summer month flow of 36 mgd (or 37 percent of the design maximum summer month flow of 98 mgd). This scenario assumes one aeration basin and one secondary clarifier out of service as decided in the October 1, 2009 workshop. For this scenario the activated sludge basins would be operated in a Modified Ludzak-Ettinger (MLE) configuration shown in Figure 1.11. With this configuration, the entire first pass would be unaerated, increasing the unaerated fraction form 12.5 percent to 25 percent. The unaerated fraction would serve as the anoxic zone where in the bacteria would convert nitrate to nitrogen gas. Additional nitrate would be returned to the anoxic zone by a mixed liquor return (MLR) pump. Based on the modeling the optimal flow rate for this pump would be 360 percent of the influent flow. The remaining 75 percent of the activated sludge basin would be aerated. It is in this portion of the basin that nitrifying bacteria would convert ammonia to nitrate. In the absence of oxygen, denitrifying bacteria use nitrate as an oxygen source. The MLE configuration is considered a pre-anoxic denitrification process, since the denitrification process precedes the nitrification process. This is an optimal configuration for denitrification because the denitrification process occurs in the zone with the highest BOD5 concentration. However, when denitrification processes follow primary clarification, the BOD5 available from the wastewater can limit the extent of denitrification. pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 1.11.docx MLE SCHEMATIC FIGURE 1.11 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT June 29, 2010 - FINAL 1-20 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch01.docx It is generally thought that a BOD5 to TKN ratio of at least 4 is required for denitrification (Randall et al., 1992). The BOD5 to TKN ratio of the STP primary effluent is approximately equal to the minimum ratio. Through modeling it was determined that for the STP without an external carbon source, a 50 percent anoxic zone size would be required. Since this severely limits the capacity of the system, if was assumed that the anoxic zone size would be limited to 25 percent and an external carbon source in the form of methanol would be used. Table 1.3 summarizes the modeling results for this scenario. To meet the TIN limit of 8 mg/L, the following modifications would be needed to the existing plant: • Added baffle wall at the end of the first pass • Mixed liquor return pumps capable of delivering 360 percent of the influent flow • Methanol delivery system and methanol storage • Additional diffusers to the second pass of the aeration basins • Additional plant capacity for the remainder of the design year flow (or 62 mgd maximum summer month). This will be addressed in the subsequent chapter. Table 1.3 Current Configuration – TIN 8 mg/L Scenario Modeling Results South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division Value Design Maximum Summer Month Flow 36 mgd Aeration Basins Aeration Basins in Service 3 Unaerated Fraction 25% RAS Rate 58% MLR Rate 360% MLSS Concentration 3,700 mg/L Aeration Air Requirement 40,000 scfm Methanol Feed Flow Rate 1,400 gpd COD Load 13,900 ppd COD Secondary Clarification Secondary Clarifiers in Service 23 Secondary Effluent Ammonia 0.2 mg/L Nitrate 7.5 mg/L Nitrite 0.07 mg/L TIN 7.8 mg/L June 29, 2010 - FINAL 1-21 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch01.docx 1.5.4 Modeling Results TIN 3 Based on the calibrated BioWin model and an assumed aerobic SRT of 13 days, the secondary effluent scenario of 3 mg/L TIN can be met with a reduced maximum month flow of 30 mgd (or 21 percent of the design maximum month flow of 144 mgd). This capacity rating assumes one aeration basin and one secondary clarifier out of service, as decided at the October 1, 2009 workshop. For this scenario the activated sludge basins would be operated in a Bardenpho configuration shown in Figure 1.12. With this configuration, the entire first pass would be unaerated, the second and third passes would be aerated, 80 percent of the fourth pass would be unaerated, and 20 percent of the fourth pass would be aerated. This process would increase the unaerated fraction form 12.5 percent to 45 percent. The Bardenpho process incorporates both pre-anoxic and post-anoxic denitrification. The first two zones (or the first three passes at STP) would function very similarly to the MLE process described above. The last two zones (or the last pass at STP) are polishing zones that, combined with an external carbon source, can reduce the residual TIN to values less than 3 mg/L. Table 1.4 summarizes the modeling results for this scenario. To meet the TIN limit of 3 mg/L, the following modifications would be needed to the existing plant: • Three additional baffle walls, one at the end of the first pass and the second and third in the fourth pass • Mixed liquor return pumps capable of delivering 350 percent of the influent flow • Methanol delivery system and methanol storage • Additional plant capacity for the remainder of the design year flow (or 114 mgd maximum summer month). This will be addressed in the subsequent chapter. pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 1.12.docx BARDENPHO SCHEMATIC FIGURE 1.12 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT June 29, 2010 - FINAL 1-23 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch01.docx Table 1.4 Current Configuration – TIN 3 mg/L Scenario Modeling Results South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division Value Design Maximum Summer Month Flow 30 mgd Aeration Basins Aeration Basins in Service 3 Unaerated Fraction 45% RAS Rate 100% MLR Rate 350% MLSS Concentration 3,700 mg/L Aeration Air Requirement 20,500 scfm Methanol Feed Flow Rate 150 gpd COD Load 1,500 ppd COD Secondary Clarification Secondary Clarifiers in Service 23 Secondary Effluent Ammonia 0.4 mg/L Nitrate 2.15 mg/L Nitrite 0.1 mg/L TIN 2.65 mg/L 1.6 CONCLUSIONS This project was initiated based on the South Puget Sound Study findings which suggest that the South Puget Sound may have excess nitrogen. A project team was assembled to evaluate the impacts of potential future nitrogen limits on the capacity of the STP. A full- plant model was developed and calibrated to operating data collected at the plant. The project team decided on two effluent nitrogen scenarios representing the anticipated “least stringent” and “most stringent” permitting scenarios at the October 1, 2009 workshop. At this workshop, the project team also decided that the capacity rating of the current plant to meet the two target nitrogen effluent scenarios would be determined with one aeration basin and one secondary clarifier out of service. Based on these assumptions, the modeled capacity of the current STP to meet the “least stringent” summer effluent limit of 8 mg/L TIN was 36 mgd. To meet this effluent limit, minor modifications would be needed at the current plant including the addition of baffle walls, MLR pumps and a chemical delivery system. Major modifications that would be needed would be the construction of a new treatment plant to treat the remainder of the summer flow (approximately 62 mgd). June 29, 2010 - FINAL 1-24 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch01.docx Based on these assumptions, the modeled capacity of the current STP to meet the “most stringent” year-round effluent limit of 3 mg/L TIN was 30 mgd. To meet this effluent limit, minor modifications would be needed at the current plant including the addition of baffle walls, MLR pumps and a chemical delivery system. Major modifications that would be needed would be the construction of a new treatment plant to treat the remainder of the flow (approximately 114 mgd). Chapter 2 addresses alternatives to treat the entire flow to the two target effluent nitrogen limits. June 29, 2010 - FINAL 2-1 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx Chapter 2 SOUTH PLANT NITROGEN REMOVAL SCENARIOS 2.1 INTRODUCTION Chapter 1 described project assumptions and evaluated how much flow the existing South Treatment Plant (STP) could process if required to comply with a summer seasonal limit of 8-milligrams per liter (mg/L) total inorganic nitrogen (TIN) or an annual limit of 3-mg/L TIN and what modifications would be required for nitrogen removal. This chapter (Chapter 2) describes potential effects on to the STP (e.g., tankage, footprint, cost, greenhouse gas emissions) if it were required to meet the assumed seasonal or year-round limit while maintaining its current rated capacity (144-million gallons per day (mgd) max month year- round and 98-mgd max month during summer). Four nitrogen (N) removal alternatives were selected for evaluation under each assumed permit limit. Two representative alternatives, one each for the seasonal limit and annual limit, were subsequently selected for a more detailed cost estimate, sensitivity analysis, and sustainability analysis. The cost estimates are considered to be order of magnitude estimates, i.e., in the +50 to -30 percent accuracy range. The representative alternative in each case was the approach that best met the weighted evaluation criteria developed by the project team for each nitrogen removal scenario. It is intended to be a “representative” approach by which the costs and effects of implementing nitrogen removal at South Plant can be assessed. 2.2 ALTERNATIVES SCREENING 2.2.1 Nitrogen Removal Alternatives Table 2.1 summarizes four different classes of nitrogen removal alternatives. These were the four classes of alternatives discussed at the first project workshop (Carollo, 2009a). At the workshop a large number of possible treatment scenarios for nitrogen removal were considered and screened by consensus of the meeting to a narrower range of alternatives as discussed below. 2.2.1.1 Land-based Alternatives Land-based alternatives rely on anoxic wetting and aerobic drying cycles to convert ammonia to nitrate and nitrate to nitrogen gas. The nitrifying and denitrifying organisms are present in both the wastewater and the soil communities. All of these alternatives are land intensive and would not fit on the available site at STP. It is not likely that any of these alternatives could reliably meet either of the two selected effluent permit levels for TIN. June 29, 2010 - FINAL 2-2 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx Table 2.1 Nitrogen Removal Alternatives South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division Land Based Aquatic Chemical Biological Infiltration Basins Wetlands Ion Exchange Suspended Growth Overland Flow Wetlands Ion Exchange Suspended Growth Spray Irrigation Floating Aquatic Plants Crystallization Breakpoint Chlorination Hybrid Side Stream 2.2.1.2 Aquatic Alternatives Aquatic alternatives rely on aerobic biological processes to convert ammonia to nitrate and anoxic biological processes to convert nitrate to nitrogen gas. As with the land-based alternatives, these processes are land intensive and would not fit on the available site at STP. Furthermore, experience with these systems elsewhere indicates that they would not likely be able to reliably meet either of the two effluent limit scenarios. 2.2.1.3 Chemical Alternatives Chemical alternatives rely on changes to effluent quality through chemical reactions. This section summarizes these processes. In ion exchange treatment systems the ammonium ion (NH4+) and the nitrate ion (NO3-) displace ions on a natural or synthetic ion exchange resin. Clinoptilolite is one of the most frequently used resins, due to its high affinity for ammonium and it’s relatively low cost. In air stripping, nitrogen - specifically, ammonia - can be stripped from the wastewater into the atmosphere by passing air through the wastewater. To ensure effective N removal, lime or caustic are typically added to raise the wastewater pH above pH 10.5-11. The high pH converts most of the ammonia species in wastewater to the molecular NH3 form, which is volatile. In general, this process requires large quantities of chemical, which produce large quantities of chemical sludge, and is less effective at the relatively low wastewater temperatures of the STP than it would be in a warmer climate. A draw back of air stripping is that while ammonia is removed from the water it is added to the atmosphere, potentially contributing to air pollution. Crystallization is the process by which nitrogen and phosphorus are removed through the formation of crystals such as struvite (ammonium magnesium phosphate - NH4MgPO4·6H2O). The Ostara Company produces struvite as a fertilizer in a proprietary fluidized bed reactor. This process is ideally suited as a side stream treatment on the anaerobic digester return stream for treatment plants employing biological phosphorus removal. Ammonia removal by struvite formation is usually limited by available phosphorus. Typical ammonia removal through this process ranges from 10 to 15 percent. Since June 29, 2010 - FINAL 2-3 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx phosphorus removal is not required in the scenarios considered for this report, struvite crystallization was not considered further for the STP. Breakpoint chlorination is the process by which sufficient chlorine is added to stepwise oxidize ammonium to chloramines and finally to nitrogen gas, as summarized in the following reaction: 2NH4+ + 2HOCl  2NH2Cl + HOCl  NHCl2 + NOH  N2(gas) + HOCl + HCl (This reaction is not balanced and does not show H2O and H+) As demonstrated in the above reaction, approximately 1.5 moles of hypochlorite (HOCI) are required for every mole of ammonium reduced. For the STP with an average effluent ammonia concentration of 30 milligrams per liter (mg/L), this process would require hypochlorite doses of approximately 200 mg/L. For comparison, the current hypochlorite dose for disinfection at the STP is about 2-2.5 mg/L with an annual product cost around $370,000. If breakpoint chlorination were implemented at the STP, additional costs would need to be incurred for alkalinity replacement. As is shown in the above reaction, breakpoint chlorination produces an acid which would cause the pH to decrease without an alkalinity supplement. None of the chemical alternatives were selected for further evaluation due to their high operating costs and low effectiveness at temperatures typical of the Pacific Northwest. 2.2.1.4 Biological Alternatives Biological nitrogen removal (BNR) alternatives can be divided into four basic groups: suspended growth, attached growth, hybrid (both suspended and attached growth), and side stream treatment. These alternatives can be coupled with a clarifier as shown in Figure 2.1 or with a membrane filter to operate as a membrane bioreactor (MBR) process. The current STP secondary process is a suspended growth, conventional activated sludge (CAS) process with clarifiers. 2.2.1.4.1 Suspended Growth Alternatives In the suspended growth nitrogen removal alternatives, the nitrifying and denitrifying organisms are suspended in the activated sludge mixed liquor. Examples of feasible suspended growth processes are the Modified Ludzak-Ettinger (MLE), Bardenpho, and step feed configurations with alternating anoxic and aerobic zones. This section briefly describes each of these configurations. A schematic of an MLE configuration is shown in Figure 2.1. The MLE process includes an unaerated zone followed by an aerated zone with mixed liquor return (MLR) flow (in the range of 200 to 500 percent of the influent flow) from the aerated zone back to the anoxic zone. In the unaerated, anoxic zone denitrifying bacteria convert nitrate to nitrogen gas and in the aerobic zone, the nitrifying organisms convert ammonia to nitrate. This configuration is considered a pre-anoxic denitrification process, since the denitrification process precedes the nitrification process. pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.1.docx MLE SCHEMATIC FIGURE 2.1 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT June 29, 2010 - FINAL 2-5 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx This is an optimal configuration for denitrification because the denitrification process occurs in the zone with the highest food or five-day biochemical oxygen demand (BOD5) concentration. However, when denitrification processes follow primary clarification, the BOD5 available from the wastewater can limit the extent of denitrification and an external carbon source (methanol is the most common carbon source used currently) could be required for effective nitrogen removal. The efficiency of the MLE process depends on the carbon to nitrogen ratio of the aeration basin influent, the MLR flow rate, and the size of the anoxic zone. Generally, this process cannot meet TIN limits below 5 mg/L and in most situations is better suited to meet a TIN limit in the range of 8 to 12 mg/L. This process can be coupled with a clarifier as shown in Figure 2.1 or with a membrane filter and operated as a MLE MBR process. A schematic of a Bardenpho configuration is shown in Figure 2.2. This is a four-zone process with an initial anoxic zone, followed by an aerobic zone, which is followed by another anoxic zone and a final aerobic zone. This process also includes a MLR from the second zone to the first zone, typically in the range of 200 to 500 percent of the influent flow. The Bardenpho process incorporates both pre-anoxic and post-anoxic denitrification. The first two zones function identically to the MLE process described above. The last two zones are polishing zones that, combined with an external carbon source, can reduce the residual TIN to values less than 3 mg/L. This process can be coupled with a clarifier as shown in Figure 2.2 or with a membrane filter and operated as a Bardenpho MBR process. A step feed configuration includes multiple anoxic and aerobic zones with the activated sludge influent split between each of the anoxic zones and the return activated sludge (RAS) directed to the first anoxic zone. A schematic of the step feed process is shown in Figure 2.3. This process is very similar to the MLE configuration, except that instead of a MLR stream, the nitrate rich effluent from the aerobic zone proceeds to an anoxic zone. The step feed process typically obtains comparable ammonia removal and better nitrogen removal than a plug flow process with the same flow and tank volume. This occurs because the split feed dilutes the mixed liquor suspended solids (MLSS) as it travels through the aeration basin, permitting a higher solids inventory to be maintained for a given clarifier flow rate. Conversely, a step feed process of the same volume can accommodate a higher flow for a given degree of nitrogen removal, but with higher effluent ammonia concentrations. Step feed can be combined with a post-anoxic zone in the last pass to meet low effluent TIN limits. 2.2.1.4.2 Attached Growth Alternatives In attached growth nitrogen removal processes, the nitrifying and denitrifying bacteria are attached to solid media. Attached growth nitrogen removal alternatives include stationary bed, trickling filter, and moving bed applications. pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.2.docx BARDENPHO SCHEMATIC FIGURE 2.2 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.3.docx STEP FEED SCHEMATIC FIGURE 2.3 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT June 29, 2010 - FINAL 2-8 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx Examples of the stationary bed process are the biological aerated filter (BAF) and the denitrifying filter (DNF). Generally, BAFs are used exclusively for nitrification followed by a DNF for denitrification. In these filters, biomass grows on expanded shale media or polystyrene pellets, and usually, no additional clarification or filtration is required. Both the BAF and DNF follow the CAS process. The initial DNFs were single media, downflow, deep bed filters. Many DNFs are now being marketed by the BAF manufacturers that are upflow reactors. If filtration is not required, these upflow DNFs can be more highly loaded than the downflow counterparts. DNFs require a source of carbon; usually methanol is added. This process can provide nearly complete denitrification. A schematic of a BAF/DNF process for the STP is shown in Figure 2.4. In trickling filters, wastewater is distributed over solid media which were originally rocks and are now almost exclusively a plastic cross flow media. The trickling filter process can provide nitrification with the denitrification process occurring in a separate DNF. The moving bed bioreactor (MBBR) is a reactor tank containing random media upon which microorganism growth is facilitated by aeration. Existing activated sludge basins could be retrofitted to MBBR basins. The media generally consists of plastic wagon wheels or sponges as illustrated in Figure 2.5. 2.2.1.4.3 Hybrid Alternatives A hybrid process combines suspended growth with attached growth. The main hybrid alternative for nitrogen removal is the integrated fixed film activated sludge (IFAS) process. In an IFAS process, plastic media, ropes, or sponges are added to an aeration tank to provide surfaces upon which bacteria attach and grow with the intent of increasing the overall biomass inventory in the aeration tank (see Figure 2.5 for media examples). An IFAS process is configured like an activated sludge process with RAS introduced into the first reactor tank in the process. Biomass growing on the media allows for greater nitrogen removal with no increase in the overall aeration basin or clarifier volume. Most IFAS media systems are proprietary, but there are many suppliers, allowing competitive selection of IFAS media and equipment. The IFAS system differs from the previously discussed MBBR system in that it incorporates both fixed film processes (the biofilm growing on the media) with suspended growth processes through the RAS recycle. Most IFAS systems only add media to aerobic zones; however, at least one supplier has some experience with the use of fixed media in anoxic zones. The IFAS process can be configured in either the MLE configuration or the Bardenpho configuration to add nitrogen removal capacity to existing aeration basins. The IFAS process requires intermediate screens and/or internal recirculation pumping at the end of the aeration basin to keep the media evenly distributed in the reactor. A schematic of an MLE IFAS alternative for the STP is shown in Figure 2.6. pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.4.docx BAF/DNF SCHEMATIC FIGURE 2.4 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.5.docx EXAMPLES OF MEDIA USED IN MBBR AND IFAS PROCESSES FIGURE 2.5 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.6.docx MLE IFAS SCHEMATIC FIGURE 2.6 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT June 29, 2010 - FINAL 2-12 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx 2.2.1.4.4 Side stream Alternatives Solids treatment processes, including the anaerobic digestion process employed at the STP, usually generate return flows, or side streams, rich in nutrients. In anaerobic digestion carbonaceous components of the treated sludge stream are converted to methane gas. Mineralized nutrients like nitrogen and phosphorus compounds remain in the liquid stream that is returned to the main liquids treatment process in the side stream flow from sludge dewatering. A number of processes, many of them proprietary, have been developed for treatment of ammonia-rich side streams from solids processing facilities. These include the Sharon® process, which operates by encouraging a special pathway for nitrogen removal: instead of employing the normal, four-stepped, process of conversion of ammonia to nitrite and then to nitrate and from nitrate to nitrite and then to nitrogen gas, this process proceeds at elevated temperature to encourage a two-step conversion from ammonia to nitrite and from nitrite directly to nitrogen gas. A full-scale installation of a Sharon® process recently was constructed in New York City. Another proprietary process, Anammox®, employs special bacteria that oxidize ammonia using nitrite and nitrate as electron acceptors. This process, which doesn’t require oxygen, operates at elevated temperature and requires strict control of pH. It operates at high (30- 50 day) solids residence time (SRT). It can be operated with Sharon®. This process has been operated only at bench scale to date in the United States (U.S.). The first full-scale Anammox® plant was started up in the Netherlands in 2002 and several are installed for operation in Europe. The InNitri® process provides nitrification of side stream flows and employs what is called bioaugmentation to return a stream of waste nitrifying organism to the main activated sludge treatment system to increase the number of viable organisms there. Although developed over ten years ago, currently there are no full-scale InNitri® installations. Two applications have progressed to pilot scale in the U.S., which has led to one full-scale installation currently being bid for construction. Perhaps the most fundamental side stream treatment alternative is centrate reaeration. A schematic of this alternative is shown in Figure 2.7. In this alternative the ammonia-rich centrate is combined with the high-suspended solids concentration RAS stream in a separate basin, where the high ammonia concentrations yield faster transformation rates of ammonia to nitrate. Nitrifiers grown in the side stream reactor are returned to the liquid stream nitrification process. An alternate configuration is to locate the treatment tank directly on the centrate return stream. This side stream treatment process can be used with a nitrogen removal alternative to add capacity. Centrate reaeration was selected at the workshop to serve as the representative process for side stream treatment. pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.7.docx CENTRATE REAERATION SCHEMATIC FIGURE 2.7 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT June 29, 2010 - FINAL 2-14 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx 2.2.2 Initial Alternatives Screening Results At the first workshop in October 2009, four nitrogen removal alternatives were selected for further evaluation for each nitrogen removal scenario. These selected alternatives represent a range of different biological alternatives including suspended growth, attached growth, and hybrid processes. For the 8 mg/L TIN (summer-only) scenario, the selected processes were: • MLE • MLE – MBR • MLE – IFAS • BAF/DNF For the 3 mg/L TIN (year-round) scenario, the selected processes were: • Bardenpho • Bardenpho – MBR • Bardenpho – IFAS • BAF/DNF The following section discusses initial evaluation of these alternatives and selection of a representative alternative for each nitrogen removal permit scenario for a more detailed evaluation. For each representative alternative, side stream treatment was evaluated to determine whether additional treatment could reduce the footprint and cost of the alternative. 2.2.3 Nitrogen Removal Alternatives Analysis The four selected alternatives for each nitrogen limit scenario were evaluated to determine a relative cost and footprint for each alternative. This section summarizes these findings. 2.2.3.1 8 mg/L TIN (summer-only) Scenario For each of the alternatives evaluated under the 8 mg/L TIN (summer-only) scenarios, except for the BAF/DNF alternative, it was assumed that the aeration basins would operate with a 9-day aerobic SRT during maximum summer month flows (98 mgd) with one basin out of service. Additionally, it was assumed that new aeration tanks would be the same side water depth as the current tanks. For the MLE alternative, nine new aeration tanks with a total volume of 42 million gallons (MG ) would be required in addition to the existing four aeration tanks. The existing four tanks would provide a capacity of 30 mgd (assuming one tank out of service) and the June 29, 2010 - FINAL 2-15 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx additional nine aeration tanks would provide an additional 68-mgd capacity. All of the aeration tanks (existing and new) would require baffles, mixers, mixed liquor return pumps and methanol storage and dosing equipment. No additional clarifiers would be required. The capacity of the existing plant would be less than the de-rated capacity described in Chapter 1 because this alternative assumes that all the summer maximum month flow is directed to the existing clarifiers, while the capacity rating in Chapter 1 assumed only 30-40 mgd through the existing clarifiers. This higher flow results in a decreased MLSS concentration and reduces the capacity of the existing plant to meet projected growth consistent with the Regional Wastewater Services Plan or to respond to future, more restrictive, effluent standards. This alternative would fit on the site but would leave no room for expansion. Figure 2.8 provides a schematic of the footprint of this alternative. For the MLE-MBR alternative, two new aeration tanks and 11 new membrane tanks would be built with a capacity for 62 mgd of maximum month flow. This new MBR facility would be operated as a separate, parallel secondary process. The two new MBR aeration tanks (with a volume of 4.7 MG each) would have a greater capacity than the CAS aeration tanks because the membranes can perform at a very concentrated MLSS concentration compared to the clarifiers. The existing aeration tanks and clarifiers would be modified for the MLE process, and have a capacity of 36 mgd assuming one aeration tank out of service. No additional clarifiers would be required. As is shown in Figure 2.9, this alternative would fit on the site and would retain room for expansion to meet projected growth. In the MLE-IFAS alternative, the existing aeration basins would be converted to IFAS basins. Depending on manufacturer’s claims and assumed packing densities, (between 1 to 5) new aeration basins would be required with a volume of 4.7 MG each. This alternative would fit on the site as is shown in Figures 2.10 and 2.11. For the BAF/DNF alternative, the existing plant would be operated in the same manner as it is currently operated, resulting in no change in capacity. To achieve the 8 mg/L TIN (summer-only) limit, 25 BAF units and 14 DNF units would be added. This sizing was based on an ammonia loading rate of 60 pounds per day per thousand cubic foot (ppd/kcf) of filter volume for nitrification and 120 ppd/kcf of nitrate loading for denitrification. Methanol addition would be required at the DNF. This alternative fits on the site and allows for expansion as is shown in Figure 2.12. Table 2.2 summarizes the footprint requirements of each alternative. Footprint estimates are primarily for comparative purposes and do not currently account for other features that can consume footprint such as roads, odor control, and ancillary equipment. The MLE alternative requires the greatest footprint and provides very little space for the plant to expand to treat future flows or to respond to future changes in effluent quality requirements while the BAF/DNF and MLE-MBR alternatives provide the most available space for future expansion. The MLE-IFAS alternative could be very attractive from a footprint standpoint if the most aggressive of the manufacturer’s performance and design criteria could be confirmed. pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.8.docx MLE FOOTPRINT 8 MG/L TIN (SUMMER ONLY) FIGURE 2.8 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT New Aeration Basins Existing aeration basins modified with new baffle walls, mixers and diffusers pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.9.docx MLE – MBR 8 MG/L TIN (SUMMER ONLY) FOOTPRINT FIGURE 2.9 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT New Aeration Basins New Membrane Tanks New aeration basins modified with baffle walls, diffusers and mixers pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.10.docx MLE – IFAS FOOTPRINT 8 MG/L TIN (SUMMER ONLY) (CONSERVATIVE SIZING) FIGURE 2.10 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT New Aeration Basins with IFAS media Existing basins modified with baffle walls, diffusers and mixers along with IFAS media pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.11.docx MLE – IFAS FOOTPRINT 8 MG/L TIN (SUMMER ONLY) (AGGRESSIVE SIZING) FIGURE 2.11 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT New Aeration Basins, with IFAS media Existing aeration basins modified with new baffle walls, mixers and diffusers along with IFAS media pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.12.docx BAF/DNF 8 MG/L TIN (SUMMER ONLY) FOOTPRINT FIGURE 2.12 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT DAF DNF June 29, 2010 - FINAL 2-21 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx Table 2.2 8 mg/L TIN (Summer-only) Alternative Footprint Analysis South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division MLE MLE-MBR MLE-IFAS BAF / DNF Total added basins, acres 8.3 2.5 .9 to 4.4 2.3 Approximate full-buildout capacity assuming no expansion on the biosolids site(1) 144 mgd 270 mgd 210 – 360 mgd 270 mgd Notes: (1) Capacity ratings are based on maximum month flows during the summer months. The maximum month flow capacity of the current plant for summer flows is 98 mgd. The assumed density of aeration basins is based on the proposed STP site buildout layout provided by the County. No extra allowances were made for roads or ancillary facilities. 2.2.3.2 3 mg/L TIN (Year-round) Scenario For the first three of the 3 mg/L TIN (year-round) scenarios (excluding the BAF/DNF alternative), it was assumed that the aeration basins would operate at a 13-day aerobic SRT during the maximum month loads and flows (144 mgd) with one basin out of service. Modification of the existing aeration tanks would be required for each of these three alternatives. Methanol addition would be required for all four alternatives. For the Bardenpho alternative, 24 new aeration tanks (each with a volume of 4.6 MG) and four new secondary clarifiers would be required in addition to the existing four aeration tanks and 24 clarifiers. Once modified, the existing four tanks would provide a capacity of 17 mgd (assuming one aeration tank is out of service) and the additional 24 aeration tanks would provide an additional capacity of 127 mgd. All of the aeration tanks would require baffles, mixers, MLR pumps, and methanol storage and dosing equipment. The capacity of the existing plant is less than the de-rated capacity described in Chapter 1 because this alternative assumes that all the maximum month flow is directed to the existing clarifiers, while the capacity rating in Chapter 1 assumed only 30 mgd through the existing clarifiers. This higher flow results in a decreased MLSS concentration and reduces the capacity of the existing plant. This does not fit within the available site area. Figure 2.13 provides a schematic of the footprint impact of this alternative. For the Bardenpho MBR alternative, the existing plant would be de-rated to approximately 30 mgd and a parallel MBR plant would be added consisting of seven new aeration tanks (with a total volume of 25 MG) and 20 new membrane tanks. Membrane tank sizing was based on continuous 20 degree flux rates of 15 gallons per day per square foot (gpd/sf) of membrane area. As is shown in Figure 2.14, this alternative fits on the site and allows room for minimal expansion. In this design the existing activated sludge system would handle peak flow rates. It was assumed that the peak flows up to 242 mgd would pass through the existing activated sludge clarifiers while the MBR process was operated at a constant flow of approximately 114 mgd. pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.13.docx BARDENPHO 3 MG/L TIN (YEAR ROUND) FOOTPRINT FIGURE 2.13 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT New Aeration Basins Existing aeration basins modified with new baffle walls, mixers and diffusers pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.14.docx BARDENPHO - MBR 3 MG/L TIN (YEAR ROUND) FOOTPRINT FIGURE 2.14 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT New Aeration Basins Membrane Tanks Existing aeration basins modified with baffle walls, mixers and diffusers June 29, 2010 - FINAL 2-24 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx The adequacy of any nutrient removal scheme depends on the interplay between loading and regulatory requirements. The Bardenpho MBR alternative was sized on the assumption that nitrogen removal requirements would be met over a maximum month of loading. The analysis was based on steady state modeling in Carollo’s Biotran program and in the commercial model BioWin, but a sensitivity analysis was performed in BioWin to investigate the effects of dynamic loading. In the Bardenpho-IFAS alternative, the existing aeration basins would be converted to IFAS basins. Depending on manufacturer’s claims and assumed packing densities, between 2 to 16 new aeration basins (with a volume of 4.4 MG each) would be required. An initial conservative sizing for IFAS using random media was based on the default packing density from the BioWin media reactor of 25 percent. Subsequent communication from the random media manufacturer indicated that densities up to 65 percent could be used. For the conservative sizing assumption (using the 25 percent packing density), four new secondary clarifiers were assumed to allow the plant to run at a higher MLSS concentration. As is shown in Figure 2.15, the conservative sizing assumption would not fit on the site. However, a Bardenpho IFAS alternative would fit on the site assuming the aggressive sizing assumption shown in Figure 2.16. The aggressive sizing was based on the assumption that an effective MLSS concentration in the existing aeration tanks could be maintained by use of sponge media of approximately 8,500 mg/L, including both free and embedded biomass. This assumption has been based on experience at one operating facility in the U.S. Sizing for this alternative by the manufacturer assumed 10,000 gpd of methanol use, approximately three times the amount required for the Bardenpho MBR alternative. For the BAF/DNF alternative, the existing plant would be operated in the same manner as it is currently operated, resulting in no change in capacity. To achieve the 3 mg/L TIN (year- round) limit, 52 BAF units and 19 DNF units would be added. This sizing was based on a loading rate of 28 ppd/kcf for nitrification and 98 ppd/kcf of nitrate loading for denitrification. Methanol addition would be required for the DNF. Peak hydraulic flows of 242 mgd would be handled through the existing plant as they currently are, with up to 144 mgd going to the BAF and DNF and the remaining flow going to effluent. This alternative fits on the site and allows for minimal expansion as is shown in Figure 2.17. Table 2.3 summarizes the footprint requirements of each alternative. Footprint estimates are primarily for comparative purposes and do not account for additional features that can consume footprint such as roads, odor control, and ancillary equipment, etc. The Bardenpho alternative requires the greatest footprint and does not fit on the site while the BAF/DNF and Bardenpho-MBR alternatives provide the most available space for future expansion. The Bardenpho-IFAS alternative could be very attractive from a footprint standpoint if the aggressive version of manufacturer’s claims and assumed packing densities could be confirmed. pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.15.docx BARDENPHO - IFAS 3 MG/L TIN (YEAR ROUND) FOOTPRINT CONSERVATIVE SIZING FIGURE 2.15 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT New Aeration Basins, with IFAS media IFAS media added to existing basins, along with baffle walls, new diffusers and mixers pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.16.docx BARDENPHO - IFAS 3 MG/L TIN (YEAR-ROUND) FOOTPRINT AGGRESSIVE SIZING FIGURE 2.16 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT New aeration basins with IFAS media and baffle walls Existing aeration basins modified with baffle walls, mixers, new diffusers and IFAS media pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.17.docx BAF/DNF 3 MG/L TIN (YEAR-ROUND) FOOTPRINT FIGURE 2.17 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT DNF BAF June 29, 2010 - FINAL 2-28 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx Table 2.3 3 mg/L TIN (Year-round) Alternative Foot Print Analysis South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division Bardenpho Bardenpho- MBR Bardenpho- IFAS BAF / DNF Total added basins, acres 23.2 6.7 1.8 – 11.6 4.3 Full buildout capacity assuming no expansion on the biosolids site(1) TL(2) 170 mgd TL - 300 mgd 240 mgd Notes: (1) Capacity ratings are based on maximum month flows. The maximum month flow capacity of the current plant is 144 mgd. The assumed density of aeration basins is based on the proposed STP site buildout layout provided by the County. No extra allowances were made for roads or ancillary facilities. (2) TL = estimated foot print is too large and does not fit on the site. 2.3 ALTERNATIVES EVALUATION Based on team input from the first workshop, the four alternatives for each nitrogen limit scenario were evaluated based on the following cost and non-cost criteria: • Onsite capital costs: Approximate planning level capital costs were estimated for construction of facilities on the STP site. Treatment of future flows off-site was not considered. Capital costs included construction costs and appropriate additional allowances for contingency, allied cost, sales tax, and other anticipated ancillary costs. Costs were indexed to estimated unit prices for March 15, 2010. The expected accuracy range for this type of estimate is defined by the Association for the Advancement of Cost Engineering (AACE) as a Level - 5 Order of Magnitude Estimate and has an expected accuracy range of +50 to -30 percent. Cost assumptions are summarized in Appendix B. • Operation and Maintenance (O&M) costs: Approximate O&M costs were considered based on average annual flows and loads for a midpoint flow. The midpoint flow was established as the average between the 2007 average annual flow of 84.9 mgd and the estimated 108 mgd average annual flow associated with the maximum month design capacity of 144 mgd. The costs were therefore based on an average annual flow of 96.5 mgd. O&M costs included: labor, energy, and chemical costs and allowances for structural maintenance and equipment replacement. O&M costs were estimated based on an Environmental Protection Agency (EPA) database for unit process labor, estimated power requirements and chemical consumption, and allowances for structural and equipment maintenance. • Risk: Risk was defined in reference to the County’s familiarity with the process and the number of worldwide installations. June 29, 2010 - FINAL 2-29 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx • Future Flexibility: Future flexibility was only considered for the 8 mg/L TIN (summer- only) effluent scenario and was defined as the ability of the selected process to meet a future 3 mg/L TIN (year-round) limit. • Footprint: An approximate process footprint for each alternative was determined based on the area required for new process tanks. No allowances were made for ancillary facilities. • Energy: Energy use was estimated for each alternative based on factors such as estimated blower demand, pumping, and membrane air scour needs. • Odor: The odor production potential of each alternative was qualitatively compared to the other alternatives for each nitrogen limit scenario. • Compatibility with existing processes: The compatibility with existing processes was defined as whether or not the selected process would result in stranding of significant assets, such as secondary clarifiers. • Biosolids Quality: The biosolids quality (nitrogen and phosphorus content) was qualitatively compared for each alternative to adversely impact on the beneficial use of biosolids. • Reclaimed water quality/quantity: Both reclaimed water quality and quantity were compared for each alternative. Aspects of this comparison included whether the alternative produced an easily filterable effluent and whether the alternative left room on the site for future reclaimed water filters. Each of these criteria was scored from 1 (low) to 3 (high) based on scoring definitions provided in Appendix A. The weighting for each criterion was established by the team at the second workshop. Criterion weights for capital and O&M costs were maintained at a weight of 1 since workshop participants did not want cost factors to overshadow evaluation of other factors. Table 2.4 and 2.5 present the weighted results for each effluent limit scenarios. Based on this analysis, the two leading alternatives for both effluent limit scenarios were the MBR and BAF/DNF. The County decided to select the MBR system as the representative alternative for both effluent limit scenarios. The team concluded that the BAF/DNF system should be considered in more detail at a facility planning or pre-design level. Since aggressive IFAS sizing potentially offers a very competitive alternative, the County may want to consider pilot testing to determine the optimum kinetic parameters and packing densities. June 29, 2010 - FINAL 2-30 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx Table 2.4 8 mg/L TIN (Summer-only) Scoring Matrix South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division Score Criteria Weight MLE MBR IFAS A(1) IFAS C(2) BAF Onsite Capital Cost 1 3 2 3 1 3 O&M Cost 1 3 1 2 2 2 Risk 2 3 3 0(3) 1 2 Future Flexibility 2 1 3 3 1 3 Footprint 3 1 3 3 2 3 Energy 2 3 2 3 1 2 Odor 1 2 2 2 2 2 Compatibility with existing processes 1 3 3 3 3 3 Biosolids Quality 1 2 2 2 2 2 Reclaimed Water Quality/Quantity 1 1 3 2 2 2 Un-weighted Total 22 24 F(4) 17 24 Weighted Total 31 38 F(4) 24 37 Notes: (1) IFAS A stands for the aggressive sizing of IFAS. (2) IFAS C stands for the conservative sizing of IFAS. (3) The aggressive IFAS sizing was determined to be too risky based on the manufacturer’s lack of sufficiently demonstrated approach to tank sizing. The County may want to consider pilot testing to further support this consideration. (4) A score of a “0” on any of the criteria results in a failure of that alternative. June 29, 2010 - FINAL 2-31 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx Table 2.5 3 mg/L TIN (Year-round) Scoring Matrix South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division Score Criteria Weight MBR IFAS A(1) IFAS C(2) BAF Onsite Capital Cost 1 2 3 3 2 O&M Cost 1 1 1 3 2 Risk 2 3 0(3) 1 2 Footprint 3 2 3 0(4) 2 Energy 2 1 3 2 2 Odor 1 2 2 2 2 Compatibility with existing processes 1 3 3 3 3 Biosolids Quality 1 2 2 2 2 Reclaimed Water Quality/Quantity 1 3 2 1 2 Un-weighted Total 19 F(5) F(5) 19 Weighted Total 27 F(5) F(5) 27 Notes: (1) IFAS A stands for the aggressive sizing of IFAS. (2) IFAS C stands for the conservative sizing of IFAS. (3) The aggressive IFAS sizing was deemed to be too risky based on the manufacturer’s lack of an adequate explanation for tank sizing. This alternative should be pilot tested before further consideration. (4) The conservative sizing of IFAS was given a “0” for footprint since this alternative did not fit on the site. (5) A score of a “0” on any of the criteria results in a failure of that alternative. 2.4 ALTERNATIVES SUBJECT TO MORE DETAILED ANALYSIS 2.4.1 Necessary Equipment Two alternatives, one each for the seasonal limit and annual limit, were selected for a more detailed cost estimate, sensitivity analysis, and sustainability analysis: • 8 mg/L TIN summer permit level: Parallel MLE/MLE MBR process • 3 mg/L TIN (year-round) permit level: Parallel Bardenpho/Bardenpho MBR process Significant elements of each alternative are summarized below. 2.4.1.1 8 mg/L TIN (summer-only) permit level: Parallel MLE/MLE MBR process In this alternative the existing activated sludge aeration tanks and clarifiers would be retained. The aeration tanks would be modified to provide for internal recycle of mixed liquor to unaerated zones, which would be operated in anoxic mode for denitrification, rather than in the current anaerobic mode for encouragement of phosphorus accumulating organisms for settleability control. Methanol feed equipment would be provided to support June 29, 2010 - FINAL 2-32 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx denitrification. The existing tanks and clarifier would be de-rated to a maximum month capacity of 36 mgd for operation during the summer months for nitrogen removal. A parallel MBR process would be constructed to provide nitrogen removal for the summer months for the remaining flow. With a maximum month flow of 98 mgd during the summer, the parallel MBR process would be designed for a maximum month summer flow of 62 mgd. Winter season operation of the MLE-MBR facilities and the existing facilities will need to be addressed during any design phase. These considerations should include further evaluation of existing facilities needed to control settleability during winter operation so peak storm flows could be properly processed. It was assumed that MBR facilities would only be operated during the summer months for nitrogen removal. For calculation of effects it was assumed that the MBR facilities would be operated for a total of seven months per year, allowing for three weeks of startup operation and one week of shut-down operation for each six-month summer season. It was assumed that the MBR tanks would be drained and cleaned and remain out of service during the winter. Major elements of each upgrade include: MLE BNR upgrade of existing aeration tanks: • Installation of internal recycle pumps and piping • Odor control covers for the aeration tanks • Odor treatment equipment • Installation of additional mixers in the first stage of the aeration tanks • Modifications to the aeration tank air diffuser grids Parallel MLE BNR MBR process: • New unaerated and aerated aeration tanks • Mixers and diffusers • Odor control covers for the reactor tanks • Odor treatment equipment • New blowers • New membrane tanks • New membrane equipment building • Chemical feed equipment and building (including methanol) • MBR tank odor control covering June 29, 2010 - FINAL 2-33 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx • MBR tank roof • Membranes and support equipment 2.4.1.2 3 mg/L TIN (year-round) permit level: Parallel Bardenpho/Bardenpho MBR process In this alternative the existing activated sludge aeration tanks and clarifiers would be retained. The aeration tanks would be modified to provide for internal recycle of mixed liquor to unaerated zones, which would be operated in anoxic mode for denitrification. In addition, aerobic zones of the existing aeration tanks would be converted to unaerated zones. Methanol feed would be provided. The modified existing tanks and clarifiers would be de-rated to a maximum month capacity of 30 mgd for operation year round for nitrogen removal. A parallel MBR process would be constructed to provide nitrogen removal year round for the remaining flow. With a maximum month flow of 144 mgd to the STP, the parallel MBR process would be designed for a maximum month flow of 114 mgd while 30 mgd is treated by the modified existing tanks. It is anticipated that this parallel design would accommodate the current peak hour secondary flow rating of 242 mgd. During peak storm events, 114-mgd would be directed to the MBR process and 128 mgd would be treated through the existing system modified for Bardenpho operation. Major elements of each upgrade include: Bardenpho BNR upgrade of existing aeration tanks: • Installation of internal recycle pumps and piping • Odor control covers for the aeration tanks • Odor treatment equipment • Installation of additional mixers in the first and third stages of the aeration tanks • Additional baffle walls • Modifications to the aeration tank air diffuser grids Parallel Bardenpho BNR MBR process: • New unaerated and aerated aeration tanks • Mixers and diffusers • Odor control covers for the reactor tanks • Odor treatment equipment • New blowers • New membrane tanks June 29, 2010 - FINAL 2-34 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx • New membrane equipment building • Chemical feed building • MBR tank odor control covering • MBR tank roof • Membranes and support equipment 2.4.2 Site layout The proposed site layouts for the representative alternatives are presented in Figures 2.9 and 2.14. 2.4.3 Cost Following selection of representative alternatives, the preliminary cost estimates prepared for the alternatives screening were adjusted to reflect factors not considered in the preliminary screening, such as odor control covering and treatment costs. The cost estimates were based on a preliminary quantity estimate for excavation and concrete for new tanks and estimated cost for new equipment. To these direct costs were added allowances for piping and miscellaneous mechanical equipment, electrical equipment, instrumentation, site work, contingency, general conditions, contractor overhead ,and profit, sales tax, allied costs (planning, design, construction management, permits, etc.). O&M costs were estimated based on an Environmental Protection Agency (EPA) database for unit process labor, estimated power requirements and chemical consumption, and allowances for structural and equipment maintenance. Costs were indexed to estimated unit prices for March 15, 2010. The expected accuracy range for this type of estimate is defined by the Association for the Advancement of Cost Engineering (AACE) as a Level -5 Order of Magnitude Estimate and has an expected accuracy range of +50 to -30 percent. Cost assumptions are summarized in Appendix B. Tables 2.6 and 2.7 present summaries of estimated costs for upgrade of the STP to provide for nitrogen removal for the two potential permit levels. The estimates include the cost of odor control covers and equipment for the reactor tanks. The existing CAS process does not currently have complete odor control covers and treatment for the aeration tanks, but the tanks are under a current upgrade to provide this. Costs for provision of these were therefore not included. The tables present summaries of costs for major project elements in five columns: • Operation of the existing CAS • Upgrade of the existing CAS to provide for BNR • New Parallel MBR BNR facilities June 29, 2010 - FINAL 2-35 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx • The total estimated cost for the BNR upgrade • The difference in cost between the BNR upgrade and the cost of the existing CAS The differential present worth cost for nitrogen removal (column 6 in Tables 2.6 and 2.7) is the present worth cost of the nitrogen removal upgrade (column 3 in Tables 2.6 and 2.7) plus the present worth cost of the parallel MBR facilities (column 4 in Tables 2.6 and 2.7) minus the present worth cost of CAS (column 2 in Tables 2.6 and 2.7). The estimated total incremental present worth cost (including both incremental capital costs and incremental operating costs) for upgrade of the STP to an 8 mg/L TIN summer discharge permit level is approximately $680 million. The estimated incremental present worth cost for upgrade to meet the requirements of a 3 mg/L TIN (year-round) discharge permit limit is approximately $1,430 million. The costs shown in the table are estimated costs for the unit processes shown based on process calculations by Carollo Engineers. As a comparison of capital costs, the lump sum construction cost for the aeration tanks for the new Brightwater Treatment Plant was approximately $50 million for a design capacity of 36 mgd or approximately $1.40 per gallon of max month flow capacity. The estimated construction cost from the current cost estimate for the MBR aeration tanks for the 3 mg/L year-round permit limit was approximately $200 million without contingency but including all other allowances or approximately the same unit cost as Brightwater for 144 mgd of capacity. The estimated operating cost from the STP budget for secondary treatment power is in the range of $1.5 to $2.0 million dollars per year. For comparison, the estimated total annual operating and maintenance cost in the current estimate for secondary treatment for the future year intermediate between current flows and design flows (89 mgd average flow) is $1.8 million per year including approximately $1.3 million for power,and $600,000 per year for labor. In the current estimate, O&M cost for structural and equipment maintenance and replacement were based on a percentage allowance of capital cost. Since the capital cost estimates were not available for the existing operation these costs were not included in the estimated O&M costs for CAS. It is estimated that operating costs would increase to a total of almost $15 million annually for the 8 mg/L TIN (summer-only) permit limit and $35 million annually for the 3 mg/L TIN (year-round) permit limit based on a similar distribution of costs for labor, power, odor control, and structural and equipment maintenance. June 29, 2010 - FINAL 2-36 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx Table 2.6 Estimate Summary for 8 mg/L TIN (Summer-only) Permit Level Upgrade to the STP South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division Treatment Element CAS MLE Upgrade MLE MBR Total BNR Upgrade Difference Present Worth Cost, $ Million Capital Cost(1) $0 $105 $425 $530 $530 Operation and Maintenance(2) $25 $46 $129 $176 $149 Total Present Worth $25 $151 $554 $706 $679 Notes: (1) Capital cost includes construction cost, contingency, tax, and allied costs (costs of planning, engineering, construction management, permitting, legal and other associated costs). All costs are in March 2010 dollars. (2) Present worth O&M values were calculated assuming a 3% discount rate over a 20-year period on calculated current yearly O&M costs. Table 2.7 Estimate Summary for 3 mg/L TIN (Year-round) Permit Level Upgrade to the STP South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division Treatment Element CAS Bardenpho Upgrade Bardenpho MBR Total BNR Upgrade Difference Present Worth Cost, $ Million Capital Cost (1) $0 $188 $779 $967 $958 Operation and Maintenance(2) $25 $128 $394 $522 $475 Total Present Worth $25 $316 $1,173 $1,489 $1,434 Notes: (1) Capital cost includes construction cost, contingency, tax, and allied costs (costs of planning, engineering, construction management, permitting, legal and other associated costs. All costs are in March 2010 dollars. (2) Present worth O&M values were calculated assuming a 3% discount rate over a 20-year period on calculated current yearly O&M costs. June 29, 2010 - FINAL 2-37 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx 2.4.4 Sensitivity Analysis Following selection of representative alternatives for each permit level, a sensitivity analysis was performed to determine the response of the representative alternative to potential changes in conditions of operation from assumed conditions. Sensitivity was investigated in three areas: 1. Sensitivity to dynamic loadings including dewatering schedule 2. Sensitivity to excursions in sludge volume index (SVI) 3. Sensitivity to loss of aeration blowers These sensitivity factors were selected during the first project workshop in October 2009. In addition to sensitivity to dewatering schedule, consideration of the effects of side stream treatment on nitrogen removal was also included as part of the sensitivity analysis for dynamic loading. 2.4.4.1 Sensitivity to Dynamic Loading In order to determine sensitivity of the representative alternatives to dynamic loading two different sources of dynamic instability were considered: 1. Dynamic influent loading 2. Dynamic dewatering return flows Preliminary analysis of process alternatives was based on steady state modeling of unit processes using both Carollo’s Biotran spreadsheet and the commercial software BioWin. In steady state modeling, maximum month loadings are identified based on plant records and peaking factors are used to estimate dynamic loading effects. For the current analysis, dynamic models were developed to represent potential effects of diurnal variation in loadings from both the influent sewer and from dewatering return flows. Diurnal variation in flow and loading was assumed based on Carollo sampling and flow measurement for Central Contra Costa Sanitary District in California, a King County peer agency. To simulate the impact of dewatering schedule on potential nitrogen removal, two potential schedules were modeled: 1. Seven days per week and eight hours per day 2. Seven days per week and centrate flow equalization A schematic of the recommended configuration developed in BioWin for the 8 mg/L TIN (summer-only) permit level is shown in Figure 2.18. A schematic for the recommended configuration for the 3 mg/L TIN (year-round) permit level is presented in Figure 2.19. pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.18.docx Anoxic Pass 1aAerobic Pass 2Aerobic Pass 3Aerobic Pass 4Anoxic Pass 1bEffluentDigesters 1- 4Storage DigesterSludge DisposalMethanolCOD InfluentMBRReaeration BIOWIN SCHEMATIC – 8 MG/L (SUMMER ONLY) PERMIT LEVEL FIGURE 2.18 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTUREWATER REUSE PROGRAMDEVELOPMENT pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.19.docx Anoxic 1Aerobic 3Aerobic 4Anoxic 2EffluentDigesters 1- 4Storage DigesterSludge DisposalMethanolScreened SewageAnoxic 5Membrane TankReaerationEQ BIOWIN SCHEMATIC – 3 MG/L (YEAR ROUND) PERMIT LEVEL FIGURE 2.19 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT June 29, 2010 - FINAL 2-40 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx Assumed influent flow and concentration variation for the two permit levels are shown in Figures 2.20 and 2.21. Predicted dynamic TIN effluent concentrations are shown on Figures 2.22 and 2.23, respectively for the 8 mg/L (summer-only) and 3 mg/L (year-round) permit level. Simulations were conducted for the new MBR units which would be constructed in parallel to existing units upgraded as discussed for nitrogen removal. It is anticipated that dynamic behavior of the conventional nitrogen removal units would be similar to that of the new parallel MBR units. For each permit level, simulations were performed under three different scenarios: • No centrate reaeration or centrate equalization • Centrate reaeration but no equalization • With both equalization and reaeration of centrate For the 8 mg/L TIN (summer-only) permit level it was found that neither centrate reaeration nor equalization were required to keep the average effluent TIN under 8 mg/L, but that without centrate reaeration and equalization there were peak hourly excursions above the 8 mg/L TIN level. A compromise configuration with centrate reaeration but without equalization is shown in the figures and was assumed in calculating costs. Different locations for the centrate equalization tank were investigated: on the dewatering return line, on the RAS line, and on the return line from the dissolved air flotation thickener (DAFT) tanks. Location of the centrate equalization tank on the centrate line indicated the lowest overall plant effluent TIN. An internal recycle configuration was initially explored for the 8 mg/L TIN (summer-only) permit level, but the modeling indicated that separate recycle beyond the recycle from the membrane tank was not required to control TIN to the 8 mg/L permit level. Likewise, use of a de-aeration tank on the return flow pipe from the membrane tank did not significantly improve effluent TIN performance. For the 3 mg/L TIN (year-round) permit level the modeling indicated that both centrate reaeration and equalization would be required to keep the average effluent TIN comfortably under the 3 mg/L TIN (year-round) level. Even with both features, however, peak hourly excursions above the permit level were seen in the simulation. It was found that an internal recycle system with up to 600 percent recycle ratio, in addition to the 400 percent recycle flow from the membrane tanks, was required to keep effluent TIN levels under the 3 mg/L TIN (year-round) level. 2.4.4.2 Sensitivity to excursions in SVI The selected alternatives for nitrogen removal both include membrane separation of biological treatment solids, rather than gravity tanks as used in the current plant. Thus, sludge settleability is not a significant issue for the parallel MBR stream. Variations in SVI would continue to affect the upgraded activated sludge system, but since existing facilities have been de-rated significantly for nitrogen removal, overflow rates on secondary sedimentation tanks would be much lower than under current operation. pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.20.docx Dynamic InfluentCOD Influent FlowCOD Influent Total Carbonaceous BODCOD Influent Total suspended solidsCOD Influent Total Kjeldahl NitrogenDATE9/10/20099/9/20099/9/20099/9/20099/9/20099/8/20099/8/20099/8/20099/8/2009CONC. (mgN/L)240220200180160140120100806040200Flow (mgd)80706050403020100 DYNAMIC INFLUENT FLOW AND CONCENTRATION 8 MG/L TIN (SUMMER ONLY) PERMIT LEVEL FIGURE 2.20 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.21.docx Dynamic Influent Flow and ConcentrationCOD Influent FlowCOD Influent Total Carbonaceous BODCOD Influent Total suspended solidsCOD Influent Total Kjeldahl NitrogenDATE9/10/20099/9/20099/9/20099/9/20099/9/20099/8/20099/8/20099/8/20099/8/2009CONC. (mgN/L)240220200180160140120100806040200Flow (mgd)1501401301201101009080706050403020100 DYNAMIC INFLUENT FLOW AND CONCENTRATION 3 MG/L TIN (YEAR ROUND) PERMIT LEVEL FIGURE 2.21 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.22.docx Dynamic EffluentEffluent Filtered Carbonaceous BODEffluent Total suspended solidsEffluent Ammonia NEffluent Nitrite + NitrateEffluent Total inorganic NEffluent Total NDATE9/10/20099/9/20099/9/20099/9/20099/9/20099/8/20099/8/20099/8/20099/8/2009CONC. (mg/L)11109876543210 DYNAMIC EFFLUENT FLOW AND CONCENTRATION 8 MG/L TIN (SUMMER ONLY) PERMIT LEVEL FIGURE 2.22 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.23.docx Dynamic Effluent ConcentrationsEffluent Filtered Carbonaceous BODEffluent Total Carbonaceous BODEffluent Ammonia NEffluent Nitrite + NitrateEffluent Total inorganic NEffluent Total NDATE9/10/20099/9/20099/9/20099/9/20099/9/20099/8/20099/8/20099/8/20099/8/2009CONC. (mgP/L)76543210 DYNAMIC EFFLUENT FLOW AND CONCENTRATION 3 MG/L TIN (YEAR ROUND) PERMIT LEVEL FIGURE 2.23 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT June 29, 2010 - FINAL 2-45 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx Figure 2.24 presents a state point diagram for secondary clarifiers based on operation in a Bardenpho configuration using existing secondary sedimentation tanks. The state point diagram compares the operating conditions for solids loading to the theoretical settling flux in pounds per day per square foot (ppd/sf) of tank area as a function of MLSS concentration. Under the conditions required, the overflow rate on the tanks would be less than 150 gallons per day per square foot (gpd/sf) with a MLSS concentration of 3,000 mg/L. The state point diagram reflects an estimate of settling characteristics assuming an operating SVI of approximately 150 milliliters per gram (mL/g). The diagram was prepared with a peak factor to the Bardenpho BNR system of 3.0 at peak wet weather flow. The diagram indicates sufficient capacity under these conditions. Calculations based on generic models for the relationship relating settling velocity to SVI indicate that the tanks could operate with a MLSS concentration of 3,000 mg/L at a peak flow up to approximately 65 mgd with SVI values over 200 mL/g. 2.4.4.3 Sensitivity to loss of aeration blowers The current blower capacity of the STP is 195,000 cubic feet per minute (cfm), provided by 10 units of various sizes. The capacity of the largest unit is 23,300 cfm, so the capacity of the system with the largest unit out of service would be 171,000 cfm. The estimated maximum month aeration demand for BNR operation of the existing four aeration tanks is less than 20,000 cfm, so there would be sufficient blower capacity for operation of the existing tanks, assuming new blower capacity were provided for the parallel MBR tanks. Required blower capacity is less than current demands because flow would be off-loaded from existing tanks by new parallel MBR tanks in the event that nitrogen removal were required, even though the oxygen demands for BNR exceed that required for carbonaceous treatment. If blower capacity from the existing blower system were used to meet part of the demand for parallel MBR aeration, then adequate standby capacity would need to be provided by additional blowers. 2.5 GREENHOUSE GAS COMPARISON 2.5.1 Overview Effects of nitrogen removal upgrades on generation of greenhouse gas (GHG) emissions from the STP were evaluated. This section provides an estimate of GHG emissions of the existing system compared to those that would be expected if the STP were required to remove nitrogen to the two different permit levels identified above. pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.24.docx 05101520253001,0002,0003,0004,0005,0006,0007,0008,0009,00010,00011,00012,000Solids Flux (ppd/sf)State Point DiagramSettling Flux80% AlertMLSSDaily AverageDiurnal PeakWet-W Peak STATE POINT DIAGRAM FOR BARDENPHO BNR FIGURE 2.24 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT June 29, 2010 - FINAL 2-47 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx 2.5.2 Background The State of California adopted the Global Warming Solutions Act of 2006 (also known as Assembly Bill 32 (AB 32)) in September of 2006. This Act is the first regulatory program in the U.S. that will require many public and private agencies statewide to reduce GHG emissions to 1990 levels by 2020 and 80 percent below 1990 levels by 2050. Currently, there is no specific mandate for reduction that applies to publicly owned treatment works (POTWs); however, the California Air Resources Board (CARB) has stated that POTWs could be included in the near future and early voluntary reporting is recommended. Due to the absence of any specific guidance based in Washington State law, the procedures and methodologies which have been implemented in California were used to develop an estimate of GHG emissions associated with nitrogen removal upgrade at the STP. The estimates use the methodologies presented in and recommended by the California Climate Action Registry General Reporting Protocol (CCAR GRP), a set of measuring standards and protocols aligned with the international GHG Protocol Initiative and adapted to California. AB 32 recommends using this protocol “where appropriate and to the maximum extent feasible.” Agencies that choose to participate in the CCAR process will not be required to significantly alter their reporting except as determined by CARB for compliance purposes. Emissions of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) GHG emissions were estimated. These gases are relevant to and comprise the majority of GHG emissions generated from treatment of wastewater. The estimated annual GHG emissions from the operation of the CAS process at the STP are compared to emissions from operation of unit processes required to remove nitrogen. In general, annual GHG emissions are a function of the flow treated, the influent water quality, and the treatment processes used. A description of the calculation methodology is provided in the following section. The GHG estimates provided are for secondary and nitrogen removal processes and solids handling. 2.5.3 Methodology The development of GHG emissions estimates requires a set of “boundary” conditions to define the life cycle stages, the unit processes, and the time frame that is included in the analysis. For this inventory, both construction and operations effects were considered. These included: • Construction of new tanks and equipment for BNR processes • Operation of the CAS process compared to BNR processes • Production and hauling of chemicals consumed for treatment (this includes methanol required for nitrogen removal) • Production and hauling of replacement materials consumed for treatment (this included membranes required for MBR treatment) June 29, 2010 - FINAL 2-48 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx • Production and hauling of materials for construction of new tanks and equipment 2.5.4 Categories and Sources of GHG Emissions There are two categories of emissions, direct and indirect, that were identified and evaluated: • Direct Emissions: Direct emissions are those resulting from sources owned or controlled by the County, such as stationary combustion sources, mobile combustion sources, and treatment unit processes. For this inventory, this includes treatment unit process emissions, and N2O emissions from effluent discharge. • Indirect Emissions: Indirect emissions are those originating from the actions of the agency, but produced by sources owned or controlled by another entity. For this inventory, this includes: production of purchased electricity for the operation of the facility, manufacturing of chemicals and replacement materials used to treat the wastewater, and transport of the chemicals and replacement materials to the facility. 2.5.5 Estimate of GHG Emissions in Terms of “CO2 Equivalents” The major sources of GHG emissions were identified and categorized, and appropriate emission factors were determined. The data was then transferred into Carollo’s GHG emissions inventory model to calculate the quantities of CO2, CH4, and N2O emissions generated from each source. Major sources included: • Electricity Consumption (kilowatt-hours (kWh)) multiplied by Emission Factor • Vehicle Fuel Consumption (gallons or miles traveled) multiplied by Emission Factor • Chemical or Material Produced (unit weight) multiplied by Specific Energy (unit energy per unit weight of material or chemical) multiplied by Emission Factor Emissions were converted into carbon dioxide equivalent (CO2e) emissions. The major GHG in the atmosphere is CO2. Other GHGs differ in their ability to absorb heat in the atmosphere. For example, CH4 has 21 times the capacity to absorb heat relative to CO2 over a 100-year time horizon, so it is considered to have a global warming potential (GWP) of 21. N2O has 310 times the capacity to absorb heat over a 100-year time horizon having a GWP of 310. Therefore, a pound of emissions of CO2 has much less climatic impact than a pound of CH4 or N2O, but typically CO2 is emitted in such large quantities compared to the other two GHGs that it dominates the final result. CO2e emissions are calculated by multiplying the amount of emissions of a particular GHG by its GWP (see Table 2.8). Example: What is the CO2e of one ton of CH4 emissions? 1 ton CH4 x 21 (GWP, tons CO2e/tons of CH4 emitted) = 21 tons CO2e June 29, 2010 - FINAL 2-49 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx Table 2.8 Greenhouse Gases and Global Warming Potentials South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division Greenhouse Gas GWP(1) (Unit Mass CO2e/Unit Mass of GHG Emitted) CO2 1 CH4 21 N2O 310 Notes: (1) GWPs are from the Intergovernmental Panel on Climate Change Second Assessment Report (1996) for a 100-year time horizon. These GWPs are still used today by international convention and the U.S. to maintain the value of the CO2 “currency,” and are used in this inventory to maintain consistency with international practice. 2.5.6 Description of GHG Emissions Estimates This section provides a summary of the system being evaluated, a brief description of types of annual GHG emissions considered in this analysis, and the sources of information used. The system to be evaluated is defined as the construction of new nitrogen removal facilities for the STP and subsequent operations compared to operation of the existing STP without significant nitrogen removal. Liquids stream treatment processes included in the analysis were: CAS aeration tanks, nitrogen removing activated sludge aeration tanks, and membrane tanks. The GHG emission effects of other treatment processes at the STP, including influent screening, grit removal, primary treatment, secondary sedimentation, and disinfection were considered to be largely unaffected by addition of nitrogen removal and therefore not included in the analysis. Solids handling unit processes considered include: anaerobic digestion and truck transport of solids for disposal. The STP has sludge thickening and dewatering processes, but the GHG effects of these were considered to be similar for both conventional and nitrogen removal alternatives and were therefore not included in the analysis. 2.5.7 Direct GHG Emissions 2.5.7.1 Process Emissions GHG emissions are not only generated due to the energy consumed for operating the STP. CH4 and N2O are also emitted as a by-product of wastewater treatment processes. 2.5.7.1.1 Methane Wastewater from domestic and industrial sources is treated to remove soluble organic matter, suspended solids, pathogenic organisms, and chemical contaminants. Soluble organic matter is removed using biological processes in which microorganisms consume the organic matter for cell maintenance and growth. The resulting biosolids are removed from the effluent prior to discharge to the receiving water. At the STP microorganisms June 29, 2010 - FINAL 2-50 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx biodegrade the soluble organic material under both anaerobic and aerobic conditions. Anaerobic conditions can generate CH4 emissions, but its unlikely that any significant CH4 production is taking place in the STP anaerobic selector tanks. Methane formation requires continuously anaerobic conditions with cell growth times exceeding four days. The STP liquid stream anaerobic zones have a solids residence time of less than one day and are immediately followed by aerobic zones; it is therefore unlikely that methane-forming bacteria have any significant growth in this system. This assumption was verified by multi- species modeling of biological growth in the tanks. The modeling predicted that there would be essentially no growth of methanogenic bacteria in the STP liquids treatment process. The STP has anaerobic digesters, which generate significant quantities of CH4. In 2007, approximately 11 percent of digester gas at the STP was flared. Of the remaining 89 percent of the gas, approximately 16 percent was used for digester heating, 16 percent was used on-site to produce electricity (co-gen) and the remainder (57 percent) was sold as fuel to Puget Sound Energy. There may be some fugitive emissions of CH4 from the STP anaerobic digesters, but there is no reason to think that there would be significant differences between conventional and nitrogen removing activated sludge processes in their tendency to produce fugitive emissions of CH4. Nitrogen removing activated sludge processes would be expected to generate less volatile waste solids due to the longer solids residence times used in treatment, but there is no reason to think that the amount of gas flared would be different with nitrogen removal in the liquid process. Therefore, CH4 process emissions were not included in the analysis. 2.5.7.1.2 Nitrous Oxide N2O emissions are estimated by methodologies adapted from the 2006 International Panel on Climate Change (IPCC) Guidelines for National GHG Inventories and Section 8.2 of the U.S. EPA document, GHG Emissions and Sinks (1990-2006). These methodologies identify that N2O emissions are generated at: 1. Centralized wastewater treatment plants (WWTPs) without nitrification/denitrification (NDN) 2. Centralized WWTPs with NDN 3. From effluent discharged to receiving aquatic environments Since NDN treatment is the central topic of this report, estimates of N2O emissions are of significant importance. To identify the impact of implementing nitrogen removal by NDN at the STP, emissions of CAS treatment without NDN were compared to estimated emissions in the future with NDN. Estimates of N2O emissions generated are dependent on the population (industrial and domestic) served by the treatment plant and the measured average daily total nitrogen load discharged from the STP. 2.5.7.2 On-site Stationary Combustion Stationary combustion refers to the combustion of fuels to produce electricity, heat, or motive (mechanical) power using equipment in a fixed location. Typical stationary June 29, 2010 - FINAL 2-51 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx combustion units at WWTPs include boilers, flares, turbines, furnaces, and internal combustion engines. It is estimated that approximately 11 percent of STP digester gas is currently flared and approximately 16 percent of the remainder is currently used for digester heating. It is possible that BNR liquid stream treatment could result in less digester gas flaring because of the relatively smaller amount of waste solids production compared to CAS, but because digester flaring could be independent of total gas production, stationary combustion GHG effects were not included in the analysis. 2.5.8 Indirect GHG Emissions 2.5.8.1 Operation of Treatment Facilities GHG emissions estimates from the operation of the treatment facilities are based on the total annual electricity demand (kWh per year). Annual energy demands were estimated using Carollo models for wastewater treatment for CAS treatment compared to models of operation of existing facilities in a modified configuration for nitrogen removal combined with MBRs configured for nitrogen removal. This is typically the most significant source of GHG emissions for WWTPs. 2.5.8.2 Chemical Production The CCAR GRP considers energy required for the production of chemicals consumed in treatment processes to be outside the boundary of this type of inventory. However, in order to provide a more complete analysis of the effects imposed by the existing system, the energy consumed for chemical production is included in this inventory. The energy used per unit chemical consumed was calculated using conversion factors from Owen (1982). The only chemical considered in this analysis was methanol, which is required for nitrogen removal at the STP, but not for CAS treatment. Annual chemical consumption was based on estimates from Carollo’s biological process modeling. 2.5.8.3 Replacement Material Production The CCAR GRP also considers energy required for the production/replacement of spent materials used in treatment processes to be outside the boundary of this type of inventory. However, in order to provide a more complete analysis of the effects imposed by the existing system, the energy consumed for material production was included in this inventory. The energy used per unit mass of material consumed was calculated using conversion factors from Owen (1982). The replacement material production considered the membrane replacement estimated from Carollo modeling. No other material replacement values were estimated. 2.5.8.4 Chemical Handling Estimates of GHG emissions generated from the transport of chemicals were based on the type of truck used, the type of fuel consumed, and the distance from the chemical’s June 29, 2010 - FINAL 2-52 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx distribution center. The chemical handling considered the methanol consumption for BNR and citric acid consumption for membrane cleaning estimated from Carollo modeling. 2.5.8.5 Solids Handling Estimates of GHG emissions generated from the transport of grit and biosolids are based on the type of truck used, the type of fuel consumed, and the distance to the disposal site. Carollo used data estimated from Carollo models for sludge production of CAS compared to nitrogen removal alternatives. Estimates for fuel consumption were based on the disposal of biosolids to the Boulder Park site in Eastern Washington. 2.5.8.6 Replacement Material Handling Estimates of GHG emissions generated from the transport of replacement materials are based on the type of truck used, the type of fuel consumed, and the distance from the material’s distribution center and disposal site (an Eastern Washington land fill). Carollo applied assumptions for the truck type and fuel type consumed. The only replacement material estimated was membranes for the BNR alternatives. 2.5.8.7 Construction Materials Estimates for the indirect GHG emissions from production and transport of construction materials for new MBR BNR facilities were estimated from quantity estimates for construction using factors for conversion to GHG emissions. 2.5.8.8 Offsets Offsets in this analysis are those emissions that were once generated from the consumption of purchased electricity, but are now avoided (or are no longer emitted) since the energy is now supplied by a renewable energy source. This analysis included estimated differences in production of digester gas which is scrubbed and sold to the Puget Sound Energy. 2.5.9 Summary of GHG Emissions Estimates A summary of the results of the GHG analysis for the project is presented in Table 2.9 and Figure 2.25. The table shows the cumulative emissions estimated for each alternative in each category of GHG emission. The figure presents a bar chart representing the total estimate annual production of CO2e for the three process alternatives: • CAS • BNR with an effluent permit goal of 8 mg/L TIN for the six summer months of the year by conversion of the existing aeration tanks to an MLE process with treatment of the remaining flow by MLE MB (Operation in CAS the remainder of the year) June 29, 2010 - FINAL 2-53 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx • BNR with an effluent permit goal of 3 mg/L TIN (year-round) by conversion of the existing aeration tanks to a Bardenpho process with treatment of the remaining flow by Bardenpho MBR The results indicate that the impact of a summer-only effluent permit level of 8 mg/L TIN would result in an approximately two thirds more GHG emissions than for secondary treatment at the STP. A 3 mg/L TIN year-round limit would than result in approximately three times more emissions of equivalent GHG emissions. The primary sources of increased GHG emissions are process N2O and purchased electricity. Table 2.9 also shows the number of vehicles that would need to be added to the Puget Sound region to have an equivalent impact on regional GHG emissions as addition of either of the two nitrogen removal permit scenarios. It is seen that implementation of the 8 mg/L (summer-only) permit level would have the equivalent impact of adding 1,200 vehicles to the Puget Sound region, while implementing the 3 mg/L year round permit limit would be equivalent to adding nearly 4,000 vehicles to the region. Table 2.9 Estimated Annual Total Metric Tons of Carbon Dioxide Equivalent Emission South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division Emission Type CAS MLE / MBR (Summer TIN = 8 mg/L) Bardenpho / MBR (Year Round TIN = 3 mg/L) Direct Process N2O 1,106 2,420 2,420 N2O Effluent Discharge 38 13 6 Indirect Offsets (Avoided Emissions) -1,396 -1,100 -1,246 Purchased Electricity 7,255 11,615 22,264 Construction Material Production 0 11 37 Chemical Production 0 93 1,739 Replacement Material Production 0 93 237 Construction Handling 0 6 22 Solids Handling 1,698 1,292 1,515 Chemicals Handling 0 19 49 Replacements Handling 0 5 13 Total 8,700 14,468 27,055 Relative Value (%) 100% 166% 311% Equivalent Number of Vehicles1 1,582 2,782 5,302 Relative Number of Vehicles 0 1,200 3,720 Notes: (1) Based on EPA estimate of 5.5 metric tons of annual CO2 equivalent emissions for an average vehicle (http://www.epa.gov/oms/climate/420f05004.htm). pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 2.25.docx GHG COMPARISON FIGURE 2.25 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT June 29, 2010 - FINAL 2-55 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx 2.6 FINDINGS AND CONCLUSIONS This chapter has presented results of evaluations undertaken to determine the effects of an effluent permit requirement for nitrogen removal at the STP. Two different potential permit requirements have been assessed: • 8 mg/L TIN for the summer period • 3 mg/L TIN year round The estimated costs and other effects of meeting each of these potential future permit requirements were compared to continuation of the current practice of CAS operation to meet a secondary treatment permit for discharge to Puget Sound. A wide range of potential alternatives were considered and screened to four final alternatives for each permit level. Costs of each of these upgrade strategies were estimated using a series of criteria including capital cost, O&M cost, risk, flexibility, footprint, energy, odor generation potential, compatibility with existing processes, impact on biosolids quantity, and the amount and quality of reclaimed water produced. The final ranking indicated that for the 8 mg/L TIN (summer-only) permit level, the most promising upgrade strategy would be to upgrade the existing CAS process at the STP to provide for anoxic and aerobic treatment in two treatment stages by a MLE process and to construct a parallel nitrogen removing MBR process to treat the remainder of the flow. For the 3 mg/L TIN (year-round) discharge alternative a similar strategy was selected, but using a four-stage anoxic and aerobic process (the Bardenpho process). It was concluded that two other processes, BAF/DNF and IFAS processes, were potentially cost-effective and have similar enough other effects that they should be considered further in the future. A sensitivity analysis was conducted to evaluate potential effects of diurnal loading variation and variation in the schedule of sludge dewatering operations, variation in activated sludge settleability, and the impact of air blower outage on nitrogen removal. It is concluded that sludge dewatering return flow equalization and treatment would be necessary to ensure meeting a 3 mg/L TIN (year-round) permit limit, but that equalization would be less necessary with the 8 mg/L TIN (summer-only) permit limit. It was concluded that variation in sludge settleability would have less impact on the MBR process selected than is experienced today with the CAS process for secondary treatment. It was assumed that additional aeration blowers would be constructed for new MBR treatment facilities at the STP and that sufficient redundancy would be constructed to provide for blower outage. The incremental present worth cost for upgrade of the STP to meet an 8 mg/L TIN permit level during the summer months is estimated at a present worth cost of approximately $680 million more than continuing operation of secondary treatment over the next twenty years. The estimated incremental present worth cost for upgrade to meet a 3 mg/L TIN (year- June 29, 2010 - FINAL 2-56 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch02.docx round) permit level is in approximately $1,430 million more than the cost of continuing with secondary treatment. In addition to evaluation of incremental present worth costs, an estimate of GHG emissions was conducted. It was concluded that meeting an 8 mg/L TIN summer permit level would result in nearly two thirds more GHG emissions from the STP compared to the currently- used CAS process and that a 3 mg/L TIN year-round permit level would result in approximately three times more GHG emissions compared to continuing with secondary treatment at the STP. The primary sources of increased GHG emissions were estimated increases in purchased electricity and N2O released during nitrogen removal treatment. Addition of these treatment technologies to the STP would have a similar GHG effect to addition of between 1,000 and 4,000 vehicles to the Puget Sound region, depending on the permit level implemented. The most significant conclusions from this analysis were: • The incremental present worth cost for upgrade of the STP to meet an 8 mg/L TIN permit level during the summer months is estimated at a present worth cost of approximately $680 million more than continuing operation of secondary treatment over the next twenty years. • The estimated incremental present worth cost for upgrade to meet a 3 mg/L TIN (year-round) permit level is in approximately $1,430 million more than the cost of continuing with secondary treatment. • Meeting an 8 mg/L TIN summer permit level would result in nearly two thirds more GHG emissions from the STP compared to the currently-used CAS process. • Meeting a 3 mg/L TIN year-round permit level would result in approximately three times more GHG emissions compared to continuing with secondary treatment. June 29, 2010 - FINAL 3-1 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch03.docx Chapter 3 SOUTH PLANT NITROGEN REMOVAL EFFECT ON RECLAIMED WATER PRODUCTION 3.1 INTRODUCTION The South Treatment Plant (STP) currently performs secondary treatment for up to 144 million gallons per day (mgd) of flow on a maximum month basis for discharge to Puget Sound. Substantial removal of ammonia is not achieved. Reclaimed water filtration facilities for up to 1.5 mgd of secondary effluent are currently available. Implementation of nitrogen removal at the STP could have a significant effect on reclaimed water availability, potential customers, and quality, depending on the technology selected. Previous chapters presented analysis used a basis for the information contained herein. Chapter 1 reported development of two target permit levels for nitrogen removal: • 8 mg/L total inorganic nitrogen (TIN) from May through October • 3 mg/L TIN year-round Chapter 2 reported results of a screening of a wide range of potential nitrogen removal treatment scenarios to one potential technology for each permit level as follows: • Parallel Modified Ludzack-Ettinger (MLE) – membrane bioreactor (MBR) process for the 8 milligrams per liter (mg/L) summer TIN limit • Parallel Bardenpho – MBR process for the 3 mg/L year round TIN limit This chapter discusses potential effects of the selected alternative on reclaimed water production and compared to the cost of implementing reclaimed water production for the current, non-nitrified effluent. 3.2 SUMMARY OF RECLAIMED WATER STANDARDS The legislative basis for reclaimed water regulation in the State of Washington is contained 90.46 RCW - Reclaimed Water Use. The current Water Reclamation and Reuse Standards (Standards) date from 1997 and have been prepared jointly by the Department of Health (DOH) and the Department of Ecology (Ecology) (See DOH and Ecology 1997). These standards define reclaimed water in four classes based on quality as summarized in Table 3.1. Nitrogen removal is not required in general for any of the four classes, but is required for specific uses. Uses mentioning nitrogen removal in the Water Reclamation and Reuse Standards are summarized in Table 3.2. Current standards are under review. New rules are expected by December 2010. This analysis is based on the current regulations. June 29, 2010 - FINAL 3-2 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch03.docx Table 3.1 Definitions of Reclaimed Water South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division "Reclaimed water" means water derived in any part from wastewater with a domestic wastewater component that has been adequately and reliably treated, so that it can be used for beneficial purposes. Reclaimed water is not considered a wastewater. "Class A Reclaimed Water" means reclaimed water that, at a minimum, is at all times an oxidized, coagulated, filtered, disinfected wastewater. The wastewater shall be considered adequately disinfected if the median number of total coliform organisms in the wastewater after disinfection does not exceed 2.2 per 100 milliliters, as determined from the bacteriological results of the last 7 days for which analyses have been completed, and the number of total coliform organisms does not exceed 23 per 100 milliliters in any sample. "Class B Reclaimed Water" means reclaimed water that, at a minimum, is at all times an oxidized, disinfected wastewater. The wastewater shall be considered adequately disinfected if the median number of total coliform organisms in the wastewater after disinfection does not exceed 2.2 per 100 milliliters, as determined from the bacteriological results of the last 7 days for which analyses have been completed, and the number of total coliform organisms does not exceed 23 per 100 milliliters in any sample. "Class C Reclaimed Water" means reclaimed water that, at a minimum, is at all times an oxidized, disinfected wastewater. The wastewater shall be considered adequately disinfected if the median number of total coliform organisms in the wastewater after disinfection does not exceed 23 per 100 milliliters, as determined from the bacteriological results of the last 7 days for which analyses have been completed, and the number of total coliform organisms does not exceed 240 per 100 milliliters in any sample. "Class D Reclaimed Water" means reclaimed water that, at a minimum, is at all times an oxidized, disinfected wastewater. The wastewater shall be considered adequately disinfected if the median number of total coliform organisms in the wastewater after disinfection does not exceed 240 per 100 milliliters, as determined from the bacteriological results of the last 7 days for which analyses have been completed. June 29, 2010 - FINAL 3-3 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch03.docx Table 3.2 Summary of Reclaimed Water Uses Requiring Nitrogen Removal South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division Intended Use Nitrogen Removal Requirement Groundwater Recharge by Surface Percolation The secondary treatment process to provide oxidized wastewater shall include an additional step to reduce nitrogen Direct Recharge to Potable Ground Water Total nitrogen ≤10 mg/L as N Discharge to Wetlands Total Kjeldahl nitrogen (as nitrogen) 3 mg/L Non-restricted Recreational Impoundments Nitrogen removal to reduce levels of phosphorus and/or nitrogen is recommended The Standards give the following requirement for disinfection: Where chlorine is used as the disinfectant in the treatment process a minimum chlorine residual of at least 1 mg/L after a contact time of at least 30 minutes is required. (DOH and Ecology, September 1997, Section I, Article 9, Section 5 [a]) This requirement does not explicitly state whether the chlorine residual should be measured as free or total chlorine. Since the reclaimed water standards were issued in 1997, the design manual for wastewater treatment plants, the Criteria for Sewage Works Design (Orange Book), has been updated and a revised issue released in 2006. The Orange Book guidelines for chlorine disinfection requirements have changed in this revised manual and now state: When using chlorine as the disinfectant, state reclaimed water standards require a minimum CT of 30, based on a minimum free available chlorine residual of 1.0 mg/L after a t10 contact time of at least 30 minutes. The basis for using this method is disinfection requirements developed for the safe drinking water act. An alternate approach is to provide a CT of 450 based on a total chlorine residual of at least 5 mg/L after a modal contact time of at least 90 minutes. Note this approach may not provide the same level of pathogen inactivation as well the first. This approach, used in the state of California, prescribe a level of disinfection to provide essentially pathogen free water (Ecology, October 2006, E1-4.5.1 B). The new Rule limits the contact time (CT) to 30 mg/L-min based on a free chlorine residual and a T10 CT. The new draft standards “permit an alternative CT measurement such as total chlorine residual and a modal T value it if is demonstrated to the satisfaction of the departments that the alternative disinfection process provides an equivalent degree of human health and environmental protection.” June 29, 2010 - FINAL 3-4 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch03.docx 3.3 RECLAIMED WATER EVALUATION 3.3.1 Reclaimed Water Effects The current flow of the STP during the summer season when reclaimed water could be potentially used for irrigation is approximately 98 mgd. Coagulation, flocculation, and filtration or membrane filtration would be required to implement production of 98 mgd of reclaimed water from the current non-nitrified secondary effluent. Assuming a typical rapid mix detention time of 1 second, flocculation detention time of 20 minutes, and a maximum month hydraulic loading rate of 4 gallons per minute per square foot (gpm/sf) for the rapid sand filters, a total of approximately 38,000 square foot (sf) of coagulation, flocculation, and filtration facilities would be required. This sizing assumes two standby units out of a total of 45. Figure 3.1 shows how these facilities could fit on the existing site. The capacity of the existing filtration units was not included in the current analysis. The MLE – MBR alternative for operation for an 8 mg/L TIN permit level during the May through October period would produce up to 62 mgd of MBR effluent water during the summer that would substantially meet the requirements for Class A reclaimed water. To produce reclaimed water equaling the full current dry weather flow of 98 mgd, sand filtration of 36 mgd from the existing secondary clarifiers would be needed. Assuming rapid mix detention time of 1 second, flocculation detention time of 20 minutes, and a maximum month hydraulic loading rate of 4 gpm/sf for the rapid sand filters, a total of approximately 13,000 sf of coagulation, flocculation, and filtration facilities would be required with one unit out of 17 out of service. Figure 3.2 shows how these facilities could fit on the existing site. The Bardenpho – MBR upgrade strategy would produce up to 114 mgd of MBR effluent year round that would substantially meet the requirements of Class A reclaimed water. This means that the STP could provide reclaimed water for almost the entire average wet weather design flow if the 3 mg/L TIN year-round alternative were implemented. To achieve Class A reclaimed water standards for disinfection, additional chlorine contact basin volume would likely be required to achieve the 30 minute T10 CT. However, this requirement would be the same for the 8 mg/L TIN summer effluent scenario, the 3 mg/L TIN year round effluent scenario, and production of reclaimed water from the current plant (non-nitrified effluent). Disinfection with a substantially nitrified effluent following membrane filtration may require chloramination. However, due to the higher quality water, the required chlorine dose may decrease from what would be required following filtration of the non- nitrified effluent. Since the effects of nitrogen removal with a MBR system on the chemical requirements of disinfection are unknown without pilot-scale testing, it has been assumed that costs and other effects of the disinfection system for all scenarios are equal. pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 3.1.docx SITE REQUIREMENTS FOR 98 MGD OF CONVENTIONAL FILTRATION FIGURE 3.1 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT pw:\\Carollo\Documents\Client\WA\King County\7683E00\Deliverables\Final Report\Fig 3.2.docx SITE REQUIREMENTS FOR 33 MGD OF CONVENTIONAL FILTRATION FIGURE 3.2 KING COUNTY DEPARTMENT OF NATURAL RESOURCES AND PARKS ASSESSMENT OF POTENTIAL NITROGEN REMOVAL TECHNOLOGIES AT THE SOUTH TREATMENT PLANT AND THEIR IMPACT ON FUTURE WATER REUSE PROGRAM DEVELOPMENT June 29, 2010 - FINAL 3-7 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch03.docx 3.3.2 Reclaimed Water Options Costs Table 3.3 compares the planning level costs of reclaimed water production for the full 98 mgd summer flow for the current non-nitrified secondary effluent to the requirements for additional filtration assuming nitrogen removal upgrade by a parallel MBR process for either the 8 mg/L (summer only) or the 3 mg/L (year-round) TIN permit level. As shown in Table 3.3, there would be no additional cost to implement reclaimed water production for the full summer flow of 98 mgd if the 3 mg/L (year-round) TIN permit limit project is implemented. Table 3.3 shows that the cost of implementing reclaimed water by conventional filtration is approximately $104 million in present worth capital and operating and maintenance costs. If a 3 mg/L (year-round) TIN permit limit project using parallel MBR were implemented, this cost would be avoided. The planning level present worth cost of implementing 36 mgd of reclaimed water production for non-nitrified effluent would be approximately $45 million. This would represent a savings of approximately $59 million over providing full summer reclaimed water production today from non-nitrified STP effluent. This relative savings in reclaimed water production would be realized if the 8 mg/L (summer-only) parallel MBR project were implemented. Table 3.3 Summary of Relative Reclaimed Water Costs Effects South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division Treatment Process Current Approach. Non-nitrified Secondary Effluent. No new facilities. Summer only. 8 mg/l TIN Summer Limit Parallel MLE-MBR Processes 3 mg/l TIN All- year Limit Add’l Sand Filtration Req’d 98 mgd sand filters MLE Effluent 36 mgd sand filters MBR Effluent 62 mgd - no sand filters MBR Effluent 114 mgd – no sand filters Capital Cost $57M $23M $0 $0 Annual O&M Cost $3.1M/yr $1.4M/yr $0 $0 Disinfection Assumed equal cost for all alternatives. Present Worth O&M $47M $22M $0 Total Present Worth $104M $45M $0 June 29, 2010 - FINAL 3-8 pw://Carollo/Documents/Client/WA/King County/7683E00/Deliverables/Final Report/Ch03.docx 3.3.3 Other Effects In addition to economic effect, there would be other effects of implementing either an 8 mg/L (summer-only) or a 3 mg/L (year-round) TIN effluent permit limit project on potential reclaimed water production. Key effects include additional land use, energy consumption, and greenhouse gas (GHG) consumption. They are summarized in Table 3.4. Table 3.4 Summary of Other Relative Reclaimed Water Effects South Plant Nitrogen Removal Study King County Department of Natural Resources and Parks Wastewater Treatment Division Element Current Approach Non-nitrified Secondary Effluent (98 mgd treated) 8 mg/L TIN Summer Effluent Limit, Parallel MLE-MBR (36 mgd treated) 3 mg/L TIM Year- round Effluent Limit, Parallel Bardenpho-MBR (0 mgd treated) Impact Land area (sf) 38,000 13,000 0 Energy consumption (kWh/year) 200,000 85,000 0 GHG Emissions (metric tons of annual eCO2) 300 100 0 3.4 CONCLUSIONS The selected alternatives for implementation of nitrogen removal at the STP include membrane filtration of a portion of the final effluent for two different flows depending on the permit level for nitrogen removal required. This presents an opportunity for reclaimed water use. If nitrogen removal were implemented at the STP, between 36 and 98 mgd of effluent would be made available that would be suitable for reclaimed water use. Assuming that the costs of production of this water were required for nitrogen removal in any case, this water would be available for reclaimed use at a relative savings over the costs of production of the water using conventional gravity sand filtration. Cost savings would be in the range of $45 to $104 million, depending on the level of nitrogen removal required. There would also be a savings in land area of between one quarter and one acre and a savings of a small amount in electricity consumption and GHG emissions, compared to production of the same amount of reclaimed water using media filtration if nitrogen removal treatment facilities were not available. REFERENCES Brown and Caldwell (July 2004), South Plant Capacity and Re-rating Evaluation, Final Draft. Carollo Engineers (2010) South Plant Peak Flow Management Report. Carollo Engineers (2009a) Project Kickoff Meeting Minutes, Conference Date, October 1, 2009. Carollo Engineers (2009b) Alternative Selection Meeting Minutes, Conference Date, December 15, 2009. C. W. Randall, J. L. Barnard, H. D. Stensel. (1992) Design and Retrofit of Wastewater Treatment Plants for Biological Nutrient Removal, Technomic Publishing Company, Inc.; Lancaster. Daigger, Glenn T. (1995) Development of refined clarifier operating diagrams using an updated settling characteristics database, Water Environment Research, Volume 67, Number 1. Jenkins, David et. al. (2004) Manual on the Causes and Control of Activated Sludge Bulking, Foaming, and Other Solids Separation Problems, IWA Publishing, 3rd Edition. Owen, William F. (1982) Energy in Wastewater Treatment, Prentice-Hall. Pittman, A.R. (1985) Settling of Nutrient Removal Activated Sludge, Wat. Sci. Tech., Vol. 17, Amsterdam, pg. 493-504. State of Washington Department of Ecology (November 2008a) South Puget Sound Dissolved Oxygen Study, Key Findings on Nitrogen Sources from the Data Report, Publication No. 08-10-099. State of Washington Department of Ecology (December 2008b) South Puget Sound Dissolved Oxygen Study Interim Data Report, Publication No. 08-03-037. State of Washington Department of Ecology (2009) EXTERNAL REVIEW DRAFT – 10-15- 09, South Puget Sound Dissolved Oxygen Study—South and Central Puget Sound Water Circulation Model Development and Calibration, Publication No. 09-03-0xx. U.S. EPA (April 15, 2010), Inventory of U.S. Greenhouse Gas Emissions and Sinks; 1990- 2008. Washington State Department of Health and Washington State Department of Ecology (September 1997) Water Reclamation and Reuse Standards. Washington State Department of Ecology, Water Quality Program (October 2006) Criteria for Sewage Works Design. APPENDIX A EVALUATION CRITERIA Criteria MBR IFAS Linpor IFAS Kruger BAF Capital Cost > 1.25 X lowest cost = 2 lowest cost = 3 < 1.25 x lowest = 3 > 1.25 X lowest cost = 2 1.37 1.00 1.24 1.48 O&M Cost, PW > 1.5 x lowest = 1 > 1.5 x lowest = 1 lowest = 3 < 1.5 x lowest = 2 1.58 1.50 1.00 1.41 Risk County familiar with process. Brightwater will be of a similar size range = 3 County not familiar with process. No US installations of a similar size = 1 County not familiar with process. No US installations of a similar size = 1 County not familiar with process. 1 US installation of a similar size, 1 additional planned for 2010 = 1 Footprint, sf < 1.5 x lowest = 2 Lowest impact = 3 > 1.5 x lowest = 1 < 1.5 x lowest = 2 607,429 425,880 849,221 560,030 1.43 1.00 1.99 1.31 Energy > 1.5 x lowest = 1 Lowest = 3 < 1.5 x lowest = 2 < 1.5 x lowest = 2 1.69 1.00 1.30 1.49 Odor All processes equally odoriforous All processes equally odoriforous All processes equally odoriforous All processes equally odoriforous Compatibility with existing processes No stranded assetts No stranded assetts No stranded assetts No stranded assetts Biosolids Quality Nitrogen removed by N2 gas evoluation, some N lost from biosolids = 2 Nitrogen removed by N2 gas evoluation, some N lost from biosolids = 2 Nitrogen removed by N2 gas evoluation, some N lost from biosolids = 2 Nitrogen removed by N2 gas evoluation, some N lost from biosolids = 2 RW Quality Reclaimed water quality effluent = 3 Nitrifying system, better effluent = 2 nitrifying system, better effluent, no room for filters = 1 Nonnitrifying system = 1 TIN 3 Score Reasoning Criteria MLE MBR IFAS Linpoor IFAS Kaldness BAF Capital Cost Lowest capital cost = 3 < 2 X lowest cost = 2 < 1.25 X lowest = 3 > 2 X lowest = 1 < 2 X lowest = 2 1.00 1.72 1.15 2.11 1.73 O&M Cost, PW Lowest cost = 3 > 2 X lowest cost = 1 < 2 x lowest = 2 < 2 x lowest = 2 < 2 x lowest = 2 1.00 2.11 1.72 1.69 1.77 Risk Very similar to existing process. County familiar with process. Numerous US installations in size range = 3 County familiar with process. Brightwater will be of a similar size range = 3 County not familiar with process. No US installations of a similar size = 1 County not familiar with process. No US installations of a similar size = 1 County not familiar with process. 1 US installation of a similar size, 1 additional planned for 2010 = 1 Future Flexibility Cannot meet future limit of 3 mg/L = 1 Can meet future limit of 3 mg/L = 3 Can meet future limit of 3 mg/L = 3 Cannot meet future limit of 3 mg/L = 1 Can meet future limit of 3 mg/L = 3 Footprint, sf > 1.5 x lowest alternative = 1 < 1.25 x lowest alternative = 3 Lowest impact = 3 > 1.25 X lowest = 2 < 1.25 x lowest alternative = 3 725,935 438,148 383,196 500,016 457,745 1.89 1.14 1.00 1.30 1.19 Energy Lowest energy use = 3 < 1.5 x lowest = 2 < 1.25 x = 3 > 1.5 x lowest = 1 < 1.5 x lowest = 2 1.00 1.26 1.10 1.71 1.34 Odor All processes equally odoriforous All processes equally odoriforous All processes equally odoriforous All processes equally odoriforous All processes equally odoriforous Compatibility with existing processes No stranded assetts No stranded assetts No stranded assetts No stranded assetts No stranded assetts Biosolids Quality Nitrogen removed by N2 gas evoluation, some N lost from biosolids = 2 Nitrogen removed by N2 gas evoluation, some N lost from biosolids = 2 Nitrogen removed by N2 gas evoluation, some N lost from biosolids = 2 Nitrogen removed by N2 gas evoluation, some N lost from biosolids = 3 Nitrogen removed by N2 gas evoluation, some N lost from biosolids = 2 RW Quality Nitrifying system, better effluent quality, but no room on site for more filters = 1 Reclaimed water quality effluent = 3 Nitrifying system, better effluent = 2 Nitrifying system, better effluent = 3 Nonnitrifying system = 1 TIN 8 Score Reasoning APPENDIX B COST ASSUMPTIONS AND SUMMARIES Client: Project: Subject: Cost Assumptions Cost Assumptions By :RWS Estimate Cost Base :3/15/2010 Bordered Cells are Input Cells Item Value Period of analysis, years 20 Discount rate, %3.0% Construction Escalation rate, %6.0% Mid-Point Construction date 15-Mar-10 Operations labor rate, $/hr $50 Diesel oil cost, $/gal $3.00 Power cost, $/kwh $0.07 Biosolids Management, $ / wet ton (with trucking)$50.00 Chemical Cost, $/lb Chlorine $0.62 Sulfur Dioxide $0.19 Citric Acid $0.50 Alum $0.10 Ferric Chloride $0.35 Sodium hypochlorite $0.90 Methanol $0.33 Cationic Polymer $1.60 Structural Annual Replacement Cost, %2% Equipment Annual Replacement Cost, %4% Contingency, %40% Allied Costs (Planning, Design, CM, Permits, etc.)45% Sales tax, %10.0% ENR Cost Index 10350 Present Worth Factor 14.87747 King County Nutrient Removal Analysis - 3 mg/L Year-round TIN Cost Comparison of Treatment AlternativesKing CountyNutrient Removal Analysis - 8 mg/L Summer TIN (98 mgd Max Month Flow)Treatment Element CAS MLE MLE MBR Total NR Cost DifferenceCapital Cost, $Fine Screening $0 $11,000,000 $11,000,000 $11,000,000CAS Aeration Tanks $0 $0 $0BNR Reactor Tanks $0 $105,200,000 $105,200,000 $105,200,000MBR Reactor Tanks $0 $179,600,000 $179,600,000 $179,600,000MBR Membrane Tanks and Equipment $0 $227,800,000 $227,800,000 $227,800,000Centrate Treatment Tanks $0 $6,300,000 $6,300,000 $6,300,000Total Project Cost $0 $105,000,000 $425,000,000 $530,000,000 $530,000,000Design Max Month Flow (mgd) 98 33 65 98 98Unit Project Cost ($/gpd) $0.00 $3.18 $6.54 $5.41 $5.41Operation and Maintenance Cost, $/yearFine Screening $0 $0 $660,000 $660,000 $660,000CAS Aeration Tanks $1,730,000 $721,000 $0 $721,000 -$1,009,000BNR Reactor Tanks $0 $2,390,000 $0 $2,390,000 $2,390,000MBR Reactor Tanks $0 $0 $2,870,000 $2,870,000 $2,870,000MBR Membrane Tanks and Equipment $0 $0 $4,920,000 $4,920,000 $4,920,000Centrate Treatment Tanks $0 $0 $200,000 $200,000 $200,000Total $1,700,000 $3,100,000 $8,700,000 $11,800,000 $10,000,000Present Worth Cost, $ MillionCapital $0 $105 $425 $530 $530Operation and Maintenance $25 $46 $129 $176 $149Total Present Present Worth $25 $151 $554 $706 $679 Cost Comparison of Treatment AlternativesKing CountyNutrient Removal Analysis - 3 mg/L Year-round TIN (144 mgd Max Month Flow)Treatment ElementCAS Bardenpho Upgrade Bardenpho MBRTotal NR UpgradeDifferenceCapital Cost, $Fine Screening$0$14,100,000 $14,100,000 $14,100,000CAS Aeration Tanks$0$0$0BNR Reactor Tanks $0 $179,800,000$179,800,000 $179,800,000BNR Secondary Sed Tanks$0 $8,300,000$8,300,000MBR Reactor Tanks$0$385,300,000 $385,300,000 $385,300,000MBR Membrane Tanks and Equipment$0$367,600,000 $367,600,000 $367,600,000Centrate Treatment Tanks$0$12,100,000 $12,100,000 $12,100,000Total Project Cost$0 $188,000,000 $779,000,000 $967,000,000 $959,000,000Design Flow, mgd14430114144144Unit Project Cost ($/gpd)$0.00$6.27$6.83$6.72$6.66Operation and Maintenance Cost, $/yearFine Screening$1,315,000 $1,315,000 $1,315,000CAS Aeration Tanks$1,840,000$0 -$1,840,000BNR Reactor Tanks$7,212,000$7,212,000 $7,212,000BNR Secondary Sed Tanks$1,367,000$1,367,000MBR Reactor Tanks$11,764,000 $11,764,000 $11,764,000MBR Membrane Tanks and Equipment$13,013,000 $13,013,000 $13,013,000Centrate Treatment Tanks$410,000 $410,000 $410,000Total$1,800,000 $8,600,000 $26,500,000 $35,100,000 $31,900,000Present Worth, $ MillionCapital$0$188$779$967$959Operation and Maintenance$27$128$394$522$475Total Present Worth$27$316$1,173 $1,489 $1,434