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HomeMy WebLinkAboutTIR-4110 ENGINEERING REPORT TECHNICAL INFORMATION REPORT FAMILY FIRST COMMUNITY CENTER RENTON, WA November 4, 2019 PREPARED FOR: City of Renton 1055 South Grady Way Renton, WA 98057 PREPARED THROUGH: City of Renton 1055 South Grady Way Renton, WA 98057 PREPARED BY: COUGHLIN PORTER LUNDEEN 801 Second Avenue, Suite 900 Seattle, WA 98104 P 206.343.0460 CONTACT / Keith Kruger, P.E. May 8, 2020 SURFACE WATER UTILITY jfarah 07/07/2020APPROVED 07/08/2020 msippo DEVELOPMENT ENGINEERING DIVISION i Technical Information Report Renton School District Coughlin Porter Lundeen Project No. C180040-01 May 8, 2020 TABLE OF CONTENTS I PROJECT OVERVIEW ................................................................................................................................ 1 FIGURES .......................................................................................................................................................... 1 GENERAL DESCRIPTION .............................................................................................................................. 1 EXISTING CONDITIONS ................................................................................................................................. 1 PROPOSED CONDITIONS ............................................................................................................................. 2 II. CONDITIONS AND REQUIREMENTS SUMMARY ..................................................................................... 3 CORE REQUIREMENTS: ................................................................................................................................ 3 SPECIAL REQUIREMENTS: ........................................................................................................................... 3 PROJECT-SPECIFIC REQUIREMENTS: ....................................................................................................... 4 III. OFF-SITE ANALYSIS .................................................................................................................................. 5 TASK 1 – STUDY AREA DEFINITION AND MAPS ........................................................................................ 5 TASK 2 - RESOURCE REVIEW ...................................................................................................................... 5 TASK 3 - FIELD INSPECTION ........................................................................................................................ 6 TASK 4 - DRAINAGE SYSTEM DESCRIPTION AND PROBLEM DESCRIPTIONS .................................... 7 TASK 5 – MITIGATION OF EXISTING OR POTENTIAL PROBLEMS .......................................................... 7 UPSTREAM ANALYSIS ................................................................................................................................... 7 CONCLUSION .................................................................................................................................................. 8 IV. FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN ..................................... 9 EXISTING SITE HYDROLOGY (PART A) ...................................................................................................... 9 DEVELOPED SITE HYDROLOGY (PART B) ................................................................................................. 9 PERFORMANCE STANDARDS AND FLOW CONTROL SYSTEM (PARTS C) ........................................10 FLOW CONTROL BEST MANAGEMENT PRACTICES (PART D) .............................................................10 WATER QUALITY SYSTEM (PART E) .........................................................................................................11 V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN ................................................................................ 13 CONVEYANCE STANDARDS.......................................................................................................................13 ON-SITE CONVEYANCE SYSTEMS ............................................................................................................13 VI. SPECIAL REPORTS AND STUDIES ........................................................................................................ 16 VII. OTHER PERMITS ...................................................................................................................................... 17 VIII. CSWPPP ANALYSIS AND DESIGN ......................................................................................................... 18 EROSION AND SEDIMENT CONTROL ANALYSIS AND DESIGN (PART A) ...........................................18 SWPPS PLAN DESIGN (PART B) ................................................................................................................19 IX. BOND QUANTITY, FACILITY SUMMARIES, AND DECLARATION OF COVENANT ............................ 20 CITY OF RENTON BOND QUANTITY WORKSHEET .................................................................................20 FLOW CONTROL AND WATER QUALITY FACILITY SUMMARY SHEET AND SKETCH .......................20 DECLARATION OF COVENANT FOR PRIVATELY MAINTAINED FLOW CONTROL AND WATER QUALITY FACILITIES ....................................................................................................................................20 ii DECLARATION OF COVENANT FOR PRIVATELY MAINTAINED FLOW CONTROL BMPS ..................20 X. OPERATION AND MAINTENANCE MANUAL ......................................................................................... 21 APPENDIX A – FIGURES .................................................................................................................................. 22 FIGURE 1 – TIR WORKSHEET ....................................................................................................................22 FIGURE 2 – VICINITY MAP ...........................................................................................................................22 FIGURE 3 – EXISTING SITE CONDITIONS ................................................................................................22 FIGURE 4 – PROPOSED SITE CONDITIONS .............................................................................................22 FIGURE 5 – DRAINAGE BASIN MAP ...........................................................................................................22 FIGURE 6 – 100-YR FLOODPLAIN MAP .....................................................................................................22 FIGURE 7 – AQUIFER RECHARGE AREA MAP ........................................................................................22 FIGURE 8 – OFF-SITE DRAINAGE ANALYSIS MAP ..................................................................................22 FIGURE 8A –OFF-SITE DRAINAGE TABLE ................................................................................................22 FIGURE 9 – COAL MINE HAZARD AREA....................................................................................................22 FIGURE 10 – SOILS MAP .............................................................................................................................22 FIGURE 10A – SOILS MAP TABLE ..............................................................................................................22 FIGURE 11 – UPSTREAM BASIN DELINEATION MAP ..............................................................................22 FIGURE 12 – TESC PLAN .............................................................................................................................22 APPENDIX B – ENGINEERING CALCULATIONS ............................................................................................ 23 APPENDIX C – CSWPPP ................................................................................................................................... 24 APPENDIX D – OPERATIONS AND MAINTENANCE MANUAL...................................................................... 25 APPENDIX E – FACILITIES SUMMARY AND DECLARATIONS OF COVENANT .......................................... 26 LIST OF TABLES TABLE 1 - DEVELOPED SITE CONDITIONS AREA BREAKDOWN ................................................ 2 TABLE 2 - EXISTING SITE CONDITIONS AREA BREAKDOWN ..................................................... 9 TABLE 3 – SUB-BASIN AREAS .................................................................................................. 10 TABLE 3 – DETENTION FACILITY SUMMARY ............................................................................ 10 FAMILY FIRST COMMUNITY CENTER 1 I PROJECT OVERVIEW FIGURES Refer to Appendix A for figures. GENERAL DESCRIPTION The following Technical Information Report (TIR) provides the technical information and design analysis required for developing the Stormwater Drainage and Temporary Erosion and Sedimentation Control (TESC) Plans for the Family First Community Center. The stormwater design for the project is based on the requirements set forth by the 2017 City of Renton Surface Water Design Manual (2017 CRSWDM) The Family First Community Center is located at 16022 116th Avenue SE, Renton WA 98058 (See Figure 2 – Vicinity Map) adjacent to the existing Cascade Elementary School. The property is owned by Renton School District and is bound by an easement to Pacific Northwest Pipe Line Corporation to the north, 116th Avenue SE to the west and single-family residences to the east and south. The project is located on a 14.9 acre parcel and the parcel number 152823059034. The project is in the NW ¼ of Section 28, Township 23 North, Range 5 East, Willamette Meridian. The project is currently pursuing a short plat for the development area, which is 2.51 acres, to separate the Family First Community Center property from the existing Cascade Elementary School property. The project consists of the construction of a new one-story community recreational center that is 27,000 square feet and approximately 120 surface parking stalls. The community center will include a new gymnasium, activity rooms, gathering places, offices, a kitchen, parking lot and associated landscaping and sidewalks. An existing biofiltration swale and associated storm piping will be removed to accommodate the new development. The project will be removing the existing water quality treatment facility for the Cascade Elementary School (biofiltration swale) and replacing the facility with a Modular Wetland System to treat the pollution generating runoff from the existing site. The project will result in 2.03 -acres of new or replaced impervious area and 0.48-acres of new or replaced pervious area within the parcel. The total project area is 2.51 acres. EXISTING CONDITIONS The existing site consists of an 0.6-acre parking lot, a grass field and an existing biofiltration swale on the southern side of the existing Cascade Elementary School site. The project site is fully developed with existing stormwater facilities. The topography generally slopes from west to east with the project site outfall located on the southeast corner of the site. (See Figure 3 – Existing Site Conditions). The project high point is located at the western property line, at elevations of 465 and 466 respectively. The existing low point is located at the southeast corner of the site at an elevation of 452 feet. The overall drop across the site from the northwest corner down to the southeast corner is 13 feet. Stormwater runoff flows from west to east. Stormwater runoff from the existing site consists of surface, shallow, and piped flow to the existing biofiltration swale located on the south side of the site, which then discharges to the existing stormwater system at the southeast corner of the site. The upstream area from the existing Cascade Elementary School and properties to the west side of 116th Avenue is routed through our site via the onsite bypass (see Figure 11 – Upstream Delineation Basin Map). Based on the existing contours from survey and City of Renton GIS, there are no onsite flows from the southern properties. There are no critical areas within with the existing site. The adjacent street is 116th Avenue SE located to the west. 116th Avenue SE is generally flat but slopes down to the south at slopes ranging from 0 percent to 0.5 percent. It is developed with a sidewalk, curb, landscape strip and catch basins on the side adjacent to the site. The Soils Conservation Service maps the soils as generally Arents, Alderwood material (See figure 8 – Soil Map) . A geotechnical analysis of the site was performed by The Riley Group, Inc (RGI) and published in a report dated June 8, 2018. The RGI investigation found “The site is underlain by up to 11 feet of fill FAMILY FIRST COMMUNITY CENTER 2 comprised of loose to medium dense silty sand with varying amounts of gravel over medium dense to very dense silty sand with varying amounts of gravel, and localized silty sand, sandy gravel, and sand with some silt and gravel.” PROPOSED CONDITIONS The proposed project consists of the construction of a new one-story community recreational center that is 27,000 square feet and approximately 120 surface parking stalls (see Figure 4 – Proposed Site Conditions). The community center will include a new gymnasium, activity rooms, gathering places, offices, a kitchen, parking lot and associated landscaping and sidewalks. The proposed project, including frontage improvements, will result in 2.08 acres of new or replaced impervious surface, which triggers a “Full Drainage Review” (2017 City of Renton Surface Water Manual 1.1.2.4) and the analysis of all “Core” and “Special” requirements. Please see Table 1 – Developed Site Conditions Area breakdown for a summary of the proposed land coverages. TABLE 1 - DEVELOPED SITE CONDITIONS AREA BREAKDOWN LAND COVER AREA (ACRES) DESCRIPTION Impervious Surface 2.08 Parking and drive aisles, building, and sidewalk Pervious Surface (Landscape) 0.49 Lawn and landscape area Total Disturbed Area 2.57 Disturbed area % Impervious Area 80.9% The Core Requirements include Minimum Requirement #3 which requires flow control for the total disturbed area. The detention facilities are to be modeled using MGSFlood software with 15-minute time steps. Two detention facilities will provide flow control: an SC-740 Stormtech Chamber System and a MC-3500 Stormtech Chamber System. Both Stormtech Chamber systems will discharge to the existing storm system located in the southeast corner of the site. The Core Requirements also include Minimum Requirement #8 which requires water quality treatment for pollution generating surfaces. Water quality treatment will be provided by a proprietary Modular Wetland System and bioretention that will be used to mitigate pollution generating areas. For Core Requirement #9: On-Site BMPs, Flow Control Best Management Practices (FCBMPs), since the project has over 80% impervious surface coverage the project does not need to apply FCBMPs for any target surface area, according to table C1.3.A of the 2017 RSWDM. See Section IV for further detail for the flow control and water quality systems. FAMILY FIRST COMMUNITY CENTER 3 II. CONDITIONS AND REQUIREMENTS SUMMARY This section addresses the requirements set forth by the Core and Special Requirements listed in Chapter 1 of the City of Renton Surface Water Design Manual. CORE REQUIREMENTS: 1. Discharge at the Natural Location (1.2.1): Stormwater runoff from the existing site discharges to the existing City of Renton Stormwater system via surface flow and via a ditch and pipe conveyance system on the southeast corner of the site. The existing site contains a biofiltration swale that collects runoff from the site via surface and piped flow, which then discharges to the City’s existing stormwater system. In the developed condition, stormwater runoff will continue to discharge to the City’s stormwater system via surface and pipe flow. The development will be installing a new structure over the existing stormwater system at the natural discharge location, where the project will be tying into the existing stormwater system. 2. Off-site Analysis (1.2.2): A Level 1 analysis of the upstream and downstream flow paths for the project was performed on September 9, 2018 and is detailed in Section III. This analysis showed that no downstream problems will occur by the construction of the project. 3. Flow Control (1.2.3): Level II flow control requires the project to meet flow durations for forested conditions. This requirement will be met by providing two Stormtech Chamber detention systems. Further information is presented in Section IV of this report. 4. Conveyance System (1.2.4): Closed pipe systems will be provided for on-site stormwater conveyance. Further details are provided in Section V. 5. Erosion and Sedimentation Control (1.2.5): Erosion and Sediment Control (ESC) measures will be provided during construction to address the specific conditions at the site. Further details can be found in Section VIII. 6. Maintenance and Operations (1.2.6): The proposed storm drainage system will be owned, operated and maintained by the City of Renton. Further details can be found in Section X. 7. Financial Guarantees and Liability (1.2.7): The Owner and Contractor will obtain all necessary permits prior to the beginning of construction. 8. Water Quality (1.2.8): The project is considered a “commercial” project and drains to the City of Renton Stormwater system, therefore, Enhanced Basic water quality is required for this project. Enhanced Basic water quality treatment will be addressed using a proprietary Modular Wetland System and bioretention to treat runoff from all target surfaces. Further details are provided in Section IV of this report. 9. Flow Control BMPs (1.2.9): According to table C1.3.A of the 2017 RSWDM, projects that has over 80% of impervious surface coverage do not need to apply FCBMPs. Since the project has 81% impervious surface coverage, the project is not required to implement FCBMPs. SPECIAL REQUIREMENTS: 1. Other Adopted Area-Specific Requirements (1.3.1): · Critical Drainage Areas (CDAs): The project site is not located within any Critical Drainage Areas. · Master Drainage Plans (MDPs): There are no known master drainage plans covering this project site. · Basin Plans (BPs): The project is located within the Lower Cedar River Drainage Basin (see Figure 5 – Drainage Basin Map). The basin plan does not include any special drainage requirements. · Stormwater Compliance Plans (SWCPs): There are no Stormwater Compliance Plans that are applicable to this project. · Lake Management Plans(LMPs): There are no Lake Management Plans that are applicable to this project. FAMILY FIRST COMMUNITY CENTER 4 · Shared Facility Drainage Plans(SFDPs): There are no shared Facility Drainage Plans that are applicable to this project. 2. Flood Hazard Area Delineation (1.3.2): The project site is not located within the 100-year floodplain (see Figure 6 – 100-yr Floodplain Map). 3. Flood Protection Facilities (1.3.3): The project will not rely on or modify an existing flood protection facility. 4. Source Controls (1.3.4): The project will be providing spill control for catch basins that are directly upstream of the detention systems to meet source control requirements. 5. Oil Control (1.3.5): Vehicle use and traffic concentration on the site will not reach levels that require oil control facilities. The developed new plus replaced pollution generating surface area does not exceed the high use site threshold amount. 6. Aquifer Protection Area (1.3.6): Not applicable. Project site nor downstream flow path located within 1 mile from an Aquifer Recharge Area (See Figure 7 – Aquifer Recharge Area Map). PROJECT-SPECIFIC REQUIREMENTS: There are no additional requirements for the project. Design and construction will abide by requirements set forth in these documents and the 2017 City of Renton Surface Water Design Manual. FAMILY FIRST COMMUNITY CENTER 5 III. OFF-SITE ANALYSIS TASK 1 – STUDY AREA DEFINITION AND MAPS This off-site analysis examines the stormwater systems upstream and downstream of the Family First Community Center project, located at 16022 116th Avenue SE, Renton WA, 98058. The Family First Community Center project consists of the construction of a new recreational center that is approximately 27,000 square feet and will include a new gymnasium, activity rooms, gathering spaces, and a demonstration kitchen. The community center project will construct 120 surface parking lot stalls and associated sidewalks and landscape areas. The existing site is roughly 2.51 acres with about 0.46 acres of impervious area and is not constrained by any critical areas or corresponding buffers. The proposed project will add or replace roughly 2.03 acres of impervious surface and will not convert any square feet of impervious area to landscape. The Figure 2 - Vicinity Map, Figure 8 - Off-Site Drainage Analysis Map, and Figure 8A – Off-Site Drainage Analysis Table in the Appendix depict the location of the project site and the basins being analyzed. TASK 2 - RESOURCE REVIEW a) Adopted Basin Plans: According to the King County Drainage Basin iMap, this project is in the Lower Cedar River Drainage Basin, as depicted in Figure 5 - Drainage Basin Map. The Lower Cedar River Basin and Nonpoint Pollution Action Plan, adopted in 1997, depicts basin boundaries that are slightly different than the basin boundaries in the King County Drainage Basin iMap. According to the Lower Cedar River Basin and Nonpoint Pollution Action Plan, there are not issues regarding potential flooding erosion and water quality problems upstream nor one mile downstream of the project site, as of 1997. b) Floodplain/Floodway FEMA Maps: The project site nor the downstream flow path is not located within a Floodplain/floodway (FEMA). See Figure 6 – 100-Year Floodplain c) Other Off-site Analysis Reports: No off-site analysis reports were available within one mile of the site as of September 2018. d) Critical Areas: · No Coal Mine Hazard Areas are mapped within the downstream flowpath (see Figure 9) · Critical Wetland Areas are mapped within the downstream flowpath (see Figure 8) · No Erosion Hazard Areas are mapped within the downstream flowpath (see Figure 8) · No Landslide Hazard Areas are mapped within the downstream flowpath (see Figure 8) · Steep Slope Hazard Areas are mapped within the downstream flowpath (see Figure 8) · No Seismic Hazard Areas are mapped within the downstream flowpath (see Figure 8) · No Critical Aquifer Recharge Areas are mapped within the downstream flowpath (see Figure 7) e) Soils Survey: The soils that are expected to underlay the project site have been classified by the USDA Natural Resources Conservation Service (NRCS) as Arents, Alderwood material, 6 to 15 percent slopes (AmC). See Figure 10 - Soils map. FAMILY FIRST COMMUNITY CENTER 6 f) Wetland Inventory Map: According to City of Renton GIS, wetlands are within the study area are identified on King County’s of City of Renton’s iMap (see figure 8). g) Section 303d List of Polluted Waters: Not applicable to the study area. h) City of Renton Erosion Maps and Landslide Maps: No Erosion or Landslide Hazards are included within the study are for this Project. See Figure 8 – Off Site Drainage Analysis Map. i) Other reports: Cascade Elementary School Portables Project TIR. TASK 3 - FIELD INSPECTION A Level 1 Downstream Analysis site visit was made on 9/6/2018 under dry conditions. Total precipitation for 9/6/2018 was 0 inches. No rainfall occurred on the day prior to the site visit. Results of the field inspection are shown in the Off-Site Drainage Systems Table attached to Figure 8 - Off-Site Drainage Analysis Map in the Appendix. 1. Investigate any problems reported or observed during the resource review. · No problems were reported or observed during the resource review. 2. Locate all existing/potential constrictions or lack of capacity in the existing drainage system. · No constrictions or lack of capacity in the existing drainage system was observed. 3. Identify all existing/potential downstream drainage problems as defined in Section 1.2.2.1. · No existing/potential downstream drainage problems were observed. 4. Identify existing/potential overtopping, scouring, bank sloughing, or sedimentation. · No existing/potential overtopping, scouring, bank sloughing, or sedimentation was observed. 5. Identify significant destruction of aquatic habitat or organisms (e.g., severe siltation, bank erosion, or incision in a stream). · No significant destruction of aquatic habitat or organisms was observed. 6. Collect qualitative data on features such as land use, impervious surfaces, topography, and soil types. · The land use of the project site is a school site that consists of approximately 30% impervious area and sports fields to the east side. The conveyance system drains through a residential area to the east before reaching 119th Avenue SE, where the road slopes down to a catch basin before being conveyed farther east. The upstream basin was delineated by determining what portion of the existing Cascade Elementary School site drains to the existing bioswale and reviewing existing contours from the City of Renton GIS to see which portions of the residential area to the west of 116th avenue drains onto the site (See Figure 11 – Upstream Basin Delineation Map). The upstream basin, that will bypass our detention system, was determined to be 10.09 acres (see Figure 11) The existing bioswale will be replaced as a part of the proposed development and the same basin draining to the bioswale is the upstream basin for the proposed project. Based on the FAMILY FIRST COMMUNITY CENTER 7 survey, City of Renton GIS and observations on site, no other upstream basin was delineated. 7. Collect information on pipe sizes, channel characteristics, drainage structures, and relevant critical areas (e.g., wetlands, streams, steep slopes). · See Figure 8 for information on pipe sizes and drainage structures. No critical areas were observed. 8. Verify tributary basins delineated in Task 1. · Based on the topography onsite, the basin delineation based on the survey and COR maps was confirmed (see figure 11 for more information on upstream delineation). 9. Contact neighboring property owners or residents in the area about past or existing drainage problems and describe these in the report (optional). · This requirement is not applicable for this project. 10. Note the date and weather conditions at the time of the inspection. · The site visit occurred on September 6, 2018. The weather was sunny, and temperature was 65 degrees. TASK 4 - DRAINAGE SYSTEM DESCRIPTION AND PROBLEM DESCRIPTIONS See Figure 8 for a map of the downstream drainage system. The site currently discharges from a catch basin at the southeast corner of the site located directly downstream of an existing bioswale and then through a series of catch basins in residential streets. This catch basin and bioswale will be replaced as a part of the proposed development. Downstream of the replaced catch basin, stormwater is conveyed approximately 200 feet through an existing 15” pipe to an existing type 1 catch basin located at the southeast corner of the Cascade Elementary School property. Stormwater is then conveyed roughly 320 feet to a type two catch basin located in 119th Ave SE, which is adjacent to the property. Stormwater is then conveyed approximately 300 feet through a 24” concrete pipe at approximately 2% to another type two catch basin located in 120th Ave SE. From here stormwater is directed through a 24” concrete pipe at 2% slope to a type two catch basin located in 121st Ave SE, approximately 300 feet downstream. The downhill discharge point of the offsite drainage system is located at Ginger Creek, approximately one-half mile downstream. Existing downstream drainage infrastructure is located near wetland areas. See Off-Site Drainage System (attached to Figure 8) for more information regarding the downstream drainage system. TASK 5 – MITIGATION OF EXISTING OR POTENTIAL PROBLEMS No existing or potential problems were observed during the downstream analysis. UPSTREAM ANALYSIS Based on survey and the City of Renton GIS, 10.09 acres of upstream residential and ROW area currently flows to the existing bioswale located onsite (see Figure 11 for a breakdown of impervious and pervious areas). The upstream basin was delineated by determining what portion of the existing Cascade Elementary School site drains to the existing bioswale and reviewing existing contours shown on the City of Renton GIS. This upstream area also includes a portion of the right-of-way, including a portion of 116th Avenue. The existing bioswale will be replaced as a part of the proposed development and the same basin draining to the bioswale is the upstream basin for the proposed project. This upstream basin will be treated for water quality and will bypass the detention system. Based on the survey and observations on site, no other upstream basin was delineated. See Figure 11 for the upstream basin delineation. FAMILY FIRST COMMUNITY CENTER 8 CONCLUSION Based on the observations made during the Level 1 downstream analysis that was performed on 9/6/2018, no existing or potential downstream drainage issues such as flooding, overtopping, or erosion were evident. FAMILY FIRST COMMUNITY CENTER 9 IV. FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN EXISTING SITE HYDROLOGY (PART A) The existing site consists of a park with a grass field, parking lot and landscaping area (See Figure 3 – Existing Site Conditions). The site slopes in a southeasterly direction with drainage described in Section III Downstream Analysis. These conditions are summarized in Table 2 below. TABLE 2 - EXISTING SITE CONDITIONS AREA BREAKDOWN LAND COVER AREA (ACRES) DESCRIPTION MODELLED AS Impervious Area 0.52 Existing parking lot Till Forest Pervious & Landscape 2.05 Grass Field and Native vegetation Till Forest Total Project Area 2.57 % Impervious Area 30.7% The existing site contains a biofiltration swale that has a large tributary off-site area. The upstream area is approximately 10 acres of residential area and a portion of 116th avenue. See figure 11 for more information. DEVELOPED SITE HYDROLOGY (PART B) The developed site will increase the amount of impervious area to 2.08 acres and the remaining site area with be pervious landscaping or bioretention and green roof areas. (See Figure 4 – Proposed Site Conditions). The area impacted by the development is 2.57 acres. The project will be using two Stormtech Chamber detention systems to meet the project’s flow control requirements. By dividing into two different size chamber systems, the project can utilize the existing topography to minimize earthwork. However, the project will only have one discharge location. The site has been divided into two separate sub-basins, one for each of the Stormtech Chamber detention systems. The table below provides a breakdown of the areas of each of the sub-basins. See Figure 4 – Proposed Site Conditions for more information. FAMILY FIRST COMMUNITY CENTER 10 TABLE 3 – SUB-BASIN AREAS SUB- BASIN LAND COVER AREA (ACRES) DESCRIPTION MODELLED AS East Impervious Area 0.70 Parking lot, Sidewalk Impervious Pervious Area 0.14 Landscaping, Planters Till Grass East Flow Through Impervious Area 0.11* Existing parking lot Impervious West Impervious Area 1.38 Parking lot, Sidewalk, Roof Impervious Pervious Area 0.16 Landscaping, Planters Till Grass Bypass Pervious Area 0.18 Landscaping Till Grass Total Project Area 2.57 % Impervious Area 80.9% *flow through area not included in total project area but is included in detention calculations. PERFORMANCE STANDARDS AND FLOW CONTROL SYSTEM (PARTS C) Level II flow control (conservation flow control assuming historic site conditions) is required for this project. Level II flow control requires the proposed discharge durations to match the predeveloped durations for the range of predeveloped discharge rates from 50 percent of the 2-year peak flow up to the full 50-year peak flow. MGSFlood software was used to size the detention facilities in compliance with the CRSWDM standards. The calculations for the detention facilities are included in Appendix B. Runoff from the site will be detained in two detention facilities, an SC-310 Stormtech Chamber system and a MC-3500 Stormtech Chamber system. The proposed detention volumes are summarized in Table 3 below. TABLE 3 – DETENTION FACILITY SUMMARY DETENTION FACILITY PROVIDED [CF] REQUIRED (CF) SC-310 StormTech Chambers 18,907 18,907 MC-3500 StormTech Chambers 29,259 29,259 FLOW CONTROL BEST MANAGEMENT PRACTICES (PART D) According to table C1.3.A of the 2017 RSWDM, projects that has over 80% of impervious surface coverage do not need to apply FCBMPs. Since the project has 81% impervious surface coverage, the project is not required to implement FCBMPs. See below for table C1.3.A from the 2017 CRSWDM. FAMILY FIRST COMMUNITY CENTER 11 WATER QUALITY SYSTEM (PART E) Under Core Requirement #8 the project is required to provide Enhanced Basic water quality treatment for the pollution generating surfaces. To meet the water quality standards, the project will treat pollution generating surfaces by using one proprietary Modular Wetland Systems (MWS) and one bioretention cell. Water quality design calculations are provided in Appendix B. The Family First Community Center project will be removing the existing biofiltration swale that is currently being used as a water quality treatment facility for the Cascade Elementary School site. One of the proposed Modular Wetland System will be used to treat the pollution generating runoff from the existing Cascade Elementary School site in replacement of the biofiltration swale. The other Modular Wetland System will be used to treat the pollution generating runoff from the proposed pollution generating surfaces that will be constructed as a part of the Family First Community Center project before discharging to the existing City of Renton stormwater system. The MWSs are sized according to 2-year flow rates provided in the MGSFlood report in Appendix B. These water quality flow rates are based on the total upstream area to each system. These flow rates are then provided to BioClean who provide the required MWS size to meet water quality treatment. They are located downstream of the detention facilities and so are sized to treat the full 2-year release rate post detention. Runoff enters each MWS vault via pipe. In the vault, trash, sediment and debris are separated before runoff enters the pre-filter cartridges. The pre-filter cartridges utilize a media filter material which removes over 80 percent of total suspended solids and over 90 percent of hydrocarbons. After pre-filtering, the runoff enters a chamber with a patented wetland media. The wetland media removes any phosphorous in the water. The MWSs have an internal bypass weir for large storm events (up to the 100-year event). See table below for water quality flow rates used to size the MWS systems. As shown in the plans. Both systems are sized to be MWS L-4-6. The water quality flow rate used to design the north MWS that is in place for the upstream bypass, is subject to a correction factor (k) as discussed in section 6.2.1 of the 2017 CRSWDM. The correction factor is based on the 6-month precipitation depth which can be found by taking 72% of the 2-year 24 hour precipitation depth. Using the 2-year 24-hour isopluvial map, 72% of the 2-year 24-hour precipitation depth for the project is 1.44 inches. Per table 6.2.1.A in the 2017 CRSWDM, the correction factor (k) for this 6-month FAMILY FIRST COMMUNITY CENTER 12 precipitation depth is can be found be linear interpolation. See calculation and table below for the corrected water quality flow rate used to design the north MWS. Per table 6.21.A of the 2017 CRSWDM: k = 2.477(P72%, 2-yr) – 0.0352 k = 2.477 (1.44 in) – 0.0352 = 3.53 in TABLE 4 – MWS SUMMARY MWS SYSTEM WATER QUALITY FLOW RATE [CFS] CORRECTION FACTOR (K) CORRECTED 2-YEAR WATER QUALITY FLOW RATE [CFS] North MWS (Upstream Bypass) 0.15 3.53 0.53 South MWS (downstream MC-3500 Stormtech Chambers) 0.045 - - The bioretention cell is modeled in MGSFlood and sized to remove at least 91% percent of pollutants per requirements in section 6.2 of the 2017 CRSWDM. The bioretention is designed to have 18” of bioretention soil, 6” of live storage, 6” of freeboard, with 3:1 side slopes and 5 weir walls to separate the bioretention into six cells. Due to the amount of tributary area, six bioretention cells are required. Based on the MGSFlood report, the bioretention is meeting the water quality requirements by removing over 91% of pollutants. See Appendix C for more information. Spill Control is required for projects constructing or replacing onsite pipe systems that receive runoff from pollution generating surfaces such as parking lots (Section 1.2.4.3 of the CRSWDM). Spill control will be provided by a tee with a cap to prevent floatables from entering the drainage system located in the catch basin immediately upstream of the flow control system. FAMILY FIRST COMMUNITY CENTER 13 V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN CONVEYANCE STANDARDS The conveyance systems have been designed to meet the requirements set forth in Chapter 4 of the 2017 CRSWDM. The requirements and the way the design will meet them are presented, below. 1. Facilities must convey the 100-year flow without overtopping the crown of the roadway, flooding buildings, and if sheet flow occurs it must pass through a drainage easement. Facilities will be designed to convey the 100-year storm without affecting surrounding infrastructure. No sheet flow to neighboring properties is expected to occur. 2. New pipe systems and culverts must convey the 25-year flow. New pipe systems are designed to convey the 25-year flow without overtopping structures. 3. Bridges must convey the 100-year flow and provide a minimum of two feet, varying up to six feet, of clearance based on 25% of the mean channel width. This project will not construct bridges. 4. Drainage ditches must convey the 25-year flow with 0.5 feet of freeboard and the 100-year flow without overtopping. This project will not construct drainage ditches. 5. Floodplain Crossings must not increase the base flood elevation by more than 0.01 feet and shall not reduce the flood storage volume. Piers shall not be constructed in the FEMA floodway. There are no floodplain crossings or piers associated with this project. 6. Stream Crossings shall require a bridge for Class 1 Streams that does not disturb or banks. For Type 2 and Type 3 steams, open bottom culverts or other method may be used that will not harm the stream or inhibit fish passage. There are no stream crossings associated with this project. 7. Discharge at natural location is required and produce no significant impacts to the downstream property. This project will provide Level II flow control and will discharge at the natural location. The flow control facilities will reduce the rate of flow discharging from the existing site. ON-SITE CONVEYANCE SYSTEMS Existing Conditions The existing conveyance system consists of catch basins, storm pipes and a biofiltration swale. The existing biofiltration swale and some of the existing catch basins and storm pipes that are located within the development area will be removed and new catch basins and storm pipes will be installed. Developed Conditions The developed on-site conveyance system will consist of catch basins and storm pipes. The existing storm pipe that conveys runoff from the existing Cascade Elementary school site that will be removed to construct the new Family First Community Center building will be rerouted to the existing conveyance system. The conveyance system conveys runoff from the redevelopment and upstream areas to the existing conveyance system. Since the upstream bypass will be rerouted through the project site, the proposed storm system is designed and sized to convey the runoff from the entire upstream basin. There will be one connection point to the existing storm system. The connection point to the existing system is in the southeast corner of the site, where the Family First project and the rerouted stormwater from the Cascade ES site will discharge. Peak flow rates for the proposed conveyance systems were calculated using the Rational Method. The hydraulic grade line was calculated using the Direct Step Backwater Method. Conveyance calculations are provided in Appendix B. FAMILY FIRST COMMUNITY CENTER 14 Conveyance and Backwater Analysis: The conveyance analysis for this development has been performed using Autodesk Storm and Sanitary Analysis (SSA) for each sub-basin within the site, following the 2017 City of Renton Surface Water Design Manual standards for conveyance analysis. This analysis uses the storm network designed in Civil 3D to perform the conveyance analysis and backwater calculations for the designed storm system. From the Civil 3D model, SSA can extract pipe size, length, slope, and invert elevations, along with the rim elevation for each structure. In order to meet City of Renton requirements for conveyance analysis, settings within SSA were updated to reflect the correct analysis options. Because the tributary area is less than 10 acres and located upstream of the detention facility, Table 3.2- Acceptable Uses of Runoff Computation Methods in the CRSWDM states that analysis should be performed using the Modified Rational Method, the time of concentration should be 6.3 minutes for all runs, and Link Routing is set to “Hydrodynamic” for SSA to calculate backwater analysis within the model. These system settings can be seen in Figure 12 - SSA Settings within Appendix B. With SSA set to use the Modified Rational Method (QR=C*IR*A), the “C”, “IR” and “A” values must be entered into the program for it to calculate the QR for the proposed system. The first step in these calculations was to find the catchment area in acres for each structure on site, which can be seen in Figure 11 – Conveyance Areas within Appendix B, within this section. These areas are then input as the “A” within the characteristics for each structure in SSA. With the catchment areas calculated for each structure, the “C” values could then be found for each of those sub-basins. This value was calculated by first finding the total pervious and impervious surface area for each sub-basin. Using a “C” value of 0.25 for pervious lawn areas, and 0.90 for impervious pavement (Table 3.2.1.A – Runoff Coefficients, 2017 CRSWDM), a weighted “C” value was found for each area and entered into SSA for each sub-basin. The final value to input for SSA to use the Modified Rational Method is “IR”, which is input as a system setting, rather than a characteristic for each sub-basin. To do this, an IDF curve is created within SSA for the design storm, which in this case is the 25-year 24-hour storm. Using the equations within section 3.2.1 – Rational Method of the CRSWDM for “IR” (IR = PR * iR, where iR = aR * TC - bR) the IDF curve could be created within SSA. To begin, PR is calculated to be 3.4 using Figure 3.2.1.D – 25-Year 24-Hour Isopluvials (See Figure 42 – 25-yr, 24-hr Isopluvial Map in Appendix B). The time of concentration, “TC”, is set at a constant 6.3 minutes, while aR and bR are values found in Table 3.2.1.B – Coefficients for the Rational Method “iR” Equation within the CRSWDM, which are 2.66 and 0.65, respectively. Detailed calculations showing the correlation between CRSWDM formulas and the SSA IDF curve can be seen below. CRSWDM: IR = PR * aR * TC –bR = (3.4 in * 2.66 * 6.3 min -0.65) = 2.734 in/hr SSA: i = B / (TC + D)E = (9.044 in) / (6.3 min + 0) .65 = 2.734 in/hr A node referred to as an outfall is also an important part of computing a conveyance analysis within SSA. This site has one outfall, representing the downstream point of connection to the existing conveyance system. Outfalls within SSA are where initial tailwater elevations are input to conduct a backwater analysis. Due to a lack of available information pertaining to the existing conveyance system, an initial tailwater elevation was set to assume that the existing pipe is flowing full, which is a conservative estimate assuming that if the system was designed to accommodate the full buildout of the school site, the pipe would not be flowing full. Details for the site outfall can be found in the SSA results (Figure 15 – 25-yr, 24-hr Outfall Analysis Results in Appendix B). Results: The results provided within SSA are broken into four tables, which are included in Appendix B. The first table is a description of all pipes within the site conveyance system, including the length, slope, upstream and downstream structures, entrance and exit losses, available capacity, and peak flow within each pipe. It is important to note that pipes labeled as “Surcharged” and “> Capacity” are acceptable, because the City of Renton requirement for the conveyance system states that the rim of each structure cannot be overtopped, FAMILY FIRST COMMUNITY CENTER 15 therefore a surcharged pipe does not mean the requirement is not met (Figure 14 – 25-yr, 24-hr Pipe Analysis Results Table in Appendix B). The second table shows the results of the outfall for the site, stating the peak flow leaving the site, invert elevation for the pipe at the point of connection, and the fixed water elevation, which in this case is set 24” above the invert elevation, representing the full pipe (Figure 15 – 25-yr, 24-hr Outfall Analysis Results in Appendix B). The third table is a summary of every structure within the conveyance system. This table contains the rim elevation for each structure, outlet pipe invert elevation, peak inflow, max HGL attained, and minimum freeboard attained. Emphasis should be placed on the minimum freeboard attained. Values greater than zero in this column demonstrate that the requirement not to overtop the rim of any structure has been met (Figure 16 – 25-yr, 24-hr Structure Analysis Results in Appendix B). The final table of results provided from SSA summarizes each sub-basin within the site including the area, the name of the structure it drains to, the weighted C value for each sub-basin, rainfall intensity, and time of concentration. See Figure 17 – 25-yr, 24-hr Subbasin Analysis Results, Appendix B. To accompany these results, Figure 11 – Catchment areas (Appendix B) is a map showing the catchment areas used to calculate the catchment area and C Value for each structure. Also included within the results are profiles of the conveyance system. These profiles are created within SSA and show each structure and pipe within the system with the max HGL. See Figure 18 – SSA Profile Layout in Appendix B for clarification on which structures and pipes included in each profile. Outfalls: Energy dissipation of pipe outfalls is required per the CRSWDM Section 1.2.4.3. Since the conveyance system will connect to an existing catch basin, an external drop connection will be used. FAMILY FIRST COMMUNITY CENTER 16 VI. SPECIAL REPORTS AND STUDIES 1. Geotechnical Engineering Report. Renton, Washington. Prepared by The Riley Group, Incorporated on June 8, 2018. FAMILY FIRST COMMUNITY CENTER 17 VII. OTHER PERMITS This project will require building and demolition permits from the City of Renton and an NPDES permit from the Department of Ecology. The NPDES will include a SWPPP and a spill prevention and cleanup report (included in the SWPPP). This project will also require a Developer Extension agreement from Soos Creek Water and Sewer District. FAMILY FIRST COMMUNITY CENTER 18 VIII. CSWPPP ANALYSIS AND DESIGN This section lists the requirements that were met when designing the TESC plan for this site. The project will be publicly bid and a contractor will be determined at a future date. EROSION AND SEDIMENT CONTROL ANALYSIS AND DESIGN (PART A) Erosion/Sedimentation Plan shall include the following: 1. Clearing Limits – Construction limits are delineated on the project erosion control plans and shall be physically surveyed and marked on site. 2. Cover Measures – Contractor will use plastic sheeting, hydroseeding, and mulching to protect soils from erosion. 3. Perimeter Protection – Temporary construction fencing will be used to delineate and protect the project clearing limits and provide a secure site. Silt fencing and interceptor swales will be used to prevent sediment-laden water from discharging from the site. 4. Traffic Area Stabilization – Stabilized construction entrances and a wheel wash will be used for traffic area stabilization. 5. Sediment Retention – Site temporary erosion and sediment control plans will include baker tanks, temporary sediment pond, and catch basin protection to provide sediment control. 6. Surface Water Collection – Interceptor swales will be used in the appropriate areas of the site to collect stormwater runoff. The swales are then routed to the sediment pond and baker tanks. 7. Dewatering Control – Dewatering is not necessary for this site; therefore, no dewatering control measures are implemented. 8. Dust Control – Soils will be appropriately sprinkled with water to limit airborne dust during dry weather. 9. Flow Control –Discharge from the baker tanks and sediment pond will be restricted and will therefore serve as a flow control measure during construction. 10. Control Pollutants – The discharged runoff from the construction site will be monitored for turbidity and pollutants before leaving the site. 11. Protect Existing and Proposed Flow Control BMPs – Proposed FCBMPs consist of bioretention. The bioretention areas will be protected during construction. 12. Maintain BMPs – BMPs for the project will be monitored for effectiveness on a regular basis. The Construction Stormwater Pollution Prevention (CSWPP) Supervisor will typically monitor the BMPs and ensure they are repaired and replaced as necessary. 13. Manage the Project – The BMPs will be inspected maintained and repaired as needed to ensure their intended performance. Site inspections and monitoring will be in accordance with the Construction Stormwater General Permit, specific BMP conditions and the City of Renton requirements. The CSWPP will be maintained and updated and any updates will be coordinated with the site inspector. FAMILY FIRST COMMUNITY CENTER 19 SWPPS PLAN DESIGN (PART B) See figure 12 – TESC Plan for more information. See Appendix C for the CSWPPP. FAMILY FIRST COMMUNITY CENTER 20 IX. BOND QUANTITY, FACILITY SUMMARIES, AND DECLARATION OF COVENANT CITY OF RENTON BOND QUANTITY WORKSHEET A Bond Quantity Worksheet is provided in Appendix E. FLOW CONTROL AND WATER QUALITY FACILITY SUMMARY SHEET AND SKETCH A Facility Summary sheet and sketch are provided in Appendix E. DECLARATION OF COVENANT FOR PRIVATELY MAINTAINED FLOW CONTROL AND WATER QUALITY FACILITIES Declaration of Covenant for Stormwater Facilities is included in Appendix E of this report. DECLARATION OF COVENANT FOR PRIVATELY MAINTAINED FLOW CONTROL BMPS Declaration of Covenant for Stormwater Facilities and BMPs is included in Appendix E of this report. FAMILY FIRST COMMUNITY CENTER 21 X. OPERATION AND MAINTENANCE MANUAL The Operations and Maintenance manual are provided in Appendix D. FAMILY FIRST COMMUNITY CENTER APPENDIX A – FIGURES FIGURE 1 – TIR WORKSHEET FIGURE 2 – VICINITY MAP FIGURE 3 – EXISTING SITE CONDITIONS FIGURE 4 – PROPOSED SITE CONDITIONS FIGURE 5 – DRAINAGE BASIN MAP FIGURE 6 – 100-YR FLOODPLAIN MAP FIGURE 7 – AQUIFER RECHARGE AREA MAP FIGURE 8 – OFF-SITE DRAINAGE ANALYSIS MAP FIGURE 8A –OFF-SITE DRAINAGE TABLE FIGURE 9 – COAL MINE HAZARD AREA FIGURE 10 – SOILS MAP FIGURE 10A – SOILS MAP TABLE FIGURE 11 – UPSTREAM BASIN DELINEATION MAP FIGURE 12 – TESC PLAN City of Renton Family First Community Center 1055 South Grady Way Aaron Fjelstad Coughlin Porter Lundeen 206-343-0460 23N 5E 28 16022 116th Ave SE Renton, WA Civil Construction Permit FIGURE 1 - TIR WORKSHEET C19-006718 Lower Cedar River Full Drainage Review - City of Renton Surface Water Design Manual FIGURE 1 - TIR WORKSHEET (cont'd) Stormwater adjustment form has been submitted. Level 2 bioretention 1 1-9 Alderwood gravelly sandy loam 8 to 15% Arents, Alderwood Material 6 to 15% The site is considered one Threshold Discharge area, discharging at one location at southeast corner of site. 9/6/2018 catch basins directly upstream of detention TBD FIGURE 1 - TIR WORKSHEET (cont'd) Geotechnical Report infiltrative BMPs FIGURE 1 - TIR WORKSHEET (cont'd) Commercial Aquifer Recharge Area, located > 1 mile away (Fig. 7) Stormtech Chambers Modular Wetland Systems Bioretention Bioretention FIGURE 1 - TIR WORKSHEET (cont'd) FIGURE 1 - TIR WORKSHEET (cont'd) Aaron Fjelstad 4/9/20 FIGURE 2 - VICINITY MAP Family First Community Center Baylis Architects 9/4/2018CPS AJF 1 OF 12014 801 SECOND AVENUE, SUITE 900 SEATTLE, WA 98104 / P 206.343.0460 / cplinc.com Project Site SCALE 1" = 40' LEGEND TOTAL IMPERVIOUS AREA (AC) 0.52 PERVIOUS AREA (AC) 2.05 116TH AVE SEEXISTING CASCADE ELEMENTARY SCHOOL Family First Community Center C180040-01 12/03/19 FIGURE 3 - EXISTING CONDITIONS EXISTING BIOFILTRATION SWALE HIGH POINT LOW POINT NATURAL DISCHARGE POINT SCALE 1" = 40' LEGEND BASIN EAST WEST BYPASS SUB-TOTAL WEST FLOW THROUGH TOTAL IMPERVIOUS AREA (AC) 0.70 1.38 0 2.08 .11 2.19 PERVIOUS AREA (AC) 0.14 0.16 0.18 0.49 - 0.49 WEST BASIN EAST BASIN BASIN BREAK LINE EXISTING PARKING LOT TO REMAIN (MODELED AS FLOW-THROUGH) MC-3500 STORMTECH CHAMBER SYSTEM116TH AVE SEEXISTING CASCADE ELEMENTARY SCHOOL BIORETENTION CELL (772 SF) FIGURE 4 - PROPOSED CONDITIONS PGIS AREA TREATED BY BIORETENTION CELL = 25,091 SF SC-310 STORMTECH CHAMBER SYSTEM MODULAR WETLAND SYSTEM MODULAR WETLAND SYSTEM (TREATING EXISTING CASCADE ES PGIS) PGIS TREATED BY MODULAR WETLAND SEE FIGURE 11 FOR OFFSITE BYPASS AREAS NATURAL DISCHARGE POINT Project Site Drainage Basin Boundary NTS Project Site 100-YR FLOODPLAIN NTS FIGURE 6 - 100-YR FLOODPLAIN MAP Pictometry, King County, King County King County iMap - Family First Community Center Date: 2/4/2020 Notes:±The information included on this map has been compiled by King County staff from a variety of sources and is subject to change without notice. King Countymakes no representations or warranties, express or implied, as to accuracy, completeness, timeliness, or rights to the use of such information. This document isnot intended for use as a survey product. King County shall not be liable for any general, special, indirect, incidental, or consequential damages including,but not limited to, lost revenues or lost profits resulting from the use or misuse of the information contained on this map. Any sale of this map or information onthis map is prohibited except by written permission of King County. Legend Critical aquifer rechargeareas category 1 category 2 category 3 FIGURE 7 - AQUIFER RECHARGE AREA MAP Project Site 5,222870 City of Renton - Family First Community Center Site This map is a user generated static output from an Internet mapping site and is for reference only. Data layers that appear on this map may or may not be accurate, current, or otherwise reliable. THIS MAP IS NOT TO BE USED FOR NAVIGATIONWGS_1984_Web_Mercator_Auxiliary_Sphere Notes None 02/04/2020 Legend 592 0 296 592 Feet Information Technology - GIS RentonMapSupport@Rentonwa.gov Floodway Special Flood Hazard Areas (100 year flood) Slope City of Renton >15% & <=25% >25% & <=40% (Sensitive) >40% & <=90% (Protected) >90% (Protected) Environment Designations Natural Shoreline High Intensity Shoreline Isolated High Intensity Shoreline Residential Urban Conservancy Jurisdictions Streams (Classified) <all other values> Type S Shoreline Type F Fish Type Np Non-Fish Type Ns Non-Fish Seasonal Unclassified Not Visited Wetlands 5' Primary 5' Intermediate Network Structures Access Riser Inlet Manhole Utility Vault Clean Out Unknown Pump Stations Discharge Points Stormwater Mains Culverts Open Drains Facility Outlines Private Network Structures Access Riser Inlet Manhole Clean Out Utility Vault Unknown Private Pump Stations Private Discharge Points Private Pipes Private Culverts Private Open Drains Private Facility Outlines Inactive Pipes Streets Parks Waterbodies 2019.sid Red: Band_1 Project Site Site Discharge Point FIGURE 8 - OFF-SITE DRAINAGE MAP Downstream Flow Path 1/4 Mile Downstream 0 1 2 3 4 18" Concrete Pipe at 2.4% slope 24" Concrete Pipe at 2.3% slope 15" Concrete Pipe at approximately 2% slope 24" Concrete Pipe at 4.4% slope Discharge to Ginger Creek 9,0281505 City of Renton - Family First Community Center Site This map is a user generated static output from an Internet mapping site and is for reference only. Data layers that appear on this map may or may not be accurate, current, or otherwise reliable. THIS MAP IS NOT TO BE USED FOR NAVIGATIONWGS_1984_Web_Mercator_Auxiliary_Sphere Notes None 02/04/2020 Legend 1023 0 512 1023Feet Information Technology - GIS RentonMapSupport@Rentonwa.gov Coalmines High Moderate Unclassified Streets Parks Waterbodies 2019.sid Red: Band_1 Green: Band_2 Blue: Band_3 Extent2010 FIGURE 9 - COAL MINE HAZARD AREA Project Site Soil Map—King County Area, Washington (Family First Community Center) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 9/4/2018 Page 1 of 3525625052563005256350525640052564505256500525655052566005256650525625052563005256350525640052564505256500525655052566005256650561340561390561440561490561540561590561640 561340 561390 561440 561490 561540 561590 561640 47° 27' 37'' N 122° 11' 10'' W47° 27' 37'' N122° 10' 55'' W47° 27' 24'' N 122° 11' 10'' W47° 27' 24'' N 122° 10' 55'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 10N WGS84 0 50 100 200 300 Feet 0 30 60 120 180 Meters Map Scale: 1:2,030 if printed on A portrait (8.5" x 11") sheet. Soil Map may not be valid at this scale. Project Site FIGURE 10 - SOILS MAP SEE ATTACHED TABLE FOR SOIL TYPES MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: King County Area, Washington Survey Area Data: Version 13, Sep 7, 2017 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 31, 2013—Oct 6, 2013 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Soil Map—King County Area, Washington (Family First Community Center) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 9/4/2018 Page 2 of 3 FIGURE 4 - SOILS MAP (CONT) Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI AgC Alderwood gravelly sandy loam, 8 to 15 percent slopes 0.2 1.1% AmC Arents, Alderwood material, 6 to 15 percent slopes 16.8 98.9% Totals for Area of Interest 17.0 100.0% Soil Map—King County Area, Washington Family First Community Center Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 9/4/2018 Page 3 of 3 FIGURE 4 - SOILS MAP (CONT) 4,514752 City of Renton - Family First Community Center Site This map is a user generated static output from an Internet mapping site and is for reference only. Data layers that appear on this map may or may not be accurate, current, or otherwise reliable. THIS MAP IS NOT TO BE USED FOR NAVIGATIONWGS_1984_Web_Mercator_Auxiliary_Sphere Notes None 02/03/2020 Legend 512 0 256 512 Feet Information Technology - GIS RentonMapSupport@Rentonwa.gov 5' Primary Streams (Classified) <all other values> Type S Shoreline Type F Fish Type Np Non-Fish Type Ns Non-Fish Seasonal Unclassified Not Visited Wetlands 5' Intermediate Network Structures Access Riser Inlet Manhole Utility Vault Clean Out Unknown Control Structures Pump Stations Discharge Points Water Quality Detention Facilities Pond Tank Vault Bioswale Wetland Other Stormwater Mains Culverts Open Drains Facility Outlines Private Network Structures Access Riser Inlet Manhole Clean Out Utility Vault Unknown Private Control Structures Private Pump Stations Private Discharge Points Private Water Quality Private Detention Facilities Tank, No Stormwater Wetland, No; Natural Wetland, No Filter Strip, No Infiltration Trench, No Vault, No Pond, No; Pond, Unknown Bioswale, No Stormtech Chamber, No Other, No Private Pipes Private Culverts Private Open Drains UPSTREAM OFF-SITE BASIN = 10.09 ACRES 4.77 ac of impervious Area 5.32 ac of pervious area (FLOWS THROUGH ON-STE BYPASS - INCLUDED IN CONVEYANCE CALCS BUT NOT INLCUDED DETENTION SIZING) PROJECT SITE FIGURE 11 - UPSTREAM DELINEATION BASIN MAP BASIN HIGH POINT A B C E D E.2 E.3 F 1110988.2765.554321 F E D C B A 1 1.4 2 3 4 5 5.5 6 7 8 8.2 9 10 11 PROTECT EXISTING CASCADE ELEMENTARY SCHOOL PROTECT EXISTING SIDEWALK CB PROTECTION (TYP) WCUT (TYP) PROTECT EX PARKING LOT DURING CONSTRUCTION INTERCEPTOR SWALE WITH ROCK CHECK DAMS SEE DETAILS SEDIMENT TRAP WITHMOVABLE 55 GALLON DRUM AND SUMP PUMP SEE DETAIL INSTALL SEDIMENT STORAGE TANKS.ONCE EXISTING SWALE CAN NO LONGER BE USED AS A SEDIMENT TRAP. ROUTE CONSTRUCTION STORMWATER RUNOFF TO TANK(S) PRIOR TO DISCHARGE TO EX STORM SYSTEM SEE DETAIL PUMP CLEAN STORMWATERFROM SEDIMENT TANK TO EX STORM MAIN REMOVE EX GATESAWCUT (TYP) SAWCUT (TYP) SAWCUT (TYP) PROTECT EX ELEC'L POLE AND ASSOCIATED GUY WIRE PROTECT EX LIGHT POLE PROTECT "NO ACCESS SIGN" PROTECT EXAREA DRAIN PROTECT EX AREA DRAIN TECT EX CAMERA OTECT EX -ING" SIGN 116TH AVE SEREMOVE EX LIGHT POLE TREE PROTECTIONFENCING SEE DETAIL PROTECT EX CATCH BASIN PROTECT EX WATER METER VAULT ECT EX OL SIGN DEMO EX "LOADING ZONE" SIGN DEMO EX "LOADING ZONE" SIGN REMOVE EX SDMH CUT AND CAP EX STORM MAIN PROTECT EX FIRE HYDRANT PROTECT EX SSMH PROPOSED BUILDING OUTLINE 15 C1.10 19 C1.10 20 C1.10 10 C1.10PROTECT EX VERT CURB PROTECT EX "STOP" SIGN REMOVE EX LIGHT POLE REMOVE EX "STOP" SIGN WHEEL WASHSEE DETAIL CONSTRUCTION ACCESS GATE SEE DETAIL SEDIMENT TRAP WITH MOVABLE 55 GALLON DRUM AND SUMP PUMP SEE DETAIL REMOVE EX TREES (TYP)9 C1.10 INTERCEPTOR SWALE WITH ROCK CHECK DAMSSEE DETAILS AND20 C1.10 9 C1.10 EX SWALE AS SEDIMENT TRAP FOR CONSTRUCTION RUNOFF DURING CONSTRUCTION UNTILINSTALLATION OF STORMTECH CHAMBERS REMOVE BENCHES AND SALVAGE TO RENTON SCHOOL DISTRICT 15 C1.10 5 C1.10 19 C1.10 PROPOSED LOT LINE PER SHORTPLAN PROCESS PROPERTY LINE TREE PROTECTION FENCE BMP C101 REMOVE ASPHALT PAVEMENT REMOVE CONCRETE PAVEMENT INLET PROTECTION BMP C220 Legend LIMITS OF CONSTRUCTION TEMPORARY CONSTRUCTION FENCING BMP FILTER FABRIC FENCING BMP C233 INTERCEPTOR SWALE BMP C200 CHECK DAMS BMP C207 REMOVE TREE REMOVE CURBING SAWCUT LINE FIGURE 12 - TESC PLAN NTS FAMILY FIRST COMMUNITY CENTER APPENDIX B – ENGINEERING CALCULATIONS ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.46 Program License Number: 200610002 Project Simulation Performed on: 02/17/2020 6:41 PM Report Generation Date: 02/17/2020 6:42 PM ————————————————————————————————— Input File Name: 2020-2-11 Stormtech Sizing.fld Project Name: Family First Community Center Analysis Title: Stormtech Chamber Sizing Comments: 02-11-2020 CPS Stormtech Sizing for Civil Construction Permit Revisions ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 15 Full Period of Record Available used for Routing Precipitation Station : 96004005 Puget East 40 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961040 Puget East 40 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 2.680 2.662 Area of Links that Include Precip/Evap (acres) 0.000 0.018 Total (acres) 2.680 2.680 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Subbasin 1 ---------- -------Area (Acres) -------- Till Forest 2.570 Impervious 0.110 ---------------------------------------------- TOTAL DEVELOPED AREA PLUS OFF-SITE FLOW THROUGH Subbasin Total 2.680 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 4 ---------- Subbasin : West ---------- -------Area (Acres) -------- Till Grass 0.160 Impervious 1.490 ---------------------------------------------- Subbasin Total 1.650 ---------- Subbasin : East ---------- -------Area (Acres) -------- Till Grass 0.140 Impervious 0.120 ---------------------------------------------- Subbasin Total 0.260 ---------- Subbasin : Bypass ---------- -------Area (Acres) -------- Till Grass 0.180 ---------------------------------------------- Subbasin Total 0.180 ---------- Subbasin : East Parking Lot to Biocell ---------- -------Area (Acres) -------- Impervious 0.572 ---------------------------------------------- Subbasin Total 0.572 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 1 ------------------------------------------ Link Name: New Copy Lnk1 Link Type: Copy Downstream Link: None ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 4 ------------------------------------------ Link Name: MC-3500 Link Type: Structure Downstream Link Name: New Copy Lnk2 User Specified Elevation Volume Table Used Elevation (ft) Pond Volume (cu-ft) 450.53 0. 450.62 540. 450.70 809. 450.78 1079. 450.87 1349. 450.95 1619. 451.03 1888. 451.12 2158. 451.20 2428. 451.28 2698. 451.37 2968. 451.45 3237. 451.53 3847. 451.62 4454. 451.70 5059. 451.78 5662. 451.87 6263. 451.95 6862. 452.03 7458. 452.12 8052. 452.20 8643. 452.28 9232. 452.37 9818. 452.45 10401. 452.53 10980. 452.62 11557. 452.70 12130. 452.78 12699. 452.87 13265. 452.95 13826. 453.03 14384. 453.12 14936. 453.20 15485. 453.28 16028. 453.37 16566. 453.45 17098. 453.53 17625. 453.62 18146. 453.70 18660. 453.78 19168. 453.87 19668. 453.95 20161. 454.03 20646. 454.12 21122. 454.20 21589. 454.28 22046. 454.37 22492. 454.45 22927. 454.53 23348. 454.62 23756. 454.70 24146. 454.78 24515. 454.87 24851. 454.95 25160. 455.03 25458. 455.12 25747. 455.20 26022. 455.28 26292. 455.37 26562. 455.45 26831. 455.53 27101. 455.62 27371. 455.70 27641. 455.78 27910. 455.87 28180. 455.95 28450. 456.03 28720. 456.12 28990. 456.20 29259. Massmann Infiltration Option Used Hydraulic Conductivity (in/hr) : 0.00 Depth to Water Table (ft) : 100.00 Bio-Fouling Potential : Low Maintenance : Average or Better Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 8.00 Common Length (ft) : 0.000 Riser Crest Elevation : 456.20 ft Hydraulic Structure Geometry Number of Devices: 2 ---Device Number 1 --- Device Type : Circular Orifice Control Elevation (ft) : 450.45 Diameter (in) : 0.75 Orientation : Horizontal Elbow : No ---Device Number 2 --- Device Type : Circular Orifice Control Elevation (ft) : 454.85 Diameter (in) : 1.25 Orientation : Horizontal Elbow : Yes ------------------------------------------ Link Name: New Copy Lnk2 Link Type: Copy Downstream Link: None REQUIRED AND PROVIDED VOLUME AT OVERFLOW ------------------------------------------ Link Name: SC-310 Link Type: Structure Downstream Link Name: New Copy Lnk2 User Specified Elevation Volume Table Used Elevation (ft) Pond Volume (cu-ft) 450.75 0. 450.84 837. 450.92 1255. 451.00 1673. 451.09 2092. 451.17 2510. 451.25 2928. 451.34 3346. 451.42 3765. 451.50 4638. 451.59 5503. 451.67 6354. 451.75 7193. 451.84 8016. 451.92 8820. 452.00 9604. 452.09 10370. 452.17 11111. 452.25 11822. 452.34 12502. 452.42 13144. 452.50 13735. 452.59 14238. 452.67 14705. 452.75 15142. 452.84 15561. 452.92 15979. 453.00 16397. 453.09 16816. 453.17 17234. 453.25 17652. 453.34 18071. 453.42 18489. 453.50 18907. Massmann Infiltration Option Used Hydraulic Conductivity (in/hr) : 0.00 Depth to Water Table (ft) : 100.00 Bio-Fouling Potential : Low Maintenance : Average or Better Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 8.00 Common Length (ft) : 0.000 Riser Crest Elevation : 453.50 ft Hydraulic Structure Geometry REQUIRED AND PROVIDED VOLUME AT OVERFLOW Number of Devices: 2 ---Device Number 1 --- Device Type : Circular Orifice Control Elevation (ft) : 448.67 Diameter (in) : 0.50 Orientation : Horizontal Elbow : No ---Device Number 2 --- Device Type : Circular Orifice Control Elevation (ft) : 451.99 Diameter (in) : 0.87 Orientation : Horizontal Elbow : Yes ------------------------------------------ Link Name: Bioretention Cell Link Type: Bioretention Facility Downstream Link Name: SC-310 Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 100.50 Storage Depth (ft) : 0.50 Bottom Length (ft) : 100.0 Bottom Width (ft) : 7.7 Side Slopes (ft/ft) : L1= 3.00 L2= 3.00 W1= 3.00 W2= 3.00 Bottom Area (sq-ft) : 772. Area at Riser Crest El (sq-ft) : 1,104. (acres) : 0.025 Volume at Riser Crest (cu-ft) : 931. (ac-ft) : 0.021 Infiltration on Bottom and Sideslopes Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 2.00 Biosoil Porosity (Percent) : 40.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 0.00 Underdrain Present Orifice NOT Present in Under Drain Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 100.50 ft Hydraulic Structure Geometry Number of Devices: 0 **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 1 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 4 Number of Links: 4 ********** Link: MC-3500 ********** Link Outflow 1 Frequency Stats Flood Frequency Data(cfs) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) Flood Peak (cfs) ====================================== 2-Year 2.303E-02 5-Year 2.706E-02 10-Year 3.058E-02 25-Year 4.466E-02 50-Year 6.086E-02 100-Year 7.429E-02 200-Year 0.107 ********** Link: MC-3500 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 452.026 1.11-Year 452.162 1.25-Year 452.322 2.00-Year 452.804 3.33-Year 453.232 5-Year 453.701 10-Year 454.601 25-Year 454.978 50-Year 455.341 100-Year 455.843 ********** Link: SC-310 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 451.192 1.11-Year 451.316 1.25-Year 451.407 2.00-Year 451.574 3.33-Year 451.712 5-Year 451.851 10-Year 452.119 25-Year 452.252 50-Year 452.388 100-Year 452.557 ********** Link: Bioretention Cell ********** Link Outflow 1 Frequency Stats Flood Frequency Data(cfs) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) Flood Peak (cfs) ====================================== 2-Year 0.166 5-Year 0.234 10-Year 0.269 25-Year 0.312 50-Year 0.388 100-Year 0.421 200-Year 0.453 ********** Link: Bioretention Cell ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.506 1.11-Year 100.533 1.25-Year 100.548 2.00-Year 100.577 3.33-Year 100.598 5-Year 100.608 10-Year 100.624 25-Year 100.646 50-Year 100.693 100-Year 100.717 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Subbasin 1 443.142 Link: New Copy Lnk1 0.000 _____________________________________ Total: 443.142 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: West 19.554 Subbasin: East 17.109 Subbasin: Bypass 21.998 Subbasin: East Parking Lot to 0.000 Link: MC-3500 0.000 Link: New Copy Lnk2 0.000 Link: SC-310 Not Computed Link: Bioretention Cell 0.000 _____________________________________ Total: 58.661 Total Predevelopment Recharge is Greater than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 2.805 ac-ft/year, Post Developed: 0.371 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 1 ********** Link: New Copy Lnk1 ********** Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 283.23 Inflow Volume Including PPT-Evap (ac-ft): 283.23 Total Runoff Infiltrated (ac-ft): 0.00, 0.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 283.23 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 0.00% ----------------------SCENARIO: POSTDEVELOPED Number of Links: 4 ********** Link: MC-3500 ********** 2-Year Discharge Rate : 0.023 cfs 15-Minute Timestep, Water Quality Treatment Design Discharge On-line Design Discharge Rate (91% Exceedance): 0.22 cfs Off-line Design Discharge Rate (91% Exceedance): 0.12 cfs Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 700.22 Inflow Volume Including PPT-Evap (ac-ft): 700.22 Total Runoff Infiltrated (ac-ft): 0.00, 0.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% WATER QUALITY FLOW RATE USED FOR SOUTH MWS SIZING Primary Outflow To Downstream System (ac-ft): 929.20 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 0.00% ********** Link: New Copy Lnk2 ********** Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 2082.20 Inflow Volume Including PPT-Evap (ac-ft): 2082.20 Total Runoff Infiltrated (ac-ft): 0.00, 0.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 2082.20 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 0.00% ********** Link: Bioretention Cell ********** 2-Year Discharge Rate : 0.166 cfs 15-Minute Timestep, Water Quality Treatment Design Discharge On-line Design Discharge Rate (91% Exceedance): 0.08 cfs Off-line Design Discharge Rate (91% Exceedance): 0.05 cfs Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 256.46 Inflow Volume Including PPT-Evap (ac-ft): 264.70 Total Runoff Infiltrated (ac-ft): 0.00, 0.00% Total Runoff Filtered (ac-ft): 258.67, 97.72% Primary Outflow To Downstream System (ac-ft): 264.95 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 97.72% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Link: New Copy Lnk1 Scenario Postdeveloped Compliance Link: New Copy Lnk2 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 7.862E-02 2-Year 4.502E-02 5-Year 0.124 5-Year 6.132E-02 10-Year 0.162 10-Year 8.363E-02 25-Year 0.202 25-Year 0.101 50-Year 0.251 50-Year 0.111 100-Year 0.282 100-Year 0.126 200-Year 0.404 200-Year 0.150 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals **** Flow Duration Performance **** PERCENT OF POLLUTANTS TREATED BY BIORETENTION CELL Excursion at Predeveloped 50%Q2 (Must be Less Than or Equal to 0%): -10.7% PASS Maximum Excursion from 50%Q2 to Q2 (Must be Less Than or Equal to 0%): -10.7% PASS Maximum Excursion from Q2 to Q50 (Must be less than 10%): -78.3% PASS Percent Excursion from Q2 to Q50 (Must be less than 50%): 0.0% PASS ------------------------------------------------------------------------------------------------- MEETS ALL FLOW DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- **** LID Duration Performance **** Excursion at Predeveloped 8%Q2 (Must be Less Than 0%): 768.3% FAIL Maximum Excursion from 8%Q2 to 50%Q2 (Must be Less Than 0%): 1533.4% FAIL ------------------------------------------------------------------------------------------------- LID DURATION DESIGN CRITERIA: FAIL ------------------------------------------------------------------------------------------------- FLOW CONTROL CRITERIA MET Project: Chamber Model - SC-310 Units -Imperial Number of chambers - 529 Voids in the stone (porosity) - 40 % Base of Stone Elevation - 450.67 ft Amount of Stone Above Chambers - 9 in Amount of Stone Below Chambers - 9 in 6 Height of System Incremental Single Chamber Incremental Total Chamber Incremental Stone Incremental Ch & St Cumulative Chamber Elevation (inches) (cubic feet) (cubic feet) (cubic feet) (cubic feet) (cubic feet) (feet) 34 0.00 0.00 418.30 418.30 18907.12 453.50 33 0.00 0.00 418.30 418.30 18488.82 453.42 32 0.00 0.00 418.30 418.30 18070.52 453.34 31 0.00 0.00 418.30 418.30 17652.22 453.25 30 0.00 0.00 418.30 418.30 17233.92 453.17 29 0.00 0.00 418.30 418.30 16815.61 453.09 28 0.00 0.00 418.30 418.30 16397.31 453.00 27 0.00 0.00 418.30 418.30 15979.01 452.92 26 0.00 0.00 418.30 418.30 15560.71 452.84 25 0.06 31.11 405.86 436.97 15142.41 452.75 24 0.15 81.84 385.56 467.41 14705.44 452.67 23 0.27 140.64 362.05 502.69 14238.03 452.59 22 0.54 288.20 303.02 591.22 13735.35 452.50 21 0.70 372.44 269.33 641.77 13144.13 452.42 20 0.82 436.18 243.83 680.01 12502.36 452.34 19 0.92 489.09 222.67 711.76 11822.36 452.25 18 1.01 536.93 203.53 740.46 11110.60 452.17 17 1.09 579.02 186.69 765.71 10370.14 452.09 16 1.15 610.61 174.06 784.67 9604.42 452.00 15 1.21 642.70 161.22 803.92 8819.75 451.92 14 1.27 674.41 148.54 822.95 8015.83 451.84 13 1.32 700.69 138.02 838.72 7192.88 451.75 12 1.36 722.08 129.47 851.55 6354.16 451.67 11 1.40 743.24 121.00 864.25 5502.61 451.59 10 1.43 758.91 114.74 873.65 4638.37 451.50 9 0.00 0.00 418.30 418.30 3764.72 451.42 8 0.00 0.00 418.30 418.30 3346.41 451.34 7 0.00 0.00 418.30 418.30 2928.11 451.25 6 0.00 0.00 418.30 418.30 2509.81 451.17 5 0.00 0.00 418.30 418.30 2091.51 451.09 4 0.00 0.00 418.30 418.30 1673.21 451.00 3 0.00 0.00 418.30 418.30 1254.91 450.92 2 0.00 0.00 418.30 418.30 836.60 450.84 1 0.00 0.00 418.30 418.30 418.30 450.75 StormTech SC-310 Cumulative Storage Volumes Include Perimeter Stone in Calculations Click Here for Metric STAGE STORAGE TABLE USED IN MGS FLOOD CALCULATIONS FOR SC-310 SYSTEM Project: Chamber Model - MC-3500 Units -Imperial Number of Chambers -160 Number of End Caps - 10 Voids in the stone (porosity) - 40 % Base of Stone Elevation - 450.45 ft Amount of Stone Above Chambers - 12 in Amount of Stone Below Chambers - 12 in Amount of Stone Between Chambers - 6 in Height of System Incremental Single Chamber Incremental Single End Cap Incremental Chambers Incremental End Cap Incremental Stone Incremental Ch, EC and Stone Cumulative System Elevation (inches) (cubic feet) (cubic feet) (cubic feet) (cubic feet) (cubic feet) (cubic feet)(cubic feet) (feet) 69 0.00 0.00 0.00 0.00 269.78 269.78 29259.32 456.20 68 0.00 0.00 0.00 0.00 269.78 269.78 28989.54 456.12 67 0.00 0.00 0.00 0.00 269.78 269.78 28719.77 456.03 66 0.00 0.00 0.00 0.00 269.78 269.78 28449.99 455.95 65 0.00 0.00 0.00 0.00 269.78 269.78 28180.21 455.87 64 0.00 0.00 0.00 0.00 269.78 269.78 27910.43 455.78 63 0.00 0.00 0.00 0.00 269.78 269.78 27640.66 455.70 62 0.00 0.00 0.00 0.00 269.78 269.78 27370.88 455.62 61 0.00 0.00 0.00 0.00 269.78 269.78 27101.10 455.53 60 0.00 0.00 0.00 0.00 269.78 269.78 26831.32 455.45 59 0.00 0.00 0.00 0.00 269.78 269.78 26561.55 455.37 58 0.00 0.00 0.00 0.00 269.78 269.78 26291.77 455.28 57 0.06 0.00 9.29 0.00 266.06 275.35 26021.99 455.20 56 0.19 0.02 31.06 0.24 257.26 288.55 25746.64 455.12 55 0.29 0.04 47.03 0.38 250.81 298.22 25458.08 455.03 54 0.40 0.05 64.58 0.52 243.74 308.84 25159.86 454.95 53 0.69 0.07 109.95 0.68 225.53 336.15 24851.02 454.87 52 1.03 0.09 164.53 0.88 203.61 369.02 24514.87 454.78 51 1.25 0.11 199.92 1.07 189.38 390.38 24145.85 454.70 50 1.42 0.13 227.56 1.26 178.25 407.07 23755.47 454.62 49 1.57 0.14 251.70 1.44 168.52 421.67 23348.40 454.53 48 1.71 0.16 273.14 1.63 159.87 434.64 22926.74 454.45 47 1.83 0.18 292.56 1.82 152.03 446.40 22492.09 454.37 46 1.94 0.20 310.04 2.01 144.96 457.01 22045.69 454.28 45 2.04 0.22 326.53 2.18 138.29 467.01 21588.68 454.20 44 2.13 0.23 341.55 2.35 132.22 476.12 21121.68 454.12 43 2.22 0.25 355.88 2.51 126.43 484.81 20645.56 454.03 42 2.31 0.27 369.09 2.66 121.08 492.82 20160.75 453.95 41 2.38 0.28 381.56 2.80 116.03 500.40 19667.93 453.87 40 2.46 0.29 393.46 2.94 111.22 507.61 19167.54 453.78 39 2.53 0.31 404.51 3.08 106.74 514.33 18659.92 453.70 38 2.59 0.32 415.00 3.21 102.49 520.70 18145.59 453.62 37 2.66 0.33 424.97 3.34 98.45 526.77 17624.89 453.53 36 2.72 0.35 434.42 3.47 94.62 532.51 17098.12 453.45 35 2.77 0.36 443.41 3.60 90.98 537.98 16565.61 453.37 34 2.82 0.37 451.94 3.72 87.51 543.18 16027.63 453.28 33 2.88 0.38 460.07 3.84 84.21 548.13 15484.45 453.20 32 2.92 0.40 467.86 3.96 81.05 552.87 14936.33 453.12 31 2.97 0.41 475.18 4.08 78.07 557.33 14383.45 453.03 30 3.01 0.42 481.99 4.19 75.31 561.49 13826.12 452.95 29 3.05 0.43 488.52 4.30 72.65 565.47 13264.64 452.87 28 3.09 0.44 495.08 4.40 69.98 569.47 12699.17 452.78 27 3.13 0.45 500.89 4.51 67.62 573.02 12129.70 452.70 26 3.17 0.46 506.51 4.61 65.33 576.45 11556.68 452.62 25 3.20 0.47 511.91 4.71 63.13 579.75 10980.24 452.53 24 3.23 0.48 516.98 4.80 61.07 582.85 10400.49 452.45 23 3.26 0.49 521.83 4.89 59.09 585.81 9817.64 452.37 22 3.29 0.50 526.44 4.98 57.21 588.63 9231.83 452.28 21 3.32 0.51 530.87 5.06 55.40 591.34 8643.20 452.20 20 3.34 0.51 535.06 5.14 53.70 593.90 8051.86 452.12 19 3.37 0.52 538.98 5.22 52.10 596.30 7457.96 452.03 18 3.39 0.53 542.80 5.30 50.54 598.64 6861.66 451.95 17 3.41 0.54 546.33 5.37 49.10 600.79 6263.03 451.87 16 3.44 0.54 549.92 5.43 47.64 602.99 5662.24 451.78 15 3.46 0.55 553.23 5.49 46.29 605.01 5059.25 451.70 14 3.48 0.56 556.59 5.55 44.92 607.06 4454.23 451.62 13 3.51 0.59 560.81 5.95 43.07 609.84 3847.17 451.53 12 0.00 0.00 0.00 0.00 269.78 269.78 3237.33 451.45 11 0.00 0.00 0.00 0.00 269.78 269.78 2967.55 451.37 10 0.00 0.00 0.00 0.00 269.78 269.78 2697.78 451.28 9 0.00 0.00 0.00 0.00 269.78 269.78 2428.00 451.20 8 0.00 0.00 0.00 0.00 269.78 269.78 2158.22 451.12 7 0.00 0.00 0.00 0.00 269.78 269.78 1888.44 451.03 6 0.00 0.00 0.00 0.00 269.78 269.78 1618.67 450.95 5 0.00 0.00 0.00 0.00 269.78 269.78 1348.89 450.87 4 0.00 0.00 0.00 0.00 269.78 269.78 1079.11 450.78 StormTech MC-3500 Cumulative Storage Volumes Include Perimeter Stone in Calculations Click Here for Metric STAGE STORAGE TABLE USED IN MGS FLOOD CALCULATIONS FOR MC-3500 SYSTEM DESIGN REQUEST – MODULAR WETLAND SYSTEM - LINEAR Fill out the information below. This will assist us in providing you with detailed sizing, drawings & pricing. 1. Project Name: _________________________________________________________ 2. Project State & City: ___________________________________________________ 3. Unit ID (if several units are on same project): ______________________________________ 4. Your Name: __________________________________________________________ 5. Your Contact Email/Phone #: / ___________________________________________ 6. Desired Date to Receive Sizing/Drawings/Pricing: ___________________________ 7. Configuration: Standard (open vegetated planter-depth limited) Underground (no plants-full concrete top) NOTE: Some regulators will only accept units with vegetated open planters to meet their definition of biofiltration. 8. Loading Requirements: Parkway Indirect Traffic Direct Traffic Other 8a. If Other Please List Details (i.e. HS25): ________________________________________ NOTE: Standard units have parkway rated manholes and/or hatches. Underground configurations can have traffic rated manholes/hatches by request. All will be bolt & pull style. Hinged hatches are available per request but will add cost. Standard units require irrigation and must be placed in a landscape area. 9. Runoff Entry Method: Piped Flow Built-In Curb Inlet Built-In Grate Inlet NOTE: Units may have only piped flow or a combination of piped flow and a grate or curb inlet. Units may be able to accept multiple inflow pipes. Size of pipe is limited based upon the size of the unit. 10. Water Quality Flow Rate: ___________CFS (standalone offline or online flow rate) OR 10a. 2-Year Release Rate: _____________CFS (downstream of detention release rate) OR 10b. Drainage Area (acres) & Impervious Coefficient: ___________________________ NOTE: Units may be sized for either the water quality flow or water quality volume. For water quality volume a pre-detention is required. For areas of the country where flow based design is desired but local regulations do not offer a method to calculate water quality flow please provide the drainage area (acres) and the impervious coefficient. Our engineering team will determine the necessary size required based upon local rainfall patterns to treat 90% of storm events. 11. Internal Bypass Desired: Yes No 11b. Peak Flow Rate (if internal bypass desired): _____________CFS (Dependent on local regulations) NOTE: Side-by-side orientation units have the option of internal bypass. End-to-end units do not have an internal bypass option. Internal bypass needs to be used with caution and a hydraulic assessment is required for each unit including running the HGL calculations over the bypass weir during peak flow and comparing this to FS elevations of the units and all upstream catch basins. For a standard height unit (4.13 ft) the water level must build to 3.4 ft above invert of outflow pipe to treat listed flow capacity on sizing sheet. Shallower and deeper units are available. Weir can be set lower to accommodate higher bypass flows and lower the associated HGL but will reduce flow capacity of the unit. Please contact manufacturer for calculations and assistance. Other external bypass configurations available such as an external diversions structure, secondary catch basin, or DVERT trough. 12. Finish Grade Elevation (FS, TC, TG): _______________________________________ 13. Inlet Pipe Invert Elevation (if applicable): ___________________________________ 13a. Inlet Pipe Diameter/Type (i.e. 8” / PVC): ____________________________________ 14. Outlet Pipe Invert Elevation: ____________________________________________ 14a. Outlet Pipe Diameter/Type (i.e. 12” / RCP): _________________________________ NOTE: For flow based design at least 16” of fall required between invert in and invert out. For volume based design at least 6” of fall required between invert in and invert out for hydraulically connected pre-detention. 15. Ground Water Elevation (if applicable): _____________________________________ 16. Corrosive Soil Conditions (if applicable): ____________________________________ Please email to us: info@modularwetlands.com Any questions, contact: (866) 566-3938 DOES IT NEED BUY AMERICA CERTIFICATION? ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.46 Program License Number: 200610002 Project Simulation Performed on: 03/31/2020 12:46 PM Report Generation Date: 03/31/2020 12:47 PM ————————————————————————————————— Input File Name: 2020-03-31 North MWS Sizing Upstream.fld Project Name: Family First Community Center Analysis Title: Civil Permit MWS Sizing Comments: 3-31-20 CPS MWS Sizing Civil Construction Permit ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 15 Full Period of Record Available used for Routing Precipitation Station : 96004005 Puget East 40 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961040 Puget East 40 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 2.420 2.420 Area of Links that Include Precip/Evap (acres) 0.000 0.000 Total (acres) 2.420 2.420 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Subbasin 1 ---------- -------Area (Acres) -------- Till Forest 2.420 ---------------------------------------------- Subbasin Total 2.420 MGSFLOOD REPORT FOR DESIGNING UPSTREAM BYPASS NORTH MWS AND DETERMINING WATER QUALITY DESIGN FLOW RATE ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Upstream ---------- -------Area (Acres) -------- Till Grass 0.500 Impervious 1.920 ---------------------------------------------- Subbasin Total 2.420 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 1 ------------------------------------------ Link Name: New Copy Lnk1 Link Type: Copy Downstream Link: None ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ------------------------------------------ Link Name: New Copy Lnk2 Link Type: Copy Downstream Link: None **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 1 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 Number of Links: 1 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Subbasin 1 417.278 Link: New Copy Lnk1 0.000 _____________________________________ Total: 417.278 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Upstream 61.105 Link: New Copy Lnk2 0.000 _____________________________________ Total: 61.105 Total Predevelopment Recharge is Greater than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 2.641 ac-ft/year, Post Developed: 0.387 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 1 ********** Link: New Copy Lnk1 ********** Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 220.26 Inflow Volume Including PPT-Evap (ac-ft): 220.26 Total Runoff Infiltrated (ac-ft): 0.00, 0.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 220.26 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 0.00% ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ********** Link: New Copy Lnk2 ********** 2-Year Discharge Rate : 0.761 cfs 15-Minute Timestep, Water Quality Treatment Design Discharge On-line Design Discharge Rate (91% Exceedance): 0.28 cfs Off-line Design Discharge Rate (91% Exceedance): 0.15 cfs Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 961.38 Inflow Volume Including PPT-Evap (ac-ft): 961.38 Total Runoff Infiltrated (ac-ft): 0.00, 0.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 961.38 Secondary Outflow To Downstream System (ac-ft): 0.00 OFF-LINE DESIGN DISCHARGE RATE FOR UPSTREAM BYPASS NORTH MWS SYSTEM. SUBJECT TO CORRECTION FACTOR (K) PER 2017 CRSWDM. SEE SECTION 4 PART E FOR CALCULATION Percent Treated (Infiltrated+Filtered)/Total Volume: 0.00% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Link: New Copy Lnk1 Scenario Postdeveloped Compliance Link: New Copy Lnk2 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 5.157E-02 2-Year 0.761 5-Year 8.405E-02 5-Year 0.975 10-Year 0.113 10-Year 1.155 25-Year 0.144 25-Year 1.533 50-Year 0.183 50-Year 1.797 100-Year 0.199 100-Year 2.227 200-Year 0.309 200-Year 2.270 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals **** Flow Duration Performance **** Excursion at Predeveloped 50%Q2 (Must be Less Than or Equal to 0%): 614.0% FAIL Maximum Excursion from 50%Q2 to Q2 (Must be Less Than or Equal to 0%): 2721.9% FAIL Maximum Excursion from Q2 to Q50 (Must be less than 10%): 99999.0% FAIL Percent Excursion from Q2 to Q50 (Must be less than 50%): 100.0% FAIL ------------------------------------------------------------------------------------------------- FLOW DURATION DESIGN CRITERIA: FAIL ------------------------------------------------------------------------------------------------- **** LID Duration Performance **** Excursion at Predeveloped 8%Q2 (Must be Less Than 0%): 68.8% FAIL Maximum Excursion from 8%Q2 to 50%Q2 (Must be Less Than 0%): 614.0% FAIL ------------------------------------------------------------------------------------------------- LID DURATION DESIGN CRITERIA: FAIL ------------------------------------------------------------------------------------------------- 2-YR DISCHARGE RATE FOR NORTH MWS DESIGN REQUEST – MODULAR WETLAND SYSTEM - LINEAR Fill out the information below. This will assist us in providing you with detailed sizing, drawings & pricing. 1. Project Name: _________________________________________________________ 2. Project State & City: ___________________________________________________ 3. Unit ID (if several units are on same project): ______________________________________ 4. Your Name: __________________________________________________________ 5. Your Contact Email/Phone #: / ___________________________________________ 6. Desired Date to Receive Sizing/Drawings/Pricing: ___________________________ 7. Configuration: Standard (open vegetated planter-depth limited) Underground (no plants-full concrete top) NOTE: Some regulators will only accept units with vegetated open planters to meet their definition of biofiltration. 8. Loading Requirements: Parkway Indirect Traffic Direct Traffic Other 8a. If Other Please List Details (i.e. HS25): ________________________________________ NOTE: Standard units have parkway rated manholes and/or hatches. Underground configurations can have traffic rated manholes/hatches by request. All will be bolt & pull style. Hinged hatches are available per request but will add cost. Standard units require irrigation and must be placed in a landscape area. 9. Runoff Entry Method: Piped Flow Built-In Curb Inlet Built-In Grate Inlet NOTE: Units may have only piped flow or a combination of piped flow and a grate or curb inlet. Units may be able to accept multiple inflow pipes. Size of pipe is limited based upon the size of the unit. 10. Water Quality Flow Rate: ___________CFS (standalone offline or online flow rate) OR 10a. 2-Year Release Rate: _____________CFS (downstream of detention release rate) OR 10b. Drainage Area (acres) & Impervious Coefficient: ___________________________ NOTE: Units may be sized for either the water quality flow or water quality volume. For water quality volume a pre-detention is required. For areas of the country where flow based design is desired but local regulations do not offer a method to calculate water quality flow please provide the drainage area (acres) and the impervious coefficient. Our engineering team will determine the necessary size required based upon local rainfall patterns to treat 90% of storm events. 11. Internal Bypass Desired: Yes No 11b. Peak Flow Rate (if internal bypass desired): _____________CFS (Dependent on local regulations) NOTE: Side-by-side orientation units have the option of internal bypass. End-to-end units do not have an internal bypass option. Internal bypass needs to be used with caution and a hydraulic assessment is required for each unit including running the HGL calculations over the bypass weir during peak flow and comparing this to FS elevations of the units and all upstream catch basins. For a standard height unit (4.13 ft) the water level must build to 3.4 ft above invert of outflow pipe to treat listed flow capacity on sizing sheet. Shallower and deeper units are available. Weir can be set lower to accommodate higher bypass flows and lower the associated HGL but will reduce flow capacity of the unit. Please contact manufacturer for calculations and assistance. Other external bypass configurations available such as an external diversions structure, secondary catch basin, or DVERT trough. 12. Finish Grade Elevation (FS, TC, TG): _______________________________________ 13. Inlet Pipe Invert Elevation (if applicable): ___________________________________ 13a. Inlet Pipe Diameter/Type (i.e. 8” / PVC): ____________________________________ 14. Outlet Pipe Invert Elevation: ____________________________________________ 14a. Outlet Pipe Diameter/Type (i.e. 12” / RCP): _________________________________ NOTE: For flow based design at least 16” of fall required between invert in and invert out. For volume based design at least 6” of fall required between invert in and invert out for hydraulically connected pre-detention. 15. Ground Water Elevation (if applicable): _____________________________________ 16. Corrosive Soil Conditions (if applicable): ____________________________________ Please email to us: info@modularwetlands.com Any questions, contact: (866) 566-3938 DOES IT NEED BUY AMERICA CERTIFICATION? DESIGN REQUEST FOR MODULAR WETLAND DOWNSTREAM OF MC-3500 CHAMBER SYSTEM CONVEYANCE AREAS SCALE 50 ft UPSTREAM STORM SYSTEM 3,114.1 sf 253.7 sf 3,609.4 sf 6,655.6 sf 329.6 sf 5,530.7 sf 2,144.9 sf 425.2 sf 210.4 sf 746.2 sf 5,531 sf 514.5 sf 372.7 sf 7,484.6 sf 86.3 sf190.6 sf 204.7 sf 500.8 sf 6,622.8 sf78 sf 181.9 sf 385.2 sf 241.6 sf 24.8 sf 26,217.1 sf 1,717.8 sf 139.4 sf 653.1 sf230.7 sf 1,434.4 sf 574.4 sf 7,049.2 sf 5,247.3 sf 6,302.1 sf 1,314 sf 905.8 sf 865.7 sf 1,081.5 sf 1,299.7 sf 4,560 sf 201.2 sf 193.1 sf Time of Concentration is set to a minimum 6.3 minutes for all runs (unless otherwise noted). Setting the Link Routing to "Hydrodynamic" allows a backwater analysis to be performed. See below for more information. Excerpt from Storm and Sanitary Analysis 2016 User's Guide: SSA SETTINGS IDF CURVE CALCULATIONS SSA IDF Curve Input: B = (PR)(aR) = (3.4)(2.66) = 9.044 (P25 = 3.4 per the King County Surface Water Design Manual, a25 = 2.66 for the 25-Year, 24-Hour Storm) E = bR = 0.65 (b25 = 0.65 for the 25-Year, 24-Hour Storm. *Note that the (-) negative sign is dropped because the exponent has been brought to the denominator in the SSA equation. ) Tc+D = Tc = 6.3 + 0 (*Note that the time of concentration in SSA is set to 6.3 minutes. The "D" variable is used to show a variance in the time of concentration, which in this case is zero.) SSA uses the "i" value calculated in this equation to plug into the rational method (Q=CiA) to calculate the flow for each structure on the site. For the 100-year 24-hour storm, P100 = 3.9, a100 = 2.61, b100 = 0.63, and D=0. Rational Calculation: IR = (PR)(aR)(Tc)-br SSA Equation: i = B /(Tc+D)^E 25-YEAR, 24-HR PIPE ANALYSIS RESULTS 25-YEAR, 24-HOUR OUTFALL ANALYSIS RESULTS Fixed boundaries represent a downstream condition where the downstream pipe is assumed to be completely full. Outfall into detention system is modeled as a storage node with the water surface set to the max water surface elevation. 25-YEAR, 24-HOUR STRUCTURE ANALYSIS RESULTS 25-YEAR, 24-HOUR SUBBASIN ANALYSIS RESULTS SSA PROFILE LAYOUT SCALE 50 ft A B C E D E.2 E.3 F 1110988.2765.554321 F E D C B A 1 1.4 2 3 4 5 5.5 6 7 88.2 9 10 11 2.0%PROFILE 1 PROFILE 2 PROFILE 3 PROFILE 4 PROFILE 5 PROFILE 6 PROFILE 7 PROFILE 8 PROFILE 9 25-YEAR, 24-HOUR STORM PROFILE 1 Maximum water elevation in structure Hydraulic Grade Line (HGL) Connection to EX Storm System Rim - Max HGL = Min Freeboard attained Structure name 25-YEAR, 24-HOUR STORM PROFILE 2 25-YEAR, 24-HOUR STORM PROFILE 3 25-YEAR, 24-HOUR STORM PROFILE 4 25-YEAR, 24-HOUR STORM PROFILE 5 25-YEAR, 24-HOUR STORM PROFILE 6 25-YEAR, 24-HOUR STORM PROFILE 7 25-YEAR, 24-HOUR STORM PROFILE 8 25-YEAR, 24-HOUR STORM PROFILE 9 100-YEAR, 24-HR PIPE ANALYSIS RESULTS 100-YEAR, 24-HOUR OUTFALL ANALYSIS RESULTS 100-YEAR, 24-HOUR STRUCTURE ANALYSIS RESULTS 100-YEAR, 24-HOUR SUBBASIN ANALYSIS RESULTS 100-YEAR, 24-HOUR STORM PROFILE 1 100-YEAR, 24-HOUR STORM PROFILE 2 100-YEAR, 24-HOUR STORM PROFILE 3 100-YEAR, 24-HOUR STORM PROFILE 4 100-YEAR, 24-HOUR STORM PROFILE 5 100-YEAR, 24-HOUR STORM PROFILE 6 100-YEAR, 24-HOUR STORM PROFILE 7 100-YEAR, 24-HOUR STORM PROFILE 8 100-YEAR, 24-HOUR STORM PROFILE 9 PROJECT SITE Pr = 3.4 FIGURE 41 - 25-yr, 24-hr Isopluvial Map PROJECT SITE Pr = 3.9 FIGURE 42 - 100-yr, 24-hr Isopluvial Map FAMILY FIRST COMMUNITY CENTER APPENDIX C – CSWPPP Construction Stormwater General Permit Stormwater Pollution Prevention Plan (SWPPP) for Family First Community Center Prepared for: The Washington State Department of Ecology Northwest Regional Office 3190 160th Ave. SE Bellevue, WA 98008 Permittee / Owner Developer Operator / Contractor Renton School District City of Renton TBD Project Site Location: 16022 116th Ave SE, Renton WA Certified Erosion and Sediment Control Lead (CESCL) Name Organization Contact Phone Number TBD TBD TBD SWPPP Prepared By Name Organization Contact Phone Number Aaron Fjelstad Coughlin Porter Lundeen 206-343-0460 SWPPP Preparation Date 12-03-2019 Project Construction Dates Activity / Phase Start Date End Date Clearing and Grading TBD TBD Foundation and Slab TBD TBD Final Completion TBD TBD P a g e | 1 Table of Contents 1 Project Information .............................................................................................................. 4 1.1 Existing Conditions ...................................................................................................... 4 1.2 Proposed Construction Activities .................................................................................. 4 2 Construction Stormwater Best Management Practices (BMPs) ........................................... 6 2.1 The 13 Elements .......................................................................................................... 6 2.1.1 Element 1: Preserve Vegetation / Mark Clearing Limits ........................................ 6 2.1.2 Element 2: Establish Construction Access ............................................................ 7 2.1.3 Element 3: Control Flow Rates ............................................................................. 8 2.1.4 Element 4: Install Sediment Controls .................................................................... 9 2.1.5 Element 5: Stabilize Soils ....................................................................................10 2.1.6 Element 6: Protect Slopes....................................................................................11 2.1.7 Element 7: Protect Drain Inlets ............................................................................12 2.1.8 Element 8: Stabilize Channels and Outlets ..........................................................13 2.1.9 Element 9: Control Pollutants ...............................................................................14 2.1.10 Element 10: Control Dewatering ..........................................................................18 2.1.11 Element 11: Maintain BMPs .................................................................................19 2.1.12 Element 12: Manage the Project ..........................................................................20 2.1.13 Element 13: Protect Low Impact Development (LID) BMPs .................................23 3 Pollution Prevention Team .................................................................................................24 4 Monitoring and Sampling Requirements ............................................................................25 4.1 Site Inspection ............................................................................................................25 4.2 Stormwater Quality Sampling ......................................................................................25 4.2.1 Turbidity Sampling ...............................................................................................25 4.2.2 pH Sampling ........................................................................................................27 5 Discharges to 303(d) or Total Maximum Daily Load (TMDL) Waterbodies .........................28 5.1 303(d) Listed Waterbodies ..........................................................................................28 5.2 TMDL Waterbodies .....................................................................................................28 6 Reporting and Record Keeping ..........................................................................................29 6.1 Record Keeping ..........................................................................................................29 6.1.1 Site Log Book ......................................................................................................29 6.1.2 Records Retention ...............................................................................................29 6.1.3 Updating the SWPPP ...........................................................................................29 6.2 Reporting ....................................................................................................................30 6.2.1 Discharge Monitoring Reports ..............................................................................30 6.2.2 Notification of Noncompliance ..............................................................................30 P a g e | 2 List of Tables Table 1 – Summary of Site Pollutant Constituents ..................................................................... 4 Table 2 – Pollutants ..................................................................................................................14 Table 3 – pH-Modifying Sources ...............................................................................................16 Table 4 – Dewatering BMPs ......................................................................................................18 Table 5 – Management .............................................................................................................20 Table 6 – BMP Implementation Schedule .................................................................................21 Table 7 – Team Information ......................................................................................................24 Table 8 – Turbidity Sampling Method ........................................................................................25 Table 9 – pH Sampling Method .................................................................................................27 List of Appendices Appendix/Glossary A. Site Map B. BMP Detail C. Correspondence D. Site Inspection Form E. Construction Stormwater General Permit (CSWGP) F. 303(d) List Waterbodies / TMDL Waterbodies Information G. Contaminated Site Information H. Engineering Calculations P a g e | 3 List of Acronyms and Abbreviations Acronym / Abbreviation Explanation 303(d) Section of the Clean Water Act pertaining to Impaired Waterbodies BFO Bellingham Field Office of the Department of Ecology BMP(s) Best Management Practice(s) CESCL Certified Erosion and Sediment Control Lead CO2 Carbon Dioxide CRO Central Regional Office of the Department of Ecology CSWGP Construction Stormwater General Permit CWA Clean Water Act DMR Discharge Monitoring Report DO Dissolved Oxygen Ecology Washington State Department of Ecology EPA United States Environmental Protection Agency ERO Eastern Regional Office of the Department of Ecology ERTS Environmental Report Tracking System ESC Erosion and Sediment Control GULD General Use Level Designation NPDES National Pollutant Discharge Elimination System NTU Nephelometric Turbidity Units NWRO Northwest Regional Office of the Department of Ecology pH Power of Hydrogen RCW Revised Code of Washington SPCC Spill Prevention, Control, and Countermeasure su Standard Units SWMMEW Stormwater Management Manual for Eastern Washington SWMMWW Stormwater Management Manual for Western Washington SWPPP Stormwater Pollution Prevention Plan TESC Temporary Erosion and Sediment Control SWRO Southwest Regional Office of the Department of Ecology TMDL Total Maximum Daily Load VFO Vancouver Field Office of the Department of Ecology WAC Washington Administrative Code WSDOT Washington Department of Transportation WWHM Western Washington Hydrology Model P a g e | 4 1 Project Information Project/Site Name: Family First Community Center Street/Location: 16022 116th Avenue SE City: Renton State: WA Zip code: 98058 Subdivision: Receiving waterbody: Lower Cedar River 1.1 Existing Conditions Total acreage (including support activities such as off-site equipment staging yards, material storage areas, borrow areas). Total acreage (total parcel area): 14.9 Disturbed acreage: 2.51 Existing structures: 0 Landscape topography: 1.61 Drainage patterns: The site drains through a residential area to the east of the site before reaching 119th Avenue SE, where the road slopes down towards a catch basin before being conveyed further east. Existing Vegetation: Approximately 1.6 acres of undisturbed forest and landscape areas, with 0.9 acres of existing impervious surfaces. Critical Areas (wetlands, streams, high erosion risk, steep or difficult to stabilize slopes): There are no Critical Areas mapped down or upstream of the project site. List of known impairments for 303(d) listed or Total Maximum Daily Load (TMDL) for the receiving waterbody: The site discharges to the Cedar River, which is a 303(d) listed water body. The Cedar River is listed for temperature, dissolved oxygen, ammonia, pH, bacteria, arsenic, mercury, selenium, and copper impairments. 1.2 Proposed Construction Activities Description of site development (example: subdivision): The site development will consist of a new one-story community recreational center with an asphalt parking lot. It will include a new gymnasium, activity rooms, gathering places, offices, a kitchen, and associated landscaping and sidewalks Description of construction activities (example: site preparation, demolition, excavation): Construction activities will include site preparation, demolition, excavation, grading, poured concrete sidewalks, asphalt paving and construction of the new recreational center. Description of site drainage including flow from and onto adjacent properties. Must be consistent with Site Map in Appendix A: P a g e | 5 The project will remove the existing water quality treatment facility for the Cascade Elementary school and replace the facility with a Modular Wetland System to treat the pollution-generating runoff from the existing site. Runoff will then be re-routed to the existing storm system located at the southeast corner of the site before reaching the system within 119th Ave SE. Description of final stabilization (example: extent of revegetation, paving, landscaping): Natural vegetation will be kept to the maximum extent feasible, the rest of the site will be developed with paving or landscaping. Contaminated Site Information: Proposed activities regarding contaminated soils or groundwater (example: on-site treatment system, authorized sanitary sewer discharge): There are no contaminated soils or groundwater on this site. P a g e | 6 2 Construction Stormwater Best Management Practices (BMPs) The SWPPP is a living document reflecting current conditions and changes throughout the life of the project. These changes may be informal (i.e., hand-written notes and deletions). Update the SWPPP when the CESCL has noted a deficiency in BMPs or deviation from original design. 2.1 The 13 Elements 2.1.1 Element 1: Preserve Vegetation / Mark Clearing Limits To protect adjacent properties and to reduce the area of soil exposed to construction, the limits of construction will be clearly marked before land-disturbing activities begin. Trees that are to be preserved, as well as all sensitive areas and their buffers, shall be clearly delineated, both in the field and on the plans. In general, natural vegetation and native topsoil shall be retained in an undisturbed state to the maximum extent possible. List and describe BMPs:  Preserving Natural Vegetation (Tree Protection Fence) (BMP C101)  High Visibility Plastic or Metal Fence (BMP C103) Installation Schedules: TBD Inspection and Maintenance plan: TBD Responsible Staff: TBD P a g e | 7 2.1.2 Element 2: Establish Construction Access Construction access or activities occurring on unpaved areas shall be minimized, yet where necessary, access points shall be stabilized to minimize the tracking of sediment onto public roads, and wheel washing, street sweeping, and street cleaning shall be employed to prevent sediment from entering state waters. All wash wastewater shall be controlled on site. All site ingress/egress stabilization BMPs shall be installed according to BMP C105. Sediment will be removed from paved areas in and adjacent to construction work areas manually or using mechanical sweepers, as needed, to minimize tracking of sediments on vehicle tires away from the site and to minimize washoff of sediments from adjacent streets in runoff. List and describe BMPs:  High Visibility Fence (Construction Fencing) (BMP C103)  Stabilized Construction Entrance (BMP C105)  Wheel Wash (BMP C106) Installation Schedules: TBD Inspection and Maintenance plan: TBD Responsible Staff: TBD P a g e | 8 2.1.3 Element 3: Control Flow Rates In order to protect the properties and waterways downstream of the project site, stormwater discharges from the site will be controlled. This project will utilize two Stormtech Chamber detention systems to direct construction runoff to a sediment trap, where it will be pumped to a baker tank. Baker tanks will be used for on site stormwater and discharged to the existing storm system via the proposed onsite conveyance system. Will you construct stormwater retention and/or detention facilities? Yes No Will you use permanent infiltration ponds or other low impact development (example: rain gardens, bio-retention, porous pavement) to control flow during construction? Yes No List and describe BMPs:  Check Dams (BMP C207)  Sediment Trap (BMP C240)  Temporary Sediment Pond (BMP C241) Installation Schedules: TBD Inspection and Maintenance plan: TBD Responsible Staff: TBD P a g e | 9 2.1.4 Element 4: Install Sediment Controls All stormwater runoff from disturbed areas shall pass through an appropriate sediment removal BMP before leaving the construction site or prior to being discharged to an infiltration facility. A temporary sediment pond will be provided on site, and clean storm water will be discharged to the existing storm system after settling. Immediate action will be taken at the first sign of BMPs that are ineffective or failing. List and describe BMPs: • Silt Fence (BMP C233) • Interceptor Swale (BMP C200) • Sediment Trap (BMP C240) • Storm Drain Inlet Protection (BMP C220) • Materials on Hand (BMP C150) may also be applicable Installation Schedules: TBD Inspection and Maintenance plan: TBD Responsible Staff: TBD P a g e | 10 2.1.5 Element 5: Stabilize Soils Exposed and unworked soils shall be stabilized with the application of effective BMPs to prevent erosion throughout the life of the project. West of the Cascade Mountains Crest Season Dates Number of Days Soils Can be Left Exposed During the Dry Season May 1 – September 30 7 days During the Wet Season October 1 – April 30 2 days Soils must be stabilized at the end of the shift before a holiday or weekend if needed based on the weather forecast. Anticipated project dates: Start date: April 2020 End date: March 2021 Will you construct during the wet season? Yes No List and describe BMPs: • Temporary and Permanent Seeding (BMP C120) • Mulching (BMP C121) • Nets and Blankets (BMP C122) • Plastic Covering (BMP C123) • Surface Roughening (BMP C130) • Dust Control (BMP C140) • Early application of gravel base on areas to be paved • Materials on Hand (BMP C150) may also be applicable. Installation Schedules: TBD Inspection and Maintenance plan: TBD Responsible Staff: TBD P a g e | 11 2.1.6 Element 6: Protect Slopes All cut and fill slopes will be designed, constructed, and protected in a manner than minimizes erosion. Will steep slopes be present at the site during construction? Yes No List and describe BMPs: • Temporary and Permanent Seeding (BMP C120) • Surface Roughening (BMP C130) • Interceptor Swale (BMP C200) • Level Spreader (BMP C206) • Check Dams (BMP C207) • Materials on Hand (BMP C150) Installation Schedules: TBD Inspection and Maintenance plan: TBD Responsible Staff: TBD P a g e | 12 2.1.7 Element 7: Protect Drain Inlets All storm drain inlets and culverts made operable during construction shall be protected to prevent unfiltered or untreated water from entering the drainage conveyance system. However, the first priority is to keep all access roads clean of sediment and keep street wash water separate from entering storm drains until treatment can be provided. Storm Drain Inlet Protection (BMP C220) will be implemented for all drainage inlets and culverts that could potentially be impacted by sediment-laden runoff on and near the project site. List and describe BMPs: • Storm Drain Inlet Protection (BMP C220) Installation Schedules: TBD Inspection and Maintenance plan: TBD Responsible Staff: TBD P a g e | 13 2.1.8 Element 8: Stabilize Channels and Outlets Where site runoff is to be conveyed in channels, or discharged to a stream or some other natural drainage point, efforts will be taken to prevent downstream erosion. Provide stabilization, including armoring material, adequate to prevent erosion of outlets, adjacent stream banks, slopes, and downstream reaches, will be installed at the outlets of all conveyance systems. List and describe BMPs:  Outlet Protection (BMP C209)  Check Dams (BMP C207)  Interceptor Swale (BMP C200)  Materials on Hand (BMP C150) Installation Schedules: TBD Inspection and Maintenance plan: TBD Responsible Staff: TBD P a g e | 14 2.1.9 Element 9: Control Pollutants The following pollutants are anticipated to be present on-site: Table 2 – Pollutants Pollutant (List pollutants and source, if applicable) Vehicles and construction equipment Demolition Concrete and grout All pollutants, including waste materials and demolition debris, that occur onsite shall be handled and disposed of in a manner that does not cause contamination of stormwater. Good housekeeping and preventative measures will be taken to ensure that the site will be kept clean, well organized, and free of debris. Vehicles, construction equipment, and/or petroleum product storage/dispensing: • All vehicles, equipment, and petroleum product storage/dispensing areas will be inspected regularly to detect any leaks or spills, and to identify maintenance needs to prevent leaks or spills. • On-site fueling tanks and petroleum product storage containers shall include secondary containment. • Spill prevention measures, such as drip pans, will be used when conducting maintenance and repair of vehicles or equipment. • In order to perform emergency repairs on site, temporary plastic will be placed beneath and, if raining, over the vehicle. • Contaminated surfaces shall be cleaned immediately following any discharge or spill incident. Demolition: • Dust released from demolished sidewalks, buildings, or structures will be controlled using Dust Control measures (BMP C140). • Storm drain inlets vulnerable to stormwater discharge carrying dust, soil, or debris will be protected using Storm Drain Inlet Protection (BMP C220 as described above for Element 7). • Process water and slurry resulting from sawcutting and surfacing operations will be prevented from entering the waters of the State by implementing Sawcutting and Surfacing Pollution Prevention measures (BMP C152). Concrete and grout: • Process water and slurry resulting from concrete work will be prevented from entering the waters of the State by implementing Concrete Handling measures (BMP C151). P a g e | 15 Sanitary wastewater: • Portable sanitation facilities will be firmly secured, regularly maintained, and emptied when necessary. • Wheel wash or tire bath wastewater shall be discharged to a separate on-site treatment system or to the sanitary sewer as part of Wheel Wash implementation (BMP C106). List and describe BMPs: • Dust Control (BMP C140) • Storm Drain Inlet Protection (BMP C220) • Sawcutting and Surfacing Pollution Prevention (BMP C152) • Concrete Handling (BMP C151) • Wheel Wash (BMP C106) Installation Schedules: TBD Inspection and Maintenance plan: TBD Responsible Staff: TBD Will maintenance, fueling, and/or repair of heavy equipment and vehicles occur on-site? Yes No List and describe BMPs: N/A Installation Schedules: N/A Inspection and Maintenance plan: N/A Responsible Staff: N/A Will wheel wash or tire bath system BMPs be used during construction? Yes No Water discharged from the wheel wash will be routed to the baker tank on site, which will allow sediment to settle before the water is sent to a level spreader on site. List and describe BMPs: • Wheel Wash (BMP C106) Installation Schedules: TBD Inspection and Maintenance plan: TBD Responsible Staff: TBD P a g e | 16 Will pH-modifying sources be present on-site? Yes No Table 3 – pH-Modifying Sources None Bulk cement Cement kiln dust Fly ash Other cementitious materials New concrete washing or curing waters Waste streams generated from concrete grinding and sawing Exposed aggregate processes Dewatering concrete vaults Concrete pumping and mixer washout waters Recycled concrete Recycled concrete stockpiles Other (i.e., calcium lignosulfate) [please describe: ] List and describe BMPs: • Sawcutting and Surfacing Pollution Prevention (BMP C152) • Concrete Handling (BMP C151) • Wheel Wash (BMP C106) Installation Schedules: TBD Inspection and Maintenance plan: TBD Responsible Staff: TBD Concrete trucks must not be washed out onto the ground, or into storm drains, open ditches, streets, or streams. Excess concrete must not be dumped on-site, except in designated concrete washout areas with appropriate BMPs installed. Will uncontaminated water from water-only based shaft drilling for construction of building, road, and bridge foundations be infiltrated provided the wastewater is managed in a way that prohibits discharge to surface waters? Yes No List and describe BMPs: N/A Installation Schedules: N/A P a g e | 17 Inspection and Maintenance plan: N/A Responsible Staff: N/A P a g e | 18 2.1.10 Element 10: Control Dewatering This project site does not propose dewatering and therefore will not be implementing any BMPs associated with Element 10. Table 4 – Dewatering BMPs Infiltration Transport off-site in a vehicle (vacuum truck for legal disposal) Ecology-approved on-site chemical treatment or other suitable treatment technologies Sanitary or combined sewer discharge with local sewer district approval (last resort) Use of sedimentation bag with discharge to ditch or swale (small volumes of localized dewatering) List and describe BMPs: N/A Installation Schedules: N/A Inspection and Maintenance plan: N/A Responsible Staff: N/A P a g e | 19 2.1.11 Element 11: Maintain BMPs All temporary and permanent Erosion and Sediment Control (ESC) BMPs shall be maintained and repaired as needed to ensure continued performance of their intended function. Maintenance and repair shall be conducted in accordance with each particular BMP specification (see Volume II of the SWMMWW or Chapter 7 of the SWMMEW). Visual monitoring of all BMPs installed at the site will be conducted at least once every calendar week and within 24 hours of any stormwater or non-stormwater discharge from the site. If the site becomes inactive and is temporarily stabilized, the inspection frequency may be reduced to once every calendar month. All temporary ESC BMPs shall be removed within 30 days after final site stabilization is achieved or after the temporary BMPs are no longer needed. Trapped sediment shall be stabilized on-site or removed. Disturbed soil resulting from removal of either BMPs or vegetation shall be permanently stabilized. The Grading Permit will be utilized as required to repair the private road for the extension of utilities. Additionally, protection must be provided for all BMPs installed for the permanent control of stormwater from sediment and compaction. BMPs that are to remain in place following completion of construction shall be examined and restored to full operating condition. If sediment enters these BMPs during construction, the sediment shall be removed and the facility shall be returned to conditions specified in the construction documents. P a g e | 20 2.1.12 Element 12: Manage the Project The project will be managed based on the following principles:  Projects will be phased to the maximum extent practicable and seasonal work limitations will be taken into account.  Inspection and monitoring: o Inspection, maintenance and repair of all BMPs will occur as needed to ensure performance of their intended function. o Site inspections and monitoring will be conducted in accordance with Special Condition S4 of the CSWGP. Sampling locations are indicated on the Site Map. Sampling station(s) are located in accordance with applicable requirements of the CSWGP.  Maintain an updated SWPPP. o The SWPPP will be updated, maintained, and implemented in accordance with Special Conditions S3, S4, and S9 of the CSWGP. As site work progresses the SWPPP will be modified routinely to reflect changing site conditions. The SWPPP will be reviewed monthly to ensure the content is current. Table 5 – Management Design the project to fit the existing topography, soils, and drainage patterns Emphasize erosion control rather than sediment control Minimize the extent and duration of the area exposed Keep runoff velocities low Retain sediment on-site Thoroughly monitor site and maintain all ESC measures Schedule major earthwork during the dry season Other (please describe) P a g e | 21 Table 6 – BMP Implementation Schedule Phase of Construction Project Stormwater BMPs Date Wet/Dry Season [Insert construction activity] [Insert BMP] [MM/DD/YYYY] [Insert Season] Phase of Construction Project Stormwater BMPs Date Wet/Dry Season P a g e | 22 [Insert construction activity] [Insert BMP] [MM/DD/YYYY] [Insert Season] P a g e | 23 2.1.13 Element 13: Protect Low Impact Development (LID) BMPs Bioretention is proposed for this project. Areas where bioretention is to be installed will be protected during construction. P a g e | 24 3 Pollution Prevention Team Table 7 – Team Information Title Name(s) Phone Number Certified Erosion and Sediment Control Lead (CESCL) TBD TBD Resident Engineer TBD TBD Emergency Ecology Contact TBD TBD Emergency Permittee/ Owner Contact TBD TBD Non-Emergency Owner Contact TBD TBD Monitoring Personnel TBD TBD Ecology Regional Office Northwest Regional Office 425-649-7098 P a g e | 25 4 Monitoring and Sampling Requirements Monitoring includes visual inspection, sampling for water quality parameters of concern, and documentation of the inspection and sampling findings in a site log book. A site log book will be maintained for all on-site construction activities and will include:  A record of the implementation of the SWPPP and other permit requirements  Site inspections  Stormwater sampling data File a blank form under Appendix D. The site log book must be maintained on-site within reasonable access to the site and be made available upon request to Ecology or the local jurisdiction. Numeric effluent limits may be required for certain discharges to 303(d) listed waterbodies. See CSWGP Special Condition S8 and Section 5 of this template. 4.1 Site Inspection Site inspections will be conducted at least once every calendar week and within 24 hours following any discharge from the site. For sites that are temporarily stabilized and inactive, the required frequency is reduced to once per calendar month. The discharge point(s) are indicated on the Site Map (see Appendix A) and in accordance with the applicable requirements of the CSWGP. 4.2 Stormwater Quality Sampling 4.2.1 Turbidity Sampling Requirements include calibrated turbidity meter or transparency tube to sample site discharges for compliance with the CSWGP. Sampling will be conducted at all discharge points at least once per calendar week. Method for sampling turbidity: Table 8 – Turbidity Sampling Method Turbidity Meter/Turbidimeter (required for disturbances 5 acres or greater in size) Transparency Tube (option for disturbances less than 1 acre and up to 5 acres in size) The benchmark for turbidity value is 25 nephelometric turbidity units (NTU) and a transparency less than 33 centimeters. If the discharge’s turbidity is 26 to 249 NTU or the transparency is less than 33 cm but equal to or greater than 6 cm, the following steps will be conducted: 1. Review the SWPPP for compliance with Special Condition S9. Make appropriate revisions within 7 days of the date the discharge exceeded the benchmark. P a g e | 26 2. Immediately begin the process to fully implement and maintain appropriate source control and/or treatment BMPs as soon as possible. Address the problems within 10 days of the date the discharge exceeded the benchmark. If installation of necessary treatment BMPs is not feasible within 10 days, Ecology may approve additional time when the Permittee requests an extension within the initial 10-day response period. 3. Document BMP implementation and maintenance in the site log book. If the turbidity exceeds 250 NTU or the transparency is 6 cm or less at any time, the following steps will be conducted: 1. Telephone or submit an electronic report to the applicable Ecology Region’s Environmental Report Tracking System (ERTS) within 24 hours.  Central Region (Benton, Chelan, Douglas, Kittitas, Klickitat, Okanogan, Yakima): (509) 575-2490 or http://www.ecy.wa.gov/programs/spills/forms/nerts_online/CRO_nerts_online.html  Eastern Region (Adams, Asotin, Columbia, Ferry, Franklin, Garfield, Grant, Lincoln, Pend Oreille, Spokane, Stevens, Walla Walla, Whitman): (509) 329-3400 or http://www.ecy.wa.gov/programs/spills/forms/nerts_online/ERO_nerts_online.html  Northwest Region (King, Kitsap, Island, San Juan, Skagit, Snohomish, Whatcom): (425) 649-7000 or http://www.ecy.wa.gov/programs/spills/forms/nerts_online/NWRO_nerts_online.html  Southwest Region (Clallam, Clark, Cowlitz, Grays Harbor, Jefferson, Lewis, Mason, Pacific, Pierce, Skamania, Thurston, Wahkiakum,): (360) 407-6300 or http://www.ecy.wa.gov/programs/spills/forms/nerts_online/SWRO_nerts_online.html 2. Immediately begin the process to fully implement and maintain appropriate source control and/or treatment BMPs as soon as possible. Address the problems within 10 days of the date the discharge exceeded the benchmark. If installation of necessary treatment BMPs is not feasible within 10 days, Ecology may approve additional time when the Permittee requests an extension within the initial 10-day response period 3. Document BMP implementation and maintenance in the site log book. 4. Continue to sample discharges daily until one of the following is true:  Turbidity is 25 NTU (or lower).  Transparency is 33 cm (or greater).  Compliance with the water quality limit for turbidity is achieved. o 1 - 5 NTU over background turbidity, if background is less than 50 NTU o 1% - 10% over background turbidity, if background is 50 NTU or greater  The discharge stops or is eliminated. P a g e | 27 4.2.2 pH Sampling pH monitoring is required for “Significant concrete work” (i.e., greater than 1000 cubic yards poured concrete over the life of the project). The use of recycled concrete or engineered soils (soil amendments including but not limited to Portland cement-treated base [CTB], cement kiln dust [CKD] or fly ash) also requires pH monitoring. For significant concrete work, pH sampling will start the first day concrete is poured and continue until it is cured, typically three (3) weeks after the last pour. For engineered soils and recycled concrete, pH sampling begins when engineered soils or recycled concrete are first exposed to precipitation and continues until the area is fully stabilized. If the measured pH is 8.5 or greater, the following measures will be taken: 1. Prevent high pH water from entering storm sewer systems or surface water. 2. Adjust or neutralize the high pH water to the range of 6.5 to 8.5 su using appropriate technology such as carbon dioxide (CO2) sparging (liquid or dry ice). 3. Written approval will be obtained from Ecology prior to the use of chemical treatment other than CO2 sparging or dry ice. Method for sampling pH: Table 9 – pH Sampling Method pH meter pH test kit Wide range pH indicator paper P a g e | 28 5 Discharges to 303(d) or Total Maximum Daily Load (TMDL) Waterbodies 5.1 303(d) Listed Waterbodies Is the receiving water 303(d) (Category 5) listed for turbidity, fine sediment, phosphorus, or pH? Yes No 5.2 TMDL Waterbodies Waste Load Allocation for CWSGP discharges: The site drains through a residential area to the east of the site before reaching 119th Avenue SE, where the road slopes down towards a catch basin before being conveyed further east. The project will remove the existing water quality treatment facility for the Cascade Elementary school and replace the facility with a Modular Wetland System to treat the pollution-generating runoff from the existing site. Runoff will then be re-routed to the existing storm system located at the southeast corner of the site before reaching the system within 119th Ave SE. List and describe BMPs: N/A Discharges to TMDL receiving waterbodies will meet in-stream water quality criteria at the point of discharge. The Construction Stormwater General Permit Proposed New Discharge to an Impaired Water Body form is included in Appendix F. P a g e | 29 6 Reporting and Record Keeping 6.1 Record Keeping 6.1.1 Site Log Book A site log book will be maintained for all on-site construction activities and will include:  A record of the implementation of the SWPPP and other permit requirements  Site inspections  Sample logs 6.1.2 Records Retention Records will be retained during the life of the project and for a minimum of three (3) years following the termination of permit coverage in accordance with Special Condition S5.C of the CSWGP. Permit documentation to be retained on-site:  CSWGP  Permit Coverage Letter  SWPPP  Site Log Book Permit documentation will be provided within 14 days of receipt of a written request from Ecology. A copy of the SWPPP or access to the SWPPP will be provided to the public when requested in writing in accordance with Special Condition S5.G.2.b of the CSWGP. 6.1.3 Updating the SWPPP The SWPPP will be modified if:  Found ineffective in eliminating or significantly minimizing pollutants in stormwater discharges from the site.  There is a change in design, construction, operation, or maintenance at the construction site that has, or could have, a significant effect on the discharge of pollutants to waters of the State. The SWPPP will be modified within seven (7) days if inspection(s) or investigation(s) determine additional or modified BMPs are necessary for compliance. An updated timeline for BMP implementation will be prepared. P a g e | 30 6.2 Reporting 6.2.1 Discharge Monitoring Reports Cumulative soil disturbance is one (1) acre or larger; therefore, Discharge Monitoring Reports (DMRs) will be submitted to Ecology monthly. If there was no discharge during a given monitoring period the DMR will be submitted as required, reporting “No Discharge”. The DMR due date is fifteen (15) days following the end of each calendar month. DMRs will be reported online through Ecology’s WQWebDMR System. 6.2.2 Notification of Noncompliance If any of the terms and conditions of the permit is not met, and the resulting noncompliance may cause a threat to human health or the environment, the following actions will be taken: 1. Ecology will be notified within 24-hours of the failure to comply by calling the applicable Regional office ERTS phone number (Regional office numbers listed below). 2. Immediate action will be taken to prevent the discharge/pollution or otherwise stop or correct the noncompliance. If applicable, sampling and analysis of any noncompliance will be repeated immediately and the results submitted to Ecology within five (5) days of becoming aware of the violation. 3. A detailed written report describing the noncompliance will be submitted to Ecology within five (5) days, unless requested earlier by Ecology. Anytime turbidity sampling indicates turbidity is 250 NTUs or greater, or water transparency is 6 cm or less, the Ecology Regional office will be notified by phone within 24 hours of analysis as required by Special Condition S5.A of the CSWGP.  Northwest Region at (425) 649-7000 for Island, King, Kitsap, San Juan, Skagit, Snohomish, or Whatcom County Include the following information: 1. Your name and / Phone number 2. Permit number 3. City / County of project 4. Sample results 5. Date / Time of call 6. Date / Time of sample 7. Project name In accordance with Special Condition S4.D.5.b of the CSWGP, the Ecology Regional office will be notified if chemical treatment other than CO2 sparging is planned for adjustment of high pH water. P a g e | 31 Appendix/Glossary A. Site Map B. BMP Detail C. Correspondence N/A D. Site Inspection Form E. Construction Stormwater General Permit (CSWGP) F. 303(d) List Waterbodies / TMDL Waterbodies Information N/A G. Contaminated Site Information N/A H. Engineering Calculations P a g e | 32 Appendix A – Site Map Family First Community Center C180040-01 Baylis Architects 12/4/19CPS AJF 1 OF 1 FIGURE 1 - VICINITY MAP2014 801 SECOND AVENUE, SUITE 900 SEATTLE, WA 98104 / P 206.343.0460 / cplinc.com Project Site SCALE 1" = 40' Legend Description Quantity Unit Existing Landscape to Remain 31,085.60 sf NPGIS 36,657.40 sf PGIS 59,327.72 sf Proposed Pervious 22,202.14 sf FIGURE 2 - PROPOSED CONDITIONSFamily First Community Center C180040-01 12/03/19 P a g e | 33 Appendix B – BMP Details BMP C101: Preserving Natural Vegetation Purpose The purpose of preserving natural vegetation is to reduce erosion wherever practicable. Limiting site disturbance is the single most effective method for reducing erosion. For example, conifers can hold up to about 50 percent of all rain that falls during a storm. Up to 20-30 percent of this rain may never reach the ground but is taken up by the tree or evaporates. Another benefit is that the rain held in the tree can be released slowly to the ground after the storm. Conditions of Use Natural vegetation should be preserved on steep slopes, near perennial and intermittent watercourses or swales, and on building sites in wooded areas.  As required by local governments.  Phase construction to preserve natural vegetation on the project site for as long as possible during the construction period. Design and Installation Specifications Natural vegetation can be preserved in natural clumps or as individual trees, shrubs and vines. The preservation of individual plants is more difficult because heavy equipment is generally used to remove unwanted vegetation. The points to remember when attempting to save individual plants are:  Is the plant worth saving? Consider the location, species, size, age, vigor, and the work involved. Local governments may also have ordinances to save natural vegetation and trees.  Fence or clearly mark areas around trees that are to be saved. It is preferable to keep ground disturbance away from the trees at least as far out as the dripline. Plants need protection from three kinds of injuries:  Construction Equipment - This injury can be above or below the ground level. Damage results from scarring, cutting of roots, and compaction of the soil. Placing a fenced buffer zone around plants to be saved prior to construction can prevent construction equipment injuries.  Grade Changes - Changing the natural ground level will alter grades, which affects the plant's ability to obtain the necessary air, water, and minerals. Minor fills usually do not cause problems although sensitivity between species does vary and should be checked. Trees can typically tolerate fill of 6 inches or less. For shrubs and other plants, the fill should be less. When there are major changes in grade, it may become necessary to supply air to the roots of plants. This can be done by placing a layer of gravel and a tile system over the roots before the fill is made. A tile system protects a tree from a raised grade. The tile system should be laid out on the original grade leading from a dry well around the tree trunk. The system should then be covered with small stones to allow air to circulate over the root area. Lowering the natural ground level can seriously damage trees and shrubs. The highest percentage of the plant roots are in the upper 12 inches of the soil and cuts of only 2-3 inches can cause serious injury. To protect the roots it may be necessary to terrace the immediate area around the plants to be saved. If roots are exposed, construction of retaining walls may be needed to keep the soil in place. Plants can also be preserved by leaving them on an undisturbed, gently sloping mound. To increase the chances for survival, it is best to limit grade changes and other soil disturbances to areas outside the dripline of the plant.  Excavations - Protect trees and other plants when excavating for drainfields, power, water, and sewer lines. Where possible, the trenches should be routed around trees and large shrubs. When this is not possible, it is best to tunnel under them. This can be done with hand tools or with power augers. If it is not possible to route the trench around plants to be saved, then the following should be observed: o Cut as few roots as possible. When you have to cut, cut clean. Paint cut root ends with a wood dressing like asphalt base paint if roots will be exposed for more than 24-hours. o Backfill the trench as soon as possible. o Tunnel beneath root systems as close to the center of the main trunk to preserve most of the important feeder roots. Some problems that can be encountered with a few specific trees are:  Maple, Dogwood, Red alder, Western hemlock, Western red cedar, and Douglas fir do not readily adjust to changes in environment and special care should be taken to protect these trees.  The windthrow hazard of Pacific silver fir and madrona is high, while that of Western hemlock is moderate. The danger of windthrow increases where dense stands have been thinned. Other species (unless they are on shallow, wet soils less than 20 inches deep) have a low windthrow hazard.  Cottonwoods, maples, and willows have water-seeking roots. These can cause trouble in sewer lines and infiltration fields. On the other hand, they thrive in high moisture conditions that other trees would not.  Thinning operations in pure or mixed stands of Grand fir, Pacific silver fir, Noble fir, Sitka spruce, Western red cedar, Western hemlock, Pacific dogwood, and Red alder can cause serious disease problems. Disease can become established through damaged limbs, trunks, roots, and freshly cut stumps. Diseased and weakened trees are also susceptible to insect attack. Maintenance Standards Inspect flagged and/or fenced areas regularly to make sure flagging or fencing has not been removed or damaged. If the flagging or fencing has been damaged or visibility reduced, it shall be repaired or replaced immediately and visibility restored.  If tree roots have been exposed or injured, “prune” cleanly with an appropriate pruning saw or loppers directly above the damaged roots and recover with native soils. Treatment of sap flowing trees (fir, hemlock, pine, soft maples) is not advised as sap forms a natural healing barrier. BMP C103: High Visibility Fence Purpose Fencing is intended to: 1. Restrict clearing to approved limits. 2. Prevent disturbance of sensitive areas, their buffers, and other areas required to be left undisturbed. 3. Limit construction traffic to designated construction entrances, exits, or internal roads. 4. Protect areas where marking with survey tape may not provide adequate protection. Conditions of Use To establish clearing limits plastic, fabric, or metal fence may be used:  At the boundary of sensitive areas, their buffers, and other areas required to be left uncleared.  As necessary to control vehicle access to and on the site. Design and Installation Specifications High visibility plastic fence shall be composed of a high-density polyethylene material and shall be at least four feet in height. Posts for the fencing shall be steel or wood and placed every 6 feet on center (maximum) or as needed to ensure rigidity. The fencing shall be fastened to the post every six inches with a polyethylene tie. On long continuous lengths of fencing, a tension wire or rope shall be used as a top stringer to prevent sagging between posts. The fence color shall be high visibility orange. The fence tensile strength shall be 360 lbs./ft. using the ASTM D4595 testing method. If appropriate install fabric silt fence in accordance with BMP C233: Silt Fence to act as high visibility fence. Silt fence shall be at least 3 feet high and must be highly visible to meet the requirements of this BMP. Metal fences shall be designed and installed according to the manufacturer's specifications. Metal fences shall be at least 3 feet high and must be highly visible. Fences shall not be wired or stapled to trees. Maintenance Standards If the fence has been damaged or visibility reduced, it shall be repaired or replaced immediately and visibility restored. BMP C105: Stabilized Construction Entrance / Exit Purpose Stabilized Construction entrances are established to reduce the amount of sediment transported onto paved roads by vehicles or equipment. This is done by constructing a stabilized pad of quarry spalls at entrances and exits for construction sites. Conditions of Use Construction entrances shall be stabilized wherever traffic will be entering or leaving a construction site if paved roads or other paved areas are within 1,000 feet of the site. For residential construction provide stabilized construction entrances for each residence, rather than only at the main subdivision entrance. Stabilized surfaces shall be of sufficient length/width to provide vehicle access/parking, based on lot size/configuration. On large commercial, highway, and road projects, the designer should include enough extra materials in the contract to allow for additional stabilized entrances not shown in the initial Construction SWPPP. It is difficult to determine exactly where access to these projects will take place; additional materials will enable the contractor to install them where needed. Design and Installation Specifications See Figure II-4.1.1 Stabilized Construction Entrance for details. Note: the 100’ minimum length of the entrance shall be reduced to the maximum practicable size when the size or configuration of the site does not allow the full length (100’). Construct stabilized construction entrances with a 12-inch thick pad of 4-inch to 8-inch quarry spalls, a 4-inch course of asphalt treated base (ATB), or use existing pavement. Do not use crushed concrete, cement, or calcium chloride for construction entrance stabilization because these products raise pH levels in stormwater and concrete discharge to surface waters of the State is prohibited. A separation geotextile shall be placed under the spalls to prevent fine sediment from pumping up into the rock pad. The geotextile shall meet the following standards: Grab Tensile Strength (ASTM D4751) 200 psi min. Grab Tensile Elongation (ASTM D4632) 30% max. Mullen Burst Strength (ASTM D3786-80a) 400 psi min. AOS (ASTM D4751) 20-45 (U.S. standard sieve size)  Consider early installation of the first lift of asphalt in areas that will paved; this can be used as a stabilized entrance. Also consider the installation of excess concrete as a stabilized entrance. During large concrete pours, excess concrete is often available for this purpose.  Fencing (see BMP C103: High Visibility Fence) shall be installed as necessary to restrict traffic to the construction entrance.  Whenever possible, the entrance shall be constructed on a firm, compacted subgrade. This can substantially increase the effectiveness of the pad and reduce the need for maintenance.  Construction entrances should avoid crossing existing sidewalks and back of walk drains if at all possible. If a construction entrance must cross a sidewalk or back of walk drain, the full length of the sidewalk and back of walk drain must be covered and protected from sediment leaving the site. Maintenance Standards Quarry spalls shall be added if the pad is no longer in accordance with the specifications.  If the entrance is not preventing sediment from being tracked onto pavement, then alternative measures to keep the streets free of sediment shall be used. This may include replacement/cleaning of the existing quarry spalls, street sweeping, an increase in the dimensions of the entrance, or the installation of a wheel wash.  Any sediment that is tracked onto pavement shall be removed by shoveling or street sweeping. The sediment collected by sweeping shall be removed or stabilized on site. The pavement shall not be cleaned by washing down the street, except when high efficiency sweeping is ineffective and there is a threat to public safety. If it is necessary to wash the streets, the construction of a small sump to contain the wash water shall be considered. The sediment would then be washed into the sump where it can be controlled.  Perform street sweeping by hand or with a high efficiency sweeper. Do not use a non- high efficiency mechanical sweeper because this creates dust and throws soils into storm systems or conveyance ditches.  Any quarry spalls that are loosened from the pad, which end up on the roadway shall be removed immediately.  If vehicles are entering or exiting the site at points other than the construction entrance(s), fencing (see BMP C103) shall be installed to control traffic.  Upon project completion and site stabilization, all construction accesses intended as permanent access for maintenance shall be permanently stabilized.  Approved as Equivalent  Ecology has approved products as able to meet the requirements of BMP C105: Stabilized Construction Entrance / Exit. The products did not pass through the Technology Assessment Protocol – Ecology (TAPE) process. Local jurisdictions may choose not to accept this product approved as equivalent, or may require additional testing prior to consideration for local use. The products are available for review on Ecology’s website at http://www.ecy.wa.gov/programs/wq/stormwater/newtech/equivalent.html DEPAR TM E N T OF ECOLOGY State of Washington Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, limitation of liability, and disclaimer. Figure II-4.1.1 Stabilized Construction Entrance Revised June 2015 NOT TO SCALE Existing R o a d Notes: 1.Driveway shall meet the requirements of the permitting agency. 2.It is recommended that the entrance be crowned so that runoff drains off the pad. Install driveway culvert if there is a roadside ditch present 4" - 8" quarry spalls Geotextile 12" minimum thickness 15' min. 100' min. Provide full width of ingress/egress area BMP C106: Wheel Wash Purpose Wheel washes reduce the amount of sediment transported onto paved roads by motor vehicles. Conditions of Use When a stabilized construction entrance (see BMP C105: Stabilized Construction Entrance / Exit) is not preventing sediment from being tracked onto pavement.  Wheel washing is generally an effective BMP when installed with careful attention to topography. For example, a wheel wash can be detrimental if installed at the top of a slope abutting a right-of-way where the water from the dripping truck can run unimpeded into the street.  Pressure washing combined with an adequately sized and surfaced pad with direct drainage to a large 10-foot x 10-foot sump can be very effective.  Discharge wheel wash or tire bath wastewater to a separate on-site treatment system that prevents discharge to surface water, such as closed-loop recirculation or upland land application, or to the sanitary sewer with local sewer district approval.  Wheel wash or tire bath wastewater should not include wastewater from concrete washout areas. Design and Installation Specifications Suggested details are shown in Figure II-4.1.2 Wheel Wash. The Local Permitting Authority may allow other designs. A minimum of 6 inches of asphalt treated base (ATB) over crushed base material or 8 inches over a good subgrade is recommended to pave the wheel wash. Use a low clearance truck to test the wheel wash before paving. Either a belly dump or lowboy will work well to test clearance. Keep the water level from 12 to 14 inches deep to avoid damage to truck hubs and filling the truck tongues with water. Midpoint spray nozzles are only needed in extremely muddy conditions. Wheel wash systems should be designed with a small grade change, 6- to 12-inches for a 10- foot-wide pond, to allow sediment to flow to the low side of pond to help prevent re-suspension of sediment. A drainpipe with a 2- to 3-foot riser should be installed on the low side of the pond to allow for easy cleaning and refilling. Polymers may be used to promote coagulation and flocculation in a closed-loop system. Polyacrylamide (PAM) added to the wheel wash water at a rate of 0.25 - 0.5 pounds per 1,000 gallons of water increases effectiveness and reduces cleanup time. If PAM is already being used for dust or erosion control and is being applied by a water truck, the same truck can be used to change the wash water. Maintenance Standards The wheel wash should start out the day with fresh water. The wash water should be changed a minimum of once per day. On large earthwork jobs where more than 10-20 trucks per hour are expected, the wash water will need to be changed more often. DEPAR TM E N T OF ECOLOGY State of Washington Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, limitation of liability, and disclaimer. Figure II-4.1.2 Wheel Wash Revised June 2015 NOT TO SCALE Notes: 1.Build 8' x 8' sump to accomodate cleaning by trackhoe. 6" sewer pipe with butterfly valves 8' x 8' sump with 5' of catch 3" trash pump with floats on suction hose 2" schedule 40 1 12 " schedule 40 for sprayers midpoint spray nozzles, if needed 15' ATB apron to protect ground from splashing water 6" sleeve under road 6" ATB construction entrance Asphalt curb on the low road side to direct water back to pond Ball valves 2% slope 5:1 slope 1:1 slope 5:1 slope 2% slope A A Plan View 15'15'20'15'50' Curb 6" sleeve Elevation View Locate invert of top pipe 1' above bottom of wheel wash 8' x 8' sump 5' Drain pipe 12' 3' 18' Water level 1:1 slope Section A-A BMP C120: Temporary and Permanent Seeding Purpose Seeding reduces erosion by stabilizing exposed soils. A well-established vegetative cover is one of the most effective methods of reducing erosion. Conditions of Use Use seeding throughout the project on disturbed areas that have reached final grade or that will remain unworked for more than 30 days. The optimum seeding windows for western Washington are April 1 through June 30 and September 1 through October 1. Between July 1 and August 30 seeding requires irrigation until 75 percent grass cover is established. Between October 1 and March 30 seeding requires a cover of mulch with straw or an erosion control blanket until 75 percent grass cover is established. Review all disturbed areas in late August to early September and complete all seeding by the end of September. Otherwise, vegetation will not establish itself enough to provide more than average protection.  Mulch is required at all times for seeding because it protects seeds from heat, moisture loss, and transport due to runoff. Mulch can be applied on top of the seed or simultaneously by hydroseeding. See BMP C121: Mulching for specifications.  Seed and mulch, all disturbed areas not otherwise vegetated at final site stabilization. Final stabilization means the completion of all soil disturbing activities at the site and the establishment of a permanent vegetative cover, or equivalent permanent stabilization measures (such as pavement, riprap, gabions, or geotextiles) which will prevent erosion. Design and Installation Specifications Seed retention/detention ponds as required. Install channels intended for vegetation before starting major earthwork and hydroseed with a Bonded Fiber Matrix. For vegetated channels that will have high flows, install erosion control blankets over hydroseed. Before allowing water to flow in vegetated channels, establish 75 percent vegetation cover. If vegetated channels cannot be established by seed before water flow; install sod in the channel bottom—over hydromulch and erosion control blankets.  Confirm the installation of all required surface water control measures to prevent seed from washing away.  Hydroseed applications shall include a minimum of 1,500 pounds per acre of mulch with 3 percent tackifier. See BMP C121: Mulching for specifications.  Areas that will have seeding only and not landscaping may need compost or meal-based mulch included in the hydroseed in order to establish vegetation. Re-install native topsoil on the disturbed soil surface before application.  When installing seed via hydroseeding operations, only about 1/3 of the seed actually ends up in contact with the soil surface. This reduces the ability to establish a good stand of grass quickly. To overcome this, consider increasing seed quantities by up to 50 percent.  Enhance vegetation establishment by dividing the hydromulch operation into two phases: 1. Phase 1- Install all seed and fertilizer with 25-30 percent mulch and tackifier onto soil in the first lift. 2. Phase 2- Install the rest of the mulch and tackifier over the first lift. Or, enhance vegetation by: 1. Installing the mulch, seed, fertilizer, and tackifier in one lift. 2. Spread or blow straw over the top of the hydromulch at a rate of 800-1000 pounds per acre. 3. Hold straw in place with a standard tackifier. Both of these approaches will increase cost moderately but will greatly improve and enhance vegetative establishment. The increased cost may be offset by the reduced need for: o Irrigation. o Reapplication of mulch. o Repair of failed slope surfaces. This technique works with standard hydromulch (1,500 pounds per acre minimum) and BFM/MBFMs (3,000 pounds per acre minimum).  Seed may be installed by hand if: o Temporary and covered by straw, mulch, or topsoil. o Permanent in small areas (usually less than 1 acre) and covered with mulch, topsoil, or erosion blankets. o The seed mixes listed in the tables below include recommended mixes for both temporary and permanent seeding. o Apply these mixes, with the exception of the wetland mix, at a rate of 120 pounds per acre. This rate can be reduced if soil amendments or slow-release fertilizers are used. o Consult the local suppliers or the local conservation district for their recommendations because the appropriate mix depends on a variety of factors, including location, exposure, soil type, slope, and expected foot traffic. Alternative seed mixes approved by the local authority may be used. o Other mixes may be appropriate, depending on the soil type and hydrology of the area.  Table II-4.1.2 Temporary Erosion Control Seed Mix lists the standard mix for areas requiring a temporary vegetative cover. Table II-4.1.2 Temporary Erosion Control Seed Mix % Weight % Purity % Germination Chewings or annual blue grass Festuca rubra var. commutata or Poa anna 40 98 90 Perennial rye Lolium perenne 50 98 90 Redtop or colonial bentgrass Agrostis alba or Agrostis tenuis 5 92 85 White dutch clover Trifolium repens 5 98 90  Table II-4.1.3 Landscaping Seed Mix lists a recommended mix for landscaping seed. Table II-4.1.3 Landscaping Seed Mix % Weight % Purity % Germination Perennial rye blend 70 98 90 Table II-4.1.3 Landscaping Seed Mix % Weight % Purity % Germination Lolium perenne Chewings and red fescue blend Festuca rubra var. commutata or Festuca rubra 30 98 90  Table II-4.1.4 Low-Growing Turf Seed Mix lists a turf seed mix for dry situations where there is no need for watering. This mix requires very little maintenance. Table II-4.1.4 Low-Growing Turf Seed Mix % Weight % Purity % Germination Dwarf tall fescue (several varieties) Festuca arundinacea var. 45 98 90 Dwarf perennial rye (Barclay) Lolium perenne var. barclay 30 98 90 Red fescue Festuca rubra 20 98 90 Colonial bentgrass Agrostis tenuis 5 98 90  Table II-4.1.5 Bioswale Seed Mix* lists a mix for bioswales and other intermittently wet areas. Table II-4.1.5 Bioswale Seed Mix* % Weight % Purity % Germination Tall or meadow fescue Festuca arundinacea or Festuca elatior 75-80 98 90 Table II-4.1.5 Bioswale Seed Mix* % Weight % Purity % Germination Seaside/Creeping bentgrass Agrostis palustris 10-15 92 85 Redtop bentgrass Agrostis alba or Agrostis gigantea 5-10 90 80 * Modified Briargreen, Inc. Hydroseeding Guide Wetlands Seed Mix  Table II-4.1.6 Wet Area Seed Mix* lists a low-growing, relatively non-invasive seed mix appropriate for very wet areas that are not regulated wetlands. Apply this mixture at a rate of 60 pounds per acre. Consult Hydraulic Permit Authority (HPA) for seed mixes if applicable. Table II-4.1.6 Wet Area Seed Mix* % Weight % Purity % Germination Tall or meadow fescue Festuca arundinacea or Festuca elatior 60-70 98 90 Seaside/Creeping bentgrass Agrostis palustris 10-15 98 85 Meadow foxtail Alepocurus pratensis 10-15 90 80 Alsike clover Trifolium hybridum 1-6 98 90 Redtop bentgrass Agrostis alba 1-6 92 85 * Modified Briargreen, Inc. Hydroseeding Guide Wetlands Seed Mix  Table II-4.1.7 Meadow Seed Mix lists a recommended meadow seed mix for infrequently maintained areas or non-maintained areas where colonization by native plants is desirable. Likely applications include rural road and utility right-of-way. Seeding should take place in September or very early October in order to obtain adequate establishment prior to the winter months. Consider the appropriateness of clover, a fairly invasive species, in the mix. Amending the soil can reduce the need for clover. Table II-4.1.7 Meadow Seed Mix % Weight % Purity % Germination Redtop or Oregon bentgrass Agrostis alba or Agrostis oregonensis 20 92 85 Red fescue Festuca rubra 70 98 90 White dutch clover Trifolium repens 10 98 90  Roughening and Rototilling: o The seedbed should be firm and rough. Roughen all soil no matter what the slope. Track walk slopes before seeding if engineering purposes require compaction. Backblading or smoothing of slopes greater than 4H:1V is not allowed if they are to be seeded. o Restoration-based landscape practices require deeper incorporation than that provided by a simple single-pass rototilling treatment. Wherever practical, initially rip the subgrade to improve long-term permeability, infiltration, and water inflow qualities. At a minimum, permanent areas shall use soil amendments to achieve organic matter and permeability performance defined in engineered soil/landscape systems. For systems that are deeper than 8 inches complete the rototilling process in multiple lifts, or prepare the engineered soil system per specifications and place to achieve the specified depth.  Fertilizers: o Conducting soil tests to determine the exact type and quantity of fertilizer is recommended. This will prevent the over-application of fertilizer. o Organic matter is the most appropriate form of fertilizer because it provides nutrients (including nitrogen, phosphorus, and potassium) in the least water- soluble form. o In general, use 10-4-6 N-P-K (nitrogen-phosphorus-potassium) fertilizer at a rate of 90 pounds per acre. Always use slow-release fertilizers because they are more efficient and have fewer environmental impacts. Do not add fertilizer to the hydromulch machine, or agitate, more than 20 minutes before use. Too much agitation destroys the slow-release coating. o There are numerous products available that take the place of chemical fertilizers. These include several with seaweed extracts that are beneficial to soil microbes and organisms. If 100 percent cottonseed meal is used as the mulch in hydroseed, chemical fertilizer may not be necessary. Cottonseed meal provides a good source of long-term, slow-release, available nitrogen.  Bonded Fiber Matrix and Mechanically Bonded Fiber Matrix: o On steep slopes use Bonded Fiber Matrix (BFM) or Mechanically Bonded Fiber Matrix (MBFM) products. Apply BFM/MBFM products at a minimum rate of 3,000 pounds per acre of mulch with approximately 10 percent tackifier. Achieve a minimum of 95 percent soil coverage during application. Numerous products are available commercially. Installed products per manufacturer’s instructions. Most products require 24-36 hours to cure before rainfall and cannot be installed on wet or saturated soils. Generally, products come in 40-50 pound bags and include all necessary ingredients except for seed and fertilizer. o BFMs and MBFMs provide good alternatives to blankets in most areas requiring vegetation establishment. Advantages over blankets include:  BFM and MBFMs do not require surface preparation.  Helicopters can assist in installing BFM and MBFMs in remote areas.  On slopes steeper than 2.5H:1V, blanket installers may require ropes and harnesses for safety.  Installing BFM and MBFMs can save at least $1,000 per acre compared to blankets. Maintenance Standards Reseed any seeded areas that fail to establish at least 80 percent cover (100 percent cover for areas that receive sheet or concentrated flows). If reseeding is ineffective, use an alternate method such as sodding, mulching, or nets/blankets. If winter weather prevents adequate grass growth, this time limit may be relaxed at the discretion of the local authority when sensitive areas would otherwise be protected.  Reseed and protect by mulch any areas that experience erosion after achieving adequate cover. Reseed and protect by mulch any eroded area.  Supply seeded areas with adequate moisture, but do not water to the extent that it causes runoff. Approved as Equivalent Ecology has approved products as able to meet the requirements of BMP C120: Temporary and Permanent Seeding. The products did not pass through the Technology Assessment Protocol – Ecology (TAPE) process. Local jurisdictions may choose not to accept this product approved as equivalent, or may require additional testing prior to consideration for local use. The products are available for review on Ecology’s website at http://www.ecy.wa.gov/programs/wq/stormwater/newtech/equivalent.html. BMP C121: Mulching Purpose Mulching soils provides immediate temporary protection from erosion. Mulch also enhances plant establishment by conserving moisture, holding fertilizer, seed, and topsoil in place, and moderating soil temperatures. There is an enormous variety of mulches that can be used. This section discusses only the most common types of mulch. Conditions of Use As a temporary cover measure, mulch should be used:  For less than 30 days on disturbed areas that require cover.  At all times for seeded areas, especially during the wet season and during the hot summer months.  During the wet season on slopes steeper than 3H:1V with more than 10 feet of vertical relief. Mulch may be applied at any time of the year and must be refreshed periodically.  For seeded areas mulch may be made up of 100 percent: cottonseed meal; fibers made of wood, recycled cellulose, hemp, kenaf; compost; or blends of these. Tackifier shall be plant-based, such as guar or alpha plantago, or chemical-based such as polyacrylamide or polymers. Any mulch or tackifier product used shall be installed per manufacturer’s instructions. Generally, mulches come in 40-50 pound bags. Seed and fertilizer are added at time of application. Design and Installation Specifications For mulch materials, application rates, and specifications, see Table II-4.1.8 Mulch Standards and Guidelines. Always use a 2-inch minimum mulch thickness; increase the thickness until the ground is 95% covered (i.e. not visible under the mulch layer). Note: Thickness may be increased for disturbed areas in or near sensitive areas or other areas highly susceptible to erosion. Where the option of “Compost” is selected, it should be a coarse compost that meets the following size gradations when tested in accordance with the U.S. Composting Council “Test Methods for the Examination of Compost and Composting” (TMECC) Test Method 02.02-B. Coarse Compost Minimum Percent passing 3” sieve openings 100% Minimum Percent passing 1” sieve openings 90% Minimum Percent passing ¾” sieve openings 70% Minimum Percent passing ¼” sieve openings 40% Mulch used within the ordinary high-water mark of surface waters should be selected to minimize potential flotation of organic matter. Composted organic materials have higher specific gravities (densities) than straw, wood, or chipped material. Consult Hydraulic Permit Authority (HPA) for mulch mixes if applicable. Maintenance Standards  The thickness of the cover must be maintained.  Any areas that experience erosion shall be remulched and/or protected with a net or blanket. If the erosion problem is drainage related, then the problem shall be fixed and the eroded area remulched. Table II-4.1.8 Mulch Standards and Guidelines Mulch Material Quality Standards Application Rates Remarks Straw Air-dried; free from undesirable seed and coarse material. 2"-3" thick; 5 bales per 1,000 sf or 2- 3 tons per acre Cost-effective protection when applied with adequate thickness. Hand-application generally requires greater thickness than blown straw. The thickness of straw may be reduced by half when used in conjunction with seeding. In windy areas straw must be held in place by crimping, using a tackifier, or covering with netting. Blown straw always has to be held in place with a tackifier as even light winds will blow it away. Straw, however, has several deficiencies that should be considered when selecting mulch materials. It often introduces and/or encourages the propagation of Table II-4.1.8 Mulch Standards and Guidelines Mulch Material Quality Standards Application Rates Remarks weed species and it has no significant long-term benefits It should also not be used within the ordinary high-water elevation of surface waters (due to flotation). Hydromulch No growth inhibiting factors. Approx. 25-30 lbs per 1,000 sf or 1,500 - 2,000 lbs per acre Shall be applied with hydromulcher. Shall not be used without seed and tackifier unless the application rate is at least doubled. Fibers longer than about 3/4 - 1 inch clog hydromulch equipment. Fibers should be kept to less than 3/4 inch. Compost No visible water or dust during handling. Must be produced per WAC 173-350, Solid Waste Handling Standards, but may have up to 35% biosolids. 2" thick min.; approx. 100 tons per acre (approx. 800 lbs per yard) More effective control can be obtained by increasing thickness to 3". Excellent mulch for protecting final grades until landscaping because it can be directly seeded or tilled into soil as an amendment. Compost used for mulch has a coarser size gradation than compost used for BMP C125: Topsoiling / Composting or BMP T5.13: Post-Construction Soil Quality and Depth. It is more stable and practical to use in wet areas and during rainy weather conditions. Do not use near wetlands or near phosphorous impaired water bodies. Chipped Site Vegetation Average size shall be several inches. Gradations from fines to 6 inches in length for texture, variation, and interlocking properties. 2" thick min.; This is a cost-effective way to dispose of debris from clearing and grubbing, and it eliminates the problems associated with burning. Generally, it should not be used on slopes above approx. 10% because of its tendency to be transported by runoff. It is not recommended within 200 feet of surface waters. If seeding is expected shortly after mulch, the decomposition of the chipped vegetation may tie up nutrients important to grass establishment. Wood-based Mulch or Wood Straw No visible water or dust during handling. Must be purchased from a supplier with a Solid Waste Handling Permit or one exempt from solid waste regulations. 2" thick min.; approx. 100 tons per acre (approx. 800 lbs. per cubic yard) This material is often called "hog or hogged fuel". The use of mulch ultimately improves the organic matter in the soil. Special caution is advised regarding the source and composition of wood-based mulches. Its preparation typically does not provide any weed seed control, so evidence of residual vegetation in its composition or known inclusion of weed plants or seeds should be monitored and prevented (or minimized). Wood Strand Mulch A blend of loose, long, thin wood pieces derived from native conifer 2" thick min. Cost-effective protection when applied with adequate thickness. A minimum of 95-percent of the wood strand shall have lengths between 2 and 10-inches, with a width and thickness between 1/16 and 3/8-inches. The mulch Table II-4.1.8 Mulch Standards and Guidelines Mulch Material Quality Standards Application Rates Remarks or deciduous trees with high length-to- width ratio. shall not contain resin, tannin, or other compounds in quantities that would be detrimental to plant life. Sawdust or wood shavings shall not be used as mulch. (WSDOT specification (9-14.4(4)) BMP C122: Nets and Blankets Purpose Erosion control nets and blankets are intended to prevent erosion and hold seed and mulch in place on steep slopes and in channels so that vegetation can become well established. In addition, some nets and blankets can be used to permanently reinforce turf to protect drainage ways during high flows. Nets (commonly called matting) are strands of material woven into an open, but high-tensile strength net (for example, coconut fiber matting). Blankets are strands of material that are not tightly woven, but instead form a layer of interlocking fibers, typically held together by a biodegradable or photodegradable netting (for example, excelsior or straw blankets). They generally have lower tensile strength than nets, but cover the ground more completely. Coir (coconut fiber) fabric comes as both nets and blankets. Conditions of Use Erosion control nets and blankets should be used:  To aid permanent vegetated stabilization of slopes 2H:1V or greater and with more than 10 feet of vertical relief.  For drainage ditches and swales (highly recommended). The application of appropriate netting or blanket to drainage ditches and swales can protect bare soil from channelized runoff while vegetation is established. Nets and blankets also can capture a great deal of sediment due to their open, porous structure. Nets and blankets can be used to permanently stabilize channels and may provide a cost-effective, environmentally preferable alternative to riprap. 100 percent synthetic blankets manufactured for use in ditches may be easily reused as temporary ditch liners. Disadvantages of blankets include:  Surface preparation required.  On slopes steeper than 2.5H:1V, blanket installers may need to be roped and harnessed for safety.  They cost at least $4,000-6,000 per acre installed. Advantages of blankets include:  Installation without mobilizing special equipment.  Installation by anyone with minimal training  Installation in stages or phases as the project progresses.  Installers can hand place seed and fertilizer as they progress down the slope.  Installation in any weather.  There are numerous types of blankets that can be designed with various parameters in mind. Those parameters include: fiber blend, mesh strength, longevity, biodegradability, cost, and availability. Design and Installation Specifications  See Figure II-4.1.3 Channel Installation and Figure II-4.1.4 Slope Installation for typical orientation and installation of blankets used in channels and as slope protection. Note: these are typical only; all blankets must be installed per manufacturer’s installation instructions.  Installation is critical to the effectiveness of these products. If good ground contact is not achieved, runoff can concentrate under the product, resulting in significant erosion.  Installation of Blankets on Slopes: 1. Complete final grade and track walk up and down the slope. 2. Install hydromulch with seed and fertilizer. 3. Dig a small trench, approximately 12 inches wide by 6 inches deep along the top of the slope. 4. Install the leading edge of the blanket into the small trench and staple approximately every 18 inches. NOTE: Staples are metal, “U”-shaped, and a minimum of 6 inches long. Longer staples are used in sandy soils. Biodegradable stakes are also available. 5. Roll the blanket slowly down the slope as installer walks backwards. NOTE: The blanket rests against the installer’s legs. Staples are installed as the blanket is unrolled. It is critical that the proper staple pattern is used for the blanket being installed. The blanket is not to be allowed to roll down the slope on its own as this stretches the blanket making it impossible to maintain soil contact. In addition, no one is allowed to walk on the blanket after it is in place. 6. If the blanket is not long enough to cover the entire slope length, the trailing edge of the upper blanket should overlap the leading edge of the lower blanket and be stapled. On steeper slopes, this overlap should be installed in a small trench, stapled, and covered with soil.  With the variety of products available, it is impossible to cover all the details of appropriate use and installation. Therefore, it is critical that the design engineer consult the manufacturer's information and that a site visit takes place in order to ensure that the product specified is appropriate. Information is also available at the following web sites: 1. WSDOT (Section 3.2.4): http://www.wsdot.wa.gov/NR/rdonlyres/3B41E087-FA86-4717-932D- D7A8556CCD57/0/ErosionTrainingManual.pdf 2. Texas Transportation Institute: http://www.txdot.gov/business/doing_business/product_evaluation/erosion_control .htm  Use jute matting in conjunction with mulch (BMP C121: Mulching). Excelsior, woven straw blankets and coir (coconut fiber) blankets may be installed without mulch. There are many other types of erosion control nets and blankets on the market that may be appropriate in certain circumstances.  In general, most nets (e.g., jute matting) require mulch in order to prevent erosion because they have a fairly open structure. Blankets typically do not require mulch because they usually provide complete protection of the surface.  Extremely steep, unstable, wet, or rocky slopes are often appropriate candidates for use of synthetic blankets, as are riverbanks, beaches and other high-energy environments. If synthetic blankets are used, the soil should be hydromulched first.  100-percent biodegradable blankets are available for use in sensitive areas. These organic blankets are usually held together with a paper or fiber mesh and stitching which may last up to a year.  Most netting used with blankets is photodegradable, meaning they break down under sunlight (not UV stabilized). However, this process can take months or years even under bright sun. Once vegetation is established, sunlight does not reach the mesh. It is not uncommon to find non-degraded netting still in place several years after installation. This can be a problem if maintenance requires the use of mowers or ditch cleaning equipment. In addition, birds and small animals can become trapped in the netting. Maintenance Standards  Maintain good contact with the ground. Erosion must not occur beneath the net or blanket.  Repair and staple any areas of the net or blanket that are damaged or not in close contact with the ground.  Fix and protect eroded areas if erosion occurs due to poorly controlled drainage. DEPAR TM E N T OF ECOLOGY State of Washington Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, limitation of liability, and disclaimer. Figure II-4.1.3 Channel Installation Revised June 2015 NOT TO SCALE Source: Clackamas County 2009 Erosion Prevention Planning and Design Manual Notes: 1.Check slots to be constructed per manufacturers specifications. 2.Staking or stapling layout per manufacturers specifications. DEPAR TM E N T OF ECOLOGY State of Washington Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, limitation of liability, and disclaimer. Figure II-4.1.4 Slope Installation Revised June 2015 NOT TO SCALE Notes: 1.Slope surface shall be smooth before placement for proper soil contact. 2.Stapling pattern as per manufacturer's recommendations. 3.Do not stretch blankets/mattings tight - allow the rolls to mold to any irregularities. 4.For slopes less than 3H:1V, rolls may be placed in horizontal strips. 5.If there is a berm at the top of the slope, anchor upslope of the berm. 6.Lime, fertilize, and seed before installation. Planting of shrubs, trees, etc. should occur after installation. Min. 2" overlap Anchor in 6" x 6" min. trench and staple at 12" intervals Min. 6" overlap Staple overlaps max. 5" spacing Bring material down to a level area, turn the end under 4" and staple at 12" intervals BMP C123: Plastic Covering Purpose Plastic covering provides immediate, short-term erosion protection to slopes and disturbed areas. Conditions of Use Plastic covering may be used on disturbed areas that require cover measures for less than 30 days, except as stated below.  Plastic is particularly useful for protecting cut and fill slopes and stockpiles. Note: The relatively rapid breakdown of most polyethylene sheeting makes it unsuitable for long- term (greater than six months) applications.  Due to rapid runoff caused by plastic covering, do not use this method upslope of areas that might be adversely impacted by concentrated runoff. Such areas include steep and/or unstable slopes.  Plastic sheeting may result in increased runoff volumes and velocities, requiring additional on-site measures to counteract the increases. Creating a trough with wattles or other material can convey clean water away from these areas.  To prevent undercutting, trench and backfill rolled plastic covering products.  While plastic is inexpensive to purchase, the added cost of installation, maintenance, removal, and disposal make this an expensive material, up to $1.50-2.00 per square yard.  Whenever plastic is used to protect slopes install water collection measures at the base of the slope. These measures include plastic-covered berms, channels, and pipes used to covey clean rainwater away from bare soil and disturbed areas. Do not mix clean runoff from a plastic covered slope with dirty runoff from a project.  Other uses for plastic include: 1. Temporary ditch liner. 2. Pond liner in temporary sediment pond. 3. Liner for bermed temporary fuel storage area if plastic is not reactive to the type of fuel being stored. 4. Emergency slope protection during heavy rains. 5. Temporary drainpipe (“elephant trunk”) used to direct water. Design and Installation Specifications  Plastic slope cover must be installed as follows: 1. Run plastic up and down slope, not across slope. 2. Plastic may be installed perpendicular to a slope if the slope length is less than 10 feet. 3. Minimum of 8-inch overlap at seams. 4. On long or wide slopes, or slopes subject to wind, tape all seams. 5. Place plastic into a small (12-inch wide by 6-inch deep) slot trench at the top of the slope and backfill with soil to keep water from flowing underneath. 6. Place sand filled burlap or geotextile bags every 3 to 6 feet along seams and tie them together with twine to hold them in place. 7. Inspect plastic for rips, tears, and open seams regularly and repair immediately. This prevents high velocity runoff from contacting bare soil which causes extreme erosion. 8. Sandbags may be lowered into place tied to ropes. However, all sandbags must be staked in place.  Plastic sheeting shall have a minimum thickness of 0.06 millimeters.  If erosion at the toe of a slope is likely, a gravel berm, riprap, or other suitable protection shall be installed at the toe of the slope in order to reduce the velocity of runoff. Maintenance Standards  Torn sheets must be replaced and open seams repaired.  Completely remove and replace the plastic if it begins to deteriorate due to ultraviolet radiation.  Completely remove plastic when no longer needed.  Dispose of old tires used to weight down plastic sheeting appropriately. Approved as Equivalent Ecology has approved products as able to meet the requirements of BMP C123: Plastic Covering. The products did not pass through the Technology Assessment Protocol – Ecology (TAPE) process. Local jurisdictions may choose not to accept this product approved as equivalent, or may require additional testing prior to consideration for local use. The products are available for review on Ecology’s website at http://www.ecy.wa.gov/programs/wq/stormwater/newtech/equivalent.html BMP C130: Surface Roughening Purpose Surface roughening aids in the establishment of vegetative cover, reduces runoff velocity, increases infiltration, and provides for sediment trapping through the provision of a rough soil surface. Horizontal depressions are created by operating a tiller or other suitable equipment on the contour or by leaving slopes in a roughened condition by not fine grading them. Use this BMP in conjunction with other BMPs such as seeding, mulching, or sodding. Conditions for Use  All slopes steeper than 3H:1V and greater than 5 vertical feet require surface roughening to a depth of 2 to 4 inches prior to seeding..  Areas that will not be stabilized immediately may be roughened to reduce runoff velocity until seeding takes place.  Slopes with a stable rock face do not require roughening.  Slopes where mowing is planned should not be excessively roughened. Design and Installation Specifications There are different methods for achieving a roughened soil surface on a slope, and the selection of an appropriate method depends upon the type of slope. Roughening methods include stair- step grading, grooving, contour furrows, and tracking. See Figure II-4.1.5 Surface Roughening by Tracking and Contour Furrows for tracking and contour furrows. Factors to be considered in choosing a method are slope steepness, mowing requirements, and whether the slope is formed by cutting or filling.  Disturbed areas that will not require mowing may be stair-step graded, grooved, or left rough after filling.  Stair-step grading is particularly appropriate in soils containing large amounts of soft rock. Each "step" catches material that sloughs from above, and provides a level site where vegetation can become established. Stairs should be wide enough to work with standard earth moving equipment. Stair steps must be on contour or gullies will form on the slope.  Areas that will be mowed (these areas should have slopes less steep than 3H:1V) may have small furrows left by disking, harrowing, raking, or seed-planting machinery operated on the contour.  Graded areas with slopes steeper than 3H:1V but less than 2H:1V should be roughened before seeding. This can be accomplished in a variety of ways, including "track walking," or driving a crawler tractor up and down the slope, leaving a pattern of cleat imprints parallel to slope contours.  Tracking is done by operating equipment up and down the slope to leave horizontal depressions in the soil. Maintenance Standards  Areas that are graded in this manner should be seeded as quickly as possible.  Regular inspections should be made of the area. If rills appear, they should be re-graded and re-seeded immediately. DEPAR TM E N T OF ECOLOGY State of Washington Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, limitation of liability, and disclaimer. Figure II-4.1.5 Surface Roughening by Tracking and Contour Furrows Revised June 2015 NOT TO SCALE Tracking Tracking with machinery up and down the slope provides grooves that will catch seed, rainfall, and reduce runoff. Contour Furrows 50' (15m) 6" min (150mm) Grooves will catch seed, fertilizer, mulch, rainfall, and decrease runoff. 3 1 Maximum BMP C140: Dust Control Purpose Dust control prevents wind transport of dust from disturbed soil surfaces onto roadways, drainage ways, and surface waters. Conditions of Use  In areas (including roadways) subject to surface and air movement of dust where on-site and off-site impacts to roadways, drainage ways, or surface waters are likely. Design and Installation Specifications  Vegetate or mulch areas that will not receive vehicle traffic. In areas where planting, mulching, or paving is impractical, apply gravel or landscaping rock.  Limit dust generation by clearing only those areas where immediate activity will take place, leaving the remaining area(s) in the original condition. Maintain the original ground cover as long as practical.  Construct natural or artificial windbreaks or windscreens. These may be designed as enclosures for small dust sources.  Sprinkle the site with water until surface is wet. Repeat as needed. To prevent carryout of mud onto street, refer to BMP C105: Stabilized Construction Entrance / Exit.  Irrigation water can be used for dust control. Irrigation systems should be installed as a first step on sites where dust control is a concern.  Spray exposed soil areas with a dust palliative, following the manufacturer’s instructions and cautions regarding handling and application. Used oil is prohibited from use as a dust suppressant. Local governments may approve other dust palliatives such as calcium chloride or PAM.  PAM (BMP C126: Polyacrylamide (PAM) for Soil Erosion Protection) added to water at a rate of 0.5 lbs. per 1,000 gallons of water per acre and applied from a water truck is more effective than water alone. This is due to increased infiltration of water into the soil and reduced evaporation. In addition, small soil particles are bonded together and are not as easily transported by wind. Adding PAM may actually reduce the quantity of water needed for dust control. Use of PAM could be a cost-effective dust control method. Techniques that can be used for unpaved roads and lots include:  Lower speed limits. High vehicle speed increases the amount of dust stirred up from unpaved roads and lots.  Upgrade the road surface strength by improving particle size, shape, and mineral types that make up the surface and base materials.  Add surface gravel to reduce the source of dust emission. Limit the amount of fine particles (those smaller than .075 mm) to 10 to 20 percent.  Use geotextile fabrics to increase the strength of new roads or roads undergoing reconstruction.  Encourage the use of alternate, paved routes, if available.  Restrict use of paved roadways by tracked vehicles and heavy trucks to prevent damage to road surface and base.  Apply chemical dust suppressants using the admix method, blending the product with the top few inches of surface material. Suppressants may also be applied as surface treatments.  Pave unpaved permanent roads and other trafficked areas.  Use vacuum street sweepers.  Remove mud and other dirt promptly so it does not dry and then turn into dust.  Limit dust-causing work on windy days.  Contact your local Air Pollution Control Authority for guidance and training on other dust control measures. Compliance with the local Air Pollution Control Authority constitutes compliance with this BMP. Maintenance Standards Respray area as necessary to keep dust to a minimum. BMP C150: Materials on Hand Purpose Keep quantities of erosion prevention and sediment control materials on the project site at all times to be used for regular maintenance and emergency situations such as unexpected heavy summer rains. Having these materials on-site reduces the time needed to implement BMPs when inspections indicate that existing BMPs are not meeting the Construction SWPPP requirements. In addition, contractors can save money by buying some materials in bulk and storing them at their office or yard. Conditions of Use  Construction projects of any size or type can benefit from having materials on hand. A small commercial development project could have a roll of plastic and some gravel available for immediate protection of bare soil and temporary berm construction. A large earthwork project, such as highway construction, might have several tons of straw, several rolls of plastic, flexible pipe, sandbags, geotextile fabric and steel “T” posts.  Materials are stockpiled and readily available before any site clearing, grubbing, or earthwork begins. A large contractor or developer could keep a stockpile of materials that are available for use on several projects.  If storage space at the project site is at a premium, the contractor could maintain the materials at their office or yard. The office or yard must be less than an hour from the project site. Design and Installation Specifications Depending on project type, size, complexity, and length, materials and quantities will vary. A good minimum list of items that will cover numerous situations includes: Material Clear Plastic, 6 mil Drainpipe, 6 or 8 inch diameter Sandbags, filled Straw Bales for mulching, Quarry Spalls Washed Gravel Geotextile Fabric Catch Basin Inserts Steel "T" Posts Silt fence material Straw Wattles Maintenance Standards  All materials with the exception of the quarry spalls, steel “T” posts, and gravel should be kept covered and out of both sun and rain.  Re-stock materials used as needed. BMP C151: Concrete Handling Purpose Concrete work can generate process water and slurry that contain fine particles and high pH, both of which can violate water quality standards in the receiving water. Concrete spillage or concrete discharge to surface waters of the State is prohibited. Use this BMP to minimize and eliminate concrete, concrete process water, and concrete slurry from entering waters of the state. Conditions of Use Any time concrete is used, utilize these management practices. Concrete construction projects include, but are not limited to, the following:  Curbs  Sidewalks  Roads  Bridges  Foundations  Floors  Runways Design and Installation Specifications  Assure that washout of concrete trucks, chutes, pumps, and internals is performed at an approved off-site location or in designated concrete washout areas. Do not wash out concrete trucks onto the ground, or into storm drains, open ditches, streets, or streams. Refer to BMP C154: Concrete Washout Area for information on concrete washout areas.  Return unused concrete remaining in the truck and pump to the originating batch plant for recycling. Do not dump excess concrete on site, except in designated concrete washout areas.  Wash off hand tools including, but not limited to, screeds, shovels, rakes, floats, and trowels into formed areas only.  Wash equipment difficult to move, such as concrete pavers in areas that do not directly drain to natural or constructed stormwater conveyances.  Do not allow washdown from areas, such as concrete aggregate driveways, to drain directly to natural or constructed stormwater conveyances.  Contain washwater and leftover product in a lined container when no formed areas are available. Dispose of contained concrete in a manner that does not violate ground water or surface water quality standards.  Always use forms or solid barriers for concrete pours, such as pilings, within 15-feet of surface waters.  Refer to BMP C252: High pH Neutralization Using CO2 and BMP C253: pH Control for High pH Water for pH adjustment requirements.  Refer to the Construction Stormwater General Permit for pH monitoring requirements if the project involves one of the following activities: o Significant concrete work (greater than 1,000 cubic yards poured concrete or recycled concrete used over the life of a project). o The use of engineered soils amended with (but not limited to) Portland cement- treated base, cement kiln dust or fly ash. o Discharging stormwater to segments of water bodies on the 303(d) list (Category 5) for high pH. Maintenance Standards Check containers for holes in the liner daily during concrete pours and repair the same day. BMP C152: Sawcutting and Surfacing Pollution Prevention Purpose Sawcutting and surfacing operations generate slurry and process water that contains fine particles and high pH (concrete cutting), both of which can violate the water quality standards in the receiving water. Concrete spillage or concrete discharge to surface waters of the State is prohibited. Use this BMP to minimize and eliminate process water and slurry created through sawcutting or surfacing from entering waters of the State. Conditions of Use Utilize these management practices anytime sawcutting or surfacing operations take place. Sawcutting and surfacing operations include, but are not limited to, the following:  Sawing  Coring  Grinding  Roughening  Hydro-demolition  Bridge and road surfacing Design and Installation Specifications  Vacuum slurry and cuttings during cutting and surfacing operations.  Slurry and cuttings shall not remain on permanent concrete or asphalt pavement overnight.  Slurry and cuttings shall not drain to any natural or constructed drainage conveyance including stormwater systems. This may require temporarily blocking catch basins.  Dispose of collected slurry and cuttings in a manner that does not violate ground water or surface water quality standards.  Do not allow process water generated during hydro-demolition, surface roughening or similar operations to drain to any natural or constructed drainage conveyance including stormwater systems. Dispose process water in a manner that does not violate ground water or surface water quality standards.  Handle and dispose cleaning waste material and demolition debris in a manner that does not cause contamination of water. Dispose of sweeping material from a pick-up sweeper at an appropriate disposal site. Maintenance Standards Continually monitor operations to determine whether slurry, cuttings, or process water could enter waters of the state. If inspections show that a violation of water quality standards could occur, stop operations and immediately implement preventive measures such as berms, barriers, secondary containment, and vacuum trucks. BMP C200: Interceptor Dike and Swale Purpose Provide a ridge of compacted soil, or a ridge with an upslope swale, at the top or base of a disturbed slope or along the perimeter of a disturbed construction area to convey stormwater. Use the dike and/or swale to intercept the runoff from unprotected areas and direct it to areas where erosion can be controlled. This can prevent storm runoff from entering the work area or sediment-laden runoff from leaving the construction site. Conditions of Use Where the runoff from an exposed site or disturbed slope must be conveyed to an erosion control facility which can safely convey the stormwater.  Locate upslope of a construction site to prevent runoff from entering disturbed area.  When placed horizontally across a disturbed slope, it reduces the amount and velocity of runoff flowing down the slope.  Locate downslope to collect runoff from a disturbed area and direct water to a sediment basin. Design and Installation Specifications  Dike and/or swale and channel must be stabilized with temporary or permanent vegetation or other channel protection during construction.  Channel requires a positive grade for drainage; steeper grades require channel protection and check dams.  Review construction for areas where overtopping may occur.  Can be used at top of new fill before vegetation is established.  May be used as a permanent diversion channel to carry the runoff.  Sub-basin tributary area should be one acre or less.  Design capacity for the peak volumetric flow rate calculated using a 10-minute time step from a 10-year, 24-hour storm, assuming a Type 1A rainfall distribution, for temporary facilities. Alternatively, use 1.6 times the 10-year, 1-hour flow indicated by an approved continuous runoff model. For facilities that will also serve on a permanent basis, consult the local government’s drainage requirements. Interceptor dikes shall meet the following criteria:  Top Width: 2 feet minimum.  Height: 1.5 feet minimum on berm.  Side Slope: 2H:1V or flatter.  Grade: Depends on topography, however, dike system minimum is 0.5%, and maximum is 1%.  Compaction: Minimum of 90 percent ASTM D698 standard proctor.  Horizontal Spacing of Interceptor Dikes: Average Slope Slope Percent Flowpath Length 20H:1V or less 3-5% 300 feet (10 to 20)H:1V 5-10% 200 feet (4 to 10)H:1V 10-25% 100 feet (2 to 4)H:1V 25-50% 50 feet  Stabilization: depends on velocity and reach  Slopes <5%: Seed and mulch applied within 5 days of dike construction (see BMP C121: Mulching).  Slopes 5 - 40%: Dependent on runoff velocities and dike materials. Stabilization should be done immediately using either sod or riprap or other measures to avoid erosion.  The upslope side of the dike shall provide positive drainage to the dike outlet. No erosion shall occur at the outlet. Provide energy dissipation measures as necessary. Sediment- laden runoff must be released through a sediment trapping facility.  Minimize construction traffic over temporary dikes. Use temporary cross culverts for channel crossing. Interceptor swales shall meet the following criteria:  Bottom Width: 2 feet minimum; the cross-section bottom shall be level.  Depth: 1-foot minimum.  Side Slope: 2H:1V or flatter.  Grade: Maximum 5 percent, with positive drainage to a suitable outlet (such as a sediment pond).  Stabilization: Seed as per BMP C120: Temporary and Permanent Seeding, or BMP C202: Channel Lining, 12 inches thick riprap pressed into the bank and extending at least 8 inches vertical from the bottom. Inspect diversion dikes and interceptor swales once a week and after every rainfall. Immediately remove sediment from the flow area. Damage caused by construction traffic or other activity must be repaired before the end of each working day. Check outlets and make timely repairs as needed to avoid gully formation. When the area below the temporary diversion dike is permanently stabilized, remove the dike and fill and stabilize the channel to blend with the natural surface. BMP C206: Level Spreader Purpose To provide a temporary outlet for dikes and diversions consisting of an excavated depression constructed at zero grade across a slope. To convert concentrated runoff to sheet flow and release it onto areas stabilized by existing vegetation or an engineered filter strip. Conditions of Use Used when a concentrated flow of water needs to be dispersed over a large area with existing stable vegetation.  Items to consider are: 1. What is the risk of erosion or damage if the flow may become concentrated? 2. Is an easement required if discharged to adjoining property? 3. Most of the flow should be as ground water and not as surface flow. 4. Is there an unstable area downstream that cannot accept additional ground water?  Use only where the slopes are gentle, the water volume is relatively low, and the soil will adsorb most of the low flow events. Design and Installation Specifications Use above undisturbed areas that are stabilized by existing vegetation. If the level spreader has any low points, flow will concentrate, create channels and may cause erosion.  Discharge area below the outlet must be uniform with a slope flatter than 5H:1V.  Outlet to be constructed level in a stable, undisturbed soil profile (not on fill).  The runoff shall not re-concentrate after release unless intercepted by another downstream measure.  The grade of the channel for the last 20 feet of the dike or interceptor entering the level spreader shall be less than or equal to 1 percent. The grade of the level spreader shall be 0 percent to ensure uniform spreading of storm runoff.  A 6-inch high gravel berm placed across the level lip shall consist of washed crushed rock, 2- to 4-inch or 3/4-inch to 1½-inch size.  The spreader length shall be determined by estimating the peak flow expected from the 10-year, 24-hour design storm. The length of the spreader shall be a minimum of 15 feet for 0.1 cfs and shall increase by 10 feet for each 0.1 cfs thereafter to a maximum of 0.5 cfs per spreader. Use multiple spreaders for higher flows.  The width of the spreader should be at least 6 feet.  The depth of the spreader as measured from the lip should be at least 6 inches and it should be uniform across the entire length.  Level spreaders shall be setback from the property line unless there is an easement for flow.  Level spreaders, when installed every so often in grassy swales, keep the flows from concentrating. Materials that can be used include sand bags, lumber, logs, concrete, and pipe. To function properly, the material needs to be installed level and on contour. BMP C206: Level Spreader and Figure II-4.2.6 Detail of Level Spreader provide a cross- section and a detail of a level spreader. A capped perforated pipe could also be used as a spreader. Maintenance Standards The spreader should be inspected after every runoff event to ensure that it is functioning correctly.  The contractor should avoid the placement of any material on the structure and should prevent construction traffic from crossing over the structure.  If the spreader is damaged by construction traffic, it shall be immediately repaired. DEPAR TM E N T OF ECOLOGY State of Washington Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, limitation of liability, and disclaimer. Figure II-4.2.5 Cross Section of Level Spreader Revised July 2015 NOT TO SCALE Densely vegetated for a min. of 100' and slope less than 5:1 Pressure-treated 2"x10" 2:1 Max. 1' Min. 3' Min. DEPAR TM E N T OF ECOLOGY State of Washington Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, limitation of liability, and disclaimer. Figure II-4.2.6 Detail of Level Spreader Revised July 2015 NOT TO SCALE Spreader must be level 6" min. 6" min. Treated 2" x 10" may be abutted end to end for max. spreader length of 50' 1" min. 18" min. rebar supports 8' max. spacing BMP C207: Check Dams Purpose Construction of small dams across a swale or ditch reduces the velocity of concentrated flow and dissipates energy at the check dam. Conditions of Use Where temporary channels or permanent channels are not yet vegetated, channel lining is infeasible, and/or velocity checks are required.  Check dams may not be placed in streams unless approved by the State Department of Fish and Wildlife. Check dams may not be placed in wetlands without approval from a permitting agency.  Do not place check dams below the expected backwater from any salmonid bearing water between October 1 and May 31 to ensure that there is no loss of high flow refuge habitat for overwintering juvenile salmonids and emergent salmonid fry.  Construct rock check dams from appropriately sized rock. The rock used must be large enough to stay in place given the expected design flow through the channel. The rock must be placed by hand or by mechanical means (no dumping of rock to form dam) to achieve complete coverage of the ditch or swale and to ensure that the center of the dam is lower than the edges.  Check dams may also be constructed of either rock or pea-gravel filled bags. Numerous new products are also available for this purpose. They tend to be re-usable, quick and easy to install, effective, and cost efficient.  Place check dams perpendicular to the flow of water.  The dam should form a triangle when viewed from the side. This prevents undercutting as water flows over the face of the dam rather than falling directly onto the ditch bottom.  Before installing check dams impound and bypass upstream water flow away from the work area. Options for bypassing include pumps, siphons, or temporary channels.  Check dams in association with sumps work more effectively at slowing flow and retaining sediment than just a check dam alone. A deep sump should be provided immediately upstream of the check dam.  In some cases, if carefully located and designed, check dams can remain as permanent installations with very minor regrading. They may be left as either spillways, in which case accumulated sediment would be graded and seeded, or as check dams to prevent further sediment from leaving the site.  The maximum spacing between the dams shall be such that the toe of the upstream dam is at the same elevation as the top of the downstream dam.  Keep the maximum height at 2 feet at the center of the dam.  Keep the center of the check dam at least 12 inches lower than the outer edges at natural ground elevation.  Keep the side slopes of the check dam at 2H:1V or flatter.  Key the stone into the ditch banks and extend it beyond the abutments a minimum of 18 inches to avoid washouts from overflow around the dam.  Use filter fabric foundation under a rock or sand bag check dam. If a blanket ditch liner is used, filter fabric is not necessary. A piece of organic or synthetic blanket cut to fit will also work for this purpose.  In the case of grass-lined ditches and swales, all check dams and accumulated sediment shall be removed when the grass has matured sufficiently to protect the ditch or swale - unless the slope of the swale is greater than 4 percent. The area beneath the check dams shall be seeded and mulched immediately after dam removal.  Ensure that channel appurtenances, such as culvert entrances below check dams, are not subject to damage or blockage from displaced stones. Figure II-4.2.7 Rock Check Dam depicts a typical rock check dam. Maintenance Standards Check dams shall be monitored for performance and sediment accumulation during and after each runoff producing rainfall. Sediment shall be removed when it reaches one half the sump depth.  Anticipate submergence and deposition above the check dam and erosion from high flows around the edges of the dam.  If significant erosion occurs between dams, install a protective riprap liner in that portion of the channel. Approved as Equivalent Ecology has approved products as able to meet the requirements of BMP C207: Check Dams. The products did not pass through the Technology Assessment Protocol – Ecology (TAPE) process. Local jurisdictions may choose not to accept this product approved as equivalent, or may require additional testing prior to consideration for local use. The products are available for review on Ecology’s website at http://www.ecy.wa.gov/programs/wq/stormwater/newtech/equivalent.html DEPAR TM E N T OF ECOLOGY State of Washington Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, limitation of liability, and disclaimer. Figure II-4.2.7 Rock Check Dam Revised July 2015 NOT TO SCALE View Looking Upstream Section A-A Spacing Between Check Dams Note: Key stone into channel banks and extend it beyond the abutments a minimum of 18" (0.5m) to prevent flow around dam. A A 12" (150mm) 18" (0.5m) 24" (0.6m) Flow 24" (0.6m) 8' (2.4m) Point 'A'Point 'B' 'L' 'L' = the distance such that points 'A' and 'B' are of equal elevation. BMP C209: Outlet Protection Purpose Outlet protection prevents scour at conveyance outlets and minimizes the potential for downstream erosion by reducing the velocity of concentrated stormwater flows. Conditions of Use Outlet protection is required at the outlets of all ponds, pipes, ditches, or other conveyances, and where runoff is conveyed to a natural or manmade drainage feature such as a stream, wetland, lake, or ditch. Design and Installation Specifications The receiving channel at the outlet of a culvert shall be protected from erosion by rock lining a minimum of 6 feet downstream and extending up the channel sides a minimum of 1–foot above the maximum tailwater elevation or 1-foot above the crown, whichever is higher. For large pipes (more than 18 inches in diameter), the outlet protection lining of the channel is lengthened to four times the diameter of the culvert.  Standard wingwalls, and tapered outlets and paved channels should also be considered when appropriate for permanent culvert outlet protection. (See WSDOT Hydraulic Manual, available through WSDOT Engineering Publications).  Organic or synthetic erosion blankets, with or without vegetation, are usually more effective than rock, cheaper, and easier to install. Materials can be chosen using manufacturer product specifications. ASTM test results are available for most products and the designer can choose the correct material for the expected flow.  With low flows, vegetation (including sod) can be effective.  The following guidelines shall be used for riprap outlet protection: 1. If the discharge velocity at the outlet is less than 5 fps (pipe slope less than 1 percent), use 2-inch to 8-inch riprap. Minimum thickness is 1-foot. 2. For 5 to 10 fps discharge velocity at the outlet (pipe slope less than 3 percent), use 24-inch to 48-inch riprap. Minimum thickness is 2 feet. 3. For outlets at the base of steep slope pipes (pipe slope greater than 10 percent), an engineered energy dissipater shall be used.  Filter fabric or erosion control blankets should always be used under riprap to prevent scour and channel erosion.  New pipe outfalls can provide an opportunity for low-cost fish habitat improvements. For example, an alcove of low-velocity water can be created by constructing the pipe outfall and associated energy dissipater back from the stream edge and digging a channel, over-widened to the upstream side, from the outfall. Overwintering juvenile and migrating adult salmonids may use the alcove as shelter during high flows. Bank stabilization, bioengineering, and habitat features may be required for disturbed areas. This work may require a HPA. See Volume V for more information on outfall system design. Maintenance Standards  Inspect and repair as needed.  Add rock as needed to maintain the intended function.  Clean energy dissipater if sediment builds up. BMP C220: Storm Drain Inlet Protection Purpose Storm drain inlet protection prevents coarse sediment from entering drainage systems prior to permanent stabilization of the disturbed area. Conditions of Use Use storm drain inlet protection at inlets that are operational before permanent stabilization of the disturbed drainage area. Provide protection for all storm drain inlets downslope and within 500 feet of a disturbed or construction area, unless conveying runoff entering catch basins to a sediment pond or trap. Also consider inlet protection for lawn and yard drains on new home construction. These small and numerous drains coupled with lack of gutters in new home construction can add significant amounts of sediment into the roof drain system. If possible delay installing lawn and yard drains until just before landscaping or cap these drains to prevent sediment from entering the system until completion of landscaping. Provide 18-inches of sod around each finished lawn and yard drain. Table II-4.2.2 Storm Drain Inlet Protection lists several options for inlet protection. All of the methods for storm drain inlet protection tend to plug and require a high frequency of maintenance. Limit drainage areas to one acre or less. Possibly provide emergency overflows with additional end-of-pipe treatment where stormwater ponding would cause a hazard. Table II-4.2.2 Storm Drain Inlet Protection Type of Inlet Protection Emergency Overflow Applicable for Paved/ Earthen Surfaces Conditions of Use Drop Inlet Protection Excavated drop inlet protection Yes, temporary flooding will occur Earthen Applicable for heavy flows. Easy to maintain. Large area Requirement: 30'x30'/acre Block and gravel drop inlet protection Yes Paved or Earthen Applicable for heavy concentrated flows. Will not pond. Gravel and wire drop inlet protection No Applicable for heavy concentrated flows. Will pond. Can withstand traffic. Catch basin filters Yes Paved or Earthen Frequent Maintenance required. Curb Inlet Protection Curb inlet protection with wooden weir Small capacity overflow Paved Used for sturdy, more compact installation. Block and gravel curb inlet protection Yes Paved Sturdy, but limited filtration. Culvert Inlet Protection Culvert inlet Sediment trap 18 month expected life. Design and Installation Specifications Excavated Drop Inlet Protection - An excavated impoundment around the storm drain. Sediment settles out of the stormwater prior to entering the storm drain.  Provide a depth of 1-2 ft as measured from the crest of the inlet structure.  Slope sides of excavation no steeper than 2H:1V.  Minimum volume of excavation 35 cubic yards.  Shape basin to fit site with longest dimension oriented toward the longest inflow area.  Install provisions for draining to prevent standing water problems.  Clear the area of all debris.  Grade the approach to the inlet uniformly.  Drill weep holes into the side of the inlet.  Protect weep holes with screen wire and washed aggregate.  Seal weep holes when removing structure and stabilizing area.  Build a temporary dike, if necessary, to the down slope side of the structure to prevent bypass flow. Block and Gravel Filter - A barrier formed around the storm drain inlet with standard concrete blocks and gravel. See Figure II-4.2.8 Block and Gravel Filter.  Provide a height of 1 to 2 feet above inlet.  Recess the first row 2-inches into the ground for stability.  Support subsequent courses by placing a 2x4 through the block opening.  Do not use mortar.  Lay some blocks in the bottom row on their side for dewatering the pool.  Place hardware cloth or comparable wire mesh with ½-inch openings over all block openings.  Place gravel just below the top of blocks on slopes of 2H:1V or flatter.  An alternative design is a gravel donut.  Provide an inlet slope of 3H:1V.  Provide an outlet slope of 2H:1V.  Provide a1-foot wide level stone area between the structure and the inlet.  Use inlet slope stones 3 inches in diameter or larger.  Use gravel ½- to ¾-inch at a minimum thickness of 1-foot for the outlet slope. DEPAR TM E N T OF ECOLOGY State of Washington Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, limitation of liability, and disclaimer. Figure II-4.2.8 Block and Gravel Filter Revised August 2015 NOT TO SCALE Plan View A A Section A-A Drain grate Concrete block Gravel backfill Less than5% slope Gravel backfill Concrete block Water Overflow water Drop inlet Ponding height Wire screen or filter fabric Notes: 1.Drop inlet sediment barriers are to be used for small, nearly level drainage areas. (less than 5%) 2.Excavate a basin of sufficient size adjacent to the drop inlet. 3.The top of the structure (ponding height) must be well below the ground elevation downslope to prevent runoff from bypassing the inlet. A temporary dike may be necessary on the downslope side of the structure. Gravel and Wire Mesh Filter - A gravel barrier placed over the top of the inlet. This structure does not provide an overflow.  Use a hardware cloth or comparable wire mesh with ½-inch openings.  Use coarse aggregate.  Provide a height 1-foot or more, 18-inches wider than inlet on all sides.  Place wire mesh over the drop inlet so that the wire extends a minimum of 1-foot beyond each side of the inlet structure.  Overlap the strips if more than one strip of mesh is necessary.  Place coarse aggregate over the wire mesh.  Provide at least a 12-inch depth of gravel over the entire inlet opening and extend at least 18-inches on all sides. Catchbasin Filters – Use inserts designed by manufacturers for construction sites. The limited sediment storage capacity increases the amount of inspection and maintenance required, which may be daily for heavy sediment loads. To reduce maintenance requirements combine a catchbasin filter with another type of inlet protection. This type of inlet protection provides flow bypass without overflow and therefore may be a better method for inlets located along active rights-of-way.  Provides 5 cubic feet of storage.  Requires dewatering provisions.  Provides a high-flow bypass that will not clog under normal use at a construction site.  Insert the catchbasin filter in the catchbasin just below the grating. Curb Inlet Protection with Wooden Weir – Barrier formed around a curb inlet with a wooden frame and gravel.  Use wire mesh with ½-inch openings.  Use extra strength filter cloth.  Construct a frame.  Attach the wire and filter fabric to the frame.  Pile coarse washed aggregate against wire/fabric.  Place weight on frame anchors. Block and Gravel Curb Inlet Protection – Barrier formed around a curb inlet with concrete blocks and gravel. See Figure II-4.2.9 Block and Gravel Curb Inlet Protection.  Use wire mesh with ½-inch openings.  Place two concrete blocks on their sides abutting the curb at either side of the inlet opening. These are spacer blocks.  Place a 2x4 stud through the outer holes of each spacer block to align the front blocks.  Place blocks on their sides across the front of the inlet and abutting the spacer blocks.  Place wire mesh over the outside vertical face.  Pile coarse aggregate against the wire to the top of the barrier. Curb and Gutter Sediment Barrier – Sandbag or rock berm (riprap and aggregate) 3 feet high and 3 feet wide in a horseshoe shape. See Figure II-4.2.10 Curb and Gutter Barrier.  Construct a horseshoe shaped berm, faced with coarse aggregate if using riprap, 3 feet high and 3 feet wide, at least 2 feet from the inlet.  Construct a horseshoe shaped sedimentation trap on the outside of the berm sized to sediment trap standards for protecting a culvert inlet. Maintenance Standards  Inspect catch basin filters frequently, especially after storm events. Clean and replace clogged inserts. For systems with clogged stone filters: pull away the stones from the inlet and clean or replace. An alternative approach would be to use the clogged stone as fill and put fresh stone around the inlet.  Do not wash sediment into storm drains while cleaning. Spread all excavated material evenly over the surrounding land area or stockpile and stabilize as appropriate. Approved as Equivalent Ecology has approved products as able to meet the requirements of BMP C220: Storm Drain Inlet Protection. The products did not pass through the Technology Assessment Protocol – Ecology (TAPE) process. Local jurisdictions may choose not to accept this product approved as equivalent, or may require additional testing prior to consideration for local use. The products are available for review on Ecology’s website at http://www.ecy.wa.gov/programs/wq/stormwater/newtech/equivalent.html DEPAR TM E N T OF ECOLOGY State of Washington Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, limitation of liability, and disclaimer. Figure II-4.2.9 Block and Gravel Curb Inlet Protection Revised August 2015 NOT TO SCALE Plan View A A Section A-A Notes: 1.Use block and gravel type sediment barrier when curb inlet is located in gently sloping street segment, where water can pond and allow sediment to separate from runoff. 2.Barrier shall allow for overflow from severe storm event. 3.Inspect barriers and remove sediment after each storm event. Sediment and gravel must be removed from the traveled way immediately. Back of sidewalk Catch basin Back of curb Curb inlet Concrete block 2x4 Wood stud Concrete block34 inch (20 mm) Drain gravel Wire screen or filter fabric 34 inch (20 mm) Drain gravel Wire screen or filter fabric Ponding height Overflow 2x4 Wood stud (100x50 Timber stud) Concrete block Curb inlet Catch basin DEPAR TM E N T OF ECOLOGY State of Washington Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, limitation of liability, and disclaimer. Figure II-4.2.10 Curb and Gutter Barrier Revised September 2015 NOT TO SCALE Plan View Back of sidewalk Runoff Runoff Spillway Burlap sacks to overlap onto curb Gravel filled sandbags stacked tightly Curb inlet Catch basin Back of curb Notes: 1.Place curb type sediment barriers on gently sloping street segments, where water can pond and allow sediment to separate from runoff. 2.Sandbags of either burlap or woven 'geotextile' fabric, are filled with gravel, layered and packed tightly. 3.Leave a one sandbag gap in the top row to provide a spillway for overflow. 4.Inspect barriers and remove sediment after each storm event. Sediment and gravel must be removed from the traveled way immediately. BMP C233: Silt Fence Purpose Use of a silt fence reduces the transport of coarse sediment from a construction site by providing a temporary physical barrier to sediment and reducing the runoff velocities of overland flow. See Figure II-4.2.12 Silt Fence for details on silt fence construction. Conditions of Use Silt fence may be used downslope of all disturbed areas.  Silt fence shall prevent soil carried by runoff water from going beneath, through, or over the top of the silt fence, but shall allow the water to pass through the fence.  Silt fence is not intended to treat concentrated flows, nor is it intended to treat substantial amounts of overland flow. Convey any concentrated flows through the drainage system to a sediment pond.  Do not construct silt fences in streams or use in V-shaped ditches. Silt fences do not provide an adequate method of silt control for anything deeper than sheet or overland flow. DEPAR TM E N T OF ECOLOGY State of Washington Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, limitation of liability, and disclaimer. Figure II-4.2.12 Silt Fence Revised October 2014 NOT TO SCALE Joints in filter fabric shall be spliced at posts. Use staples, wire rings or equivalent to attach fabric to posts 6' max Post spacing may be increased to 8' if wire backing is used 2"x2" by 14 Ga. wire or equivalent, if standard strength fabric used Minimum 4"x4" trench 2"x2" wood posts, steel fence posts, or equivalent 12" min 2' min 2"x2" by 14 Ga. wire or equivalent, if standard strength fabric used Filter fabric Minimum 4"x4" trench 2"x2" wood posts, steel fence posts, or equivalent Backfill trench with native soil or 34" - 1.5" washed gravel Design and Installation Specifications  Use in combination with sediment basins or other BMPs.  Maximum slope steepness (normal (perpendicular) to fence line) 1H:1V.  Maximum sheet or overland flow path length to the fence of 100 feet.  Do not allow flows greater than 0.5 cfs.  The geotextile used shall meet the following standards. All geotextile properties listed below are minimum average roll values (i.e., the test result for any sampled roll in a lot shall meet or exceed the values shown in Table II-4.2.3 Geotextile Standards): Table II-4.2.3 Geotextile Standards Polymeric Mesh AOS (ASTM D4751) 0.60 mm maximum for slit film woven (#30 sieve). 0.30 mm maximum for all other geotextile types (#50 sieve). 0.15 mm minimum for all fabric types (#100 sieve). Water Permittivity (ASTM D4491) 0.02 sec-1 minimum Grab Tensile Strength (ASTM D4632) 180 lbs. Minimum for extra strength fabric. 100 lbs minimum for standard strength fabric. Grab Tensile Strength (ASTM D4632) 30% maximum Ultraviolet Resistance (ASTM D4355) 70% minimum  Support standard strength fabrics with wire mesh, chicken wire, 2-inch x 2-inch wire, safety fence, or jute mesh to increase the strength of the fabric. Silt fence materials are available that have synthetic mesh backing attached.  Filter fabric material shall contain ultraviolet ray inhibitors and stabilizers to provide a minimum of six months of expected usable construction life at a temperature range of 0°F. to 120°F.  One-hundred percent biodegradable silt fence is available that is strong, long lasting, and can be left in place after the project is completed, if permitted by local regulations.  Refer to Figure II-4.2.12 Silt Fence for standard silt fence details. Include the following standard Notes for silt fence on construction plans and specifications: 1. The contractor shall install and maintain temporary silt fences at the locations shown in the Plans. 2. Construct silt fences in areas of clearing, grading, or drainage prior to starting those activities. 3. The silt fence shall have a 2-feet min. and a 2½-feet max. height above the original ground surface. 4. The filter fabric shall be sewn together at the point of manufacture to form filter fabric lengths as required. Locate all sewn seams at support posts. Alternatively, two sections of silt fence can be overlapped, provided the Contractor can demonstrate, to the satisfaction of the Engineer, that the overlap is long enough and that the adjacent fence sections are close enough together to prevent silt laden water from escaping through the fence at the overlap. 5. Attach the filter fabric on the up-slope side of the posts and secure with staples, wire, or in accordance with the manufacturer's recommendations. Attach the filter fabric to the posts in a manner that reduces the potential for tearing. 6. Support the filter fabric with wire or plastic mesh, dependent on the properties of the geotextile selected for use. If wire or plastic mesh is used, fasten the mesh securely to the up-slope side of the posts with the filter fabric up-slope of the mesh. 7. Mesh support, if used, shall consist of steel wire with a maximum mesh spacing of 2-inches, or a prefabricated polymeric mesh. The strength of the wire or polymeric mesh shall be equivalent to or greater than 180 lbs. grab tensile strength. The polymeric mesh must be as resistant to the same level of ultraviolet radiation as the filter fabric it supports. 8. Bury the bottom of the filter fabric 4-inches min. below the ground surface. Backfill and tamp soil in place over the buried portion of the filter fabric, so that no flow can pass beneath the fence and scouring cannot occur. When wire or polymeric back- up support mesh is used, the wire or polymeric mesh shall extend into the ground 3-inches min. 9. Drive or place the fence posts into the ground 18-inches min. A 12–inch min. depth is allowed if topsoil or other soft subgrade soil is not present and 18-inches cannot be reached. Increase fence post min. depths by 6 inches if the fence is located on slopes of 3H:1V or steeper and the slope is perpendicular to the fence. If required post depths cannot be obtained, the posts shall be adequately secured by bracing or guying to prevent overturning of the fence due to sediment loading. 10. Use wood, steel or equivalent posts. The spacing of the support posts shall be a maximum of 6-feet. Posts shall consist of either:  Wood with dimensions of 2-inches by 2-inches wide min. and a 3-feet min. length. Wood posts shall be free of defects such as knots, splits, or gouges.  No. 6 steel rebar or larger.  ASTM A 120 steel pipe with a minimum diameter of 1-inch.  U, T, L, or C shape steel posts with a minimum weight of 1.35 lbs./ft.  Other steel posts having equivalent strength and bending resistance to the post sizes listed above. 11. Locate silt fences on contour as much as possible, except at the ends of the fence, where the fence shall be turned uphill such that the silt fence captures the runoff water and prevents water from flowing around the end of the fence. 12. If the fence must cross contours, with the exception of the ends of the fence, place gravel check dams perpendicular to the back of the fence to minimize concentrated flow and erosion. The slope of the fence line where contours must be crossed shall not be steeper than 3H:1V.  Gravel check dams shall be approximately 1-foot deep at the back of the fence. Gravel check dams shall be continued perpendicular to the fence at the same elevation until the top of the check dam intercepts the ground surface behind the fence.  Gravel check dams shall consist of crushed surfacing base course, gravel backfill for walls, or shoulder ballast. Gravel check dams shall be located every 10 feet along the fence where the fence must cross contours.  Refer to Figure II-4.2.13 Silt Fence Installation by Slicing Method for slicing method details. Silt fence installation using the slicing method specifications: 1. The base of both end posts must be at least 2- to 4-inches above the top of the filter fabric on the middle posts for ditch checks to drain properly. Use a hand level or string level, if necessary, to mark base points before installation. 2. Install posts 3- to 4-feet apart in critical retention areas and 6- to 7-feet apart in standard applications. 3. Install posts 24-inches deep on the downstream side of the silt fence, and as close as possible to the filter fabric, enabling posts to support the filter fabric from upstream water pressure. 4. Install posts with the nipples facing away from the filter fabric. 5. Attach the filter fabric to each post with three ties, all spaced within the top 8- inches of the filter fabric. Attach each tie diagonally 45 degrees through the filter fabric, with each puncture at least 1-inch vertically apart. Each tie should be positioned to hang on a post nipple when tightening to prevent sagging. 6. Wrap approximately 6-inches of fabric around the end posts and secure with 3 ties. 7. No more than 24-inches of a 36-inch filter fabric is allowed above ground level. Compact the soil immediately next to the filter fabric with the front wheel of the tractor, skid steer, or roller exerting at least 60 pounds per square inch. Compact the upstream side first and then each side twice for a total of four trips. Check and correct the silt fence installation for any deviation before compaction. Use a flat- bladed shovel to tuck fabric deeper into the ground if necessary. DEPAR TM E N T OF ECOLOGY State of Washington Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, limitation of liability, and disclaimer. Figure II-4.2.13 Silt Fence Installation by Slicing Method Revised November 2015 NOT TO SCALE Completed Installation Silt Fence Post installed after compaction Vibratory plow is not acceptable because of horizontal compaction Slicing blade (18 mm width) Horizontal chisel point (76 mm width) Fabric above ground 200 - 300mm Roll of silt fenceOperation No more than 24" of a 36" fabric is allowed above groundSteel support post100% compaction 100% compaction FLOW Drive over each side of silt fence 2 to 4 times with device exerting 60 p.s.i. or greater Attach fabric to upstream side of post Ponding height max. 24" POST SPACING: 7' max. on open runs 4' max. on pooling areas POST DEPTH: As much below ground as fabric above ground Top of Fabric Belt top 8" Diagonal attachment doubles strength Attachment Details: x Gather fabric at posts, if needed. x Utilize three ties per post, all within top 8" of fabric. x Position each tie diagonally, puncturing holes vertically a minimum of 1" apart. x Hang each tie on a post nipple and tighten securely. Use cable ties (50 lbs) or soft wire. Maintenance Standards  Repair any damage immediately.  Intercept and convey all evident concentrated flows uphill of the silt fence to a sediment pond.  Check the uphill side of the fence for signs of the fence clogging and acting as a barrier to flow and then causing channelization of flows parallel to the fence. If this occurs, replace the fence or remove the trapped sediment.  Remove sediment deposits when the deposit reaches approximately one-third the height of the silt fence, or install a second silt fence.  Replace filter fabric that has deteriorated due to ultraviolet breakdown. BMP C240: Sediment Trap Purpose A sediment trap is a small temporary ponding area with a gravel outlet used to collect and store sediment from sites cleared and/or graded during construction. Sediment traps, along with other perimeter controls, shall be installed before any land disturbance takes place in the drainage area. Conditions of Use Prior to leaving a construction site, stormwater runoff must pass through a sediment pond or trap or other appropriate sediment removal best management practice. Non-engineered sediment traps may be used on-site prior to an engineered sediment trap or sediment pond to provide additional sediment removal capacity. It is intended for use on sites where the tributary drainage area is less than 3 acres, with no unusual drainage features, and a projected build-out time of six months or less. The sediment trap is a temporary measure (with a design life of approximately 6 months) and shall be maintained until the site area is permanently protected against erosion by vegetation and/or structures. Sediment traps and ponds are only effective in removing sediment down to about the medium silt size fraction. Runoff with sediment of finer grades (fine silt and clay) will pass through untreated, emphasizing the need to control erosion to the maximum extent first. Whenever possible, sediment-laden water shall be discharged into on-site, relatively level, vegetated areas (see BMP C234: Vegetated Strip). This is the only way to effectively remove fine particles from runoff unless chemical treatment or filtration is used. This can be particularly useful after initial treatment in a sediment trap or pond. The areas of release must be evaluated on a site-by-site basis in order to determine appropriate locations for and methods of releasing runoff. Vegetated wetlands shall not be used for this purpose. Frequently, it may be possible to pump water from the collection point at the downhill end of the site to an upslope vegetated area. Pumping shall only augment the treatment system, not replace it, because of the possibility of pump failure or runoff volume in excess of pump capacity. All projects that are constructing permanent facilities for runoff quantity control should use the rough-graded or final-graded permanent facilities for traps and ponds. This includes combined facilities and infiltration facilities. When permanent facilities are used as temporary sedimentation facilities, the surface area requirement of a sediment trap or pond must be met. If the surface area requirements are larger than the surface area of the permanent facility, then the trap or pond shall be enlarged to comply with the surface area requirement. The permanent pond shall also be divided into two cells as required for sediment ponds. Either a permanent control structure or the temporary control structure (described in BMP C241: Temporary Sediment Pond) can be used. If a permanent control structure is used, it may be advisable to partially restrict the lower orifice with gravel to increase residence time while still allowing dewatering of the pond. A shut-off valve may be added to the control structure to allow complete retention of stormwater in emergency situations. In this case, an emergency overflow weir must be added. A skimmer may be used for the sediment trap outlet if approved by the Local Permitting Authority. Design and Installation Specifications  See Figure II-4.2.16 Cross Section of Sediment Trap and Figure II-4.2.17 Sediment Trap Outlet for details.  If permanent runoff control facilities are part of the project, they should be used for sediment retention.  To determine the sediment trap geometry, first calculate the design surface area (SA) of the trap, measured at the invert of the weir. Use the following equation: SA = FS(Q2/Vs) where Q2 = Design inflow based on the peak discharge from the developed 2-year runoff event from the contributing drainage area as computed in the hydrologic analysis. The 10-year peak flow shall be used if the project size, expected timing and duration of construction, or downstream conditions warrant a higher level of protection. If no hydrologic analysis is required, the Rational Method may be used. Vs = The settling velocity of the soil particle of interest. The 0.02 mm (medium silt) particle with an assumed density of 2.65 g/cm3 has been selected as the particle of interest and has a settling velocity (Vs) of 0.00096 ft/sec. FS = A safety factor of 2 to account for non-ideal settling. Therefore, the equation for computing surface area becomes: SA = 2 x Q2/0.00096 or 2080 square feet per cfs of inflow Note: Even if permanent facilities are used, they must still have a surface area that is at least as large as that derived from the above formula. If they do not, the pond must be enlarged.  To aid in determining sediment depth, all sediment traps shall have a staff gauge with a prominent mark 1-foot above the bottom of the trap.  Sediment traps may not be feasible on utility projects due to the limited work space or the short-term nature of the work. Portable tanks may be used in place of sediment traps for utility projects. Maintenance Standards  Sediment shall be removed from the trap when it reaches 1-foot in depth.  Any damage to the pond embankments or slopes shall be repaired. DEPAR TM E N T OF ECOLOGY State of Washington Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, limitation of liability, and disclaimer. Figure II-4.2.16 Cross Section of Sediment Trap Revised November 2015 NOT TO SCALE 3 H : 1 V M a x . 3.5' - 5' Flat Bottom 1.5' Min. 1' Min. Surface area determined at top of weir 34" - 1.5" Washed gravel Geotextile 2" - 4" Rock Rip Rap Discharge to stabilized conveyance, outlet, or level spreader 4' Min. 1' Min. 1' Min. Overflow Note: Trap may be formed by berm or by partial or complete excavation. DEPAR TM E N T OF ECOLOGY State of Washington Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, limitation of liability, and disclaimer. Figure II-4.2.17 Sediment Trap Outlet Revised November 2015 NOT TO SCALE 6' Min. 1' Min. depth overflow spillway Native soil or compacted backfill Geotextile Min. 1' depth 2" - 4" rock Min. 1' depth 3 4" - 1.5" washed gravel BMP C241: Temporary Sediment Pond Purpose Sediment ponds remove sediment from runoff originating from disturbed areas of the site. Sediment ponds are typically designed to remove sediment no smaller than medium silt (0.02 mm). Consequently, they usually reduce turbidity only slightly. Conditions of Use Prior to leaving a construction site, stormwater runoff must pass through a sediment pond or other appropriate sediment removal best management practice. A sediment pond shall be used where the contributing drainage area is 3 acres or more. Ponds must be used in conjunction with erosion control practices to reduce the amount of sediment flowing into the basin. Design and Installation Specifications  Sediment basins must be installed only on sites where failure of the structure would not result in loss of life, damage to homes or buildings, or interruption of use or service of public roads or utilities. Also, sediment traps and ponds are attractive to children and can be very dangerous. Compliance with local ordinances regarding health and safety must be addressed. If fencing of the pond is required, the type of fence and its location shall be shown on the ESC plan.  Structures having a maximum storage capacity at the top of the dam of 10 acre-ft (435,600 ft3) or more are subject to the Washington Dam Safety Regulations (Chapter 173-175 WAC).  See Figure II-4.2.18 Sediment Pond Plan View, Figure II-4.2.19 Sediment Pond Cross Section, and Figure II-4.2.20 Sediment Pond Riser Detail for details.  If permanent runoff control facilities are part of the project, they should be used for sediment retention. The surface area requirements of the sediment basin must be met. This may require temporarily enlarging the permanent basin to comply with the surface area requirements. The permanent control structure must be temporarily replaced with a control structure that only allows water to leave the pond from the surface or by pumping. The permanent control structure must be installed after the site is fully stabilized. .  Use of infiltration facilities for sedimentation basins during construction tends to clog the soils and reduce their capacity to infiltrate. If infiltration facilities are to be used, the sides and bottom of the facility must only be rough excavated to a minimum of 2 feet above final grade. Final grading of the infiltration facility shall occur only when all contributing drainage areas are fully stabilized. The infiltration pretreatment facility should be fully constructed and used with the sedimentation basin to help prevent clogging.  Determining Pond Geometry Obtain the discharge from the hydrologic calculations of the peak flow for the 2-year runoff event (Q2). The 10-year peak flow shall be used if the project size, expected timing and duration of construction, or downstream conditions warrant a higher level of protection. If no hydrologic analysis is required, the Rational Method may be used. Determine the required surface area at the top of the riser pipe with the equation: SA = 2 x Q2/0.00096 or 2080 square feet per cfs of inflow See BMP C240: Sediment Trap for more information on the derivation of the surface area calculation. The basic geometry of the pond can now be determined using the following design criteria:  Required surface area SA (from Step 2 above) at top of riser.  Minimum 3.5-foot depth from top of riser to bottom of pond.  Maximum 3H:1V interior side slopes and maximum 2H:1V exterior slopes. The interior slopes can be increased to a maximum of 2H:1V if fencing is provided at or above the maximum water surface.  One foot of freeboard between the top of the riser and the crest of the emergency spillway.  Flat bottom.  Minimum 1-foot deep spillway.  Length-to-width ratio between 3:1 and 6:1.  Sizing of Discharge Mechanisms. The outlet for the basin consists of a combination of principal and emergency spillways. These outlets must pass the peak runoff expected from the contributing drainage area for a 100-year storm. If, due to site conditions and basin geometry, a separate emergency spill-way is not feasible, the principal spillway must pass the entire peak runoff expected from the 100-year storm. However, an attempt to provide a separate emergency spillway should always be made. The runoff calculations should be based on the site conditions during construction. The flow through the dewatering orifice cannot be utilized when calculating the 100-year storm elevation because of its potential to become clogged; therefore, available spillway storage must begin at the principal spillway riser crest. The principal spillway designed by the procedures contained in this standard will result in some reduction in the peak rate of runoff. However, the riser outlet design will not adequately control the basin discharge to the predevelopment discharge limitations as stated in I-2.5.7 Minimum Requirement #7: Flow Control. However, if the basin for a permanent stormwater detention pond is used for a temporary sedimentation basin, the control structure for the permanent pond can be used to maintain predevelopment discharge limitations. The size of the basin, the expected life of the construction project, the anticipated downstream effects and the anticipated weather conditions during construction, should be considered to determine the need of additional discharge control. See Figure II-4.2.21 Riser Inflow Curves for riser inflow curves. DEPAR TM E N T OF ECOLOGY State of Washington Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, limitation of liability, and disclaimer. Figure II-4.2.18 Sediment Pond Plan View Revised November 2015 NOT TO SCALE Note: Pond may be formed by berm or by partial or complete excavation Inflow Silt fence or equivalent divider Pond length The pond length shall be 3 to 6 times the maximum pond width Key divider into slope to prevent flow around sides Riser pipe Emergency overflow spillway Discharge to stabilized conveyance, outlet, or level spreader DEPAR TM E N T OF ECOLOGY State of Washington Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, limitation of liability, and disclaimer. Figure II-4.2.19 Sediment Pond Cross Section Revised November 2015 NOT TO SCALE3H : 1V Max .3H : 1V Max.2H : 1V Max . 1.5' 1' 1' Min. Wire-backed silt fence staked haybales wrapped with filter fabric, or equivalent divider Dewatering orifice Concrete base (see riser detail) Discharge to stabilized conveyance outlet or level spreader Dewatering device (see riser detail) Riser pipe (principal spillway) open at top with trash rack Crest of emergency spillway 6' Min. width. Embankment compacted 95% pervious materials such as gravel or clean sand shall not be used DEPAR TM E N T OF ECOLOGY State of Washington Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, limitation of liability, and disclaimer. Figure II-4.2.20 Sediment Pond Riser Detail Revised November 2015 NOT TO SCALE Tack weld Dewatering orifice, schedule 40 steel stub min. diameter per calculations Provide adequate strapping Alternatively, metal stakes and wire may be used to prevent flotation Polyethylene cap Perforated polyethylene drainage tubing, diameter min. 2" larger than dewatering orifice. Tubing shall comply with ASTM F667 and AASHTO M294. Watertight coupling Corrugated metal riser 3.5' min. 18" min. 6" min. Concrete base 2X riser dia. min. DEPAR TM E N T OF ECOLOGY State of Washington Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions, limitation of liability, and disclaimer. Figure II-4.2.21 Riser Inflow Curves Revised November 2015 Principal Spillway: Determine the required diameter for the principal spillway (riser pipe). The diameter shall be the minimum necessary to pass the site’s 15-minute, 10-year flowrate. If using the Western Washington Hydrology Model (WWHM), Version 2 or 3, design flow is the 10-year (1 hour) flow for the developed (unmitigated) site, multiplied by a factor of 1.6. Use Figure II- 4.2.21 Riser Inflow Curves to determine this diameter (h = 1-foot). Note: A permanent control structure may be used instead of a temporary riser. Emergency Overflow Spillway: Determine the required size and design of the emergency overflow spillway for the developed 100-year peak flow using the method contained in Volume III. Dewatering Orifice: Determine the size of the dewatering orifice(s) (minimum 1-inch diameter) using a modified version of the discharge equation for a vertical orifice and a basic equation for the area of a circular orifice. Determine the required area of the orifice with the following equation: where Ao = orifice area (square feet) AS = pond surface area (square feet) h = head of water above orifice (height of riser in feet) T = dewatering time (24 hours) g = acceleration of gravity (32.2 feet/second2) Convert the required surface area to the required diameter D of the orifice: The vertical, perforated tubing connected to the dewatering orifice must be at least 2 inches larger in diameter than the orifice to improve flow characteristics. The size and number of perforations in the tubing should be large enough so that the tubing does not restrict flow. The orifice should control the flow rate.  Additional Design Specifications The pond shall be divided into two roughly equal volume cells by a permeable divider that will reduce turbulence while allowing movement of water between cells. The divider shall be at least one-half the height of the riser and a minimum of one foot below the top of the riser. Wire-backed, 2- to 3-foot high, extra strength filter fabric supported by treated 4"x4"s can be used as a divider. Alternatively, staked straw bales wrapped with filter fabric (geotextile) may be used. If the pond is more than 6 feet deep, a different mechanism must be proposed. A riprap embankment is one acceptable method of separation for deeper ponds. Other designs that satisfy the intent of this provision are allowed as long as the divider is permeable, structurally sound, and designed to prevent erosion under or around the barrier. To aid in determining sediment depth, one-foot intervals shall be prominently marked on the riser. If an embankment of more than 6 feet is proposed, the pond must comply with the criteria contained in Volume III regarding dam safety for detention BMPs.  The most common structural failure of sedimentation basins is caused by piping. Piping refers to two phenomena: (1) water seeping through fine-grained soil, eroding the soil grain by grain and forming pipes or tunnels; and, (2) water under pressure flowing upward through a granular soil with a head of sufficient magnitude to cause soil grains to lose contact and capability for support. The most critical construction sequences to prevent piping will be: 1. Tight connections between riser and barrel and other pipe connections. 2. Adequate anchoring of riser. 3. Proper soil compaction of the embankment and riser footing. 4. Proper construction of anti-seep devices. Maintenance Standards  Sediment shall be removed from the pond when it reaches 1–foot in depth.  Any damage to the pond embankments or slopes shall be repaired. P a g e | 34 Appendix D – Site Inspection Form Construction Stormwater Site Inspection Form Page 1 Project Name The New Elementary School in Redmond Ridge East Permit # Inspection Date Time Name of Certified Erosion Sediment Control Lead (CESCL) or qualified inspector if less than one acre Print Name: Approximate rainfall amount since the last inspection (in inches): Approximate rainfall amount in the last 24 hours (in inches): Current Weather Clear Cloudy Mist Rain Wind Fog A. Type of inspection: Weekly Post Storm Event Other B. Phase of Active Construction (check all that apply): Pre Construction/installation of erosion/sediment controls Clearing/Demo/Grading Infrastructure/storm/roads Concrete pours Vertical Construction/buildings Utilities Offsite improvements Site temporary stabilized Final stabilization C. Questions: 1. Were all areas of construction and discharge points inspected? Yes No 2. Did you observe the presence of suspended sediment, turbidity, discoloration, or oil sheen Yes No 3. Was a water quality sample taken during inspection? (refer to permit conditions S4 & S5) Yes No 4. Was there a turbid discharge 250 NTU or greater, or Transparency 6 cm or less?* Yes No 5. If yes to #4 was it reported to Ecology? Yes No 6. Is pH sampling required? pH range required is 6.5 to 8.5. Yes No If answering yes to a discharge, describe the event. Include when, where, and why it happened; what action was taken, and when. *If answering yes to # 4 record NTU/Transparency with continual sampling daily until turbidity is 25 NTU or less/ transparency is 33 cm or greater. Sampling Results: Date: Parameter Method (circle one) Result Other/Note NTU cm pH Turbidity tube, meter, laboratory pH Paper, kit, meter Family First Community Center Construction Stormwater Site Inspection Form Page 2 D. Check the observed status of all items. Provide “Action Required “details and dates. Element # Inspection BMPs Inspected BMP needs maintenance BMP failed Action required (describe in section F) yes no n/a 1 Clearing Limits Before beginning land disturbing activities are all clearing limits, natural resource areas (streams, wetlands, buffers, trees) protected with barriers or similar BMPs? (high visibility recommended) 2 Construction Access Construction access is stabilized with quarry spalls or equivalent BMP to prevent sediment from being tracked onto roads? Sediment tracked onto the road way was cleaned thoroughly at the end of the day or more frequent as necessary. 3 Control Flow Rates Are flow control measures installed to control stormwater volumes and velocity during construction and do they protect downstream properties and waterways from erosion? If permanent infiltration ponds are used for flow control during construction, are they protected from siltation? 4 Sediment Controls All perimeter sediment controls (e.g. silt fence, wattles, compost socks, berms, etc.) installed, and maintained in accordance with the Stormwater Pollution Prevention Plan (SWPPP). Sediment control BMPs (sediment ponds, traps, filters etc.) have been constructed and functional as the first step of grading. Stormwater runoff from disturbed areas is directed to sediment removal BMP. 5 Stabilize Soils Have exposed un-worked soils been stabilized with effective BMP to prevent erosion and sediment deposition? Construction Stormwater Site Inspection Form Page 3 Element # Inspection BMPs Inspected BMP needs maintenance BMP failed Action required (describe in section F) yes no n/a 5 Stabilize Soils Cont. Are stockpiles stabilized from erosion, protected with sediment trapping measures and located away from drain inlet, waterways, and drainage channels? Have soils been stabilized at the end of the shift, before a holiday or weekend if needed based on the weather forecast? 6 Protect Slopes Has stormwater and ground water been diverted away from slopes and disturbed areas with interceptor dikes, pipes and or swales? Is off-site storm water managed separately from stormwater generated on the site? Is excavated material placed on uphill side of trenches consistent with safety and space considerations? Have check dams been placed at regular intervals within constructed channels that are cut down a slope? 7 Drain Inlets Storm drain inlets made operable during construction are protected. Are existing storm drains within the influence of the project protected? 8 Stabilize Channel and Outlets Have all on-site conveyance channels been designed, constructed and stabilized to prevent erosion from expected peak flows? Is stabilization, including armoring material, adequate to prevent erosion of outlets, adjacent stream banks, slopes and downstream conveyance systems? 9 Control Pollutants Are waste materials and demolition debris handled and disposed of to prevent contamination of stormwater? Has cover been provided for all chemicals, liquid products, petroleum products, and other material? Has secondary containment been provided capable of containing 110% of the volume? Were contaminated surfaces cleaned immediately after a spill incident? Were BMPs used to prevent contamination of stormwater by a pH modifying sources? Construction Stormwater Site Inspection Form Page 4 Element # Inspection BMPs Inspected BMP needs maintenance BMP failed Action required (describe in section F) yes no n/a 9 Cont. Wheel wash wastewater is handled and disposed of properly. 10 Control Dewatering Concrete washout in designated areas. No washout or excess concrete on the ground. Dewatering has been done to an approved source and in compliance with the SWPPP. Were there any clean non turbid dewatering discharges? 11 Maintain BMP Are all temporary and permanent erosion and sediment control BMPs maintained to perform as intended? 12 Manage the Project Has the project been phased to the maximum degree practicable? Has regular inspection, monitoring and maintenance been performed as required by the permit? Has the SWPPP been updated, implemented and records maintained? 13 Protect LID Is all Bioretention and Rain Garden Facilities protected from sedimentation with appropriate BMPs? Is the Bioretention and Rain Garden protected against over compaction of construction equipment and foot traffic to retain its infiltration capabilities? Permeable pavements are clean and free of sediment and sediment laden- water runoff. Muddy construction equipment has not been on the base material or pavement. Have soiled permeable pavements been cleaned of sediments and pass infiltration test as required by stormwater manual methodology? Heavy equipment has been kept off existing soils under LID facilities to retain infiltration rate. E. Check all areas that have been inspected. All in place BMPs All disturbed soils All concrete wash out area All material storage areas All discharge locations All equipment storage areas All construction entrances/exits Construction Stormwater Site Inspection Form Page 5 F. Elements checked “Action Required” (section D) describe corrective action to be taken. List the element number; be specific on location and work needed. Document, initial, and date when the corrective action has been completed and inspected. Element # Description and Location Action Required Completion Date Initials Attach additional page if needed Sign the following certification: “I certify that this report is true, accurate, and complete, to the best of my knowledge and belief” Inspected by: (print) (Signature) Date: Title/Qualification of Inspector: P a g e | 35 Appendix E - Construction Stormwater General Permit (CSWGP) 3 4 . – – 5 S1.E.3. 1. ,, b. . 2. . , . b. . 6 1.. . “surface ” may exist on a construction site as well as off site; for 2.. on n b. . 3.Non . . b.. ,. d.. . . g.. h.. . . k.. . 7 , –8.5 . . 1.. 2.up . 3.40 C 122.2 4., unless . 5. . 6. 7., unless 8. . , . 1. . 2.p CFR Subpart 122. 3. 4.on “Country” as defined in 18 §1151, . . b. . . . . 5. . 6. . 1. 9 . unless by 226 . d. Condition S9.C.4 (“demonstrably equivalent” BMPs), the . . . ’ on , . y. . , v.. 10 2. . . 1.A statement that “The applicant is seeking coverage under the Washington State Department of Ecology’s Construction Stormwater NPDES and State Waste ”. 2.. 3.. 4. , . 5. . 6.“ , ’s ,30 . 320. , 98504 ” 11 b. . 4. . . 5.non . 12 6. Recalculate the rainfall erosivity “R” factor using the original start date and a new projected ending date and, if the “R” factor is still under 5 and b. . . . . 1. . 2. . . 218 13 , . The Permittee’s ’ . requirements of the Permittee’s Certified Erosion and Sediment Control Lead . . . 1. . . by . b. as soon as possible, no . g . 2., . . . 14 3. . b. 4. on . . 5. book. b. . d.ions . . g. h. . 15 statement: “I certify that this report is true, accurate, and complete to the best of and belief.” 1 2 – 1 . 2 . 3 . 4 . 16 1. b. 2. b.. d. . . . g. . 3.o . b. . d. systems. 17 4. . b. 60 . . s s 5. . . bodies on Washington State’s 303(d) list . . –249 – . . . 18 b. If a discharge point’s turbidity is 250 Region’s Environmental Report Tracking System (ERTS) number through Ecology’s Water Quality Permitting Portal [WQWebPortal] – . . . . v. 25 19 , 50 – . bodies on Washington State’s 303(d) list 1. 8.5 . 2. . 3. . 4. . 5. . 6.. b. 8.5 2 . 2 . 7. . . 21 . . 1.. 2. . 3.. 4.. 5.. 6.. Permittee’s DMR. , 22 Ecology’s Water Quality Permitting . . . by . 1. b. d. 2. 23 b. . Permittee’s plans and records, the Permittee must either: . . . PERMIT FEES . . . 216 110 TMDL b 24 1. and S4.C.3.b d . 2. 6, or the date when the operator’s complete permit unless 1. 2. 3. Provides . b. . 1. S4.C.2 and . 25 2. , . . . b. . 3. . 4. . 1. of pH 6.5 to 8.5 . 26 6 – 2.’ . . . . b. 27 . . d. . 2. y 1, 2016 before the date the operator’s complete permit application is received by Ecology, . TMDLs completed after the operator’s complete permit . . The Permittee’s SWPPP must meet the following objectives: 1. 2. 3. 1.. . . . b.. 13 13 . 28 d.. — . 2. . b. . . . s to . 1. 2. 3.. n 226 230 29 4. . b. – 13 13 . 1. . b. . 2. . b. . d. . . . 3. 30 b. . 4. mus . . . b.. . . . d. . . . 5. . 31 b. . . d. West of the Cascade Mountains Crest During the dry season (May 1 - September 30): 7 days During the wet season (October 1 - April 30): 2 days East of the Cascade Mountains Crest, except for Central Basin* During the dry season (July 1 - September 30): 10 days During the wet season (October 1 - June 30): 5 days The Central Basin*, East of the Cascade Mountains Crest During the dry season (July 1 - September 30): 30 days During the wet season (October 1 - June 30): 15 days g. . h.. 6. . 32 b. . . . . 1 . . . soil areas should be modeled as "landscaped area.” . d. 7. . b. . 8. 10 . . 33 . . soil areas should be modeled as "landscaped area.” . b. 9. . d b. . . . . . d. . .Follow manufacturers’ label . 34 . g. . h. . . . , 2 . . Prior 10. pond. b. . . Note that “surface waters tate” may exist on a construction si . . . . Sa . 35 v. d. 11. b. wi . 12. b.– . . u d onstruction SWPPP – Conditions S3, S4 and S9. 13. . . . b. . . 36 . d. the manufacturer’s – The Permittee’s SWPPP must also include . 1.. 2.. 3. . 4.. 5. . 6. 7.. 8. . 9. . 10. 11. 37 1. 2. o 3. . – 98504 7696 . 38 . . 1. 2. 3. 4. . . 1. 2. . . “I certify under penalty of law, that this document and all attachments . 39 . possibility of fine and imprisonment for knowing violations.” –– –– –– ON . . . , o . . . 40 . . . . 226 . 226 . . . form (NOI) available on Ecology’s website. 98504 7696 41 AGE The Director does not notify the current discharger and new discharger of the Director’s . . . . . 42 . separate and distinct offense, and in case of a continuing violation, every day’s continuan – “Upset” means an exceptional incident in which there is unintentional and . , . . 43 p . . . . . . A change in the construction plans and/or activity that affects the Permittee’s monitoring . . . 44 . 220 216 070, . . . . . permit coverage of an individual discharger is limited to the general permit’s . 45 . 1. . 2. 3. . “Severe property damage” means substantial physical damage to . b. . 4. . . . b. . . d.. . 46 . g.. h. 173 . 5. . . b. . . . 47 – “ ” . 2016 ’ . operator Benchmark . . . . . Calendar . Calendar . Certified Erosion and Sediment Co . 217, 95 576, 96 . 48 n. . . . W . . S ground water. . . “”340 200. , , 1.. 49 2.. 3. . 4.. 5. . ground wat . . operator . . ground water . Erosion . . synonymous with . is an entity that meets the definition of “” in this permit and is either 50 . 0 law, 42 U.S.C., Sec. . . . . 226 200. 51 means a liquid’s measure of acidity or alkalinity. . 6.5 8.5. . . . . W . W . . 52 . ,. Ecology’s Construction . Responsible Corporate O . . Sediment Sedimentation . Work . Significant Contributor of Pollutants . 53 sodding. . . Manual . . . . . on. substitute for the more permanent “.” . . . . . 54 . . Transparency . . as a “ube.” . . See definition of “” and 173 340 200. Waste Load Allocation (WLA)means the portion of a receiving water’s loading capacity that . h only Based Shaft Drilling . . W W . 55 – EPA NOT TMDL P a g e | 36 Appendix H – Engineering Calculations COUGHLINPORTERLUNDEEN A CONSULTING STRUCTURAL AND CIVIL ENGINEERING CORPORATION Proposed Runoff Conditions for TESC - Temporary Sediment Pond Total Site:Area (ac) Pervious Area 0.000 Impervious Area 2.510 Total Area 2.510 MGS Flood 15-minute time step 10-Yr Developed Flow 1.46 cfs Temporary Sediment Pond Sizing: Storage Volume per 2016 KCSWDM Vr=S.A. x 3.5'Vr = Minimum Required Storage Volume S.A. = Minimum allowable top surface area of pond S.A. = (2Q10)/Vsed Q = design peak flow rate Vsed = 0.00096 Settling Velocity (0.00096 ft/sec) Q=1.459 cfs INPUT (note that this is the 10-yr design peak flow rate in cfs) S.A. = 3040 sf Vr=10639 cf Volume Required Project: Family First Community Center Designed by: CPS Project No.: C180040-01 Client: COR Checked by: AJF Sheet 1 of 1 * the volume is based a minimum pond depth of 3.5' - this depth does not include the minimum sediment storage volume or freeboard 801 Second Avenue ∙ Suite 900 ∙ Seattle, WA 98104 ∙ P: (206) 343-0460 Date: 2/17/20 ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.46 Program License Number: 200610002 Project Simulation Performed on: 02/17/2020 7:03 PM Report Generation Date: 02/17/2020 7:04 PM ————————————————————————————————— Input File Name: 20-2-17 FFCC - TESC Calcs.fld Project Name: FFCC - TESC Calcs Analysis Title: Baker tank sizing Comments: 2/17/20 TESC Calcs for permit ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 15 Full Period of Record Available used for Routing Precipitation Station : 96004005 Puget East 40 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961040 Puget East 40 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 2.680 2.680 Area of Links that Include Precip/Evap (acres) 0.000 0.000 Total (acres) 2.680 2.680 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Subbasin 1 ---------- -------Area (Acres) -------- Till Forest 2.680 ---------------------------------------------- Subbasin Total 2.680 MGSFLOOD REPORT FOR BAKER TANK SIZING CALCULATION ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Subbasin 1 ---------- -------Area (Acres) -------- Impervious 2.680 ---------------------------------------------- Subbasin Total 2.680 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 0 **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 Number of Links: 0 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Subbasin 1 462.110 _____________________________________ Total: 462.110 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Subbasin 1 0.000 _____________________________________ Total: 0.000 Total Predevelopment Recharge is Greater than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 2.925 ac-ft/year, Post Developed: 0.000 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Links: 0 ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Subbasin 1 Scenario Postdeveloped Compliance Subbasin: Subbasin 1 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 5.711E-02 2-Year 0.999 5-Year 9.308E-02 5-Year 1.297 10-Year 0.125 10-Year 1.459 25-Year 0.159 25-Year 1.837 50-Year 0.203 50-Year 2.338 100-Year 0.220 100-Year 2.704 200-Year 0.342 200-Year 2.802 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals **** Flow Duration Performance **** Excursion at Predeveloped 50%Q2 (Must be Less Than or Equal to 0%): 671.4% FAIL Maximum Excursion from 50%Q2 to Q2 (Must be Less Than or Equal to 0%): 3182.2% FAIL Maximum Excursion from Q2 to Q50 (Must be less than 10%): 99999.0% FAIL Percent Excursion from Q2 to Q50 (Must be less than 50%): 100.0% FAIL ------------------------------------------------------------------------------------------------- FLOW DURATION DESIGN CRITERIA: FAIL ------------------------------------------------------------------------------------------------- **** LID Duration Performance **** Excursion at Predeveloped 8%Q2 (Must be Less Than 0%): 47.8% FAIL Maximum Excursion from 8%Q2 to 50%Q2 (Must be Less Than 0%): 671.4% FAIL ------------------------------------------------------------------------------------------------- LID DURATION DESIGN CRITERIA: FAIL ------------------------------------------------------------------------------------------------- FAMILY FIRST COMMUNITY CENTER APPENDIX D – OPERATIONS AND MAINTENANCE MANUAL www.modularwetlands.com Maintenance Guidelines for Modular Wetland System - Linear Maintenance Summary o Remove Trash from Screening Device – average maintenance interval is 6 to 12 months.  (5 minute average service time). o Remove Sediment from Separation Chamber – average maintenance interval is 12 to 24 months.  (10 minute average service time). o Replace Cartridge Filter Media – average maintenance interval 12 to 24 months.  (10-15 minute per cartridge average service time). o Replace Drain Down Filter Media – average maintenance interval is 12 to 24 months.  (5 minute average service time). o Trim Vegetation – average maintenance interval is 6 to 12 months.  (Service time varies). System Diagram Access to screening device, separation chamber and cartridge filter Access to drain down filter Pre-Treatment Chamber Biofiltration Chamber Discharge Chamber Outflow Pipe Inflow Pipe (optional) www.modularwetlands.com Maintenance Procedures Screening Device 1. Remove grate or manhole cover to gain access to the screening device in the Pre- Treatment Chamber. Vault type units do not have screening device. Maintenance can be performed without entry. 2. Remove all pollutants collected by the screening device. Removal can be done manually or with the use of a vacuum truck. The hose of the vacuum truck will not damage the screening device. 3. Screening device can easily be removed from the Pre-Treatment Chamber to gain access to separation chamber and media filters below. Replace grate or manhole cover when completed. Separation Chamber 1. Perform maintenance procedures of screening device listed above before maintaining the separation chamber. 2. With a pressure washer spray down pollutants accumulated on walls and cartridge filters. 3. Vacuum out Separation Chamber and remove all accumulated pollutants. Replace screening device, grate or manhole cover when completed. Cartridge Filters 1. Perform maintenance procedures on screening device and separation chamber before maintaining cartridge filters. 2. Enter separation chamber. 3. Unscrew the two bolts holding the lid on each cartridge filter and remove lid. 4. Remove each of 4 to 8 media cages holding the media in place. 5. Spray down the cartridge filter to remove any accumulated pollutants. 6. Vacuum out old media and accumulated pollutants. 7. Reinstall media cages and fill with new media from manufacturer or outside supplier. Manufacturer will provide specification of media and sources to purchase. 8. Replace the lid and tighten down bolts. Replace screening device, grate or manhole cover when completed. Drain Down Filter 1. Remove hatch or manhole cover over discharge chamber and enter chamber. 2. Unlock and lift drain down filter housing and remove old media block. Replace with new media block. Lower drain down filter housing and lock into place. 3. Exit chamber and replace hatch or manhole cover. www.modularwetlands.com Maintenance Notes 1. Following maintenance and/or inspection, it is recommended the maintenance operator prepare a maintenance/inspection record. The record should include any maintenance activities performed, amount and description of debris collected, and condition of the system and its various filter mechanisms. 2. The owner should keep maintenance/inspection record(s) for a minimum of five years from the date of maintenance. These records should be made available to the governing municipality for inspection upon request at any time. 3. Transport all debris, trash, organics and sediments to approved facility for disposal in accordance with local and state requirements. 4. Entry into chambers may require confined space training based on state and local regulations. 5. No fertilizer shall be used in the Biofiltration Chamber. 6. Irrigation should be provided as recommended by manufacturer and/or landscape architect. Amount of irrigation required is dependent on plant species. Some plants may require irrigation. www.modularwetlands.com Maintenance Procedure Illustration Screening Device The screening device is located directly under the manhole or grate over the Pre-Treatment Chamber. It’s mounted directly underneath for easy access and cleaning. Device can be cleaned by hand or with a vacuum truck. Separation Chamber The separation chamber is located directly beneath the screening device. It can be quickly cleaned using a vacuum truck or by hand. A pressure washer is useful to assist in the cleaning process. www.modularwetlands.com Cartridge Filters The cartridge filters are located in the Pre-Treatment chamber connected to the wall adjacent to the biofiltration chamber. The cartridges have removable tops to access the individual media filters. Once the cartridge is open media can be easily removed and replaced by hand or a vacuum truck. Drain Down Filter The drain down filter is located in the Discharge Chamber. The drain filter unlocks from the wall mount and hinges up. Remove filter block and replace with new block. www.modularwetlands.com Trim Vegetation Vegetation should be maintained in the same manner as surrounding vegetation and trimmed as needed. No fertilizer shall be used on the plants. Irrigation per the recommendation of the manufacturer and or landscape architect. Different types of vegetation requires different amounts of irrigation. www.modularwetlands.com Inspection Form Modular Wetland System, Inc. P. 760.433-7640 F. 760-433-3176 E. Info@modularwetlands.com For Office Use Only (city) (Zip Code)(Reviewed By) Owner / Management Company (Date) Contact Phone ( )_ Inspector Name Date / / Time AM / PM Weather Condition Additional Notes Yes Depth: Yes No Modular Wetland System Type (Curb, Grate or UG Vault):Size (22', 14' or etc.): Other Inspection Items: Storm Event in Last 72-hours? No Yes Type of Inspection Routine Follow Up Complaint Storm Office personnel to complete section to the left. 2972 San Luis Rey Road, Oceanside, CA 92058 P (760) 433-7640 F (760) 433-3176 Inspection Report Modular Wetlands System Is the filter insert (if applicable) at capacity and/or is there an accumulation of debris/trash on the shelf system? Does the cartridge filter media need replacement in pre-treatment chamber and/or discharge chamber? Any signs of improper functioning in the discharge chamber? Note issues in comments section. Chamber: Is the inlet/outlet pipe or drain down pipe damaged or otherwise not functioning properly? Structural Integrity: Working Condition: Is there evidence of illicit discharge or excessive oil, grease, or other automobile fluids entering and clogging the unit? Is there standing water in inappropriate areas after a dry period? Damage to pre-treatment access cover (manhole cover/grate) or cannot be opened using normal lifting pressure? Damage to discharge chamber access cover (manhole cover/grate) or cannot be opened using normal lifting pressure? Does the MWS unit show signs of structural deterioration (cracks in the wall, damage to frame)? Project Name Project Address Inspection Checklist CommentsNo Does the depth of sediment/trash/debris suggest a blockage of the inflow pipe, bypass or cartridge filter? If yes, specify which one in the comments section. Note depth of accumulation in in pre-treatment chamber. Is there a septic or foul odor coming from inside the system? Is there an accumulation of sediment/trash/debris in the wetland media (if applicable)? Is it evident that the plants are alive and healthy (if applicable)? Please note Plant Information below. Sediment / Silt / Clay Trash / Bags / Bottles Green Waste / Leaves / Foliage Waste:Plant Information No Cleaning Needed Recommended Maintenance Additional Notes: Damage to Plants Plant Replacement Plant Trimming Schedule Maintenance as Planned Needs Immediate Maintenance www.modularwetlands.com Maintenance Report Modular Wetland System, Inc. P. 760.433-7640 F. 760-433-3176 E. Info@modularwetlands.com For Office Use Only (city) (Zip Code)(Reviewed By) Owner / Management Company (Date) Contact Phone ( )_ Inspector Name Date / / Time AM / PM Weather Condition Additional Notes Site Map # Comments: 2972 San Luis Rey Road, Oceanside, CA 92058 P. 760.433.7640 F. 760.433.3176 Inlet and Outlet Pipe Condition Drain Down Pipe Condition Discharge Chamber Condition Drain Down Media Condition Plant Condition Media Filter Condition Long: MWS Sedimentation Basin Total Debris Accumulation Condition of Media 25/50/75/100 (will be changed @ 75%) Operational Per Manufactures' Specifications (If not, why?) Lat:MWS Catch Basins GPS Coordinates of Insert Manufacturer / Description / Sizing Trash Accumulation Foliage Accumulation Sediment Accumulation Type of Inspection Routine Follow Up Complaint Storm Storm Event in Last 72-hours? No Yes Office personnel to complete section to the left. Project Address Project Name Cleaning and Maintenance Report Modular Wetlands System An company 2 THE MOST ADVANCED NAME IN WATER MANAGEMENT SOLUTIONS TM ECCENTRICHEADER MANHOLEWITHOVERFLOWWEIR STORMTECHISOLATOR ROW OPTIONAL PRE-TREATMENT OPTIONAL ACCESS STORMTECH CHAMBERS  )( FAMILY FIRST COMMUNITY CENTER APPENDIX E – FACILITIES SUMMARY AND DECLARATIONS OF COVENANT 2016 KING COUNTY SURFACE WATER DESIGN MANUAL, REFERENCE D 4/24/2016 Page 1 STORMWATER FACILITY SUMMARY SHEET DPER Permit No.___________________ (provide one Stormwater Facility Summary Sheet per Natural Discharge Location)Date ___________________ OVERVIEW:NPDES Permit No.___________________ Project Name Parcel No.____________________________ Project Location Retired Parcel No.____________________________ Downstream Drainage Basins:Project includes Landscape Management Plan?yes Major Basin Name ______________________________________________(include copy with TIR as Appendix)no Immediate Basin Name ______________________________________________ GENERAL FACILITY INFORMATION: Leachable Metals Infiltration Impervious Surface Limit Type # of Type # of Type # of facilities Flow Control BMPs Ponds ______ Ponds ______ Ponds ______ Basic Clearing Limit Vaults ______ Tanks ______ Vaults ______ Conservation Drainage Facility Tanks ______ Trenches _____ Tanks ______ Flood Problem Landscape Management Plan If no flow control facility, check one: Project qualifies for KCSWDM Exemption (KCSWDM 1.2.3): Basic Exemption (Applies to Commercial parcels only)Area % of Total Redevelopment projects Cost Exemption for Parcel Redevelopment projects Direct Discharge Exemption Other _____________________ Total impervious surface served by Project qualifies for 0.1 cfs Exception per KCSWDM 1.2.3 flow control facility(ies) (sq ft) Impervious surface served by flow KCSWDM Adjustment No. ___________________control facility(ies) designed 1990 or later (sq ft) approved KCSWDM Adjustment No. __________________ Impervious surface served by Shared Facility Name/Location: _________________________ pervious surface absorption (sq ft) No flow control required (other, provide justification): Impervious surface served by approved ____________________________________________________ water quality facility(ies) (sq ft) Flow Control Performance Std Declarations of Covenant Recording No. Water QualityDetention TREATMENT SUMMARY FOR TOTAL IMPERVIOUS SURFACES ----- Total Impervious Acreage (ac) No flow control required per approved Flow control provided in regional/shared facility per approved PROVIDE FACILITY DETAILS AND FACILITY SKETCH FOR EACH FACILITY ON REVERSE. USE ADDITIONAL SHEETS AS NEEDED FOR ADDITIONAL FACILITIES Impervious Surface Exemption for Transportation Total Acreage (ac) Family First Community Center 12/05/2019 16022 116th Ave SE, Renton WA 98058 Cedar River 2 1 2823059034 2.51 Lower- Cedar River -- -- TBD TBD TBD 1 2.03 80.9 1.19 47.4 0.84 33.5 2016 KING COUNTY SURFACE WATER DESIGN MANUAL, REFERENCE D 4/24/2016 Page 2 STORMWATER FACILITY SUMMARY SHEET DPER Permit No.___________________ (provide one Stormwater Facility Summary Sheet per Natural Discharge Location) Project Name Downstream Drainage Basins: Major Basin Name _______________________________ Project Location Immediate Basin Name ___________________________ FLOW CONTROL FACILITY:Basin: Facility Name/Number _______________________________________ New Facility Project Impervious Facility Location ____________________________________________ Existing Facility Acres Served ________ UIC? □ yes □ no UIC Site ID:% of Total Project Impervious cu.ft.Volume Factor Acres Served ________ _____________ ac.ft.____________of Safety _______No. of Lots Served ________ Control Structure location: _______________________________________________ Type of Control Structure:No. of Orifices/Restrictions __________ Riser in vault Size of Orifice/Restriction (in.) No.1 ______ cu.ft. Riser in Type II CB (numbered starting with lowest No.2 ______ ac.ft. Weir in Type II CB orifice): No.3 ______ (inches in decimal format)No.4 ______ WATER QUALITY FACILITIES Design Information Indicate no. of water quality facilities/BMPs for each type:Water Quality design flow (cfs) _______Flow dispersion Water Quality treated volume (sandfilter) (cu.ft.) _______Filter strip Water Quality storage volume (wetpool) (cu.ft.) _______Biofiltration swale regular, wet or Landscape management plan Farm management plan continuous inflow _______Wetvault combined w/detention ______High flow bypass structure (e.g., flow-splitter catch basin) _______Wetpond basic large combined w/detention ______Oil/water separator baffle coalescing plate _______Pre-settling pond ______Storm filter _______Stormwater wetland ______Pre-settling structure (Manufacturer:______________________) _______Sand filter basic large Sand bed depth ______Catch basin inserts (Manufacturer:________________________) regular linear vault (inches)______________Source controls _________________________________________ ● Is facility lined? yes no If so, what marker is used above liner?_____________________________________________________ Facility Summary Sheet Sketch: All detention, infiltration and water quality facilities must include a detailed sketch (11"x17" reduced size plan sheets preferred). Dam Safety Regulations (WA State Dept of Ecology): Reservoir Volume above natural grade Depth of Reservoir above natural grade (ft) Live Storage Volume Live Storage Depth (ft) Family First Community Center 16022 116th Ave SE, Renton WA 98058 Cedar River Green River Lower- Cedar River 0.86 43 STORMTECH SC-310 CHAMBERS 0.5 2 1.0 0.186 18,907 2016 KING COUNTY SURFACE WATER DESIGN MANUAL, REFERENCE D 4/24/2016 Page 2 STORMWATER FACILITY SUMMARY SHEET DPER Permit No.___________________ (provide one Stormwater Facility Summary Sheet per Natural Discharge Location) Project Name Downstream Drainage Basins: Major Basin Name _______________________________ Project Location Immediate Basin Name ___________________________ FLOW CONTROL FACILITY:Basin: Facility Name/Number _______________________________________ New Facility Project Impervious Facility Location ____________________________________________ Existing Facility Acres Served ________ UIC? □ yes □ no UIC Site ID:% of Total Project Impervious cu.ft.Volume Factor Acres Served ________ _____________ ac.ft.____________of Safety _______No. of Lots Served ________ Control Structure location: _______________________________________________ Type of Control Structure:No. of Orifices/Restrictions __________ Riser in vault Size of Orifice/Restriction (in.) No.1 ______ cu.ft. Riser in Type II CB (numbered starting with lowest No.2 ______ ac.ft. Weir in Type II CB orifice): No.3 ______ (inches in decimal format)No.4 ______ WATER QUALITY FACILITIES Design Information Indicate no. of water quality facilities/BMPs for each type:Water Quality design flow (cfs) _______Flow dispersion Water Quality treated volume (sandfilter) (cu.ft.) _______Filter strip Water Quality storage volume (wetpool) (cu.ft.) _______Biofiltration swale regular, wet or Landscape management plan Farm management plan continuous inflow _______Wetvault combined w/detention ______High flow bypass structure (e.g., flow-splitter catch basin) _______Wetpond basic large combined w/detention ______Oil/water separator baffle coalescing plate _______Pre-settling pond ______Storm filter _______Stormwater wetland ______Pre-settling structure (Manufacturer:______________________) _______Sand filter basic large Sand bed depth ______Catch basin inserts (Manufacturer:________________________) regular linear vault (inches)______________Source controls _________________________________________ ● Is facility lined? yes no If so, what marker is used above liner?_____________________________________________________ Facility Summary Sheet Sketch: All detention, infiltration and water quality facilities must include a detailed sketch (11"x17" reduced size plan sheets preferred). Dam Safety Regulations (WA State Dept of Ecology): Reservoir Volume above natural grade Depth of Reservoir above natural grade (ft) Live Storage Volume Live Storage Depth (ft) Family First Community Center 16022 116th Ave SE, Renton WA 98058 Cedar River Green River Lower- Cedar River 1.16 57 STORMTECH MC-3500 CHAMBERS 0.5 2 1.5 0.751 29,259 Modular Wetland Figure -1A Flow Control Facility Scale 1"=20' A B C E D E.2 E.3 F 184 LF 8" SD @ 1.3%SD# 16 CB TYPE II - RIM=455.27 IE=444.34 8"(IN)W IE=444.34 8"(OUT)S TC 455.88 BC 455.38 TC 457.78 BC 457.28 TC 455.89 BC 455.39 TC 455.46 BC 454.96 TC 455.60 BC 455.10TC 455.60 BC 455.10 NON-INFILTRATING BIORETENTION CELL SEE DETAIL 457.47 4 LF 6" 2.0% CONNECT TO STORMTECH CHAMBER SYSTEM IE =452.92 17 C2.10 INSPECTION PORT SEE DETAIL STORMTECH CHAMBER OUTLET IE=451.50 TC 455.46 BC 454.96 11 C2.10 TC 455.60 BC 455.10 TC 455.83 BC 455.33 C 456.99 C 456.49 S 456.41 83 LF 6" PERF PIPE @ 0.0% SDCO RIM TO GRADE IE = 453.00 ISOLATOR ROW SEE DETAIL 3 C2.12 3:1 MAX Detention Facility Bioretention Cells (non-infiltrating) Figure -1B Water Quality Facility Scale 1"=20' F 1110988.2765.554321 CONNECT TO STORMTECH CHAMBER SYSTEM 4 4 L F 8 " SD @ 9 . 6% C-3500 STORMTECH HAMBERS DETENTION YSTEM W/ 12" STONE BASE 60 CHAMBERS VOLUME ROVIDED = 29,259 CF EE SHEET C211 AND C212 OR DETAILS MWS-L-4-6.33-V-UG MODULAR WETLAND SYSTEM FOR WATER QUALITY TREATMENT SEE DETAIL . CONNECT TO STORMTECH SYSTEM 3 LF 8" SD @ 0.0% 14 LF 8" SD @ 35.5% SD# 21 CB TYPE II - 48" RIM=457.20 IE=451.45 8"(BIDIRECTIONAL)W IE=451.45 8"(OUT)SE FLOW CONTROL STRUCTURE SEE DETAIL SD# 47 CB TYPE I RIM=457.84 IE=455.02 8"(OUT)N SPILL CONTROL STRUCTURE 8 LF 8" SD @ 50.6% SD# 49 CB TYPE I RIM=459.23 IE=454.76 8"(OUT)N SPILL CONTROL STRUCTURE 8 LF 8" SD @ 42.3% 8" SD IE=446.77 WATER QUALITY VAULT OUTLET 8" SD IE=447.27 WATER QUALITY VAULT INLET 21 LF 6" SD @ 2.0% 8 C2.10 460.71 INSPECTION PORT SEE DETAIL INSPECTION PORT SEE DETAIL FLUSH CURB 17 LF 6" SD @ 44.1% 19 LF 6" SD @ 39.5% 35 LF 6" SD @ 21.4% 11 C2.10 11 C2.10 TC 457.82 BC 457.32 TC 457.11 BC 456.61 TC 458.63 BC 458.13 TC 458.90 BC 458.40 TC 458.31 BC 457.81 TC 457.36 BC 456.86 TC 456.92 BC 456.42 TC 456.99 BC 456.49 TC 459.90 BC 459.40 TC 460.07 BC 459.57 TC 459.70 BC 459.20 460.50 FFE=460.50 460.50 TC 460.59 BC 460.09 TC 460.41 BC 459.91 TC 461.32 BC 460.82 TC 461.00 BC 460.50 TC 458.61 BC 458.11 1DS 1DS GRADE BREAK ISOLATOR ROW SEE DETAIL 3 C2.11 18 C2.10 ISOLATOR ROW SEE DETAIL 3 C2.12 54 LF 8" SD @ 7.5% Water Treatment Facility Stormtech Chamber Detention Facility Page 1 of 3 Return Address: City Clerk’s Office City of Renton 1055 S Grady Way Renton, WA 98057 DECLARATION OF COVENANT AND EASEMENT FOR INSPECTION AND MAINTENANCE OF DRAINAGE FACILITIES AND ON-SITE BMPS Grantor: Grantee: City of Renton Legal Description: Assessor's Tax Parcel ID#: IN CONSIDERATION of the approved City of Renton (check one of the following) residential building permit, commercial building permit, clearing and grading permit, subdivision permit, or short subdivision permit for application file No. LUA/SWP_______________________ relating to the real property ("Property") described above, the Grantor(s), the owner(s) in fee of that Property, hereby covenants(covenant) with the City of Renton, a political subdivision of the state of Washington, that he/she(they) will observe, consent to, and abide by the conditions and obligations set forth and described in Paragraphs 1 through 9 below with regard to the Property, and hereby grants(grant) an easement as described in Paragraphs 2 and 3. Grantor(s) hereby grants(grant), covenants(covenant), and agrees(agree) as follows: 1. The Grantor(s) or his/her(their) successors in interest and assigns ("Owners ") shall at their own cost, operate, maintain, and keep in good repair, the Property's drainage facilities constructed as required in the approved construction plans and specifications __________ on file with the City of Renton and submitted to the City of Renton for the review and approval of permit(s) _____________________________. The property's drainage facilities are shown and/or listed on Exhibit A. The property’s drainage facilities shall be maintained in compliance with the operation and maintenance schedule included and attached herein as Exhibit B. Drainage facilities include pipes, channels, flow control facilities, water quality facilities, on-site best management practices (BMPs) and other engineered structures designed to manage and/or treat stormwater on the Property. On-site BMPs include dispersion and infiltration devices, bioretention, permeable pavements, rainwater harvesting systems, tree retention credit, reduced impervious surface footprint, vegetated roofs and other measures designed to mimic pre-developed hydrology and minimize stormwater runoff on the Property. 2. City of Renton shall have the right to ingress and egress over those portions of the Property necessary to perform inspections of the stormwater facilities and BMPs and conduct maintenance activities specified in this Declaration of Covenant and in accordance with the Renton Municipal Code. City of Renton shall provide at least 30 days written notice to the Owners that entry on the Property is City of Renton See attached figure. Page 2 of 3 planned for the inspection of drainage facilities. After the 30 days, the Owners shall allow the City of Renton to enter for the sole purpose of inspecting drainage facilities. In lieu of inspection by the City, the Owners may elect to engage a licensed civil engineer registered in the state of Washington who has expertise in drainage to inspect the drainage facilities and provide a written report describing their condition. If the engineer option is chosen, the Owners shall provide written notice to the City of Renton within fifteen days of receiving the City’s notice of inspection. Within 30 days of giving this notice, the Owners, or engineer on behalf of the Owners, shall provide the engineer’s report to the City of Renton. If the report is not provided in a timely manner as specified above, the City of Renton may inspect the drainage facilities without further notice. 3. If City of Renton determines from its inspection, or from an engineer’s report provided in accordance with Paragraph 2, that maintenance, repair, restoration, and/or mitigation work is required to be done to any of the drainage facilities, City of Renton shall notify the Owners of the specific maintenance, repair, restoration, and/or mitigation work (Work) required pursuant to the Renton Municipal Code. The City shall also set a reasonable deadline for the Owners to complete the Work, or to provide an engineer’s report that verifies completion of the Work. After the deadline has passed, the Owners shall allow the City access to re-inspect the drainage facilities unless an engineer’s report has been provided verifying completion of the Work. If the Work is not completed within the time frame set by the City, the City may initiate an enforcement action and/or perform the required maintenance, repair, restoration, and/or mitigation work and hereby is given access to the Property for such purposes. Written notice will be sent to the Owners stating the City’s intention to perform such work. This work will not commence until at least seven (7) days after such notice is mailed. If, within the sole discretion of the City, there exists an imminent or present danger, the seven (7) day notice period will be waived and maintenance and/or repair work will begin immediately. 4. The Owners shall assume all responsibility for the cost of any maintenance, repair work, or any measures taken by the City to address conditions as described in Paragraph 3. Such responsibility shall include reimbursement to the City within thirty (30) days of the receipt of the invoice for any such work performed. Overdue payments will require payment of interest at the maximum legal rate allowed by RCW 19.52.020 (currently twelve percent (12%)). If the City initiates legal action to enforce this agreement, the prevailing party in such action is entitled to recover reasonable litigation costs and attorney’s fees. 5. The Owners are required to obtain written approval from City of Renton prior to filling, piping, cutting, or removing vegetation (except in routine landscape maintenance) in open vegetated stormwater facilities (such as swales, channels, ditches, ponds, etc.), or performing any alterations or modifications to the drainage facilities referenced in this Declaration of Covenant. 6. Any notice or consent required to be given or otherwise provided for by the provisions of this Agreement shall be effective upon personal delivery, or three (3) days after mailing by Certified Mail, return receipt requested. 7. With regard to the matters addressed herein, this agreement constitutes the entire agreement between the parties, and supersedes all prior discussions, negotiations, and all agreements whatsoever whether oral or written. 8. This Declaration of Covenant is intended to protect the value and desirability and promote efficient and effective management of surface water drainage of the real property described above, and shall inure to the benefit of all the citizens of the City of Renton and its successors and assigns. This Page 3 of 3 Declaration of Covenant shall run with the land and be binding upon Grantor(s), and Grantor's(s') successors in interest, and assigns. 9. This Declaration of Covenant may be terminated by execution of a written agreement by the Owners and the City that is recorded by King County in its real property records. IN WITNESS WHEREOF, this Declaration of Covenant for the Inspection and Maintenance of Drainage Facilities is executed this _____ day of ____________________, 20_____. GRANTOR, owner of the Property GRANTOR, owner of the Property STATE OF WASHINGTON ) COUNTY OF KING )ss. On this day personally appeared before me: , to me known to be the individual(s) described in and who executed the within and foregoing instrument and acknowledged that they signed the same as their free and voluntary act and deed, for the uses and purposes therein stated. Given under my hand and official seal this _____ day of ____________________, 20_____. Printed name Notary Public in and for the State of Washington, residing at My appointment expires Legal Description (LEGAL DESCRIPTION PER R1) THE SOUTH 800 FEET OF THE NORTH 830 FEET OF THE WEST 816.75 FEET OF THE NORTHWEST QUARTER OF SECTION 28, TOWNSHIP 23 NORTH, RANGE 5 EAST, W.M., IN KING COUNTY, WASHINGTON; EXCEPT THE WEST 30 FEET THEREOF CONVEYED TO KING COUNTY FOR 116TH AVE SE BY DEED RECORDED UNDER RECORDING NO. 5091695; TOGETHER WITH THAT PORTION OF THE SOUTH 800 FEET OF THE NORTH 830 FEET OF THE NORTHWEST QUARTER OF SECTION 28, TOWNSHIP 23 NORTH, RANGE 5 EAST, W.M., IN KING COUNTY, WASHINGTON, LYING WESTERLY OF THE PLAT OF CASCADE HILLS NO. 2, ACCORDING TO THE PLAT THEREOF RECORDED IN VOLUME 61 OF PLATS, PAGES 13 AND 14, IN KING COUNTY WASHINGTON; EXCEPT THE WEST 816.75 FEET THEREOF. Planning Division |1055 South Grady Way – 6th Floor | Renton, WA 98057 (425) 430-7200Date Prepared: Name:PE Registration No:Firm Name:Firm Address:Phone No.Email Address:Project Name: Project Owner:CED Plan # (LUA):Phone:CED Permit # (U):Address: Site Address:Street Intersection:Addt'l Project Owner:Parcel #(s):Phone:Address: Clearing and grading greater than or equal to 5,000 board feet of timber? Yes/No:NOWater Service Provided by:If Yes, Provide Forest Practice Permit #:Sewer Service Provided by: AddressAbbreviated Legal Description:Northwest Quarter of Section 28, Township 23 N, Range 5 E, W.M., in King County, WA. Recording No. 5091695. According to the Plat Thereof Recorded in Volume 61 of Plats, Pages 13 and 14, in King County WA.City, State, Zip16022 116th Ave SE, Renton WA 98058AddressAdditional Project Owner116th Ave SE & SE 163rd StTBDPhone12/5/2019Prepared by:FOR APPROVALProject Phase 1AaronF@cplinc.comAaron FjelstadPE Registration No.Coughling Porter Lundeen801 2nd Ave Suite 900, Seattle WA 98104(206)343-0460SITE IMPROVEMENT BOND QUANTITY WORKSHEETPROJECT INFORMATIONSOOS CREEK WATER & SEWERSOOS CREEK WATER & SEWER1 Select the current project status/phase from the following options: For Approval - Preliminary Data Enclosed, pending approval from the City; For Construction - Estimated Data Enclosed, Plans have been approved for contruction by the City; Project Closeout - Final Costs and Quantities Enclosed for Project Close-out SubmittalPhoneEngineer Stamp Required (all cost estimates must have original wet stamp and signature)Clearing and GradingUtility ProvidersN/AProject Location and DescriptionProject Owner InformationFamily First Community CenterCity, State, Zip2823059034City of RentonTBDPage 2 of 14Ref 8-H Bond Quantity WorksheetSECTION I PROJECT INFORMATIONUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 12/5/2019 CED Permit #:TBDUnitReference #PriceUnitQuantity CostBackfill & compaction-embankmentESC-16.50$ CY Check dams, 4" minus rockESC-2SWDM 5.4.6.380.00$ Each161,280.00Catch Basin ProtectionESC-335.50$ Each8284.00Crushed surfacing 1 1/4" minusESC-4WSDOT 9-03.9(3)95.00$ CY DitchingESC-59.00$ CY Excavation-bulkESC-62.00$ CY Fence, siltESC-7SWDM 5.4.3.11.50$ LF Fence, Temporary (NGPE)ESC-81.50$ LF Geotextile FabricESC-92.50$ SY Hay Bale Silt TrapESC-100.50$ Each HydroseedingESC-11SWDM 5.4.2.40.80$ SY Interceptor Swale / DikeESC-121.00$ LF819819.00Jute MeshESC-13SWDM 5.4.2.23.50$ SY Level SpreaderESC-141.75$ LF Mulch, by hand, straw, 3" deepESC-15SWDM 5.4.2.12.50$ SY Mulch, by machine, straw, 2" deepESC-16SWDM 5.4.2.12.00$ SY Piping, temporary, CPP, 6"ESC-1712.00$ LF Piping, temporary, CPP, 8"ESC-1814.00$ LF Piping, temporary, CPP, 12"ESC-1918.00$ LF Plastic covering, 6mm thick, sandbaggedESC-20SWDM 5.4.2.34.00$ SY Rip Rap, machine placed; slopesESC-21WSDOT 9-13.1(2)45.00$ CY Rock Construction Entrance, 50'x15'x1'ESC-22SWDM 5.4.4.11,800.00$ Each Rock Construction Entrance, 100'x15'x1'ESC-23SWDM 5.4.4.13,200.00$ Each Sediment pond riser assemblyESC-24SWDM 5.4.5.22,200.00$ Each12,200.00Sediment trap, 5' high berm ESC-25SWDM 5.4.5.119.00$ LF Sed. trap, 5' high, riprapped spillway berm section ESC-26SWDM 5.4.5.170.00$ LF Seeding, by handESC-27SWDM 5.4.2.41.00$ SY Sodding, 1" deep, level groundESC-28SWDM 5.4.2.58.00$ SY Sodding, 1" deep, sloped groundESC-29SWDM 5.4.2.510.00$ SY TESC SupervisorESC-30110.00$ HR Water truck, dust controlESC-31SWDM 5.4.7140.00$ HR UnitReference #PriceUnitQuantity Cost EROSION/SEDIMENT SUBTOTAL:4,583.00SALES TAX @ 10%458.30EROSION/SEDIMENT TOTAL:5,041.30(A)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR EROSION & SEDIMENT CONTROLDescription No.(A)WRITE-IN-ITEMS Page 3 of 14Ref 8-H Bond Quantity WorksheetSECTION II.a EROSION_CONTROLUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 12/5/2019 CED Permit #:TBDExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostGENERAL ITEMS Backfill & Compaction- embankmentGI-16.00$ CYBackfill & Compaction- trenchGI-29.00$ CYClear/Remove Brush, by hand (SY)GI-31.00$ SYBollards - fixedGI-4240.74$ EachBollards - removableGI-5452.34$ EachClearing/Grubbing/Tree RemovalGI-610,000.00$ Acre2.5125,100.00Excavation - bulkGI-72.00$ CYExcavation - TrenchGI-85.00$ CYFencing, cedar, 6' highGI-920.00$ LFFencing, chain link, 4'GI-1038.31$ LFFencing, chain link, vinyl coated, 6' highGI-1120.00$ LF170534,100.00Fencing, chain link, gate, vinyl coated, 20' GI-121,400.00$ EachFill & compact - common barrowGI-1325.00$ CYFill & compact - gravel baseGI-1427.00$ CYFill & compact - screened topsoilGI-1539.00$ CYGabion, 12" deep, stone filled mesh GI-1665.00$ SYGabion, 18" deep, stone filled mesh GI-1790.00$ SYGabion, 36" deep, stone filled meshGI-18150.00$ SYGrading, fine, by handGI-192.50$ SYGrading, fine, with graderGI-202.00$ SYMonuments, 3' LongGI-21250.00$ EachSensitive Areas SignGI-227.00$ EachSodding, 1" deep, sloped groundGI-238.00$ SYSurveying, line & gradeGI-24850.00$ DaySurveying, lot location/linesGI-251,800.00$ AcreTopsoil Type A (imported)GI-2628.50$ CYTraffic control crew ( 2 flaggers )GI-27120.00$ HRTrail, 4" chipped woodGI-288.00$ SYTrail, 4" crushed cinderGI-299.00$ SYTrail, 4" top courseGI-3012.00$ SYConduit, 2"GI-315.00$ LFWall, retaining, concreteGI-3255.00$ SFWall, rockeryGI-3315.00$ SFSUBTOTAL THIS PAGE:59,200.00(B)(C)(D)(E)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR STREET AND SITE IMPROVEMENTSQuantity Remaining (Bond Reduction) (B)(C)Page 4 of 14Ref 8-H Bond Quantity WorksheetSECTION II.b TRANSPORTATIONUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 12/5/2019 CED Permit #:TBDExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostSITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR STREET AND SITE IMPROVEMENTSQuantity Remaining (Bond Reduction) (B)(C)ROAD IMPROVEMENT/PAVEMENT/SURFACINGAC Grinding, 4' wide machine < 1000syRI-130.00$ SYAC Grinding, 4' wide machine 1000-2000syRI-216.00$ SYAC Grinding, 4' wide machine > 2000syRI-310.00$ SYAC Removal/DisposalRI-435.00$ SY238183,335.00Barricade, Type III ( Permanent )RI-556.00$ LFGuard RailRI-630.00$ LFCurb & Gutter, rolledRI-717.00$ LF2043,468.00Curb & Gutter, verticalRI-812.50$ LF278634,825.00Curb and Gutter, demolition and disposalRI-918.00$ LF105118,918.00Curb, extruded asphaltRI-105.50$ LFCurb, extruded concreteRI-117.00$ LFSawcut, asphalt, 3" depthRI-121.85$ LF7481,383.80Sawcut, concrete, per 1" depthRI-133.00$ LFSealant, asphaltRI-142.00$ LFShoulder, gravel, 4" thickRI-1515.00$ SYSidewalk, 4" thickRI-1638.00$ SY157559,850.00Sidewalk, 4" thick, demolition and disposalRI-1732.00$ SY81225,984.00Sidewalk, 5" thickRI-1841.00$ SYSidewalk, 5" thick, demolition and disposalRI-1940.00$ SYSign, Handicap RI-2085.00$ EachStriping, per stallRI-217.00$ Each108756.00Striping, thermoplastic, ( for crosswalk )RI-223.00$ SF4401,320.00Striping, 4" reflectorized lineRI-230.50$ LFAdditional 2.5" Crushed SurfacingRI-243.60$ SYHMA 1/2" Overlay 1.5" RI-2514.00$ SYHMA 1/2" Overlay 2"RI-2618.00$ SYHMA Road, 2", 4" rock, First 2500 SYRI-2728.00$ SYHMA Road, 2", 4" rock, Qty. over 2500SYRI-2821.00$ SYHMA Road, 4", 6" rock, First 2500 SYRI-2945.00$ SYHMA Road, 4", 6" rock, Qty. over 2500 SYRI-3037.00$ SYHMA Road, 4", 4.5" ATBRI-3138.00$ SYGravel Road, 4" rock, First 2500 SYRI-3215.00$ SYGravel Road, 4" rock, Qty. over 2500 SYRI-3310.00$ SYThickened EdgeRI-348.60$ LFSUBTOTAL THIS PAGE:229,839.80(B)(C)(D)(E)Page 5 of 14Ref 8-H Bond Quantity WorksheetSECTION II.b TRANSPORTATIONUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 12/5/2019 CED Permit #:TBDExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostSITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR STREET AND SITE IMPROVEMENTSQuantity Remaining (Bond Reduction) (B)(C)PARKING LOT SURFACINGNo.2" AC, 2" top course rock & 4" borrowPL-121.00$ SY5748120,708.002" AC, 1.5" top course & 2.5" base coursePL-228.00$ SY4" select borrowPL-35.00$ SY1.5" top course rock & 2.5" base coursePL-414.00$ SYSUBTOTAL PARKING LOT SURFACING:120,708.00(B)(C)(D)(E)LANDSCAPING & VEGETATIONNo.Street TreesLA-1Median LandscapingLA-2Right-of-Way LandscapingLA-3Wetland LandscapingLA-4SUBTOTAL LANDSCAPING & VEGETATION:(B)(C)(D)(E)TRAFFIC & LIGHTINGNo.SignsTR-1Street Light System ( # of Poles)TR-2Traffic SignalTR-3Traffic Signal ModificationTR-4SUBTOTAL TRAFFIC & LIGHTING:(B)(C)(D)(E)WRITE-IN-ITEMSSUBTOTAL WRITE-IN ITEMS:STREET AND SITE IMPROVEMENTS SUBTOTAL:409,747.80SALES TAX @ 10%40,974.78STREET AND SITE IMPROVEMENTS TOTAL:450,722.58(B)(C)(D)(E)Page 6 of 14Ref 8-H Bond Quantity WorksheetSECTION II.b TRANSPORTATIONUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 12/5/2019 CED Permit #:TBDExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostDRAINAGE (CPE = Corrugated Polyethylene Pipe, N12 or Equivalent) For Culvert prices, Average of 4' cover was assumed. Assume perforated PVC is same price as solid pipe.) Access Road, R/DD-126.00$ SY* (CBs include frame and lid)BeehiveD-290.00$ Each190.00Through-curb Inlet FrameworkD-3400.00$ EachCB Type ID-41,500.00$ Each812,000.00CB Type ILD-51,750.00$ EachCB Type II, 48" diameterD-62,300.00$ Each511,500.00 for additional depth over 4' D-7480.00$ FTCB Type II, 54" diameterD-82,500.00$ Each for additional depth over 4'D-9495.00$ FTCB Type II, 60" diameterD-102,800.00$ Each25,600.00 for additional depth over 4'D-11600.00$ FTCB Type II, 72" diameterD-126,000.00$ Each for additional depth over 4'D-13850.00$ FTCB Type II, 96" diameterD-1414,000.00$ Each for additional depth over 4'D-15925.00$ FTTrash Rack, 12"D-16350.00$ EachTrash Rack, 15"D-17410.00$ EachTrash Rack, 18"D-18480.00$ EachTrash Rack, 21"D-19550.00$ EachCleanout, PVC, 4"D-20150.00$ EachCleanout, PVC, 6"D-21170.00$ Each1170.00Cleanout, PVC, 8"D-22200.00$ EachCulvert, PVC, 4" D-2310.00$ LFCulvert, PVC, 6" D-2413.00$ LFCulvert, PVC, 8" D-2515.00$ LFCulvert, PVC, 12" D-2623.00$ LFCulvert, PVC, 15" D-2735.00$ LFCulvert, PVC, 18" D-2841.00$ LFCulvert, PVC, 24"D-2956.00$ LFCulvert, PVC, 30" D-3078.00$ LFCulvert, PVC, 36" D-31130.00$ LFCulvert, CMP, 8"D-3219.00$ LFCulvert, CMP, 12"D-3329.00$ LFSUBTOTAL THIS PAGE:29,360.00(B)(C)(D)(E)Quantity Remaining (Bond Reduction) (B)(C)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESPage 7 of 14Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 12/5/2019 CED Permit #:TBDExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostQuantity Remaining (Bond Reduction) (B)(C)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESDRAINAGE (Continued)Culvert, CMP, 15"D-3435.00$ LFCulvert, CMP, 18"D-3541.00$ LFCulvert, CMP, 24"D-3656.00$ LFCulvert, CMP, 30"D-3778.00$ LFCulvert, CMP, 36"D-38130.00$ LFCulvert, CMP, 48"D-39190.00$ LFCulvert, CMP, 60"D-40270.00$ LFCulvert, CMP, 72"D-41350.00$ LFCulvert, Concrete, 8"D-4242.00$ LFCulvert, Concrete, 12"D-4348.00$ LFCulvert, Concrete, 15"D-4478.00$ LFCulvert, Concrete, 18"D-4548.00$ LFCulvert, Concrete, 24"D-4678.00$ LFCulvert, Concrete, 30"D-47125.00$ LFCulvert, Concrete, 36"D-48150.00$ LFCulvert, Concrete, 42"D-49175.00$ LFCulvert, Concrete, 48"D-50205.00$ LFCulvert, CPE Triple Wall, 6" D-5114.00$ LFCulvert, CPE Triple Wall, 8" D-5216.00$ LFCulvert, CPE Triple Wall, 12" D-5324.00$ LFCulvert, CPE Triple Wall, 15" D-5435.00$ LFCulvert, CPE Triple Wall, 18" D-5541.00$ LFCulvert, CPE Triple Wall, 24" D-5656.00$ LFCulvert, CPE Triple Wall, 30" D-5778.00$ LFCulvert, CPE Triple Wall, 36" D-58130.00$ LFCulvert, LCPE, 6"D-5960.00$ LFCulvert, LCPE, 8"D-6072.00$ LFCulvert, LCPE, 12"D-6184.00$ LFCulvert, LCPE, 15"D-6296.00$ LFCulvert, LCPE, 18"D-63108.00$ LFCulvert, LCPE, 24"D-64120.00$ LFCulvert, LCPE, 30"D-65132.00$ LFCulvert, LCPE, 36"D-66144.00$ LFCulvert, LCPE, 48"D-67156.00$ LFCulvert, LCPE, 54"D-68168.00$ LFSUBTOTAL THIS PAGE:(B)(C)(D)(E)Page 8 of 14Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 12/5/2019 CED Permit #:TBDExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostQuantity Remaining (Bond Reduction) (B)(C)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESDRAINAGE (Continued)Culvert, LCPE, 60"D-69180.00$ LFCulvert, LCPE, 72"D-70192.00$ LFCulvert, HDPE, 6"D-7142.00$ LF1506,300.00Culvert, HDPE, 8"D-7242.00$ LF120150,442.00Culvert, HDPE, 12"D-7374.00$ LFCulvert, HDPE, 15"D-74106.00$ LFCulvert, HDPE, 18"D-75138.00$ LFCulvert, HDPE, 24"D-76221.00$ LFCulvert, HDPE, 30"D-77276.00$ LFCulvert, HDPE, 36"D-78331.00$ LFCulvert, HDPE, 48"D-79386.00$ LFCulvert, HDPE, 54"D-80441.00$ LFCulvert, HDPE, 60"D-81496.00$ LFCulvert, HDPE, 72"D-82551.00$ LFPipe, Polypropylene, 6"D-8384.00$ LFPipe, Polypropylene, 8"D-8489.00$ LFPipe, Polypropylene, 12"D-8595.00$ LFPipe, Polypropylene, 15"D-86100.00$ LFPipe, Polypropylene, 18"D-87106.00$ LFPipe, Polypropylene, 24"D-88111.00$ LFPipe, Polypropylene, 30"D-89119.00$ LFPipe, Polypropylene, 36"D-90154.00$ LFPipe, Polypropylene, 48"D-91226.00$ LFPipe, Polypropylene, 54"D-92332.00$ LFPipe, Polypropylene, 60"D-93439.00$ LFPipe, Polypropylene, 72"D-94545.00$ LFCulvert, DI, 6"D-9561.00$ LFCulvert, DI, 8"D-9684.00$ LFCulvert, DI, 12"D-97106.00$ LFCulvert, DI, 15"D-98129.00$ LFCulvert, DI, 18"D-99152.00$ LFCulvert, DI, 24"D-100175.00$ LFCulvert, DI, 30"D-101198.00$ LFCulvert, DI, 36"D-102220.00$ LFCulvert, DI, 48"D-103243.00$ LFCulvert, DI, 54"D-104266.00$ LFCulvert, DI, 60"D-105289.00$ LFCulvert, DI, 72"D-106311.00$ LFSUBTOTAL THIS PAGE:56,742.00(B)(C)(D)(E)Page 9 of 14Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 12/5/2019 CED Permit #:TBDExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostQuantity Remaining (Bond Reduction) (B)(C)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESSpecialty Drainage ItemsDitching SD-19.50$ CYFlow Dispersal Trench (1,436 base+)SD-328.00$ LF French Drain (3' depth)SD-426.00$ LFGeotextile, laid in trench, polypropyleneSD-53.00$ SYMid-tank Access Riser, 48" dia, 6' deepSD-62,000.00$ EachPond Overflow SpillwaySD-716.00$ SYRestrictor/Oil Separator, 12"SD-81,150.00$ EachRestrictor/Oil Separator, 15"SD-91,350.00$ EachRestrictor/Oil Separator, 18"SD-101,700.00$ EachRiprap, placedSD-1142.00$ CYTank End Reducer (36" diameter)SD-121,200.00$ EachInfiltration pond testingSD-13125.00$ HRPermeable PavementSD-14Permeable Concrete SidewalkSD-15Culvert, Box __ ft x __ ftSD-16SUBTOTAL SPECIALTY DRAINAGE ITEMS:(B)(C)(D)(E)STORMWATER FACILITIES (Include Flow Control and Water Quality Facility Summary Sheet and Sketch)Detention PondSF-1Each Detention TankSF-2Each Detention VaultSF-3Each Infiltration PondSF-4Each Infiltration TankSF-5Each Infiltration VaultSF-6Each Infiltration TrenchesSF-7Each Basic Biofiltration SwaleSF-8Each Wet Biofiltration SwaleSF-9Each WetpondSF-10Each WetvaultSF-11Each Sand FilterSF-12Each Sand Filter VaultSF-13Each Linear Sand FilterSF-14Each Proprietary FacilitySF-15Each Bioretention FacilitySF-16Each SUBTOTAL STORMWATER FACILITIES:(B)(C)(D)(E)Page 10 of 14Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 12/5/2019 CED Permit #:TBDExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostQuantity Remaining (Bond Reduction) (B)(C)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESWRITE-IN-ITEMS (INCLUDE ON-SITE BMPs)WI-1WI-2WI-3WI-4WI-5WI-6WI-7WI-8WI-9WI-10WI-11WI-12WI-13WI-14WI-15SUBTOTAL WRITE-IN ITEMS:DRAINAGE AND STORMWATER FACILITIES SUBTOTAL:86,102.00SALES TAX @ 10%8,610.20DRAINAGE AND STORMWATER FACILITIES TOTAL:94,712.20(B) (C) (D) (E)Page 11 of 14Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 12/5/2019 CED Permit #:TBDExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostConnection to Existing WatermainW-12,000.00$ EachDuctile Iron Watermain, CL 52, 4 Inch DiameterW-250.00$ LFDuctile Iron Watermain, CL 52, 6 Inch DiameterW-356.00$ LFDuctile Iron Watermain, CL 52, 8 Inch DiameterW-460.00$ LFDuctile Iron Watermain, CL 52, 10 Inch DiameterW-570.00$ LFDuctile Iron Watermain, CL 52, 12 Inch DiameterW-680.00$ LFGate Valve, 4 inch DiameterW-7500.00$ EachGate Valve, 6 inch DiameterW-8700.00$ EachGate Valve, 8 Inch DiameterW-9800.00$ EachGate Valve, 10 Inch DiameterW-101,000.00$ EachGate Valve, 12 Inch DiameterW-111,200.00$ EachFire Hydrant AssemblyW-124,000.00$ EachPermanent Blow-Off AssemblyW-131,800.00$ EachAir-Vac Assembly, 2-Inch DiameterW-142,000.00$ EachAir-Vac Assembly, 1-Inch DiameterW-151,500.00$ EachCompound Meter Assembly 3-inch DiameterW-168,000.00$ EachCompound Meter Assembly 4-inch DiameterW-179,000.00$ EachCompound Meter Assembly 6-inch DiameterW-1810,000.00$ EachPressure Reducing Valve Station 8-inch to 10-inchW-1920,000.00$ EachWATER SUBTOTAL:SALES TAX @ 10%WATER TOTAL:(B) (C) (D) (E)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR WATERQuantity Remaining (Bond Reduction) (B)(C)Page 12 of 14Ref 8-H Bond Quantity WorksheetSECTION II.d WATERUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 12/5/2019 CED Permit #:TBDExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostClean OutsSS-11,000.00$ EachGrease Interceptor, 500 gallonSS-28,000.00$ EachGrease Interceptor, 1000 gallonSS-310,000.00$ EachGrease Interceptor, 1500 gallonSS-415,000.00$ EachSide Sewer Pipe, PVC. 4 Inch DiameterSS-580.00$ LFSide Sewer Pipe, PVC. 6 Inch DiameterSS-695.00$ LFSewer Pipe, PVC, 8 inch DiameterSS-7105.00$ LFSewer Pipe, PVC, 12 Inch DiameterSS-8120.00$ LFSewer Pipe, DI, 8 inch DiameterSS-9115.00$ LFSewer Pipe, DI, 12 Inch DiameterSS-10130.00$ LFManhole, 48 Inch DiameterSS-116,000.00$ EachManhole, 54 Inch DiameterSS-136,500.00$ EachManhole, 60 Inch DiameterSS-157,500.00$ EachManhole, 72 Inch DiameterSS-178,500.00$ EachManhole, 96 Inch DiameterSS-1914,000.00$ EachPipe, C-900, 12 Inch DiameterSS-21180.00$ LFOutside DropSS-241,500.00$ LSInside DropSS-251,000.00$ LSSewer Pipe, PVC, ____ Inch DiameterSS-26Lift Station (Entire System)SS-27LSSANITARY SEWER SUBTOTAL:SALES TAX @ 10%SANITARY SEWER TOTAL:(B) (C) (D) (E)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR SANITARY SEWERQuantity Remaining (Bond Reduction) (B)(C)Page 13 of 14Ref 8-H Bond Quantity WorksheetSECTION II.e SANITARY SEWERUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 12/5/2019 Planning Division |1055 South Grady Way – 6th Floor | Renton, WA 98057 (425) 430-7200Date:Name:Project Name: PE Registration No:CED Plan # (LUA):Firm Name:CED Permit # (U):Firm Address:Site Address:Phone No.Parcel #(s):Email Address:Project Phase: Site Restoration/Erosion Sediment Control Subtotal (a)Existing Right-of-Way Improvements Subtotal (b)(b)-$ Future Public Improvements Subtotal(c)-$ Stormwater & Drainage Facilities (Public & Private) Subtotal(d)(d)94,712.20$ (e)(f)Site RestorationCivil Construction PermitMaintenance Bond18,942.44$ Bond Reduction2Construction Permit Bond Amount 3Minimum Bond Amount is $10,000.001 Estimate Only - May involve multiple and variable components, which will be established on an individual basis by Development Engineering.2 The City of Renton allows one request only for bond reduction prior to the maintenance period. Reduction of not more than 70% of the original bond amount, provided that the remaining 30% willcover all remaining items to be constructed. 3 Required Bond Amounts are subject to review and modification by Development Engineering.* Note: The word BOND as used in this document means any financial guarantee acceptable to the City of Renton.** Note: All prices include labor, equipment, materials, overhead and profit. EST1((b) + (c) + (d)) x 20%-$ MAINTENANCE BOND */**(after final acceptance of construction)5,041.30$ -$ 94,712.20$ 5,041.30$ -$ 94,712.20$ -$ 99,753.50$ P (a) x 100%SITE IMPROVEMENT BOND QUANTITY WORKSHEET BOND CALCULATIONS12/5/2019Aaron FjelstadPE Registration No.Coughling Porter LundeenR((b x 150%) + (d x 100%))S(e) x 150% + (f) x 100%Bond Reduction: Existing Right-of-Way Improvements (Quantity Remaining)2Bond Reduction: Stormwater & Drainage Facilities (Quantity Remaining)2T(P +R - S)Prepared by:Project InformationCONSTRUCTION BOND AMOUNT */**(prior to permit issuance)(206)343-0460AaronF@cplinc.comFamily First Community CenterTBD16022 116th Ave SE, Renton WA 980582823059034FOR APPROVALTBD801 2nd Ave Suite 900, Seattle WA 98104Page 14 of 14Ref 8-H Bond Quantity WorksheetSECTION III. BOND WORKSHEETUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 12/5/2019 Corporate Office 17522 Bothell Way Northeast Bothell, Washington 98011 Phone 425.415.0551 ♦ Fax 425.415.0311 www.riley-group.com GEOTECHNICAL ENGINEERING REPORT PREPARED BY: THE RILEY GROUP, INC. 17522 BOTHELL WAY NORTHEAST BOTHELL, WASHINGTON 98011 PREPARED FOR: MS. KELLY BEYMER ADMINISTRATOR OF COMMUNITY SERVICE DEPARTMENT CITY OF RENTON 1055 SOUTH GRADY WAY RENTON, WASHINGTON 98057 RGI PROJECT NO. 2018-130 FAMILY FIRST COMMUNITY CENTER 16022 116TH AVENUE SOUTHEAST RENTON, WASHINGTON 98058 JUNE 8, 2018 Geotechnical Engineering Report June 8, 2018 Family First Community Center, Renton, Washington RGI Project No. 2018-130 TABLE OF CONTENTS 1.0 INTRODUCTION ............................................................................................................................... 1 2.0 PROJECT DESCRIPTION .................................................................................................................... 1 3.0 FIELD EXPLORATION AND LABORATORY TESTING ........................................................................... 1 4.0 SITE CONDITIONS ............................................................................................................................ 2 4.1 SURFACE .................................................................................................................................................. 2 4.2 GEOLOGY ................................................................................................................................................. 2 4.3 SOILS ....................................................................................................................................................... 2 4.4 GROUNDWATER ........................................................................................................................................ 2 4.5 SEISMIC CONSIDERATIONS ........................................................................................................................... 3 4.6 COAL MINE HAZARD .................................................................................................................................. 3 5.0 DISCUSSION AND RECOMMENDATIONS ......................................................................................... 4 5.1 GEOTECHNICAL CONSIDERATIONS ................................................................................................................. 4 5.2 EARTHWORK ............................................................................................................................................. 4 5.2.1 Erosion and Sediment Control ..................................................................................................... 4 5.2.2 Stripping ....................................................................................................................................... 5 5.2.3 Excavations................................................................................................................................... 5 5.2.4 Site Preparation ........................................................................................................................... 6 5.2.5 Structural Fill ................................................................................................................................ 6 5.2.6 Cut and Fill Slopes ........................................................................................................................ 8 5.2.7 Wet Weather Construction Considerations ................................................................................. 8 5.3 FOUNDATIONS .......................................................................................................................................... 9 5.4 RETAINING WALLS ................................................................................................................................... 10 5.5 SLAB-ON-GRADE CONSTRUCTION ............................................................................................................... 10 5.6 DRAINAGE .............................................................................................................................................. 10 5.6.1 Surface ....................................................................................................................................... 10 5.6.2 Subsurface .................................................................................................................................. 11 5.6.3 Infiltration .................................................................................................................................. 11 5.7 UTILITIES ................................................................................................................................................ 11 5.8 PAVEMENTS ............................................................................................................................................ 11 5.9 CONSTRUCTION CONSIDERATIONS ............................................................................................................... 12 6.0 ADDITIONAL SERVICES .................................................................................................................. 12 7.0 LIMITATIONS ................................................................................................................................. 12 LIST OF APPENDICES Figure 1 ..................................................................................................................... Site Vicinity Map Figure 2 ............................................................................................... Geotechnical Exploration Plan Figure 3 ............................................................................................... Retaining Wall Drainage Detail Figure 4 ....................................................................................................Typical Footing Drain Detail Appendix A .......................................................................... Field Exploration and Laboratory Testing Geotechnical Engineering Report June 8, 2018 Family First Community Center, Renton, Washington RGI Project No. 2018-130 Executive Summary This Executive Summary should be used in conjunction with the entire GER for design and/or construction purposes. It should be recognized that specific details were not included or fully developed in this section, and this GER must be read in its entirety for a comprehensive understanding of the items contained herein. Section 7.0 should be read for an understanding of limitations. RGI’s geotechnical scope of work included the advancement of seven test borings to a maximum depth of 16.5 feet below ground surface (bgs). Based on the information obtained from our subsurface exploration, the site is suitable for development of the proposed project. The following geotechnical considerations were identified. Soil Conditions: The site is underlain by up to 11 feet of fill comprised of loose to medium dense silty sand with varying amounts of gravel over medium dense to very dense silty sand with varying amounts of gravel, and localized silty sand, sandy gravel, and sand with some silt and gravel. Groundwater: Groundwater seepage was encountered at 15 feet bgs in two of the test borings during our subsurface exploration. Foundations: The proposed buildings can be supported on spread footing foundation bearing on competent native soil or structural fill. Slab-on-grade: Slab-on-grade floors can be supported on dense to medium dense native soil or new structural fill. Pavements: The following pavement sections are recommended for new driveway areas:  For flexible pavements: 2 inches of HMA over 6 inches of Crushed Rock Base (CRB) over compacted subgrade.  For concrete driveways: 5 inches of concrete over 4 inches of CRB over compacted subgrade Construction Considerations: RGI recommends that the major earthwork be performed in dry season from May to September. Geotechnical Engineering Report 1 June 8, 2018 Family First Community Center, Renton, Washington RGI Project No. 2018-130 1.0 Introduction This Geotechnical Engineering Report (GER) presents the results of the geotechnical engineering services provided for the Family First Community Center in Renton, Washington. The purpose of this GER is to assess subsurface conditions and provide geotechnical recommendations for building a one-story community center building. Our scope of services included field explorations, laboratory testing, engineering analyses, and preparation of this GER. The recommendations in the following sections of this GER are based upon our current understanding of the proposed site development as outlined below. RGI should review the proposed site grading and utility plans once they are developed in order to confirm the recommendations provided in this report are appropriate for the development as proposed. In addition, RGI requests to review the final site grading plans and specifications when available to verify that our project understanding is correct and that our recommendations have been properly interpreted and incorporated into the project design and construction. 2.0 Project Description The site is located 16022 116th Avenue Southeast in Renton, Washington. The approximate location of the site is shown on Figure 1. The site includes a rectangular shaped parcel of land about 14.9 aces in size. The northern portion of the site is occupied by a school building and facilities. The proposed development will be located at the southwest corner of the property. The proposed Family First Community Center building will be a one-story building about 30,000 square feet in size with a slab on grade floor. Our understanding of the project is based on the Master Site Plan prepared by Baylis Architecture dated February 26, 2018. RGI expects the proposed building will be a one-story, light-weight structure with a maximum column load of less than 100 kips. Slab-on-grade floor loading of 150 pounds per square foot (psf) are expected. RGI anticipates that grading with fill up to approximately 10 feet will be needed in the existing stormwater pond area to reach the design grade. 3.0 Field Exploration and Laboratory Testing On May 23, 2018, RGI performed subsurface exploration using a tracked drill rig. A total of seven test borings were advanced in the proposed development area. The approximate exploration locations are shown on Figure 2. Field logs of each exploration were prepared by the geologist who completed the borings. These logs included visual classifications of the materials encountered during excavation Geotechnical Engineering Report 2 June 8, 2018 Family First Community Center, Renton, Washington RGI Project No. 2018-130 as well as our interpretation of the subsurface conditions between samples. The boring logs included in Appendix A represent an interpretation of the field logs and include modifications based on laboratory observation and analysis of the samples. 4.0 Site Conditions 4.1 SURFACE The entire site includes a rectangular shaped parcel of land about 14.9 aces in size. The proposed development area is located in the southwest portion of the site and is approximately 3.35 acres in size. The project area is bound to the north and east by the existing school building and facilities, to the south by residential properties, and to the west by 116th Avenue Southeast. The western portion of the proposed development area is a paved parking lot. An existing storm water pond approximately 10 feet deep is located along the southern property line. To the north of the pond, there is 5-foot hump area that appears to have been created by the excavated soil from the pond excavation. 4.2 GEOLOGY Review of the Geologic Map of King County, Washington by Derek B. Booth, etc (2002) indicates that the site soil is mapped as till (Map Unit Qvt) which is compact diamict containing subrounded to well-rounded clasts, glacially transported and deposited. Generally forms undulating layers a few meters to a few tens of meters thick. The native soil below the fill encountered during field exploration appears to match the description. 4.3 SOILS The site is underlain by up to 11 feet of fill comprised of loose to medium dense silty sand with varying amounts of gravel over medium dense to very dense silty sand with varying amounts of gravel, and localized silty sand, sandy gravel, and sand with some silt and gravel. More detailed descriptions of the subsurface conditions encountered are presented in the test borings included in Appendix A. 4.4 GROUNDWATER Groundwater seepage was encountered at 15 feet bgs in two of the test borings during our subsurface exploration. It should be recognized that fluctuations of the groundwater table will occur due to seasonal variations in the amount of rainfall, runoff, and other factors not evident at the time the explorations were performed. In addition, perched water can develop within seams and layers contained in fill soils or higher permeability soils overlying less permeable soils following periods of heavy or prolonged precipitation. Therefore, Geotechnical Engineering Report 3 June 8, 2018 Family First Community Center, Renton, Washington RGI Project No. 2018-130 groundwater levels during construction or at other times in the future may be higher or lower than the levels indicated on the logs. Groundwater level fluctuations should be considered when developing the design and construction plans for the project. 4.5 SEISMIC CONSIDERATIONS Based on the 2012/2015 International Building Code (IBC), RGI recommends the follow seismic parameters in Table 1 be used for design. Table 1 IBC Seismic Parameters 2012/2015 IBC Parameter Value Site Soil Class1 D2 Site Latitude 47.45859 N Site Longitude 122.18416 W Maximum considered earthquake spectral response acceleration parameters (g) Ss = 1.399, S1 = 0.522 Spectral response acceleration parameters adjusted for site class (g) Sms = 1.399, Sm1 = 0.783 Design spectral response acceleration parameters (g) Sds = 0.933, Sd1 = 0.522 1 Note: In general accordance with the USGS 2012/2015 International Building Code. IBC Site Class is based on the average characteristics of the upper 100 feet of the subsurface profile. 2 Note: The 2012/2015 International Building Code requires a site soil profile determination extending to a depth of 100 feet for seismic site classification. The current scope of our services does not include the required 100 foot soil profile determination. Hand auger borings extended to a maximum depth of 16.5 feet, and this seismic site class definition considers that similar soil continues below the maximum depth of the subsurface exploration. Liquefaction is a phenomenon where there is a reduction or complete loss of soil strength due to an increase in water pressure induced by vibrations from a seismic event. Liquefaction mainly affects geologically recent deposits of fine-grained sands that are below the groundwater table. Soils of this nature derive their strength from intergranular friction. The generated water pressure or pore pressure essentially separates the soil grains and eliminates this intergranular friction, thus reducing or eliminating the soil’s strength. RGI reviewed the results of the field and laboratory testing and assessed the potential for liquefaction of the site’s soil during an earthquake in the area. The site is underlain by till which is considered not liquefiable. 4.6 COAL MINE HAZARD RGI has reviewed the City of Renton Coal Mine Hazards map dated November 12, 2014. The project site is not mapped as a coal mine hazard area. Geotechnical Engineering Report 4 June 8, 2018 Family First Community Center, Renton, Washington RGI Project No. 2018-130 5.0 Discussion and Recommendations 5.1 GEOTECHNICAL CONSIDERATIONS Based on our study, the site is suitable for the proposed construction from a geotechnical standpoint. RGI recommends that proposed buildings be supported on spread footings bearing on medium dense native soil or structural fill. The slab-on-grade can be similarly supported on medium dense native soil or structural fill. Detailed recommendations regarding the above issues and other geotechnical design considerations are provided in the following sections. These recommendations should be incorporated into the final design drawings and construction specifications. 5.2 EARTHWORK RGI expects that site grading will consist of cut in the high area of the site and fill in the pond area to achieve building and pavement grades and excavation for utilities including storm, water, sanitary sewer, and other utilities. 5.2.1 EROSION AND SEDIMENT CONTROL Potential sources or causes of erosion and sedimentation depend on construction methods, slope length and gradient, amount of soil exposed and/or disturbed, soil type, construction sequencing and weather. The impacts on erosion-prone areas can be reduced by implementing an erosion and sedimentation control plan. The plan should be designed in accordance with applicable city and/or county standards. RGI recommends the following erosion control Best Management Practices (BMPs):  Scheduling site preparation and grading for the drier summer and early fall months and undertaking activities that expose soil during periods of little or no rainfall  Establishing a quarry spall construction entrance  Installing siltation control fencing or anchored straw or coir wattles on the downhill side of work areas  Covering soil stockpiles with anchored plastic sheeting  Revegetating or mulching exposed soils with a minimum 3-inch thickness of straw if surfaces will be left undisturbed for more than one day during wet weather or one week in dry weather  Directing runoff away from exposed soils and slopes  Minimizing the length and steepness of slopes with exposed soils and cover excavation surfaces with anchored plastic sheeting (Graded and disturbed slopes should be tracked in place with the equipment running perpendicular to the slope contours so that the track marks provide a texture to help resist erosion and Geotechnical Engineering Report 5 June 8, 2018 Family First Community Center, Renton, Washington RGI Project No. 2018-130 channeling. Some sloughing and raveling of slopes with exposed or disturbed soil should be expected.)  Decreasing runoff velocities with check dams, straw bales or coir wattles  Confining sediment to the project site  Inspecting and maintaining erosion and sediment control measures frequently (The contractor should be aware that inspection and maintenance of erosion control BMPs is critical toward their satisfactory performance. Repair and/or replacement of dysfunctional erosion control elements should be anticipated.) Permanent erosion protection should be provided by reestablishing vegetation using hydroseeding and/or landscape planting. Until the permanent erosion protection is established, site monitoring should be performed by qualified personnel to evaluate the effectiveness of the erosion control measures. Provisions for modifications to the erosion control system based on monitoring observations should be included in the erosion and sedimentation control plan. 5.2.2 STRIPPING Stripping efforts should include removal of vegetation, organic materials, and deleterious debris from areas slated for building, pavement, and utility construction. Topsoil and rootmass is generally less than 12 inches across the site. Deeper areas of stripping may be required in heavily vegetated areas of the site. The existing pond should be dry before filling and the wet soil and vegetation should be removed before filling. 5.2.3 EXCAVATIONS All temporary cut slopes associated with the site and utility excavations should be adequately inclined to prevent sloughing and collapse. The shallow native soil is classified as Group C soil and native dense soil is classified Group A. Accordingly, for excavations more than 4 feet but less than 20 feet in depth, the temporary side slopes should be laid back with a minimum slope inclination of 1.5H:1V (Horizontal:Vertical) in the upper 5 feet and 3/4H:1V in dense native soil. If there is insufficient room to complete the excavations in this manner, or excavations greater than 20 feet in depth are planned, using temporary shoring to support the excavations should be considered. For open cuts at the site, RGI recommends:  No traffic, construction equipment, stockpiles or building supplies are allowed at the top of cut slopes within a distance of at least 5 feet from the top of the cut  Exposed soil along the slope is protected from surface erosion using waterproof tarps and/or plastic sheeting  Construction activities are scheduled so that the length of time the temporary cut is left open is minimized Geotechnical Engineering Report 6 June 8, 2018 Family First Community Center, Renton, Washington RGI Project No. 2018-130  Surface water is diverted away from the excavation  The general condition of slopes should be observed periodically by a geotechnical engineer to confirm adequate stability and erosion control measures In all cases, however, appropriate inclinations will depend on the actual soil and groundwater conditions encountered during earthwork. Ultimately, the site contractor must be responsible for maintaining safe excavation slopes that comply with applicable OSHA or WISHA guidelines. 5.2.4 SITE PREPARATION After stripping, grubbing, and prior to placement of structural fill, RGI recommends proofrolling building and pavement subgrades and areas to receive structural fill. These areas should be proofrolled under the observation of RGI and compacted to a firm and unyielding condition in order to achieve a minimum compaction level of 95 percent of the modified proctor maximum dry density as determined by the American Society of Testing and Materials D1557-09 Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort (ASTM D1557). Proofrolling and adequate subgrade compaction can only be achieved when the soils are within approximately ± 2 percent moisture content of the optimum moisture content. Soils that appear firm after stripping and grubbing may be proofrolled with a heavy compactor, loaded double-axle dump truck, or other heavy equipment under the observation of an RGI representative. This observer will assess the subgrade conditions prior to filling. The need for or advisability of proofrolling due to soil moisture conditions should be determined at the time of construction. Subgrade soils that become disturbed due to elevated moisture conditions should be overexcavated to reveal firm, non-yielding, non-organic soils and backfilled with compacted structural fill. In order to maximize utilization of site soils as structural fill, RGI recommends that the earthwork portion of this project be completed during extended periods of warm and dry weather if possible. If earthwork is completed during the wet season (typically November through May) it will be necessary to take extra precautionary measures to protect subgrade soils. Wet season earthwork will require additional mitigative measures beyond that which would be expected during the drier summer and fall months. 5.2.5 STRUCTURAL FILL RGI recommends fill below the foundation and floor slab, behind retaining walls, and below pavement and hardscape surfaces be placed in accordance with the following recommendations for structural fill. The suitability of excavated site soils and import soils for compacted structural fill use will depend on the gradation and moisture content of the soil when it is placed. As the Geotechnical Engineering Report 7 June 8, 2018 Family First Community Center, Renton, Washington RGI Project No. 2018-130 amount of fines (that portion passing the U.S. No. 200 sieve) increases, soil becomes increasingly sensitive to small changes in moisture content and adequate compaction becomes more difficult or impossible to achieve. Soils containing more than about 5 percent fines cannot be consistently compacted to a dense, non-yielding condition when the moisture content is more than 2 percent above or below optimum. Optimum moisture content is the moisture that results in the greatest compacted dry density with a specified compactive effort. Non-organic site soils are only considered suitable for structural fill provided that their moisture content is within about 2 percent of the optimum moisture level as determined by ASTM D1557. Excavated site soils may not be suitable for re-use as structural fill depending on the moisture content and weather conditions at the time of construction. If soils are stockpiled for future reuse and wet weather is anticipated, the stockpile should be protected with plastic sheeting that is securely anchored. Even during dry weather, moisture conditioning (such as, windrowing and drying) of site soils to be reused as structural fill may be required. Even during the summer, delays in grading can occur due to excessively high moisture conditions of the soils or due to precipitation. If wet weather occurs, the upper wetted portion of the site soils may need to be scarified and allowed to dry prior to further earthwork, or may need to be wasted from the site. The native soil contains a large percentage of fines and is moisture sensitive, it may necessary to import structural fill if the construction occurs in wet season. Import structural fill should meet the gradation requirements listed in Table 2 for wet weather conditions. For dry season earthwork, the percent passing the No. 200 may be increased to 10 percent maximum or materials meeting the 2012 Washington State Department of Transportation (WSDOT) Standard Specifications for Road, Bridge, and Municipal Construction, Section 9-03.14(1) may be used. Table 2 Structural Fill Gradation U.S. Sieve Size Percent Passing 4 inches 100 No. 4 sieve 75 percent No. 200 sieve 5 percent * *Based on minus 3/4 inch fraction. Prior to use, an RGI representative should observe and test all materials imported to the site for use as structural fill. Structural fill materials should be placed in uniform loose layers not exceeding 12 inches and compacted as specified in Table 3. The soil’s maximum density and optimum moisture should be determined by ASTM D1557. Geotechnical Engineering Report 8 June 8, 2018 Family First Community Center, Renton, Washington RGI Project No. 2018-130 Table 3 Structural Fill Compaction ASTM D1557 Location Material Type Minimum Compaction Percentage Moisture Content Range Foundations On-site granular or approved imported fill soils: 95 +2 -2 Retaining Wall Backfill On-site granular or approved imported fill soils: 92 +2 -2 Slab-on-grade On-site granular or approved imported fill soils: 95 +2 -2 General Fill (non- structural areas) On-site soils or approved imported fill soils: 90 +3 -2 Pavement – Subgrade and Base Course On-site granular or approved imported fill soils: 95 +2 -2 Placement and compaction of structural fill should be observed by RGI. A representative number of in-place density tests should be performed as the fill is being placed to confirm that the recommended level of compaction is achieved. 5.2.6 CUT AND FILL SLOPES All permanent cut and fill slopes should be graded with a finished inclination no greater than 2H:1V. Upon completion of construction, the slope face should be trackwalked, compacted and vegetated, or provided with other physical means to guard against erosion. All fill placed for slope construction should meet the structural fill requirements as described in Section 5.2.5. Final grades at the top of the slopes must promote surface drainage away from the slope crest. Water must not be allowed to flow in an uncontrolled fashion over the slope face. If it is necessary to direct surface runoff towards the slope, it should be controlled at the top of the slope, piped in a closed conduit installed on the slope face, and taken to an appropriate point of discharge beyond the toe of the slope. 5.2.7 WET WEATHER CONSTRUCTION CONSIDERATIONS RGI recommends that preparation for site grading and construction include procedures intended to drain ponded water, control surface water runoff, and to collect shallow subsurface seepage zones in excavations where encountered. It will not be possible to successfully compact the subgrade or utilize on-site soils as structural fill if accumulated water is not drained prior to grading or if drainage is not controlled during construction. Attempting to grade the site without adequate drainage control measures will reduce the amount of on-site soil effectively available for use, increase the amount of select import fill materials required, and ultimately increase the cost of the earthwork phases of the Geotechnical Engineering Report 9 June 8, 2018 Family First Community Center, Renton, Washington RGI Project No. 2018-130 project. Free water should not be allowed to pond on the subgrade soils. RGI anticipates that the use of berms and shallow drainage ditches, with sumps and pumps in utility trenches, will be required for surface water control during wet weather and/or wet site conditions. 5.3 FOUNDATIONS Following site preparation and grading, the proposed building foundations may be supported on conventional spread footings bearing on medium dense native soil or structural fill. The existing fill may be suitable for support of foundations and should be evaluated during construction. Where loose soils or other unsuitable soils are encountered in the proposed building footprint, they should be overexcavated and backfilled with structural fill. Perimeter foundations exposed to weather should be at a minimum depth of 18 inches below final exterior grades. Interior foundations can be constructed at any convenient depth below the floor slab. Finished grade is defined as the lowest adjacent grade within 5 feet of the foundation for perimeter (or exterior) footings and finished floor level for interior footings. Table 4 Foundation Design Design Parameter Value Allowable Bearing Capacity 2,500 psf1 Friction Coefficient 0.25 Passive pressure (equivalent fluid pressure) 250 pcf2 Minimum foundation dimensions Columns: 24 inches Walls: 16 inches 1 psf = pounds per square foot 2 pcf = pounds per cubic foot The allowable foundation bearing pressures apply to dead loads plus design live load conditions. For short-term loads, such as wind and seismic, a 1/3 increase in this allowable capacity may be used. At perimeter locations, RGI recommends not including the upper 12 inches of soil in the computation of passive pressures because it can be affected by weather or disturbed by future grading activity. The passive pressure value assumes the foundation will be constructed neat against competent soil or backfilled with structural fill as described in Section 5.2.5. The recommended base friction and passive resistance value includes a safety factor of about 1.5. With spread-footing foundations designed in accordance with the recommendations in this section, maximum total and differential post-construction settlements of 1 inch and 1/2 inch, respectively, should be expected. Geotechnical Engineering Report 10 June 8, 2018 Family First Community Center, Renton, Washington RGI Project No. 2018-130 5.4 RETAINING WALLS RGI recommends cast-in-place concrete walls be used for basement wall (if needed). The magnitude of earth pressure development on retaining walls will partly depend on the quality of the wall backfill. RGI recommends placing and compacting wall backfill as structural fill. Wall drainage will be needed behind the wall face. A typical retaining wall drainage detail is shown on Figure 3. With wall backfill placed and compacted as recommended, and drainage properly installed, RGI recommends using the values in the following table for design. Table 5 Retaining Wall Design Design Parameter Value Allowable Bearing Capacity 2,500 psf Active Earth Pressure (unrestrained walls) 35 pcf At-rest Earth Pressure (restrained walls) 50 pcf For seismic design, an additional uniform load of 7 times the wall height (H) for unrestrained walls and 14H for restrained walls should be applied to the wall surface. Friction at the base of foundations and passive earth pressure will provide resistance to these lateral loads. Values for these parameters are provided in Section 5.3. 5.5 SLAB-ON-GRADE CONSTRUCTION Once site preparation has been completed as described in Section 5.2, suitable support for slab-on-grade construction should be provided. Immediately below the floor slab, RGI recommends placing a 4-inch-thick capillary break layer of clean, free-draining pea gravel, washed rock, or crushed rock that has less than 5 percent passing the U.S. No. 200 sieve. This material will reduce the potential for upward capillary movement of water through the underlying soil and subsequent wetting of the floor slab. Where moisture by vapor transmission is undesirable, an 8- to 10-millimeter-thick plastic membrane should be placed on a 4-inch-thick layer of clean gravel or rock. For the anticipated floor slab loading, we estimate post-construction floor settlements of ¼- to ½- inch. 5.6 DRAINAGE 5.6.1 SURFACE Final exterior grades should promote free and positive drainage away from the building area. Water must not be allowed to pond or collect adjacent to foundations or within the immediate building area. For non-pavement locations, RGI recommends providing a Geotechnical Engineering Report 11 June 8, 2018 Family First Community Center, Renton, Washington RGI Project No. 2018-130 minimum drainage gradient of 3 percent for a minimum distance of 10 feet from the building perimeter. In paved locations, a minimum gradient of 1 percent should be provided unless provisions are included for collection and disposal of surface water adjacent to the structure. 5.6.2 SUBSURFACE RGI recommends installing perimeter foundation drain as shown on Figure 4. The retaining wall drains, perimeter foundation drain, and roof downspouts should be tightlined separately to an approved discharge facility. Subsurface drains must be laid with a gradient sufficient to promote positive flow to a controlled point of approved discharge. 5.6.3 INFILTRATION Based on the soil encountered, the native soil is not suitable for infiltration. 5.7 UTILITIES Utility pipes should be bedded and backfilled in accordance with American Public Works Association (APWA) specifications. For site utilities located within the right-of-ways, bedding and backfill should be completed in accordance with City of Renton specifications. At a minimum, trench backfill should be placed and compacted as structural fill, as described in Section 5.2.5. Where utilities occur below unimproved areas, the degree of compaction can be reduced to a minimum of 90 percent of the soil’s maximum density as determined by ASTM D1557. If the native soil becomes unsuitable for use as structural fill, imported structural fill will be necessary for trench backfill as recommended in Section 5.2.5. 5.8 PAVEMENTS RGI recommends that the driveway to the new garage be stripped and repaved. Pavement subgrades should be prepared as described in Section 5.2 of this GER and as discussed below. Regardless of the relative compaction achieved, the subgrade must be firm and relatively unyielding before paving. This condition should be verified by proofrolling with heavy construction equipment or hand probe by inspector. With the pavement subgrade prepared as described above, RGI recommends the following pavement section with flexible asphalt concrete surfacing.  For private asphalt driveways or parking: 2 inches of hot mix asphalt over 6 inches of crushed rock base (CRB) over compacted subgrade; The asphalt paving materials used should conform to the Washington State Department of Transportation (WSDOT) specifications for Hot Mix Asphalt Class 1/2 inch and CRB surfacing. Geotechnical Engineering Report 12 June 8, 2018 Family First Community Center, Renton, Washington RGI Project No. 2018-130 If concrete driveway is preferred, the following section can be used.  For concrete driveways: 5 inches of concrete over 4 inches of CRB over compacted subgrade Long-term pavement performance will depend on surface drainage. A poorly-drained pavement section will be subject to premature failure as a result of surface water infiltrating into the subgrade soils and reducing their supporting capability. For optimum pavement performance, surface drainage gradients of no less than 2 percent are recommended. Also, some degree of longitudinal and transverse cracking of the pavement surface should be expected over time. Regular maintenance should be planned to seal cracks when they occur. 5.9 CONSTRUCTION CONSIDERATIONS An important construction consideration is the weather and its impact on construction scheduling. Although it is not impossible, winter construction will be more difficult and will increase construction costs. RGI highly recommends that the major earthwork be performed in dry season from May to September. 6.0 Additional Services RGI is available to provide further geotechnical consultation throughout the design phase of the project. RGI should review the grading and utilities plans in order to verify that earthwork and foundation recommendations in this report are appropriate and provide supplemental recommendations as necessary. RGI should be contracted to provide geotechnical engineering and construction monitoring services during. The integrity of the earthwork and construction depends on proper site preparation and procedures. In addition, engineering decisions may arise in the field in the event that variations in subsurface conditions become apparent. Construction monitoring services are not part of this scope of work. RGI can provide an estimate for these services once the construction plans and schedule have been developed. 7.0 Limitations This GER is the property of RGI, City of Renton and her designated agents. Within the limits of the scope and budget, this GER was prepared in accordance with generally accepted geotechnical engineering practices in the area at the time this report was issued. This GER is intended for specific application to the Family First Community Center at 16022 116th Avenue Southeast in Renton, Washington, and for the exclusive use of the City of Renton and its authorized representatives. No other warranty, expressed or Geotechnical Engineering Report 13 June 8, 2018 Family First Community Center, Renton, Washington RGI Project No. 2018-130 implied, is made. Site safety, excavation support, and dewatering requirements are the responsibility of others. The scope of services for this project does not include either specifically or by implication any environmental or biological (for example, mold, fungi, bacteria) assessment of the site or identification or prevention of pollutants, hazardous materials, or conditions. If the owner is concerned about the potential for such contamination or pollution, we can provide a proposal for these services. The analyses and recommendations presented in this GER are based upon review of the previous explorations on the site by Geotechnical Investigations Group. Variations in soil conditions can occur, the nature and extent of which may not become evident until construction. If variations appear evident, RGI should be requested to reevaluate the recommendations in this GER prior to proceeding with construction. It is client’s responsibility to see that all parties to the project, including the designers, contractors, subcontractors, are made aware of this GER in its entirety. The use of information contained in this GER for bidding purposes should be done at the contractor’s option and risk. USGS, 2014, Renton, Washington 7.5-Minute Quadrangle Approximate Scale: 1"=1000' 0 500 1000 2000 N Site Vicinity Map Figure 1 06/2018 Corporate Office 17522 Bothell Way Northeast Bothell, Washington 98011 Phone: 425.415.0551 Fax: 425.415.0311 Family First Community Center RGI Project Number 2018-130 Date Drawn: Address: 16022 116th Avenue Southeast, Renton, Washington 98058 SITE B-1B-2B-3B-4B-5B-6B-706/2018Corporate Office17522 Bothell Way NortheastBothell, Washington 98011Phone: 425.415.0551Fax: 425.415.0311Family First Community CenterRGI Project Number2018-130Date Drawn:Address: 16022 116th Avenue Southeast, Renton, Washington 98058Geotechnical Exploration PlanFigure 2Approximate Scale: 1"=120'060120240N= Boring by RGI, 5/23/18= Site boundary Incliniations) 12" Over the Pipe 3" Below the Pipe Perforated Pipe 4" Diameter PVC Compacted Structural Backfill (Native or Import) 12" min. Filter Fabric Material 12" Minimum Wide Free-Draining Gravel Slope to Drain (See Report for Appropriate Excavated Slope 06/2018 Corporate Office 17522 Bothell Way Northeast Bothell, Washington 98011 Phone: 425.415.0551 Fax: 425.415.0311 Family First Community Center RGI Project Number 2018-130 Date Drawn: Address: 16022 116th Avenue Southeast, Renton, Washington 98058 Retaining Wall Drainage Detail Figure 3 Not to Scale 3/4" Washed Rock or Pea Gravel 4" Perforated Pipe Building Slab Structural Backfill Compacted Filter Fabric 06/2018 Corporate Office 17522 Bothell Way Northeast Bothell, Washington 98011 Phone: 425.415.0551 Fax: 425.415.0311 Family First Community Center RGI Project Number 2018-130 Date Drawn: Address: 16022 116th Avenue Southeast, Renton, Washington 98058 Typical Footing Drain Detail Figure 4 Not to Scale Geotechnical Engineering Report June 8, 2018 Family First Community Center, Renton, Washington RGI Project No. 2018-130 APPENDIX A FIELD EXPLORATION AND LABORATORY TESTING On May 23, 2018, RGI performed field explorations using a tracked drill rig. RGI explored subsurface soil conditions at the site by observing the drilling of 7 test borings to a maximum depth of 16.5 feet below existing grade. The boring locations are shown on Figure 2. The boring locations were approximately determined by measurements from existing site features and topography. A geologist from our office conducted the field exploration and classified the soil conditions encountered, maintained a log of each test exploration, obtained representative soil samples, and observed pertinent site features. All soil samples were visually classified in accordance with the Unified Soil Classification System (USCS). Representative soil samples obtained from the explorations were placed in closed containers and taken to our laboratory for further examination and testing. As a part of the laboratory testing program, the soil samples were classified in our in-house laboratory based on visual observation, texture, plasticity, and the limited laboratory testing described below. Moisture Content Determinations Moisture content determinations were performed in accordance with ASTM D2216-10 Standard Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass (ASTM D2216) on representative samples obtained from the exploration in order to aid in identification and correlation of soil types. The moisture content of typical samples were measured and is reported on the test pit logs. Grain Size Analysis A grain size analysis indicates the range in diameter of soil particles included in a particular sample. Grain size analyses was determined using D6913-04(2009) Standard Test Methods for Particle-Size Distribution (Gradation) of Soils Using Sieve Analysis (ASTM D6913) on four of the samples. Project Name:Family First Community Center Project Number:2018-130 Client:City of Renton Boring No.:B-1 Date(s) Drilled:5/23/2018 Drilling Method(s):Hollow Stem Auger Drill Rig Type:Track Rig Groundwater Level:Seepage at 15' Borehole Backfill:Bentonite Chips Logged By:ELW Drill Bit Size/Type:8" auger Drilling Contractor:Bortec Sampling Method(s):SPT Location:16022 116th Avenue Southeast, Renton, Washington Surface Conditions:Asphalt Total Depth of Borehole:16.5 feet bgs Approximate Surface Elevation:N/A Hammer Data :140 lb, 30" drop, rope and cathead USCS SymbolAsphalt Fill SM GP SM Moisture (%)12 17 20 11 17 13Recovery (%)Graphic LogRQD (%)MATERIAL DESCRIPTION 6" asphalt over crushed rock base Gray silty SAND with some gravel, medium dense, moist (Fill) Little recovery Becomes brown to gray, moist to wet, trace organics Brown silty SAND with some gravel, medium dense, wet 22% fines Brown sandy GRAVEL, very dense, saturated Tan silty SAND, very dense, moist Boring terminated at 16' 6"Depth (feet)0 5 10 15 Sample TypeSampling Resistance, blows/ft21 14 13 74Elevation (feet)Sheet 1 of 1 The Riley Group, Inc. 17522 Bothell Way NE, Bothell, WA 98011 Project Name:Family First Community Center Project Number:2018-130 Client:City of Renton Boring No.:B-2 Date(s) Drilled:5/23/2018 Drilling Method(s):Hollow Stem Auger Drill Rig Type:Track Rig Groundwater Level:Not Encountered Borehole Backfill:Bentonite Chips Logged By:ELW Drill Bit Size/Type:8" auger Drilling Contractor:Bortec Sampling Method(s):SPT Location:16022 116th Avenue Southeast, Renton, Washington Surface Conditions:Grass Total Depth of Borehole:16.33 feet bgs Approximate Surface Elevation:N/A Hammer Data :140 lb, 30" drop, rope and cathead USCS SymbolTPSL Fill SM Moisture (%)10 12 16 11Recovery (%)Graphic LogRQD (%)MATERIAL DESCRIPTION Topsoil Light to dark brown silty SAND with some gravel, medium dense, moist (Fill) 23% fines Becomes gray to brown, very dense, contains organics Gray to brown silty SAND with some gravel, very dense, moist Boring terminated at 16' 5"Depth (feet)0 5 10 15 Sample TypeSampling Resistance, blows/ft21 21 71 90/11"Elevation (feet)Sheet 1 of 1 The Riley Group, Inc. 17522 Bothell Way NE, Bothell, WA 98011 Project Name:Family First Community Center Project Number:2018-130 Client:City of Renton Boring No.:B-3 Date(s) Drilled:5/23/2018 Drilling Method(s):Hollow Stem Auger Drill Rig Type:Track Rig Groundwater Level:Seepage at 15' Borehole Backfill:Bentonite Chips Logged By:ELW Drill Bit Size/Type:8" auger Drilling Contractor:Bortec Sampling Method(s):SPT Location:16022 116th Avenue Southeast, Renton, Washington Surface Conditions:Grass Total Depth of Borehole:15.75 feet bgs Approximate Surface Elevation:N/A Hammer Data :140 lb, 30" drop, rope and cathead USCS SymbolTPSL Fill SM SP-SM Moisture (%)11 13 11 17Recovery (%)Graphic LogRQD (%)MATERIAL DESCRIPTION Topsoil Gray silty SAND with some gravel, medium dense, wet (Fill) Gray silty SAND with some gravel, very dense, moist to wet (Glacial Till) Becomes moist Brown SAND with some silt and gravel, very dense, water bearing Boring terminated at 15' 9"Depth (feet)0 5 10 15 Sample TypeSampling Resistance, blows/ft12 50/5" 50/6" 50/3"Elevation (feet)Sheet 1 of 1 The Riley Group, Inc. 17522 Bothell Way NE, Bothell, WA 98011 Project Name:Family First Community Center Project Number:2018-130 Client:City of Renton Boring No.:B-4 Date(s) Drilled:5/23/2018 Drilling Method(s):Hollow Stem Auger Drill Rig Type:Track Rig Groundwater Level:Not Encountered Borehole Backfill:Bentonite Chips Logged By:ELW Drill Bit Size/Type:8" auger Drilling Contractor:Bortec Sampling Method(s):SPT Location:16022 116th Avenue Southeast, Renton, Washington Surface Conditions:Grass Total Depth of Borehole:15.5 feet bgs Approximate Surface Elevation:N/A Hammer Data :140 lb, 30" drop, rope and cathead USCS SymbolTPSL Fill SM Moisture (%)12 9 9 10Recovery (%)Graphic LogRQD (%)MATERIAL DESCRIPTION Topsoil Brown silty SAND, medium dense, moist Becomes dense Gray silty SAND with some gravel, dense, moist (Glacial Till) Becomes tan, very dense Boring terminated at 15' 6"Depth (feet)0 5 10 15 Sample TypeSampling Resistance, blows/ft38 43 50/4" 50/6"Elevation (feet)Sheet 1 of 1 The Riley Group, Inc. 17522 Bothell Way NE, Bothell, WA 98011 Project Name:Family First Community Center Project Number:2018-130 Client:City of Renton Boring No.:B-5 Date(s) Drilled:5/23/2018 Drilling Method(s):Hollow Stem Auger Drill Rig Type:Track Rig Groundwater Level:Not Encountered Borehole Backfill:Bentonite Chips Logged By:ELW Drill Bit Size/Type:8" auger Drilling Contractor:Bortec Sampling Method(s):SPT Location:16022 116th Avenue Southeast, Renton, Washington Surface Conditions:Grass Total Depth of Borehole:15.42 feet bgs Approximate Surface Elevation:N/A Hammer Data :140 lb, 30" drop, rope and cathead USCS SymbolTPSL SM Moisture (%)12 9 14 7Recovery (%)Graphic LogRQD (%)MATERIAL DESCRIPTION Topsoil Gray silty SAND with trace gravel, medium dense, moist to wet (Glacial Till) 31% fines Becomes very dense Becomes moist Boring terminated at 15' 5"Depth (feet)0 5 10 15 Sample TypeSampling Resistance, blows/ft25 61 50/6" 50/5"Elevation (feet)Sheet 1 of 1 The Riley Group, Inc. 17522 Bothell Way NE, Bothell, WA 98011 Project Name:Family First Community Center Project Number:2018-130 Client:City of Renton Boring No.:B-6 Date(s) Drilled:5/23/2018 Drilling Method(s):Hollow Stem Auger Drill Rig Type:Track Rig Groundwater Level:Not Encountered Borehole Backfill:Bentonite Chips Logged By:ELW Drill Bit Size/Type:8" auger Drilling Contractor:Bortec Sampling Method(s):SPT Location:16022 116th Avenue Southeast, Renton, Washington Surface Conditions:Grass Total Depth of Borehole:16.5 feet bgs Approximate Surface Elevation:N/A Hammer Data :140 lb, 30" drop, rope and cathead USCS SymbolTPSL SM SM SP-SM Moisture (%)12 14 9 9Recovery (%)Graphic LogRQD (%)MATERIAL DESCRIPTION Topsoil Tan silty SAND with some gravel, medium dense, moist Becomes medium dense to dense, little recovery Becomes medium dense, mottled Gray silty SAND with some gravel, very dense, moist Brown SAND with some silt and gravel, very dense, moist to wet Boring terminated at 16.5'Depth (feet)0 5 10 15 Sample TypeSampling Resistance, blows/ft30 17 67 73Elevation (feet)Sheet 1 of 1 The Riley Group, Inc. 17522 Bothell Way NE, Bothell, WA 98011 Project Name:Family First Community Center Project Number:2018-130 Client:City of Renton Boring No.:B-7 Date(s) Drilled:5/23/2018 Drilling Method(s):Hollow Stem Auger Drill Rig Type:Track Rig Groundwater Level:Not Encountered Borehole Backfill:Bentonite Chips Logged By:ELW Drill Bit Size/Type:8" auger Drilling Contractor:Bortec Sampling Method(s):SPT Location:16022 116th Avenue Southeast, Renton, Washington Surface Conditions:Grass Total Depth of Borehole:16.5 feet bgs Approximate Surface Elevation:N/A Hammer Data :140 lb, 30" drop, rope and cathead USCS SymbolTPSL Fill SM SM Moisture (%)16 16 22 14Recovery (%)Graphic LogRQD (%)MATERIAL DESCRIPTION Topsoil Brown silty SAND with some gravel, loose moist to wet (Fill) Becomes medium dense, contains organics 33% fines Brown to gray silty SAND with trace gravel, medium dense, moist to wet Gray silty SAND with some gravel, medium dense, wet Boring terminated at 16.5'Depth (feet)0 5 10 15 Sample TypeSampling Resistance, blows/ft7 24 12 22Elevation (feet)Sheet 1 of 1 The Riley Group, Inc. 17522 Bothell Way NE, Bothell, WA 98011 Project Name:Family First Community Center Project Number:2018-130 Client:City of Renton Key to Log of Boring USCS SymbolMoisture (%)Recovery (%)Graphic LogRQD (%)MATERIAL DESCRIPTIONDepth (feet)Sample TypeSampling Resistance, blows/ftElevation (feet)1 2 3 4 5 6 7 8 9 10 COLUMN DESCRIPTIONS 1 Elevation (feet): Elevation (MSL, feet). 2 Depth (feet): Depth in feet below the ground surface. 3 Sample Type: Type of soil sample collected at the depth interval shown. 4 Sampling Resistance, blows/ft: Number of blows to advance driven sampler one foot (or distance shown) beyond seating interval using the hammer identified on the boring log. 5 RQD (%): Rock Quality Designation is a relative index of the rock mass quality calculated by comparing the cumulative length of intact pieces of core exceeding 100 mm in length to the cored interval length. 6 Recovery (%): Core Recovery Percentage is determined based on a ratio of the length of core sample recovered compared to the cored interval length. 7 USCS Symbol: USCS symbol of the subsurface material. 8 Graphic Log: Graphic depiction of the subsurface material encountered. 9 MATERIAL DESCRIPTION: Description of material encountered. May include consistency, moisture, color, and other descriptive text. 10 Moisture (%): Moisture, expressed as a water content. FIELD AND LABORATORY TEST ABBREVIATIONS CHEM: Chemical tests to assess corrosivity COMP: Compaction test CONS: One-dimensional consolidation test LL: Liquid Limit, percent PI: Plasticity Index, percent SA: Sieve analysis (percent passing No. 200 Sieve) UC: Unconfined compressive strength test, Qu, in ksf WA: Wash sieve (percent passing No. 200 Sieve) MATERIAL GRAPHIC SYMBOLS Asphaltic Concrete (AC) AF Poorly graded GRAVEL (GP) Silty SAND (SM) Poorly graded SAND with Silt (SP-SM) Topsoil TYPICAL SAMPLER GRAPHIC SYMBOLS Auger sampler Bulk Sample 3-inch-OD California w/ brass rings CME Sampler Grab Sample 2.5-inch-OD Modified California w/ brass liners Pitcher Sample 2-inch-OD unlined split spoon (SPT) Shelby Tube (Thin-walled, fixed head) OTHER GRAPHIC SYMBOLS Water level (at time of drilling, ATD) Water level (after waiting) Minor change in material properties within a stratum Inferred/gradational contact between strata ?Queried contact between strata GENERAL NOTES 1: Soil classifications are based on the Unified Soil Classification System. Descriptions and stratum lines are interpretive, and actual lithologic changes may be gradual. Field descriptions may have been modified to reflect results of lab tests. 2: Descriptions on these logs apply only at the specific boring locations and at the time the borings were advanced. They are not warranted to be representative of subsurface conditions at other locations or times. Sheet 1 of 1 The Riley Group, Inc. 17522 Bothell Way NE, Bothell, WA 98011 THE RILEY GROUP, INC. 17522 Bothell Way NE Bothell, WA 98011 PHONE: (425) 415-0551 FAX: (425) 415-0311 GRAIN SIZE ANALYSIS ASTM D421, D422, D1140, D2487, D6913 PROJECT TITLE Family First Community Center SAMPLE ID/TYPE B-1 PROJECT NO.2018-130 SAMPLE DEPTH 11 Feet TECH/TEST DATE LC 5/28/2018 DATE RECEIVED 5/28/2018 WATER CONTENT (Delivered Moisture) Total Weight Of Sample Used For Sieve Corrected For Hygroscopic Moisture Wt Wet Soil & Tare (gm) (w1)385.8 Weight Of Sample (gm)349.2 Wt Dry Soil & Tare (gm) (w2)349.2 Tare Weight (gm) 15.8 Weight of Tare (gm) (w3)15.8 (W6) Total Dry Weight (gm) 333.4 Weight of Water (gm) (w4=w1-w2) 36.6 SIEVE ANALYSIS Weight of Dry Soil (gm) (w5=w2-w3) 333.4 Cumulative Moisture Content (%) (w4/w5)*100 11 Wt Ret (Wt-Tare) (%Retained)% PASS +Tare {(wt ret/w6)*100}(100-%ret) % COBBLES 0.0 12.0"15.8 0.00 0.00 100.00 cobbles % C GRAVEL 7.4 3.0"15.8 0.00 0.00 100.00 coarse gravel % F GRAVEL 10.9 2.5" coarse gravel % C SAND 6.0 2.0" coarse gravel % M SAND 17.0 1.5"15.8 0.00 0.00 100.00 coarse gravel % F SAND 36.8 1.0" coarse gravel % FINES 21.8 0.75"40.6 24.80 7.44 92.56 fine gravel % TOTAL 100.0 0.50" fine gravel 0.375"57.4 41.60 12.48 87.52 fine gravel D10 (mm)#4 77.1 61.30 18.39 81.61 coarse sand D30 (mm)#10 97.2 81.40 24.42 75.58 medium sand D60 (mm)#20 medium sand Cu #40 153.9 138.10 41.42 58.58 fine sand Cc #60 fine sand #100 245.5 229.70 68.90 31.10 fine sand #200 276.6 260.80 78.22 21.78 fines PAN 349.2 333.40 100.00 0.00 silt/clay 322 306.2 91.841632 8.15836833 DESCRIPTION Silty SAND with some gravel USCS SM Prepared For: City of Renton Reviewed By: ELW 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.11101001000 % P A S S I N G Grain size in millimeters 12"3" 2" 1" .75" .375" #4 #10 #20 #40 #60 #100 #200 THE RILEY GROUP, INC. 17522 Bothell Way NE Bothell, WA 98011 PHONE: (425) 415-0551 FAX: (425) 415-0311 GRAIN SIZE ANALYSIS ASTM D421, D422, D1140, D2487, D6913 PROJECT TITLE Family First Community Center SAMPLE ID/TYPE B-2 PROJECT NO.2018-130 SAMPLE DEPTH 2.5 Feet TECH/TEST DATE LC 5/28/2018 DATE RECEIVED 5/28/2018 WATER CONTENT (Delivered Moisture) Total Weight Of Sample Used For Sieve Corrected For Hygroscopic Moisture Wt Wet Soil & Tare (gm) (w1)278.1 Weight Of Sample (gm)255.1 Wt Dry Soil & Tare (gm) (w2)255.1 Tare Weight (gm) 15.5 Weight of Tare (gm) (w3)15.5 (W6) Total Dry Weight (gm) 239.6 Weight of Water (gm) (w4=w1-w2) 23.0 SIEVE ANALYSIS Weight of Dry Soil (gm) (w5=w2-w3) 239.6 Cumulative Moisture Content (%) (w4/w5)*100 10 Wt Ret (Wt-Tare) (%Retained)% PASS +Tare {(wt ret/w6)*100}(100-%ret) % COBBLES 0.0 12.0"15.5 0.00 0.00 100.00 cobbles % C GRAVEL 15.9 3.0"15.5 0.00 0.00 100.00 coarse gravel % F GRAVEL 7.6 2.5" coarse gravel % C SAND 8.6 2.0" coarse gravel % M SAND 18.0 1.5"15.5 0.00 0.00 100.00 coarse gravel % F SAND 27.2 1.0" coarse gravel % FINES 22.6 0.75"53.6 38.10 15.90 84.10 fine gravel % TOTAL 100.0 0.50" fine gravel 0.375"57.3 41.80 17.45 82.55 fine gravel D10 (mm)#4 71.9 56.40 23.54 76.46 coarse sand D30 (mm)#10 92.5 77.00 32.14 67.86 medium sand D60 (mm)#20 medium sand Cu #40 135.7 120.20 50.17 49.83 fine sand Cc #60 fine sand #100 182.5 167.00 69.70 30.30 fine sand #200 200.9 185.40 77.38 22.62 fines PAN 255.1 239.60 100.00 0.00 silt/clay 322 306.5 127.92154 -27.921536 DESCRIPTION Silty SAND with some gravel USCS SM Prepared For: City of Renton Reviewed By: ELW 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.11101001000 % P A S S I N G Grain size in millimeters 12"3" 2" 1" .75" .375" #4 #10 #20 #40 #60 #100 #200 THE RILEY GROUP, INC. 17522 Bothell Way NE Bothell, WA 98011 PHONE: (425) 415-0551 FAX: (425) 415-0311 GRAIN SIZE ANALYSIS ASTM D421, D422, D1140, D2487, D6913 PROJECT TITLE Family First Community Center SAMPLE ID/TYPE B-5 PROJECT NO.2018-130 SAMPLE DEPTH 2.5 Feet TECH/TEST DATE LC 5/28/2018 DATE RECEIVED 5/28/2018 WATER CONTENT (Delivered Moisture) Total Weight Of Sample Used For Sieve Corrected For Hygroscopic Moisture Wt Wet Soil & Tare (gm) (w1)380.6 Weight Of Sample (gm)340.3 Wt Dry Soil & Tare (gm) (w2)340.3 Tare Weight (gm) 15.8 Weight of Tare (gm) (w3)15.8 (W6) Total Dry Weight (gm) 324.5 Weight of Water (gm) (w4=w1-w2) 40.3 SIEVE ANALYSIS Weight of Dry Soil (gm) (w5=w2-w3) 324.5 Cumulative Moisture Content (%) (w4/w5)*100 12 Wt Ret (Wt-Tare) (%Retained)% PASS +Tare {(wt ret/w6)*100}(100-%ret) % COBBLES 0.0 12.0"15.8 0.00 0.00 100.00 cobbles % C GRAVEL 0.0 3.0"15.8 0.00 0.00 100.00 coarse gravel % F GRAVEL 8.8 2.5" coarse gravel % C SAND 5.2 2.0" coarse gravel % M SAND 17.0 1.5"15.8 0.00 0.00 100.00 coarse gravel % F SAND 37.9 1.0" coarse gravel % FINES 31.2 0.75"15.8 0.00 0.00 100.00 fine gravel % TOTAL 100.0 0.50" fine gravel 0.375"22.3 6.50 2.00 98.00 fine gravel D10 (mm)#4 44.3 28.50 8.78 91.22 coarse sand D30 (mm)#10 61.2 45.40 13.99 86.01 medium sand D60 (mm)#20 medium sand Cu #40 116.3 100.50 30.97 69.03 fine sand Cc #60 fine sand #100 205.4 189.60 58.43 41.57 fine sand #200 239.2 223.40 68.84 31.16 fines PAN 340.3 324.50 100.00 0.00 silt/clay 322 306.2 94.360555 5.6394453 DESCRIPTION Silty SAND with trace gravel USCS SM Prepared For: City of Renton Reviewed By: ELW 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.11101001000 % P A S S I N G Grain size in millimeters 12"3" 2" 1" .75" .375" #4 #10 #20 #40 #60 #100 #200 THE RILEY GROUP, INC. 17522 Bothell Way NE Bothell, WA 98011 PHONE: (425) 415-0551 FAX: (425) 415-0311 GRAIN SIZE ANALYSIS ASTM D421, D422, D1140, D2487, D6913 PROJECT TITLE Family First Community Center SAMPLE ID/TYPE B-7 PROJECT NO.2018-130 SAMPLE DEPTH 5 Feet TECH/TEST DATE LC 5/28/2018 DATE RECEIVED 5/28/2018 WATER CONTENT (Delivered Moisture) Total Weight Of Sample Used For Sieve Corrected For Hygroscopic Moisture Wt Wet Soil & Tare (gm) (w1)712.1 Weight Of Sample (gm)618.1 Wt Dry Soil & Tare (gm) (w2)618.1 Tare Weight (gm) 15.7 Weight of Tare (gm) (w3)15.7 (W6) Total Dry Weight (gm) 602.4 Weight of Water (gm) (w4=w1-w2) 94.0 SIEVE ANALYSIS Weight of Dry Soil (gm) (w5=w2-w3) 602.4 Cumulative Moisture Content (%) (w4/w5)*100 16 Wt Ret (Wt-Tare) (%Retained)% PASS +Tare {(wt ret/w6)*100}(100-%ret) % COBBLES 0.0 12.0"15.7 0.00 0.00 100.00 cobbles % C GRAVEL 4.6 3.0"15.7 0.00 0.00 100.00 coarse gravel % F GRAVEL 19.5 2.5" coarse gravel % C SAND 9.1 2.0" coarse gravel % M SAND 13.6 1.5"15.7 0.00 0.00 100.00 coarse gravel % F SAND 20.6 1.0" coarse gravel % FINES 32.6 0.75"43.4 27.70 4.60 95.40 fine gravel % TOTAL 100.0 0.50" fine gravel 0.375"120.9 105.20 17.46 82.54 fine gravel D10 (mm)#4 161.1 145.40 24.14 75.86 coarse sand D30 (mm)#10 216.1 200.40 33.27 66.73 medium sand D60 (mm)#20 medium sand Cu #40 297.8 282.10 46.83 53.17 fine sand Cc #60 fine sand #100 387.2 371.50 61.67 38.33 fine sand #200 421.9 406.20 67.43 32.57 fines PAN 618.1 602.40 100.00 0.00 silt/clay 322 306.3 50.846614 49.1533865 DESCRIPTION Silty SAND with some gravel USCS SM Prepared For: City of Renton Reviewed By: ELW 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.11101001000 % P A S S I N G Grain size in millimeters 12"3" 2" 1" .75" .375" #4 #10 #20 #40 #60 #100 #200 3 SaRT l rl t TACorna . . < , ri E Technica/Information Report Y i PREPARED FOR: Greene-Gasaway Architects, PLLC PO Box 4158 Federal Way, WA 98063-4158 PROJECT.• Cascade Elementary School 16022 116th Avenue SE Renton, WA 98058 Project No. 2140258.10 PREPARED BY.• Rohin Elangovan, EIT Project Engineer REVIEWED BY.• William J. Fierst, PE Project Manager Sean M. Comfort, PE Principal I DATE.• June 2014 Revised July 2014 su 2 3 20 Civil Engineers • Structura!Engineers • Landscape Architects • Community Planners • Land Surveyors • lVeighbors 1 i Technica/Information Report PREPARED FOR: Greene-Gasaway Architects, PLLC PO Box 4158 Federal Way, WA 98063-4158 1ti4 CjI 1• O p PROJEGT.• 1 1 ,`:,6°rt "`8`,op Cascade Elementary School 16022 116"' Avenue SE Renton, WA 98058 O o?+ ' Project No. 2140258.10 sloxsL PREPARED BY.• t hereby state tnat tnis Technical Rohin Elangovan, EIT Information Report for Cascade Elementary School has been prepared by Project Engineer me or under my supervision, and meets the standard of care and expertise that is REVIEWED BY.•usual and customary in this community for professional engineers. I understand that the City of Renton does not and will William ]. Fierst, PE not assume liability for the suffiaency, Project Manager suitability, or performance of drainage facilities prepared by me.Sean M. Comfort, PE Principal DATE.• une 2014 Revised July 2014 Tab/e of Content.s Section Page 1.0 Project Overview............................................................................................................i 2.0 Conditions and Requirements Summary........................................................................i 2.1 Core Requirement 1 - Discharge at the Natural Location................................................i 2.2 Core Requirement 2 -Offsite Analysis ..........................................................................1 2.3 Core Requirement 3 - Flow Control ..............................................................................2 2.4 Core Requirement 4 - Conveyance System ...................................................................2 2.5 Core Requirement 5 - Erosion and Sediment Control.....................................................2 2.6 Core Requirement 6 - Maintenance and Operations.......................................................2 2.7 Core Requirement 7 - Financial Guarantees and Liability................................................2 2.8 Core Requirement 8 - Water Quality.............................................................................3 2.9 Special Requirement 1 - Other Adopted Requirements ..................................................3 2.10 Special Requirement 2 - Flood Hazard Delineation ........................................................3 2.11 Special Requirement 3 - Flood Protection Facilities........................................................3 2.12 Special Requirement 4 - Source Control........................................................................3 2.13 Special Requirement 5 - Oil Control..............................................................................3 2.14 Special Requirement 6 -Aquifer Protection Area...........................................................3 3.0 Offsite Analysis...............................................................................................................3 3.1 Task 1 - Study Area Definition and Maps......................................................................3 3.2 Task 2- Resource Review...........................................................................................4 3.3 Task 3 - Field Inspection.............................................................................................5 3.4 Task 4- Drainage System Description and Problem Descriptions...................................5 3.5 Quantitative Analysis...................................................................................................6 4.0 Flow Control and Water Quality Facility Analysis and Design .......................................6 5.0 Conveyance System Analysis and Design.......................................................................7 6.0 Special Reports and Studies...........................................................................................7 7.0 Other Permits.................................................................................................................7 8.0 CSWPPP Analysis and Design.........................................................................................7 9.0 Bond Quantities, Facility Summaries, and Dectaration of Covenant..............................8 10.0 Operations and Maintenance Manual.............................................................................8 11.0 Conclusion......................................................................................................................8 Technical Information Report O Q O OCascadeElementarySchool Projed No. 2140258.10 Appendices Appendix A Technical Information Report(TIR) Worksheet Exhibits A-1 ...................Vicinity Map A-2 ...................Soils Map A-3 ...................Existing Conditions Plan A-4...................Site Plan A-5 ...................Existing Basin Map A-6 ................... Developed Basin Map A-7 ...................Site Flow Rates A-8 ...................Conveyance Calculations A-9 ...................Downstream Pipe Information A-10 .................Aquifer Protection Area A-11 .................King County iMAP Information A-12 .................FIRM Rate Map A-13 .................Renton Bond Quantiry Worksheet A-14 .................Operations and Maintenance Manual Appendix B Cascade Elementary Topographic Map Prepared by Townsend-Chastain &Assoc.,Inc. October 6, 1992 Cascade Elementary School Site Drainage Plan Prepared by RoseWater Engineering, Inc.]une 14, 1994 Technical Information Report Q Q O QCascadeElementarySchool Project No. 2140258.10 1.0 PRO]ECT OVERVIEW Cascade Elementary School is located at 16022 116"' Avenue SE on Parcel No. 2823059034 in the city of Renton. See Appendix A-1 for the Vicinity Map. The 2014 portable classroom project is proposing to install two double portable classrooms, ramps, stairs, and landings at Cascade Elementary School, and to demolish an existing single classroom por[able. See Appendix A-3 for the Existing Conditions Plan and Appendix A-4 for the Site Plan. This would result in 3,436 square feet(SF) of new impervious surface and 19 SF of replaced impervious surface (total of 3,455 SF of new plus replaced impervious surfaces). In addition, 22 SF of impervious surface will be converted to pervious lawn. The site will realize a net increase of 3,433 SF of impervious surfaces. See Appendices A-5 and A-6 for Existing and Developed Basin Maps. The 2009 King County Surface Water Design Manual(KCSWOM)and City ofRenton Amendments to the King County Surface Water Design Manual(February 2010) establish the methodology and design criteria used for the project. The King County Runoff Time Series (KCRTS) software program, developed by the King County Department of Natural Resources, was used to calculate runoff and design stormwater flow control facilities. The Rational method was used to determine conveyance capacities. 2.0 CONDITIONS AND REQUIREMENTS SUMMARY The project triggers Full Drainage Review. Below is a summary of how the proposed project will meet the Core Requirements. 2.1 Core Requirement 1 - Discharge at the Natural Location The natural discharge location for stormwater from the work area is the yard drain north of the existing double classroom portable, which connects via closed pipe to an existing catch basin south of the existing double classroom portable. Stormwater in the existing catch basin is conveyed east and south around the Cascade Elementary School building and through the site to the southeast corner of the site. Stormwater is then conveyed east through a residential area in an 18-inch concrete pipe toward 119"'Avenue SE. Stormwater roof runoff from the new portables will be discharged from the roof with downspouts, and will flow to a series of proposed catch between the two proposed double classroom portables. The proposed conveyance pipes convey stormwater to a proposed catch basin overbuilt on the existing drainage system. The existing drainage pipes convey stormwater to an existing catch basin south of the existing double classroom portable. Drainage is routed downstream through the existing conveyance system onsite. All surface and stormwater runoff from the proposed development will continue to be discharged at the natural location, and thus will not adversely affect downstream properties or drainage systems. 2.2 Core Requirement 2 - Offsite Analysis AHBL staff performed a Level One Downstream Analysis for the project on June 11, 2014, and July 17, 2014. The analysis included: Defining and mapping the study area. Reviewing available information on the study area. Technical Information Report Q Q 0 OCascadeElementarySchool1 Project No. 2140258.10 Field inspecting the study area. Analyzing the existing drainage system, including its existing and predicted problems, if any. Please refer to Sedion 3.0 for the full offsite analysis. 2.3 Core Requirement 3 - Flow Control The project site lies in the Flow Control Duration Standard Area, per the King County Flow Control Application Map of the 2009 KCSWDM. This project meets Exception 2 for Flow Control Duration Standard Area because the project proposes no more than a 0.1-cfs difference in the sum of developed 100-year peak flows for target surfaces subject to this requirement, and the sum of forested site conditions 100-year peak flows for the same surface areas. See Appendix A-7 for pre-and post-developed peak flow rates. 2.4 Core Requirement 4 - Conveyance System The two new double portable classrooms will include downspouts that tie into a roof drain system prior to entering proposed catch basins onsite. Based on Section 1.2.4.1 of the KCSWDM, new pipe systems shall be designed with sufficient capacity to convey and contain the 25-year peak flow with a minimum of 6 inches of freeboard between the design water surFace and structure grate. In addition, runoff from the 100-year peak storm event cannot create or aggravate a severe flooding problem or severe erosion problem. The new pipe system has sufficient capacity for a 25-year peak flow. Catch basin rims do not overtop in the 100-year peak storm event and there is over a 6-inch freeboard between the design water surface and structure grate during the 25-year peak storm event. No severe flooding problems or severe erosion problems are created or aggravated in the 100-year storm event. A quantitative downstream analysis was completed. See Appendix A-8 for the conveyance basin and calculations, and downstream analysis. 2.5 Core Requirement 5 - Erosion and Sediment Control Onsite land disturbance will be very minimal and will consist of clearing the work site approximately 7,500 SF), small amounts of demolition, and regrading for placement of two catch basins. Erosion and sediment control will be provided with the use of temporary and permanent seeding within the work limits, silt fence or wattles, and inlet sediment protection. A Temporary Erosion and Sedimentation Control Plan is included in the plan set. See Section 8.0 for CSWPPP Analysis and Designs. 2.6 Core Requirement 6 - Maintenance and Operations Maintenance and operation of all drainage facilities will be maintained by the owner. The project proposes new catch basins onsite. See Appendix A-14 for the Operations and Maintenance Manual. 2.7 Core Requirement 7 - Financial Guarantees and Liability This project will provide financial guarantees and liability per City of Renton requirements. See Appendix A-13 for the Renton Bond Quantity Worksheet. Technical Information Report O Q O OCascadeElementarySchool2 Project No. 2140258.10 i 2.8 Core Requirement 8 - Water Quality No pollution generating surfaces are proposed as part of this development; therefore, the development meets the Surface Area Exemption. Core Requirement 8 will not apply. 2.9 Special Requirement 1 - Other Adopted Requirements The project is include in the Lower Cedar River Drainage Basin. City and County basin requirements will be followed where applicable. 2.10 Special Requirement 2 - Flood Hazard Delineation The proposed project is not in or adjacent to the 100-year floodplain. See Appendix A-12 for the FIRM Rate Map. 2.i i Special Requirement 3 - Flood Protection Facilities This project does not rely on existing flood protection facilities, nor will it modify or construct new flood protection facilities. 2.12 Special Requirement 4 - Source Control The proposed project is an educational facility; therefore, it does not t the definition of a commercial, industrial, or multi-family site for source control purposes. 2.13 Special Requirement 5 - Oil Control The site does not meet high use criteria and is not subject to oil control measures. 2.14 Special Requirement 6—Aquifer Protection Area According to the City of Renton Aquifer Protection Zone Map, the project is not located within an aquifer protection zone. See Appendix A-10 for a map of the Aquifer Protection Area. 3.0 OFFSITE ANALYSIS There are no upstream tributary areas contributing drainage to the basin area. 3.1 Task i — Study Area Definition and Maps Cascade Elementary School proposes to place two new portable buildings on the 14.88-acre site located at 16022 116'Ave SE in the city of Renton. Based on a site visit on July 17, 2014, the upstream basins that flow onsite were delineated and can be found in Appendix A-8. The project site lies within the Lower Cedar River Drainage Basin, as delineated by the King County Water Features Map. There are no wetlands on or in the vicinity of the project site. The project receives upstream stormwater from two separate basins. One basin includes the western half of the elementary school building, the parking lot to the west of the elementary school building, a portion of 116"' Avenue SE, and a residential area to the west of 116th Avenue SE. This basin includes 3.297 acres of impervious area and 2.676 acres of pervious area. This Technical Information Report O Q O QCascadeElementarySchool3 Project No. 2140258.10 basin conveys to a manhole directly southeast of Cascade Elementary School in a 12-inch concrete pipe. The second basin includes a larger portion of 116"' Avenue SE and SE 162nd Street, and a residential area to the west of 116 h Avenue SE. This basin includes 3.140 acres of impervious area and 3.439 acres of pervious area. This basin conveys stormwater through a biofiltration swale to the south of the project site before conveying to a manhole to the east of the biofiltration swale. The basins were delineated using City of Renton COR Maps and a field inspection described in Task 3. In existing conditions, there is one discharge location from the project site. Stormwater from the site flows to a yard drain onsite. Flow travels from this yard drain through a series of closed storm drain catch basins to the southeast corner of the site. Stormwater from the field to the east of Cascade Elementary School is mllected in an underdrain system and conveyed to the catch basin on the southeast corner of the project site, prior to discharging offsite to the east toward 119th Avenue SE. See Appendix A-9 for a sketch of the downstream conveyance system. 3.2 Task 2— Resource Review The following resources were reviewed to discover any existing or potential problems in the study area: Topographic Survey: Cascade Elementary Topographic Survey prepared by Townsend- Chastain &Assoc., Inc., October 6, 1992, included in Appendix B. Civil Engineering Plans: Cascade Elementary School Site Drainage Plan prepared by RoseWater Engineering, Inc., June 14, 1994, included in Appendix B. Landscape Plans: Cascade Elementary School Pla eld Grading and Sub-Drainage Plan prepared by Don Shimono Associates, included in Appendix A-8. FEMA Map: FEMA Flood Insurance Rate Map 53033C0983F, dated May 16, 1995, (see Exhibit A-12) indicates that the project site lies within Zone X—Areas determined to be outside the 500-year floodplain. -I King County iMAP: The project site is not located in any of the following mapped critical areas (see Exhibit A-11): o Coal Mine Hazard Areas o Erosion Hazard Areas o Landslide Hazard Areas o Seismic Hazard Areas o Critical Aquifer Recharge Areas 0 100-Year Flood Plain o Wetlands Soils Information: Site soils have been classified by the USDA Natural Resources Conservation Service(NRCS) as Arents, Alderwood material, 6 to 15 percent slopes (AmC) see Exhibit A-2). City of Renton COR Maps: The upstream and downstream basins were delineated I utilizing City of Renton COR Maps, along with a site visit on July 17, 2014. Technical Information Report O Q O 0CascadeElementarySchool4 Project No. 2140258.10 3.3 Task 3 — Field Inspection On June 11, 2014, and July 17, 2014, AHBL staff performed a downstream analysis of the drainage system receiving stormwater runoff from the proposed portable classrooms, and an upstream analysis of the drainage system discharging to piping at Cascade Elementary School. 1. Investigate any problems reported or observed during the resource review— No problems were reported or observed during the resource review. 2. Locate all existing/potential constrictions or lack of capacity in the existing drainage system No constrictions or lack of capacity in the existing drainage system was obseroed. 3. Identify all existing/potential downstream drainage problems as defined in Section 1.2.2.1 No existing/potential downstream drainage problems were observed. 4. Identify existing/potential overtopping, scouring, bank sloughing, or sedimentation — No existing/potential overtopping, scouring, bank sloughing, or sedimentation was observed. 5. Identify significant destruction of aquatic habitat or organisms (e.g., severe siltation, back erosion, or incision in a stream)— No significant destruction of aquatic habitat or organisms was observed. 6. Collect qualitative data on features such as land use, impervious surfaces, topography, and soil types —The land use on the project site is a school site that consists of approximately 30 percent impervious area and sports fields to the south end. The conveyance system drains through a residential area to the east before reaching 119"'Avenue SE, where the road slopes down to a catch basin before being conveyed farther east. The upstream basin was delineated by determining where the road slopes toward the site and following the piping onsite, along with the contours found in City of Renton COR Maps. 7. Collect information on pipe sizes, channel characteristics, drainage structures, and relevant critical areas (e.g., wetlands, stream, steep slopes) — See Appendix A-9 for information on pipe sizes and drainage structures. No critical areas were observed. 8. Verify tributary basins delineated in Task 1 — Based on the topography onsite, the basin delineation based on the survey was confirmed. 9. Contact neighboring property owners or residents in the area about past or existing drainage problems, and describe these in the report (optional) —This requirement is not applicable for this project. 10. Note the date and weather conditions at the time of the inspection —The first site visit occurred on June 11, 2014. The weather was sunny and the temperature was 60 degrees. The second site visit occurred on July 17, 2014. The weather was sunny and the temperature was 73 degrees. 3.4 Task 4— Drainage System Description and Problem Descriptions See Appendix A-9 for a map of the downstream drainage system. The existing point of discharge for the portables basin is an existing yard drain onsite. This yard drain is being demolished as part of this project. Three new catch basins and conveyance piping are proposed between the two proposed double classroom portables. Stormwater will flow from the proposed portables to Technical Information Report Q Q O OCascadeElementarySchool5 Project No.2140258.10 catch basins via roof drain and closed conveyance piping. A new catch basin will be overbuilt on the existing drainage system. Downstream of the overbuilt catch basin, stormwater is conveyed to an existing catch basin south of the existing double classroom portable onsite. Stormwater outfalling from the catch basin flows east approximately 154 feet in an 8-inch concrete pipe along the building perimeter to a solid-lid catch basin to the northeast of the school building. Stormwater is conveyed south in 15-inch conc ete pipe through a series of three solid-lid catch basins approximately 615 feet to a catch basin just east of the storm facility onsite. Stormwater is conveyed in a 15-inch concrete pipe approximately 390 feet east to a catch basin on the southeast corner of the project site. Stormwater is conveyed in an 18-inch concrete pipe 210 feet to a catch basin on the east side of 119"' Avenue SE. Based on the City of Renton GIS Mapping System, stormwater is then conveyed in a 24-inch concrete pipe east through a residential area toward Cascade Park, where the conveyance system ties into an existing 36-inch storm main system. No signs of flooding, overtopping, or erosion were evident at the time of the inspection. 3.5 Quantitative Analysis A quantitative analysis modeling the downstream drainage to the east properly line of the project system under existing and proposed conditions was performed at the request of the City of Renton. The analysis was completed using the StormSHED2G program and the Rational Method. The analysis determines that during the 25-year, 24-hour peak storm event, all pipes have adequate capacity and all catch basins and manholes have a minimum of 6 inches of freeboard between the design water surface and structure grate. In the 100-year peak storm event, catch basins do not overtop and no severe flooding problems or severe erosion problems are created or aggravated. Downstream basin conveyance calculations, including basin delineation and StormSHED2G outputs, can be found in Appendix A-8. The RoseWater Engineering Inc. and Don Shimano Associates plans included as part of the quantitative analysis in Appendix A-8 were on a different datum than the AHBL Civil Plans. Therefore, a conversion factor of+3.11 feet was applied to each of the rims and inverts on these plans to match the AHBL datum. As required, all storm drainage structures have in excess of 6 inches of freeboard between the computed hydraulic grade and rim elevation during the 25-year peak storm event. 4.0 FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN The project proposes an increase of no more than a 0.1-cfs difference in the sum of developed 100-year peak flows for target su faces subject to this requirement and the sum of forested site conditions 100-year peak flows for the same surface areas, which exempts the project from flow control requirements per Exception 2 in Section 1.2.3.1(B) of the 2009 KCSWDM. The existing impervious surface beneath the portable to be removed from the site is to be protected and not disturbed; therefore, the existing impervious surface beneath the portable is not a replaced impervious surface and is not considered a target surface. The sidewalk beneath the proposed double classroom portable to the north is to be protected and not disturbed; therefore, it is not a replaced impervious surface and is not considered a target surFace. The basin was modeled using KCRTS per the fallowing conditions: Technical InfoRnation Report 0 Q O OCascadeElementarySchool6 Project No. 2140258.10 Pre-Develo ed ac Post-Develo ed ac Forest 0.0710 0 Lawn 0.0810 0.0816 Im rvious 0.0816 0.1520 Total 0.2336 0.2336 100- ear Peak Flow cfs Pre-develo d 0.188 Post-develo ed 0.274 The increase in the 100-year peak flow rate is 0.086 cfs, which is less than the 0.1 cfs threshold. Detailed calculaaons to demonstrate exemption from flow control have been included in Appendix A-7. 5.0 CONVEYANCE SYSTEM ANALYSIS AND DESIGN The project proposes collection of storm drainage from the two proposed double classroom portables by roof drain systems that drain to proposed catch basins between the two proposed classroom portables and to the downstream drainage system. Conveyance capacity calculations are included in Appendix A-8. G.O SPECIAL REPORTS AND STUDIES There are no special reports or studies necessary for the proposed project. 7.0 OTHER PERMITS No other permits are required as part of this proposed development. 8.O CSWPPP ANALYSIS AND DESIGN The proposed development shall comply with guidelines set forth in City of Renton drainage requirements. The plan will include erosion/sedimentation control features designed to prevent sediment-laden runoff from leaving the site or adversely affecting critical water resources during construction. The following measures are shown on the ESC plans and will be used to control sedimentation/erosion processes: Clearing Limits—All areas to remain undisturbed during the construction of the project will be delineated prior to any site clearing or grading. Cover Measures—Cover measures will be implemented to the disturbed areas. Perimeter Protection — Filter fabric fences for site runoff protection will be provided at the downstream site perimeter. Traffic Area Stabilization —Traffic Area Stabilization is not applicable for this project Sediment Retention—Inlet sediment protection will be utilized as part of this project. Technical Information Report O Q O OCascadeElementarySchool7 Project No. 2140258.10 Storm Drain Inlet Protection—Inlet sediment protection will be provided on all new and existing catch basins downstream of construction activities. Surface Water Collection —Catch basins and conveyance pipes will provide surface water collection. Dewatering Control —Dewatering Control is not applicable for this project. Dust Control —Dust control measures including sweeping and water truck will be implemented when exposed soils are dry to the point that wind transport is possible, and roadways, drainage ways, or surface waters are likely to be impacted. Flow Control— Flow Control is not applicable for this project. 9.0 BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT See Section 2.7 above for Core Requirement 7, Financial Guarantees and Liability. See Appendix A-13 for the City of Renton Bond Quantity Worksheet. Facility Summaries and a Declaration of Covenant are not applicable to this project. I 10.0 OPERATIONS AND MAINTENANCE MANUAL II Maintenance and operation of all drainage facilities will be maintained by the owner. The project proposes new catch basins onsite. See Appendix A-14 for operations and maintenance information. 11.0 CONCLUSION This site has been designed to meet or exceed the requirements of the 2009 King County Surface Water Design Manual(KCSWDM), as amended by the City of Renton Amendments to the King County Surface Water Design Manua/(February 2010). Flow calculations and modeling utilize City of Renton standards for sizing stormwater conveyance. This analysis is based on data and records either supplied to or obtained by AHBL. These documents are referenced within the text of the analysis. The analysis has been prepared using procedures and practices within the standard accepted practices of the industry. AHBL, Inc. Rohin Elangovan, EIT Project Engineer RE/Isk June 2014 Revised July 2014 Q:12014 2140258 WORDPROC Reports 20140724_Rpt_(TiR)_2140258.10(wp dreft).doac Technical Information Report Q Q O aCascadeElementarySchool8 Project No. 2140258.10 Appendix A Technical Information Report (TIR) Worksheet Exhibits A-i ..................Vicinity Map A-2 ..................Soils Map A-3 ..................Existing Conditions Plan A-4 ..................Site Plan A-5 ..................Existing Basin Map A-6 ..................Developed Basin Map A-7 ..................Site Flow Rates A-8 ..................Conveyance Calculations A-9 ..................Downstream Pipe Information A-10.................Aquifer Protection Area A-11.................King County iMAP Information A-12.................FIRM Rate Map A-13.................Renton Bond Quantity Worksheet A-14.................Operations and Maintenance Manual Technical Infomiation Report O Q O OCascadeElementarySchool Project No. 2140258.10 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 1 PROJECT OWNER AND Part 2 PROJECT LOCATION AND PROJECT ENGINEER DESCRIPTlON ProjectOwner F 7'°" 5«t-oo D\Sl2r ProjectName CAScRD E 6'Er T.Y Phone '2 S 2 nH-N v o 3 DDES Permit# Address 7 ft 2 5 2yT" Sr, S-6-, Location Township ?3 l/ 'l7 Range O Project Engineer wl i''r hf Sj Section 2 Company 1 F`Site Address 6 ZZ //6r" A E Sr, Phone Cy53 3 3 'Zy2 Ta N WA- Q go5 Pa#3 TYPE OF PERM(T APPLICATION Part 4 OTHER REVIEWS AND PERMITS Landuse Services DFW HPA Shoreline Subdivison / Short Subd. / IPD ManagementCOE404 Building Services DOE Dam Safety Structural M/F/Commerical / SFR RockeryNault/ Clearing and Grading FEMA Floodplain ESA Section 7 Right-of-Way Use COE Wetlands Other Other Part 5 PLAN AND REPORT INFORMATION Technical Information Report Site Improvement Plan (Engr. Plans) Type of Drainage Review Ful / Targeted / Type (circle one}: Fu / Modified / circle): Large Site Small Site Date (include revision Date (include revision dates): dates): Date of Final: Date of FinaL• Part 6 ADJUSTMENT APPROVALS Type (circle one): Standard ! Complex / Preapplication / Experimental! Blanket N(f Description: (include conditions in TIR Section 2) NIA- Date of A roval: i -- 2009 Surface Water Design Manual 1/9/2009 1 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 7 MONITORING REQUlREMENTS Describe: N I RMonitoringRequired: Yes / Io Start Date:t Completion Date:R Part 8 SfTE COMMUNITY AND DRAINAGE BASIN Community Plan : Soos CRCEk Special District Overlays: Drainage Basin: D+n r`.. EDAR (v.2 1 Stormwater Requirements: Part 9 ONSITE AND ADJACENT SENSITIVE AREAS River/Stream Steep Slope Lake Erosion Hazard Wetlands Landslide Hazard I Closed Depression Coal Mine Hazard Floodplain Seismic Hazard Other ('( Habitat Protection Part 10 SOILS Soil Type Slopes Erosion Potential A, 5% op qr%-.F High Groundwater Table (within 5 feet) Sole Source Aquifer Other( Seeps/Springs Additional Sheets Attached 2009 Surface Water Design Manual 1/9/2009 2 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 11 DRAINAGE DESIGN LIMITATIONS I REFERENCE LIMITATION/SITE CONSTRAINT Core 2—Offsite Analvsis Sensitive/Critical Areas SEPA Other N C Additional Sheets Attached Part 12 TIR SUMMARY SHEET rovide one TIR Summa Sheet er Threshold Dischar e Area Threshold Discharge Area: name or descri tion Sc t u n F Core Requirements (all 8 apply) Dischar e at Natural Location Number o atural Dischar e Locations: I I Offsite Analysis Level: 1 / 2 / 3 dated:T 1 Flow Control Level: 1 / / 3 or Exemption Number Ex crn,N incl.facili summa sheet Small Site BMPs Conveyance System Spill containment located at: Erosion and Sediment Control ESC Site Supervisor: TT3 D, a+c,r P aContactPhone: W After Hours Phone: Maintenance and Operation Responsibility: Private ublic If Private, Maintenance Lo Re uired: Yes !No Financial Guarantees and Provided: es / No Liabili Water Quality Type: Basic / Sens. Lake / Enhanced Basicm / Bog include facility summary sheet} or Exemption No. I Landsca e Mana ement Plan: Yes / No S ecial Re uirements as a licable Area Specific Drainage Type: CDA/SDO/MDP/BP/LMP/Shared Fac.I None Re uirements Name: Floodplain/Floodway Delineation Type: Major / Minor / Exemption / None 1 R 100-year Base Flood Elevation (or range): Datum: Flood Protection Facilities Describe: Source Control Describe landuse: comm./industrial landuse)Describe any structural controls: ( 2009 Surface Water Design Manual 1/9/2009 3 I KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Oii Control High-use Site: Yes / Treatment BMP: Maintenance Agreement: Yes /'Vo with whom? Other Draina e Structures Describe: C- 6aS 5 $.. G oSe,, G'Qv V2 ct/v(2._ PZ- Part 13 EROSION AND SEDIMENT CONTROL REQUIREMENTS MINIMUM ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION AFTER CONSTRUCTION Clearing Limits Stabilize Exposed Surfaces Cover Measures Remove and Restore Temporary ESC Facilities Perimeter Protection Clean and Remove All Silt and Debris, Ensure Traffic Area Stabilization Operation of Permanent Facilities Sediment Retention Flag Limits of SAO and open space preseroation areas Surface Water Collection Other Dewatering Control Dust Control Flow Control Part 14 STORMWATER FACILITY DESCRIPTIONS Note: Include Facili Summa and Sketch Flow Control T e/Descri tion Water Quali T e/Descri tion Detention Biofiltration v Infiltration Wetpool Regional Facility Media Filtration Shared Facility Oil Control Flow Control Spill Control BMPs Flow Control BMPs Other Other 2009 Surface Water Design Manual 1/9/2009 4 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 15 EASEMENTSiTRACTS Part 16 STRUCTURAL ANALYSIS Drainage Easement Cast in Place Vault Covenant Retaining Wall Native Growth Protection Covenant Rockery>4' High I Tract Structural on Steep Slope Other Other Part 17 SIGNATURE OF PROFESSIONAL ENGINEER I, or a civil engineer under my supervision, have visited the site. Actual site conditions as observed were incorporated into this worksheet and the attached Technical Information Report. To the best of my knowledge the information provided here is accurate. 1 a ao Si ned/Date 2009 Surface Water Design Manual 1/9/2009 5 3 Etemeftsary SehnAt s III 3 r.:I x1:- Es F'ilt i:f'3%.4'. r TO z13:i s l ikc'+t.y+c y: r P C1,rP i1a Y ct cr d R, c:;t icag:r x.. -I s: 1 Y ':.1;Y' ct;'Y-,Y... -. i l . y i zi tdF$°ti:.: i. u zi r.rf t rnt4hr;.w-r!" y.;.,'Vo i15.ia r'Ru>nis s51aifus; P3f_"'lri.; F!11[3 k s :, f 3 1 1EPJ'i:, _ I;';ti3 y` . . 4. I i i^ L1.'.i1?P't'-j 7 4.rT. k, u::.., S IT Et : tl r;e't t'W`;cl,i w i s e' aseade lemeniary Schoo! Hl.',:,'t I r ... . .... . a I n'- b& Kj S t. 'h.i'° ... R tR}13 A f i". BfElPJltdE}SG 9 p• y'r d` . . r k. G: Y P.iiv :.k:.`y'. uS4 d:1=:;* i,th`:` I e 15'['•?{Isr li' V,, Y• . E i 8f.'t I 3>i;5" A$$j,•. i 2i-i ktpri I a. 7 16T I VICINITY MAP NOT TO SCALE I I I CASCADE ELEMENTARY SCHOOL PORTABLES VICINITY MAP A-T A C O M A S E A T T l E 215 NaM i 9Yw1.9rb D41 R M 9lIW ?51 7.24t2 1FL I 71i OrJi N Aw SaN 9 37q S il M fI1M 1 7.24t5 lE1 I USDA United States A product of the National Custom Soil Resource Department of Cooperative Soil Survey, Agriculture a joint effort of the United Report for n States Department of IV Agriculture and other K i n g C o u n tyFederalagencies, State Natural agencies including the Resources AgriculturalExperiment AreaConservationStations, and local Service participants Washington w.i I w .1 y rta e i l r „ ti:::;, i.. i r 2 ' r i _. i j z p 3 f j:' t I I .,aF$ 2' 7E•z w.... t I• k. , a Y jaa" w' _r f s 1 r.t f j' y ,. i• lf {i I l P R yry, { • s'. F L•; J w O -_______V.O O " A-2 A p v y 5256230 5256280 52;G330 ti;;"tAn 525643n 5256480 52 6530 5256580 575f;fi30 122°11'10"w 17I"11'10'W Z w rw ..,.•. l!d.E,7l vwaw*c¢aa ars ss mnzsmaww ,. ir. 310f"''J'^"...-T.,16rGC'' ,,""" wnw.-.s ....,.__.,, ' • .-f N z o 0 3 t rb`.:rh.irG .., f i o i aJAI a K^ a a. r , ia.' . w ,, q - ' a' 11i i —' g j N yr,_ i 1: ',1. r, T.e .. .k e .,J Q p,c. s: ,f w.,- . R g Pj' r y tDt w•,.:.A y " C `'Ri r, ,. c II yI " x I f o 3 0 S}' ,: ` ..;. ti C Fj' Z7i y h vi s xi +``' -y w 6 C y ',.' +K :w w ny ia 1'. f E,_.ry" ' y r r`.`,, t ' fwa i 4, xMP FC&"„ s s„'4..' Z n*Miw,. M rn r . t~.` l' M" O r; a 5, Y x.'.. ! ` i : a'+ Y 4 1 . _ . a-s #+ ,+at4Mr F,..F i_` T9y"r j f . c.. M' ' y, `. x w , . ,t. ,r, Wl Fa: r r tr"" w. . .. x o p, 4: a, -d S" e t•^py.r.; M i F j g ,` w, K', pF r. r, ns ..i..w s yr-a a,:e!. :r•l- a.- p,;_.- e•,;, a -m r ^x;Y:;,,' s. , uI izz^o 5a.w a izz io s3•w 525fi230 52562&1 5256330 525G3II0 5256430 5256480 5256530 5256580 525663C y V D y N Custom Soil Resource Report MAP LEGEND MAP INFORMATION Area of interest(AOq Spoil Area The soil surveys that comprise your AOI were mapped at 1:24,000. Area oflnterest(AOI) Stony Spot Sons Very Stony Spot Warning:Soil Map may not be valid at this scale. Soil Map Unit Polygons wet Spot Enlargement of maps beyond the scale of mapping can cause N Soil Map Unit Lines Other I misunderstanding of the detail of mapping and accuracy of soil line Soii Map unit Points placement.The maps do not show the small areas of contrasting Special Line Features soils that could have been shown at a more detailed scale. Special Point Features Blowout Water Features Streams and Canals Please rely on the bar scale on each map sheet for map eorrow Pit measurements. Transportation Clay Spot Rails Source of Map: Natural Resources Conservation Service Closed Depression interscate Highways Web Soil Survey URL: http://websoilsurvey.nres.usda.gov Gravel Pit US Routes Coordinate System: Web Mercator(EPSG3857) Graveny Spot Major Roads Maps from the Web Soil Survey are based on the Web Mercator Landfill Local Roads projection,which preserves direction and shape but distorts distance and area.A projection that preserves area,such as the Lava Flow eackground Albers equal-area conic projection,should be used if more accurate Marsh or swamp Aerial Photograpny calculations of distance or area are required. nnine or Quarry This product is generated from the USDA-NRCS certified data as of o Misceuaneous Water the version date(s)listed below. Perennial Water Soil Survey Area: King County Area,Washington Rock outcrop Survey Area Data: Version 8,Dec 10,2013 Saline Spot Soil map units are labeled(as space allows)for map scales 1:50,000 Sandy Spot of lafgef. Severely Eroded Spot Date(s)aerial images were photographed: Aug 31,2013—Oct 6, Sinkhole 2013 Slide or Slip The orthophoto or other base map on which the soil lines wereSodicSpotcompiledanddigitizedprobablydiffersfromthebackground imagery displayed on these maps.As a result,some minor shifting 9 A-2 Custom Soil Resource Report Map Unit Legend King County Area,Washington(WA633) Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI AmC Arents,Alderwood material,6 to 2.5 100.0% 15 percent slopes Totals for Area of Interest 2D.5 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils.On the landscape, however,the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class.Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different mana ement.These are called contrastin or dissimilar com onents.The enerall99 P Y 9 Y are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each.A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that i have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. o A_2 II Custom Soil Resource Report An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soi!series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surFace layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps.The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha- Beta association, 0 to 2 percent slopes, is an example. An undifferentiafed group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them.Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include misce!laneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. 11 A-2 Custom Soil Resource Report King County Area, Washington AmC—Arents, Alderwood material, 6 to 15 percent slopes Map Unit Setting Mean annual precipitation: 35 to 60 inches Mean annual air temperature: 50 degrees F Frost-free period: 150 to 200 days Map Unit Composition Arents, alderwood material, and similar soils: 100 percent Description of Arents,Alderwood Material Setting Landform: Till plains Parent material: Basal till Typical profile H1 -0 to 26 inches: moderately acid, gravelly sandy loam H2-26 to 60 inches: moderately acid, very gravelly sandy loam Properties and qualities Slope: 6 to 15 percent Depth to restrictive feature: 20 to 40 inches to densic material Natural drainage class: Moderately well drained Capacity of the most limiting layer to transmit water(Ksat): Very low to moderately low(0.00 to 0.06 in/hr) Depth to water table: About 16 to 36 inches Frequency of flooding: None Frequency of ponding: None Available waterstorage in profile: Very low(about 2.3 inches) Interpretive groups Farmland classification: Not prime farmland Land capability classification(irrigated): None specified Land capability classification(nonirrigated): 4s Hydrologic Soil Group: B/D 2 A_2 a :;;., w.........._...._._.________.._.. h v,.;V_..__... ___... G AHBL•. co h d. T ._ .-v._ n. t;r; - — -- . iz•-– _:._ . . ._._ ^- ._ tx_.... w......_.... w.._...... m..._.._...q,„„w.M..................m.._..._____._..........-,. ' x;tiY ._..., ..ry M GRAPHIC SCALEm.._......__..... j R 0 10 20 40 FEET 4 Jo CONTAINER i1 o o j"I,, 1"=20 FEET r r 3 Ati:.. L`a.4 ..,. ., Y .... i. e f i Tr" w ;.,... A" ,_. 7 x. g ifo _ 5 t r i 1._.- ,.,.r y--• ',. 7 PORTABLE r _ ' f FF=461.65 p-.._ o d o ;R6O pORS A8 FF,46 4 r-.... o t w„.,., .T O ri, r 77TTlTT x A L u Y—_`,,,`' ABL NDr;_ C-: t-N IL A N:170444. AHBL #8 I w- r .r:. ;- , E:130618° SCRIBED X ELEV:459. N:170451.6706 k..,_M.-" i-- ;'"_ , a > E:1306064.9195 i Er;,.:`.s-: .. 2 1 ELEV:459.71 p- r'1 0 ' 1r .__. o ` S`o 1 s Q CASCADE ELEMENTARY SCHOOL PORTABLES T A C o , S E ,, T T EXISTING CONDTIONS A-3 k"`' ,PLAN3NOor11wWIIMSaN9b7ASdWM1011D&761.24?S lEl o 0 h AHBL.': r .. r s^; GRAPHIC SCALE I 0 10 20 40 FEET r; J,U.. 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W ,. 1 i/ y p;: c t _ i I Q CASCADE ELEMENTARY SCHOOL PORTABLES SITE PLAN A-4TACOMASEATTLE 1215 MaN N Aed.9 Re.Twa M9EIW 31 2 2 7EL r6 OodlsN Awr Sw14 9 3'q SiM M lBWI 7 1A.2475 lEl 0 BASIN LIMITS o ' AHHL•: 4.;. + + + + + + + GRAPHIC SCALE 0 10 20 40 FEET 4$ 1"=20FEET i o LEGEND 4 o i E%ISTINGWWN MC ELECHS..'M. t t t + + + + + +N r rxa eTsu Fncciro aianc, t ' + + + + }p + + + Ct`+ + + o+-. +- + + + + 1 . } t + ._t -i- t t + + exisrN iMpertveus raooe ecn.sit + + + + MPc9NO1JSIhC14'A GETS..R%ACEI D816ACrc.` S P' t + + F pF + f' , q + t h + n ELEDAS FCRESTEIj ff-: t TARGETSl,R-4CEiiC.'10.4C; 3 IJ( L . 1i: Y!j lIf I O f j`I`t71j O t f TBM 1 I TBM 2• _ f /f _ a AHBL #7 0i r r .,, s,"r -- h NAIL AND WASupRHBL 8 t S RIBED X N:170444.8929I' N:170 6 E:1306185.8762 1 I E:1306064.9195 ELEV:459..37 1 ic,u. Y "" . .ELEV:459.7/ j , is- " r M , ;k, o N s c Y " '/..H w y rlT.i. Y' w.r 5`." . it a ... Y y- M x i' ' / CAMFiyneast/ strucOia Eg cas O CASCADE ELEMENTARY SCHOOL PORTABLES EXISTING BASIN A-5TACOMASEATTLE m,., , MAP71{Oorywtr M r Srli,94]74 S dM.M 101 ffi287.242'i lEl 0O O BASIN LIMITS o AI L• a.;, + + + + + + + GRAPHIC SCALE I ' `.., + + + + + # 0 10 20 40 FEET t + t + + t + + g,_' 1 + + + + + 1"=20FEETE 0 - \\t t + + + LEGEND t + t eY... - t t + t + t + f = '+ L.4.M..MOCELED AS Ln'rJ'.H + +. E t t Q j 0\-T4RGE SURFACE;(DD816ACi 3 t +. + C + + # t t J+ t t + t t . +F + + t + o+ t t + t t i f -1 t t t t t 3 4 t 1 FJUSTINGIMPcR1'IOUS MOCELE 45 IMPERVIOUS ff 1 INON-TARGETSURFAC=7].781.Ci h + 1 p t + + Or r' k4 +f a:,. 3 i-.: t y 1 + FR:PpSED'MFERVIGUS F j + T4FGET SURFAC=I(L.7T10 AC; i J 3 ' : r"./ f} s_ i O 1 ff ', I,f 1 r'/ t„ s j '` ,f :% f TBM #1 j% ` AHBL 7 cn NAI AND IMAS R TBM #2 S YrF l s.<: r -r f HBL /8/ : ..a...,. ,,., - ,......-:~ ,,.- N 1SRIBEDX,. I ,...- „ Y-'"" 70444:8929 N•1704 1-:6•D6 E:1306185.8762 E:1306D64.9195 ELEV:459,,37 ELEV:459.71 ,f ....---,,.M--- L` ",.r- G'...-- rrr p ry"f j', j ` r I .i. N-. r h p 1 ,..,.... r.., R 4iw. 4'.-"' Ch7!EnglnensI E A CASCADE ELEMENTARY Q : SCHOOL PORTABLES A_T A o A S E A T T L E DEVELOPED BASIN N, , MAPAiOaidwNMrrSMN.9b]S aUk M 9lpl 106.t67.2475 lfl Flow Frequency Analysis LogPearson III Coefficients Time Series File:predev.tsf Mean= -1.307 StdDev= 0.173 Project Location:Sea-Tac Skew= 1.543 Annual Peak Flow Rates--- Flow Frequency Analysis------- Flow Rate Rank Time of Peak Peaks - - Rank Return Prob CFS)CFS) Period 0.071 9 2/16/49 17:45 0.226 1 89.50 0.989 0.101 4 3/03/50 15:00 0.119 2 32.13 0.969 0.038 37 8/27/51 18:00 0.105 3 19.58 0. 949 0.046 27 10/17/51 7:15 0. 101 4 14.08 0.929 0.033 45 9/30/53 3:00 0. 098 5 10.99 0.909 0.039 35 12/19/53 17:30 0. 076 6 9.01 0.889 0 .032 46 11/25/54 1:00 0.075 7 7 .64 0.869 0 .047 25 10/04/55 10:00 0.074 8 6.63 0.849 0 .049 19 12/09/56 12:45 0.071 9 5.86 0.829 0.044 32 1/16/58 10:00 0.058 10 5.24 0.809 0.054 14 10/18/58 19:45 0.057 11 4.75 0.789 0.056 12 10/10/59 22:00 0.056 12 4.34 0.769 0.049 20 2/14/61 20:15 0.056 13 3 .99 0.749 0.038 39 8/04/62 13:15 0.054 14 3 .70 0.729 0. 039 36 12/01/62 20:15 0.052 15 3 .44 0.709 0.029 49 6/05/64 15:00 0.051 16 3 .22 0.690 0.046 28 4/20/65 19:30 0.051 17 3. 03 0.670 0.030 48 1/05/66 15:00 0.050 18 2. 85 0.650 0.051 16 11/13/66 17:45 0.049 19 2.70 0.630 0.105 3 8/24/68 15:00 0.049 20 2. 56 0 .610 0.046 29 10/20/68 12:00 0.049 21 2.44 0 .590 0.028 50 1/13/70 20:45 0.049 22 2.32 0 .570 0.034 43 12/06/70 7:00 0.048 23 2.22 0 .550 0.074 8 12/08/71 17 :15 0.047 24 2.13 0.530 0.038 38 4/18/73 9:30 0. 047 25 2.04 0.510 0 .048 23 11/28/73 8:00 0. 047 26 1.96 0.490 0 .049 22 8/17/75 23 :00 0. 046 27 1.89 0.470 iij 0 .035 42 10/29/75 7:00 0. 046 28 1.82 0.450 0.031 47 8/23/77 14:30 0. 046 29 1.75 0.430 0.056 13 9/17/78 1:00 0. 045 30 1.70 0.410 0.076 6 9/08/79 13:45 0.045 31 1.64 0.390 0.058 10 12/14/79 20:00 0.044 32 1.59 0.370 0. 051 17 9/21/81 8:00 0.042 33 1.54 0.350 0.119 2 10/05/81 22:15 0.040 34 1.49 0.330 0.047 26 10/28/82 16:00 0.039 35 1.45 0.310 0.037 40 1/02/84 23:45 0.039 36 1.41 0.291 0.033 44 6/06/85 21:15 0.038 37 1 .37 0.271 0.050 18 10/27/85 10:45 0.038 38 1.33 0.251 0.057 11 10/25/86 22:45 0.038 39 1.30 0.231 0.045 30 5/13/88 17:30 0.037 40 1.27 0.211 0.042 33 8/21/89 16:00 0.037 41 1.24 0.191 0.075 7 1/09/90 5:30 0.035 42 1.21 0.171 0.049 21 4/03/91 20:15 0.034 43 1.18 0.151 0.037 41 1/27/92 15:00 0.033 44 1.15 0.131 0 .045 31 6/09/93 12:15 0.033 45 1.12 0.111 0 .040 34 11/17/93 16:45 0 .032 46 1. 10 0.091 0 .047 24 6/05/95 17 :00 0 .031 47 1 . 08 0 .071 A-7 0 .052 15 5/19/96 11 :30 0.030 48 1.05 0 . 051 0 .226 1 12/29/96 11:45 0.029 49 1.03 0.031 0 .098 5 10/04/97 14:15 0.028 50 1.01 0 .011 Com ute Pea s Computed Peaks 0.148 50. 00 0 .980 Computed Peaks i 0.116 25.00 0 .960 Computed Peaks 0. 084 10.00 0 .900 Computed Peaks 0. 079 8.00 0 .875 Computed Peaks 0. 065 5.00 0.800 Computed Peaks 0.045 2.00 0.500 Computed Peaks 0.036 1.30 0.231 i i 1-y as Pr-c e lc ec; F;c v ; R te A-7 Flow Frequency Analysis LogPearson III Coefficients Time Series File:mitigated.tsf Mean= -1. 072 StdDev= 0. 158 Project Location:Sea-Tac Skew= 1.326 Annual Peak Flow Rates--- Flow Frequency Analysis------- Flow Rate Rank Time of Peak Peaks - - Rank Return Prob CFS)CFS) Period 0.115 8 2/16/49 17:45 0.315 1 89.50 0 .989 0.151 5 3/03/50 15:00 0. 195 2 32. 13 0.969 0.071 35 8/27/51 18:00 0.176 3 19. 58 0.949 0.080 25 10/17/51 7:15 0.157 4 14.08 0.929 0.060 43 9/30/53 3:00 0.151 5 10.99 0.909 0.066 38 12/19/53 17:30 0.139 6 9. 01 0.889 0.058 45 7/30/55 21:15 0.117 7 7.64 0.869 0.088 18 10/04/55 10:00 0.115 8 6.63 0.849 0.078 29 12/09/56 12:45 0.111 9 5.86 0.829 0.074 33 1/16/58 10:00 0.102 10 5.24 0.809 0.096 12 10/18/58 19:45 0.100 11 4.75 0.789 0.095 13 10/10/59 22 :00 0. 096 12 4.34 0.769 0.079 26 2/14/61 20:15 0.095 13 3.99 0.749 0.070 36 8/04/62 13:15 0.094 14 3.70 0.729 0.066 39 12/01/62 20:15 0.094 15 3 .44 0.709 0 .053 48 6/OS/64 15:00 0.092 16 3 .22 0.690 0 .074 32 4/20/65 19:30 0.091 17 3.03 0 .670 0. 051 49 1/05/66 15:00 0.088 18 2.85 0.650 0. 087 19 11/13/66 17:45 0.087 19 2.70 0.630 0.176 3 8/24/68 15:00 0 .087 20 2.56 0.610 0.078 28 10/20/68 12:00 0. 087 21 2.44 0.590 0.047 50 1/13/70 20:45 0. 083 22 2 .32 0.570 0.057 47 12/06/70 7:00 0.082 23 2 .22 0.550 0.117 7 12/08/71 17:15 0.081 24 2.13 0.530 0.069 37 4/18/73 9:30 0.080 25 2.04 0.510 0.081 24 11/28/73 8:00 0.079 26 1 .96 0.490 0.091 17 8/17/75 23:00 0.079 27 1.89 0.470 0.060 42 10/29/75 7:00 0.078 28 1. 82 0.450 0.057 46 8/23/77 14:30 0.078 29 1.75 0.430 0.100 11 9/17/78 1:00 0.078 30 1.70 0.410 0.139 6 9/08/79 13:45 0.075 31 1.64 0.390 0. 094 15 12/14/79 20:00 0. 074 32 1.59 0.370 0. 094 14 9/21/81 8:00 0.074 33 1.54 0.350 0.195 2 10/05/81 22:15 0.074 34 1.49 0.330 0.082 23 10/28/82 16:00 0.071 35 1.45 0.310 0.063 40 1/02/84 23:30 0.070 36 1.41 0.291 0.059 44 6/06/85 21:15 0.069 37 1.37 0.271 0.087 20 10/27/85 10:45 0.066 38 1.33 0.251 0.102 10 10/25/86 22:45 0.066 39 1.30 0.231 0.083 22 5/13/88 17:30 0.063 40 1.27 0.211 0.078 30 8/21/89 16:00 0. 062 41 1.24 0.191 0.111 9 1/09/90 5:30 0. 060 42 1.21 0.171 0.079 27 4/03/91 20:15 0.060 43 1.18 0.151 0.062 41 1/27/92 15:00 0.059 44 1. 15 0.131 0.075 31 6/09/93 12:15 0.058 45 1.12 0.111 0.074 34 11/17/93 16:45 0.057 46 1.10 0.091 0. 087 21 6/05/95 17:00 0. 057 47 1. 08 0.071 A-7 0 .092 16 7/19/96 19:30 0.053 48 1. 05 0.051 0.315 1 12/29/96 11:45 0.051 49 1. 03 0.031 0.157 4 10/04/97 14:15 0.047 50 1.01 0 .011 Com uted Peaks 0.274 100 .00 0.990 Computed Peaks 0.224 50. 00 0.980 Computed Peaks 0.183 25.00 0.960 Computed Peaks i 0.138 10.00 0. 900 Computed Peaks i 0.130 8. 00 0.875 Computed Peaks i 0.110 5. 00 0 .800 Computed Peaks j 0. 078 2. 00 0.500 Computed Peaks i 0.064 1.30 0.231 i 00-yea Propos2 F c.f R te ,, 00-year Pre-d2veic p d Fl w Rafe: 0.1& cfs 10a-year Post-de eloped Flow Rate: 0.274 c#s D:ffer n: G.086 c s < 0.1 c*s A-7 City of Renton Print map Template d 100'Primary 100'Intermediate 20 Pnmary o f .r.20'IMemiediate 4 ' 5 Pnfnery fE l:. *'a.... ! R _. . , _ .. . _ . .. ..,ws-- :. _ . . 5'InOemiediate i a.r. s,.ww . ._ i _ r- _ i Si1.•.. 2'Pnmary Yajs . f: • Q,: i :5," s i=' 2'Intertnediate 0Y Network Struclures r r..' -. S 3.w{ ` ' _ 1,' P•,. 1M.ma. as r.t. a p vmb rl Y L' ,y' gASIN 6 (TO CB #6) t , i c«wa swcu,re r;i MPERVIOUS: 3.297 AC i PumpStation s Discharge PointrERVIOUS: 2.676 AC Wa.e,M K .. entio aPoTOTAL: 5.973 AC oa nFac 'es r a .. PAVED PLAY AREA f 1.a. t'+'- t'_ .. I RPeww.. e 7. M 3 t ' -':' CuNert L•t •+3 A 4 Yp. J„ v O n Drains 1 X"''r•. a nline t ' ' • ^~ f @ .., sf . qe . r iorkGRASSPLAYAREAti 3=:- . nl.' E.t- a p iNel Mw e z rr r i i O IMYVaW r f,, e ... 4 unmwm 9wcw y;- J t Private Control Struc4ire Private Diseharge Pdnt g"+."e ,.. PrivateWaterQualityC6tii `.;-- 1 '. M Mx .l' Private DeOentbn Facilities t 4r +_ •• c, ` r j`. ",:.. l .,._ :-+ . - .,, w - 7 r.kx - y. y`, n-i t - , ' 3y a s s """#. t v.n 1!• ,". i -:.. 4 . ,, 1 j . { w.a,e L ly 1. „y.,t,' -. ` ¢^.r .. Y .,ya... F t Private Pipe 1' .r t .q " tw t tQ Rf N otesi ' ..s ir, 3 :c 'i_ l sy° 1 i! xra.. . NOf19 j rwM-r r"` ,iAl"'•.t, ,. +s ''^"i' M'." BASIN 5 (TO CB #5) k.:;. IMPERVIOUS: 3.140 AC R :;P `- '' PERVIOUS: 3.439 AC f'"'-' v 9` a':`` b`.1 M' *Y - F. _ `!'i .OTOTAL: 6.579 AC t : a . r '.x.} ' r`-l.,,,`9 -- _ - - Information Technology-GIS r:,, ,;c,:>c:. ,,,." ... . _;_. . ; :a sr d 1 u i is for reference oniy.ata layers that appearon this map may or may not be Clh'Of O Y1 ,;2 RentonMapSupport([IRentonwa.grn acc rate,curcent,or othenvise reliable. j j ' 07/17/2014 THIS MAP IS NOT70 BE USED FOR NAVIGATION Finance&IT Division A-8 IrPLdTFIELD SUI AGE I FILTER FdBRIG OVERL6P EDGES LEGEND: SUBGRADE SLOPE R"1'IAN LINE9 I ' K TO DRAInI 1'L07EW1L6 PKOI'ER"LMIE w i wn+n'ro ciEDUCER LnI75 OF GR4D NG a I . I' I I I I R'n4M L E QE4N OI a I c r+aui n_d i I 1 ' c•naNTTPCAL H'Y CONLGTIOM U ' 5' 4T:C^G'AEDUClR TO 4•IetDUCER NOTES: I. I mr 'ro t•o CHe s•PE owATm rre I. ALL PIPES SHALL BE A MMIIVI OP 18"IN DEPTH. LQYaTF15 MAY VARY. r_,HIN_ g VERIFI'IN FIELD. W 4"PEI O4oiED DRAIN PiPE I> n•.O' s•1 EFpw.ArED nrE PEA GRGVEI BdC1 ILL Ey = _ DRAIN PIPE i'ox°`` IATERAL TO MAIN LINE CONNECTION2NOiTO5G4LE l a PLAYFIELD ALTERNATES S— 3 r5 —;S Q A5 S;ow S I i P F r j; l i Il i i ; - I fi v`• r BASIN 7 (TO CB#7) le rt u - W ,$_o d zs, i_ ____ IMPERVIOUS: 3.561 AC I _ _ ru 4~ -._ _ _--_ __----- _ ----_ i - --- PERVIOUS: 5.486 AC S R Pn+ t f; __' TOTAL: 9.047 AC 5 e I 1 l r' T-., TRF.B';AND STUMP REMOVAL _r a- _._ t s ,- np•J r.__ LTERNATE BID # w A EW. 443.Ho r o N} EClf`J rJ PATTD Wn HY4..4o ELV..la330 - :'. i zw w Leca la AS SN e ya i MY Lo s'" e v us.am n c c RR1.4ttD0 1 ' _ E V..4312 r r r IE.M0ID7 2 T TO I'f.4N 1 i RIH.442 1 LV..sa338 , _.. ..._. - y .43Y CQAECTION.T7PICAL_IE.4392 RH.Y43.ip- TY__--_-_- _--_ IE.L3E37 r.RR7.443 66 - IE IDS w wns K(I Ak.WG£i 5t S Oi'E I ' A!V/fSOUAlEOf1 T 45 Lr I _-_rrr. d II I I I c.. _N 5 I r`omR arF`'RE`'°s I i ,.a I I sK - RELPG47E I T7fY. ` II TY. I soc eRT I I eocceRTE emcstoP ' PFeOr'EKY LINE I G04L5 I I 5 I y . ' .. . I I I BASIN 7 J i I j_ ___ i j j j TRIBUTARY TO CB , ; , `` i I l:` I I X 1 I R I A PLAYFIELD AREA 3-1 _ il ALTERNATE BID #3 I I r ,_, 1 1 A I I f; .' .. EP ELv..4a5.9 - - . 4A597. - L _ . -_. _ _ - -_ . -- I I t<6.31 IE•41s.4 ELv..44S:446.0 OI LPLAYFIELD AREA 2 ;u4 EP GRASS PLAY AREA i' E-PLAYFIELD AREA 1 y `ALTERNATE BID R2 I ALTERNATE BID A 1 S I w i !U. I i.i nr sRucn 4 mP. I X I a , _. , , f i.. 1 T. I G-__ -,- I'il L' L7 \S f; I e. _ j ; C ' 4 I i.. A.OJ ^rB'. I ' l T\ OI p i' c o o-_o -- -. . 1 3ia , i ,. . e - IjM. ., i _. _ C u. .o INPI i E iL i I ,a.,, , ` PAVED PLAY AREA -= ( U W ` i i 8. ' 1} o -, i i i; ` 4-o•- - - - - - - :' PROTECT Ex15TiPG 45PAACT---- 7- -_.._...._..1 Jub No. 9Z31 I ARE4 NO GGNSTRIICT ON VENIGLEB 5m Drowi Br B 60LHATGNLINE705:1 T i.l v.. _ aLLou.E rw!Ca. i ELV..ybp3°fYSa,2.(. _ o- _ __ _ - `, ID I ._.. . _. . __.J'-- ET L2.1 Fie Namer PLNJE IE..t46D7..{98,7 IE.4ll5 -J a._. TOTAL . _ ELV.r450ID H TGN LINE SEE SN i JE.4485i 18/4 r.Sg-. .. IE4441 1 _-__--_ t - ELV..450b 1. Rewons 3-Z7-9a I . - l. 7. 5 ALE ,_, PLAYFIELD GRADINO ANO SUB-DRAINAQE j DQ po .,,.K PLAN CASCADE ELEMENTARY o a „z.',.,` " SCHOOL BUILDING i ' x , , SECTION ;28 T-23_N__ &--a , corrsrnucnon No s i T rF I I -: I `V D1 CRO55 OVER EXIST. 12'SD MAINTAIN I I C=m '`` I „.j 1 MIN. SEPARAiION OR PRONDE i i p a i Ix \E7HAFOAM CUSHION.VERIFY DEPhi OF I i o o d ,o C C i 2 y n EX15T SD PRIOR 70 CONS7RUC7ION. 1 I d N U W a y d w 2 1'fWNDATION DRAIN W j , w , pz I if PER DETNL D2 ON SMT. C!S T w 1 " I , Q v v<6S I i b 3 D3 qL POLLUiION CONTROL SiRUCiURE V1 q ' 1 +1. y 4 I Or '-? W/LOCKMC LIO PER DEiAIL D3 ON O j SHT. C4.3W ` j J i I n$w i z u D SEE SHT.C4.2 FOR DETAILS OF C8 I I ca TYPE 1,C8 TPE 2, AREA ORAIH.o , t x ,,- j I D5 CLEAN WT PER DETNL 05 c 7' C}. T-_--_ ON SHT. C4.3 WaI _ I i D6 DELEIED o I h W -I I " I o a q 1; S D7 DELE7ED z`s I S-T,^ 7 i+y DH DELETED C-' _ ' i C:53 Od l li J' v C 3L,C s m /. U - 4 < I _ JN I D9 7RASMRAqC PER DETAtL D9 ON SH T Ct.2. m r/ SCALE: 1'=30' i P6 zRIPRAP- 1'hilqC x.5 WIDE x 8' YADE. I i _ S%2.5'HIGH.1-1 a __ y W I I PROTECT EXISTING.ASPHALT AREA.i Q i I / 1 ROOF DRnINS ARE a' TIGHTLINE P PE AT 1. NO HEAVY CONSlT2UCTON VEHICLES ALLOWED.I y y--- i ` c; 5-0.02 UNLESS NOTED O7HERNISE. CONNECT1"' TO RNNLEADER 57U8 PER MECH. OWCi\ X_I r______________- _ oo z p Y z p' f 9iEET M3.4. DETAII 4.a - - -- U l+z 1 FOR CONTINUATION OF STORM RAIN SEE o o +L' . o SHEETS OS-1 k OS-2.BASIN 1 (PROPOSED PROJECT LOCATION) p BAS IN 5 x ' v SEE ARCH.DWG At.1 FOR DEMOIJIION y \I - IMPERVIOUS: 0.1530 AC a_ov ununes BASIN 7 PERVIOUS: 0.0816 AC TRIBUTARY TO CB I/z Z c Z ' D1 GNAIENT OF GREASENIERCEPTORAnAND CONTINUES I i, SEE PG 3) m 'o u c 4 SANITARY SEWQ2 PQt MECN. OWG. MS.1. NCB 15 RIA rv4• i ' ' 3c os.. SEE PG 2) W S I KIN ID r =J. 1 MAINTAIN 1'MIN. CLEARANCE OR PRONDE 2.j. 17qF-15'SD IE 444y1 1$ Ndd} e CONNECT 15 SD y. w- ETHOFDAM q15HI0N. a p 13 RIXI'i56V-- _ 5=0.005 IE 4aY9c b' w) , o c s..-I a 1 i a y v m TO EXIST. SDMH-IE.43.69 i j STORM DRAIN STRUCIURE COORDIHATE$O4c„ p IE 46.3 15'WkS RAISE RIM EL T9 d54.8 ` 1 531 d liY9 Z2 j I b 11-7+ Q1 n • T_ /. 7J i CB/',NOR7INNG I EA5741C iWE a 9 IMtc13FL=1 %=£1 6P II ^ eT_ r3:'__ y __ AkC8/ SB69.BE 411B.21 iIPE 2-! Q 5•5 Qf I I / I CB/1B 596281 HB].09 ME 1 O 001 1' 20LF 15 SD k/ 5]83.M 4115.90 iYPE 1 y T L, y 1 _ • - S--S! i 5=0. ceR sc3i9a a,i.,z rwe i Y I - 1 V N 1 CBN 553a.!0 a1D8.55 'YPE 1 1 2 Ol I - y L . CP 1 5a95.]I {i53.08 TYPE 1I 2 o I E 9TE SOMH / f i 1 T ceb saw.c sisi.x -wc z-.s i Z I FUNRE E 442.5 I ' - I/. ceF sas.ee 41{4.81 rnc x-u i PORTABLE F'p r< I,, J r . / . IE 446.5 cH/ Ss29.9] s259.7 hPE 1 bsb < . i -___ D.005 -- z h' I _ -_ 1 ,; D9 ce a sw.is .izo.a rwE ."'_.i_ I ///''' b, I--I .E c5.58 _ __ CB 1 ___ _ - 1 :\ __- IE 45:- DS , . - __ --__-_- _ I i I 0 5anu 13i58 rnf 2 J f S/11 .695.8 359.]B TYPE 16'Sp IN 4 5.4 6 50 II/ \ , / LPpRTAB 1-- _ Zp _ 96 8'E $z0 _- r pA C i I ce/+2 ssa}.51 a35a.29 1 l E 50.92 B W`, b 1 L i UI'N V I-_I__ ' C8F1 SB'17.6 a39H.ta ME 2-rE so.s > . r,,R-. e e 3 TRIBUTARY TO CB I `b ' _ -- r.3,s. ....ss ..z-.e , e- - e as.0 i cans sssa.;a .az.v rrc¢z- a z 1LF- 0 p I 5=0.Q20 i ' . 6 r ` 454Jr'UTURE,, S=C 20 l RIYA .4 59LF-6' V 1', `/ CO . /SEE PG 3\ 3 i II C8/16 Sba9-SS qss.oe rnE i I I ' x 1 I W; L51.91 I I' S=C.020 . _ l IaT I I: I I\ N07E:cB l7 5555.x a135.:a rnE 1 3 I T r Z- - tl i 2.ta e' y r a saoas3 .s.a.a, me t-RiM 4 3 , 1 ` c 48`_6 Sp` I ry---/ STJCNRE COORDINATES P 7--, L IE 447. 9 c 59LF- • i I Ss0.02q SOF020 i 1, q i SiREl1C1URNUNRE s os.00 'atxs.5 rC Z I D' I , 9 5]BB.JO t 3.58 IYPE Ml;'/Y IE N7. 1 N x AD 5 MARKF$WIlH AN#. DR 5860.OB i 4t98.32I s I / ' ' IE 446. 15. ) - IM 455.4 _r i. IE 452.t4( ) 4 p i I 69LF- 5 IE 45231( ) 0.0 !` 7 RI r9 - j V cINDICATES CB'S AD/1 5894.9 at98.}2 1 - 5-001 .y o 1 V, y^ IE 451.21(B'W) LOCATED AT MID-P7.fla s 1. P 55LF-6' 7 I . IE 451.38 6'NdE e /'- .'I I ADµ sso5.as a3n.73 CB/18 rg L_'-1 I I ON CURB FACE. AWS i569149 1298.72 O L a 1. RIIA 4 R... 5=0.020 f IE 2]7 I CB PoII 455.6 D/6 Ss7usa 4281.14 Qr IE 4Q 12Ej a``C .. . HP I I 1 81N I I . i 1J ___ L 1 I E r HP- L o I IE M9 8 12'IN N) I Uial. 0 1 C IE 453.a 1 , n q I IE 449.80(12'OUT 5)lo#s e"s M?E I LEGEND fI/ y. r 21M 56. 41 1E_453.24' MP-F PROPOSED V CB/F4 1 I Z V/ 1i, 7 I I IE A 3.4 2LF B SD v; J -\ 4J6.rJ B 16 . 'v RIM 45.5 5 o, ' i I 1 I 4 I j O.IE 450.51 12 lCJY! I- i \ o i OFILIF.A'IpJ I l I a„ DOWN SPWT w/a' RAIN lEAOERp0. M 4 1 , 4 7 . B RI4 456.4 SWAIE O x x- 6 c E 44BJ3\6 IE 50.8 8'N) t OIL POLLU7ION iE 44Z5o , 0 8• • q L IE 452.41(b NN I 452.00 CFD NE ''k 1 CONIROL 5'RUCNR COOROINATE LOCATIONS MATH YiylD3ARCHIiECTURALDNG. A4.1 w 8 -. ' 2 5=0.015 1 s S. I 449. W i L O •V OiSD ; - AD AREA ORAIN C I IfjIM 457.0 \., V t 'I 7 S m (1 V Oc0 IE M8.67 15' S; C IiC aSt.o R M ., tIj }flP- .. 7 ._ . .-E,_ _ V 1 1LF-15 SO G1TCH BA9N/AREA ORAIN PER PLAN L C 3li19BASIN4 3 s ooes ce CATCH BASIN m i's` ao U G W oo r- ia+ss.e ` <a9 t... kZ a. 5=0°0 45 6 IMPERVIOUS: 0.3203 AC __ CATCH BASIN w/saio ro r Y8'SD 45 .57 8 5 a5f-:43. ,z LL 5=0.010 I F- GREASE INTR.. " ' PERVIOUS: 0.1542 AC 30LF-12'SD j -E INVERT ELEVATION o g l i \ I NEOI P__ 5 0.155 U I I ' lF LINEAL FEET 3 P ' D4 70LF 6 5 STORY DRAIN, LENG7H. SIZEIi5=U. 1 I c R!M 456.85 k--_-__--___ AND SLOPE Dote 10/4/93IM4 .Cf 2 LF112"SD 5=0.010 lo i 1 I 1A<=6'SD BAS N 3 V I FD FOUNDA710N DRAIN Na. 920 0 I r BASIN 2 n4 .7 y R ou.H. ____ -_ o G'an Br KDN IMPERVIOUS: 0.3816 AC 1 SDM RiM , e• rr, '.' HP MIGH PqNT QK RdBv PAB ry' I o-£j IMPERVIOUS: 0.706 AC T 7 ow 'M,``"3 i l SD STORM DRAM FdeNoma 92040001 54.<t PERVIOUS: 0.1512 AC e. s e ,-_ao• PERVIOUS: 0.0626 ACLY a R VERHANy, G a.''_ s•,-S. 3-i y - _ t_ 7. ______99 F-_____ F l i- S RIPRAP f--- z . ; Re ions Y 9;"_u--_°_-° `' _ --- / oc.oeve ia iasa j Q > ~ I =_ __' j ' I ___ _ ___' '_ EBRUMV 16.18911 r- EB r7 L r t G`-a==a _____ i, 116t _AVE_.E. _ ii_- - x d----_ u+ca av. yM I t 3' I F 7z--- Ite a C$ o - T I 'z >-K-T:ry- _tj--_< d,Ca12WorkYipDs BelarsYouDip g 46b -i-S- 9>-9, -r 4 2-- Draina e a ' w.z 1-800-424-5555 P Ian taN E_-a63.7! s g 1- SEE SHEE7S OS-1 k 05-2 FOR rr CB.o c-v c(w.<_i 956.G o /ti m-t- 0 1 L Uws Undef 011fd LOCR1bn Cl1ilf i.E._vrn.cHnr+.=a56._? OFF-517E S7FiEET AND DRAINAGE S RuB-=wz.as I . A TIDORWNK=q53.p 2't:c(_7=5s.z,I Q 14PROYEMENTS. f /4; S,p_ ' S, \ `-2'c nC(w7•EO.ce wlRu:5.si9I y„E cotic;s;-sv:v1 e-=vc;,) NOT FlNAL UNT1L Roseli'eferEnpiieeri1Q,t1e 12- 7H15 PLAN 6 ACCURAlE FOR r B 9.T?`2.78' i .- Yccv.c:.?=o;a.:e APPROVED BY iwriy y,,m s.enaMfeia C"F.SI7E STORM RAINAGE ONLY RI^7 953.0 E.:-v`.=n:n.=.,51_ a ui-a,$ru(zis raPERMITAGENCYraf99:47 ' NiJ i K.VE4YIT SET SVBNI TAL,1ME 11,'.951 AHBL..: 0 rt ea a CiB#7 v o o a o a a o`-7 a s 1 o v • a v . p . e I o . 1 0 . . . a o aa a o l d o a a '1 a o o - - i o _ GRAPHIC SCALE o a 0 10 20 40 FEET t t t t + + t P-00t + t t t +t + + +t + + t t + + + t t t t + t t t + +t + o + + <NC,E„#T 1"=20 FEET o + +r+ + + + + + I + + + + + + o o` + + + + + + + + + + + + + + + t r LEGEND I + + + + + + F f i' v .. + f + + t t L4WN 0152A I-t.' t +t t + -}'.. o: t t t j t + t t t t '# + t t t a a + t + + t t t.. t + + t + t + + + o t t .,t.... }' -1...: i- t + + t a 1>t t t t + t. o f t o TI a+ + t + + rt t t + ; a ,.T , '}° .• + o. . imaE-,v.,s:os c t t t t t t + t o a t v o -v s' t + t + t t t t j 1 o a t a j o JNCT#2 a < 1 ° t P-002 +1 ru z. P-003 ` f f r'' t 1/ X I, a < r._.._ j f r ; f TBM #t TBM #2 I ,j,/I ,,,.r-•r,,,, 3 AHBL #7 c----~' .;.. NAIL AND INASH Rr7?-?';r-y-r ,"r'i,.'"T"'7" ` R HBL #8 v,..-,..-,.. N:170444.8929SRIBEDX_, t J N:170#.3:-&706 E:1306185.8762 E:1306064.9195 '` r~ ELEV 459,37 ELEV:459.71I h - Ye E p . .. \ r ' y^i' EXIST ING Al: j l f ri' , i, s i ;y r.t t v F GwEgreers I'/ I O CSCHOOL PORTABLESY T A o M A S E A T T EXISTING CONVEYANCE A 8 s"."`'°"`'"'' ', BASIN MAPoai..swn,r.aa s.,w sma aos.a s4n ta G - 0 AHBLe. 0 9 a v ° a p{{qc ._ ° o a ` o 1 a o rU tt 1 a o a ooe o . - , ° a71 D : . - . . , o o v a` q a p `7 . a . a , a. p .-::. y a.... _:.... e . ... a e;a ,,` ; GRAPHIC SCALEa_ voa a o 9 ti oa o 0 10 20 40 FEET p-001 f ... ., f -+ t + + t t o + + a- ° +I + + + + + + + -- + + +1"—20 FEET 3 o + +JN(.`T#1 I + + + + + - + o k LEGEND I + t + + e Q 1 LAWh 00816AC p '. + I p.. t + + + 9 a } f t + + t — + t + + + 0 + + t +t o e i a . 7'. . .....{ . . ... ' . +' i'.......+ .f.. } i + + + + t + : < `> . j + E T ":. + 0 1 a ,- . [ t o 1 , . + a+ + 1 ] . •"r o + o a a;,,; t + t t + t t t t ° o . . o. + o v . in=ea row o is.c t i -. + + t i- t +o ° a' + v vcT#2 a ° o P-002 +f + a > ` TOTA_ J2336AC P-003 a j t.. r J,r' 1. O f' 1f; f ,.:' i rj f rj Lj. j.:` t ; t o l`/ F. t„^`"".." T M # ry TgM #2 : • f f ;'1...f AHBL 7 AHBL #S ;` , ,: _ t` A.-..--,,.,.._.. NAIL AND NfASH R 1 S RIBED X,-'M' ,,..,----~'"" ' Na170444.8929 N:170 51:6706 R-"'-~'`" E , E:1306185.8762 E:1306D64.9195 - ( , r"'"" r `. r. ELEV.459,37 ELEV:459.71 v I fJ.s i. ..,..,- a-". E ,.,. .y, w-''``' EXISTING r,.,---. ,, f-, l h y' if 3 .. 1 . i . Mvr . x FS N h _ 9 n t i I', l CirflEnginaers Studural bqir s Q "' CASCADE ELEMENTARYc SCHOOL PORTABLES T A o M A S E T T PROPOSED CONYEYANCE A$ ms'"'''°`T°°"'°' ', BASIN MAP31iOcdlsAdArsueSauh,9ille 37D,SeattN,'IA 96f0 4f16.I672 25 lEL i B , P- 01 CT#1 2 JNCT 2 L P- 3 CB 2 JNCT#3 R'- `z P- 05 B#3 P- 06 C #4 il P- 07 C #5 Y P 08 C t6 CB #7 9 EXISTING 10 Page 1 of 24 Existing 25-year Storm Event History Cleared: 09:40:04 Wednesday,July 23, 2014 ROUTEHYD [] THRU [Untitled] USING KingCount Ir AND [25 yr] NOTZERO RELATIVE RATIONAL Reach Area TC Flow Full Q Full nDepth s e nVel Nel CBasin / ID ac) (min) (cfs) (cfs) ratio (ft) fds) (ft/s) Hyd P-001 0.2300 6.37 0.2958 3.1992 0.09 O.1370 Dgam 5.7229 9.1650 BASIN 1 P-002 0.2300 6.43 0.2937 2.0190 0.15 0.1715 Dgam 4.1322 5.7839 P-003 0.2300 6.62 0.2920 2.7542 0.11 0.1468 D8am 5.1215 7.8901 P-004 0.9986 7.03 2.0096 4.3874 0.46 0.5939 pam 3.4969 3.5752 BASIN 2 P-005 0.9986 7.38 1.9335 5.3041 0.36 0.5222 pam 3.9816 4.3222 P-006 1.5314 8.11 2.8127 4.5801 0.61 0.7083 Diam 3.9205 3.7322 BASIN 3 P-007 2.0059 8.49 3.4055 6.4772 0.53 0.6436 am 5.3474 5.2781 BASIN 4 P-008 8.5854 3031 5.1283 7.9856 0.64 OJ285 p am 6.9085 6.5073 BASIN 5 P-009 14.5589 31.05 8.6565 9.2963 0.93 0.9549 Diam g•6056 7.5753 BASIN 6 P-010 23.6061 31.40 12.9579 16.9804 0.76 0.9811 p am 10.5811 9.6089 BASIN 7 From Rch Loss A Bend Junct Loss HW Loss Elev Max EI Node To Node ft) t)ft) ft) ft)ft) 431.5800 CB #7 EXISTING 439.5105 0.7726 0.017 438.7554 443.3500 CB #6 CB #7 446.1251 0.2712 0.3440 446.1979 453.2100 CB #5 CB #6 448.2824 0.1196 0.0005 448.1633 457.9100 CB #4 CB #5 449.1584 0.2387 0.0029 448.9227 458.8100 CB #3 CB #4 449.8947 0.2462 0.0188 449.6673 458.8100 JNCT#3 CB #3 450.2498 0.1899 0.1851 450.2450 459.1100 No approach losses at node JNCT#2 because inverts and/or crowns are offset. I CB #2 JNCT #3 450.6817 ------ 450.6817 459.0000 I, JNCT#2 CB #2 453.9009 0.2651 0.1494 453.7851 458.5700 JNCT#1 JNCT #2 454.1437 0.5086 0.3312 453.9664 463.8000 CB #1 JNCT #1 455.1269 ------ 455.1269 457.6700 A-8 I file:///Q:/?014/2140258/10 CIV/NON CAD/CALCS/Conveyance/201 0716°/o20%20Con... 7/23/2014 L_ Page 2 of 24 Record Id: BASIN 1 Desi n Method Rational IDF Table: Kin CountyIr Com osite C Calc Description SubArea Sub c Lawn (n=025) 0.15 ac 0.25 Pavement and roofs (n=0.90) 0.08 ac 0.90 i Directh Connected TC Calc Type Description Length Slope Coeff Misc TT Fixed 6.30 min Directly Connected TC 6.30min Record Id: BASIN 2 Design Method Rational IDF Table: KingCountylr Composite C Calc Descri tion SubArea Sub c Lawn (n=0.25) 0.06 ac 0.25 Pavement and roofs (n=0.90) 0.71 ac 0.90 Directiv Connected TC Calc Ty e Descri tion Len th Slo e Coeff Misc TT Fixed 6.30 min Directiv Connected TC 6.30min I Record Id: BASIN 3 Desi n Method Rational IDF Table: Kin Count Ir Com osite C Calc Description SubArea Sub c Lawn (n=0.25) 0.15 ac 0.25 Pavement and roofs (n=0.90) 0.38 ac 0.90 Directly Connected TC Calc Type Description Length Slope Coeff Misc TT Fixed 6.30 min Directly Connected TC 6.30min Record Id: BASIN 4 A-8 file:///Q:/201/2140258/10 CIV/NON_CAD/CALCS,!Conveyancel201 0716%20%OCon... 7/23,'2014 Page 3 of 24 I Design Method I Rational I IDF Table: I( KingCountyIr Composite C Calc Descri tion SubArea Sub c Lawn (n=0.25) O.15 ac 0.25 Pavement and roofs (n=0.90) 0.32 ac 0.90 Directly Connected TC Calc Type Description Length Slope Coeff Misc TT Fixed 6.30 min Directly Connected TC 6.30min Record Id: BASIN 5 Design Method Rational IDF Table: KingCountyIr Composite C Calc Description SubArea Sub c Lawn (n=0.25) 3.44 ac 0.25 Pavement and roofs (n=0.90) 3.14 ac 0.90 Directly Connected TC Calc Type Description Length Slo e Coeff Misc TT Sheet Short rairie rass and lawns.: 0.15 393.00 ft 3.05% 0.1500 2.0 in 27.99 min Channel (interm) Concrete pipe (n=0.012) 749.00 ft 2.56% 0.0120 1.84 min Directly Connected TC 29.82min Record Id: BASIN 6 Design Method Rational IDF Table: KingCountyIr Composite C Calc Description SubArea Sub c Lawn (n=0.25) 2.68 ac 0.25 Pavement and roofs (n=0.90) 3.30 ac 0.90 Directly Connected TC Calc Type Description Length Slope Coeff Misc TT Sheet Short rairie rass and lawns.: 0.15 500.00 ft 3.20% 0.1500 2.50 in 33.29 min Channel (interm) Concrete pi e (n=0.012) 756.00 ft 1.47% 0.0120 2.45 min Directly Connected TC 35.74min Record Id: BASIN 7 A-8 file:///Q:/2014/2140258/10_CI V/NON_CAD/CALCS/Conveyance/20140716°/a20%20Con... 7/23/2014 Page 4 of 24 Design Method Rational I IDF Table: II KingCountylr I Composite C Calc Descri tion SubArea Sub c Lawn (n=025) 5.49 ac 0.25 Pavement and roofs (n=0.90) 3.56 ac 0.90 Directly Connected TC Calc Type Description Length Slope Coeff Misc TT Fixed 6.30 min Directly Connected TC 6.30min Record Id: CB #1 Descri :Prototy e Record Increment 0.10 ft Start EL 454.7900 ft Max EL 457.6700 ft Classification Catch Basin Structure Type CB-TYPE 1-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflecto Catch 1.5000 ft Bottom Area 19.6350 sf Condition Existing OPQl Sta e Storage Ratin Curve 454J900 ft 0.0000 cf 456.2900 ft 29.4525 c 454.8900 ft 1.9635 cf 456.3900 ft 31.4160 c 454.9900 ft 3.9270 cf 456.4900 ft 33.3795 c 455.0900 ft 5.8905 cf 456.5900 ft 35.3430 c 455.1900 ft 7.8540 cf 456.6900 ft 37.3065 c 455.2900 ft 9.8175 cf 456.7900 ft 39.2700 c 4553900 ft 11.7810 c 456.8900 ft 41.2335 c 455.4900 ft 13.7445 c 456.9900 ft 43.1970 c 455.5900 ft 15.7080 c 457.0900 ft 45.1605 c 455.6900 ft 17.671 c 457.1900 ft 47.1240 c 455.7900 ft 19.6350 c 457.2900 ft 49.0875 c 455.8900 ft 21.5985 c 457.3900 ft 51.0510 c 455.9900 ft 23.5620 c 457.4900 ft 53.0145 c 456.0900 ft 25.5255 c 457.5900 ft 54.9780 c 457.6700 ft 56.5489 c Record Id: CB #2 A-8 file:///Q:I2014/2140258/10_C[V/NON_CAD/CALCS,'Conveyance/201 0716%20%20Con... 7/23/2014 Page 5 of 24 Descrip: IPrototype Record I Increment I0.10 ft Start EI.449.8600 ft Max El. 459.0000 ft Classification Catch Basin Structure T e CB-TYPE 1-48 Ent Ke Groove End w/Headwall (ke=020) Channelization Curved or Deflector Catch 1.5000 ft Bottom Area 19.6350 sf Condition Pro osed Stage Storage Rating Curve 449.8600 ft 0.0001 cf 454.4600 ft 90.3211 cf 49.9600 ft 1.9636 cf 454.5600 ft 92.2846 cf 450.0600 ft 3.9271 cf 454.6600 ft 94.2481 cf 4 0.1600 ft 5.8906 cf 454.7600 ft 96.2116 cf 450.2600 ft 7.8541 cf 454.8600 ft 98.1751 cf 4 0.3600 ft 9.8176 cf 4 4.9600 ft 100.1386 c 4 0.4600 ft 11.7811 c 455.0600 ft 102.1021 c 4 0.5600 ft 13.7446 c 4 5.1600 ft 104.0656 c 450.6600 ft 15.7081 c 4».2600 ft 106.0291 c 450.7600 ft 17.6716 c 455.3600 ft 107.9926 c 4 0.8600 ft 19.6351 c 455.4600 ft 109.9561 c 4 0.9600 ft 21.5986 c 4 5.5600 ft 1 1 1.9196 c 4 1.0600 ft 23.5621 c 455.6600 ft 113.883 I c 451.1600 ft 25.5256 c 4 5.7600 ft 11.8466 c 451.2600 ft 27.4891 c 455.8600 ft 117.8101 c 451.3600 ft 29.4526 c 455.9600 ft 119.7736 c 451.4600 ft 31.4161 c 456.0600 ft 121.7371 c 451.5600 ft 33.3796 c 456.1600 ft 123.7006 c 451.6600 ft 35.3431 c 456.2600 ft 125.6641 c 451.7600 ft 37.3066 c 456.3600 ft 127.6276 c 451.8600 ft 39.2701 c 456.4600 ft 129.5911 c 451.9600 ft 41.2336 c 456.5600 ft 131.5546 c 452.0600 ft 43.1971 c 456.6600 ft 133.5181 c 452.1600 ft 45.1606 c 456.7600 ft 13.4816 c 452.2600 ft 47.1241 c 456.8600 ft 137.4451 c 452.3600 ft 49.0876 c 456.9600 ft 139.4086 c 452.4600 ft 51.0511 c 457.0600 ft 141.3721 c 452.5600 ft 53.0146 c 457.1600 ft 143.3356 c 452.6600 ft 54.9781 c 457.2600 ft 145.2991 c 452.7600 ft 56.9416 c 457.3600 ft 147.2626 c A-8 file:`//Q:/?Ol4/21402 8/10 CIVINON GAD/CALCSIConveyance.120140716°io20%20Con... 7 23/2014 Page 6 of 24 I 452.8600 ft 58.90 1 c 457.4600 ft 149.2261 c 152.9600 ft 60.8686 c 457.5600 ft 151.1896 c 453.0600 ft 62.8321 c 457.6600 ft 153.1531 c 53.1600 ft 64.7956 c 457.7600 ft 155.1166 c 453.2600 ft 66.7591 c 457.8600 ft 157.0801 c 453.3600 ft 68.7226 c 457.9600 ft 159.0436 c 453.4600 ft 70.6861 c 458.0600 ft 161.0071 c 453.5600 ft 72.6496 c 458.1600 ft 162.9706 c 453.6600 ft 74.6131 c 458.2600 ft 164.9341 c 453.7600 ft 76.5766 c 458.3600 ft 166.8976 c 453.8600 ft 78.5401 c 458.4600 ft 168.8611 c 453.9600 ft 80.5036 c 458.5600 ft 170.8246 c 454.0600 ft 82.4671 c 458.6600 ft 172.7881 c 454.1600 ft 84.4306 c 4 8.7600 ft 174.7516 c 454.2600 ft 86.3941 c 458.8600 ft 176.7151 c 459.0000 ft 179.4642 c Record Id: CB #3 Descrip:Prototv e Record Increment 0.10 ft Start EL 448.9000 ft Max E1. 458.8100 ft Classification Catch Basin Structure Type CB-TYPE 1-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflecto Catch 1.5000 ft Bottom Area 19.6350 sf Condition Proposed Sta e Stora e Ratin Curve 448.9000 ft 0.0000 cf 453.9000 ft 98.1749 cf 49.0000 ft 1.9634 cf 454.0000 ft 100.1384 c 49.1000 ft 3.9269 cf 454.1000 ft 102.1019 r! 449.2000 ft 5.8904 cf 454.2000 ft l 04.0654 c 449.3000 ft 7.8539 cf 454.3000 ft l 06.0289 c f' 449.4000 ft 9.8174 cf 454.4000 ft l 07.9924 c t1 449.5000 ft 11.7809 c 454.5000 ft 109.9559 ct 449.6000 ft 13.7444 c 454.6000 ft 1 119194 c t 449.7000 ft 1.7079 c 454.7000 ft 113.8829 ct 449.8000 ft 17.6714 c 454.8000 ft 1 15.8464 cf I, 449.9000 ft 19.6349 c 454.9000 ft 1 17.8099 c lf q_g file:,'//Q:!?O1'?140258/]0_CIV,NON CAD'CAL.CSICon eyance!?0140716%20%20Con... 7!?3'201 Page 7 of 24 450.0000 ft 21.5984 c 455.0000 ft 1 19.7734 c 450.1000 ft 23.5619 c 455.1000 ft 121.7369 c 450.2000 ft 25.5254 c 455.2000 ft 123.7004 c 450.3000 ft 27.4889 c 455.3000 ft 12.6639 c 450.4000 ft 29.4524 c 455.4000 ft 127.6274 c 450.5000 ft 31.4159 c 455.5000 ft 129.5909 c 450.6000 ft 33.3794 c 455.6000 ft 131.5544 c 450.7000 ft 3.3429 c 455.7000 ft 133.5179 c 450.8000 ft 37.3064 c 455.8000 ft 135.4814 c 450.9000 ft 39.2699 c 455.9000 ft 137.4449 c 451.0000 ft 412334 c 456.0000 ft 139.4084 c 451.1000 ft 43.1969 c 4 6.1000 ft 141.3719 c 4 1.2000 ft 4.1604 c 4562000 ft 143.3354 c 451.3000 ft 47.1239 c 456.3000 ft 145.2989 c 451.4000 ft 49.0874 c 456.4000 ft 147.2624 c 451.5000 ft S 1.0509 c 456.5000 ft 149.2259 c 451.6000 ft 53.0144 c 4 6.6000 ft 151.1894 c 451.7000 ft 54.9779 c 456.7000 ft 153.1 29 c 451.8000 ft 56.9414 c 456.8000 ft I55.1164 c 451.9000 ft 58.9049 c 456.9000 ft 157.0799 c 452.0000 ft 60.8684 c 457.0000 ft 159.0434 c 452.1000 ft 62.8319 c 4 7.1000 ft 161.0069 c 452.2000 ft 64.7954 c 457.2000 ft 162.9704 c 452.3000 ft 66.7589 c 457.3000 ft 164.9339 c 452.4000 ft 68.7224 c 457.4000 ft 166.8974 c 452.5000 ft 70.6859 c 4 7.5000 ft 168.8609 c 452.6000 ft 72.6494 c 4 7.6000 ft 170.8244 c 452.7000 ft 74.6129 c 457.7000 ft 172.7879 c 452.8000 ft 76.5764 c 457.8000 ft 174.7514 c 452.9000 ft 78.5399 c 457.9000 ft 176.7149 c 453.0000 ft 80.5034 c 458.0000 ft 178.6784 c 453.1000 ft 82.4669 c 4 8.1000 ft 180.6419 c 453.2000 ft 84.4304 c 458.2000 ft 182.6054 c 453.3000 ft 86.3939 c 458.3000 ft 184.5689 c 453.4000 ft 88.3574 c 458.4000 ft 186.5324 c 453.5000 ft 90.3209 c 4 8.5000 ft 188.4959 c 453.6000 ft 92.2844 c 458.6000 ft 190.4594 c 453.7000 ft 94.2479 c 458.7000 ft 192.4229 c A-$ file:U,'Q:/2014/21=0258,'10 CN/NON CAD/CALCS/Conveyancel20140716°/o20%?OCon... 7/23I2014 Page 8 of 24 II I 458.8100 ft 194.5829 c Record Id: CB #4 Descrip:Prototvpe Record Increment 0.10 ft Start EI.448.0500 ft Max El. 4 8.8100 ft Classification Catch Basin Structure T e CB-TYPE 1-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflecto Catch 1.5000 ft Bottom Area 19.6350 sf Condition Pro osed Stage Storage Rating Curve 448.0500 ft 0.0000 cf 4 3.4500 ft 106.0290 c 448.1500 ft 1.9635 cf 453.00 ft 107.9925 c 448.2500 ft 3.9270 cf 453.6500 ft 109.9560 c 448.3500 ft 5.8905 cf 453.7500 ft 111.9195 c 448.4500 ft 7.8540 cf 453.8500 ft 113.8830 c 448.5500 ft 9.8175 cf 453.9500 ft 115.8465 c 448.6500 ft 1 1.7810 cf 454.0500 ft 117.8100 c 448.7500 ft 13.7445 cf 454.1500 ft 119.7735 c 448.8500 ft 15.7080 cf 454.2500 ft 121.7370 c 448.9 00 ft 17.6715 cf 4 4.3500 ft 123.7005 c 449.0500 ft 19.6350 cf 454.4500 ft 125.6640 c 449.1500 ft 21.5985 cf 454.5500 ft 127.627 c 4492500 ft 23.5620 cf 454.6500 ft 129.5910 c 449.3500 ft 25.5255 cf 454.7500 ft 131.5545 c 449.4500 ft 27.4890 cf 454.8500 ft 133.5180 c 449.5500 ft 29.4525 cf 454.9500 ft 135.4815 c 449.6500 ft 31.4160 cf 4 5.0500 ft 137.44 0 c 449.7500 ft 33.3795 cf 455.1500 ft 139.408 c 449.8500 ft 35.3430 cf 455.2500 ft 141.3720 c 449.9500 ft 37.3065 cf 455.3500 ft 143.3355 c 450.0500 ft 39.2700 cf 455.4500 ft 145.2990 c 450.1500 ft 41.2335 cf 455.5500 ft 147.2625 c 450.2500 ft 43.1970 cf 455.6500 ft 149.2260 c 450.3500 ft 45.1605 cf 455.7500 ft 151.1895 c 450.4500 ft 47.1240 cf 455.8500 ft 153.1530 c 450.5500 ft 49.0875 cf 455.9500 ft 155.1165 c A-8 file:,!Q:/?014I21402 8/10_CIV/NON CAD/CALCS/Conveyancel?0140716%20%20Con... 7!23!2014 Page 9 of 24 450.6 00 ft 1.0 I O cf 456.0 00 ft 1 7.0800 ct 450.7500 ft 53.0145 cf 456.1500 ft 159.0435 c 450.8 00 ft 54.9780 cf 456.2500 ft 161.0070 c 450.9500 ft 56.9415 cf 456.3500 ft 162.9705 c 451 A 00 ft 58.9050 cf 456.4500 ft 164.9340 c 451.1500 ft 60.8685 cf 4 6.5500 ft 166.897 c 451.2500 ft 62.8320 cf 456.6500 ft 168.8610 c 451.3500 ft 64.7955 cf 456J500 ft 170.824 c 451.4500 ft 66.7590 cf 456.8500 ft 172.7880 c 4 I.5500 ft 68.7225 cf 4569 00 ft 174.7515 c 4 1.6500 ft 70.6860 cf 457A 00 ft 176.7150 c 4 1.7500 ft 72.649 cf 457.1 00 ft 178.6785 c 4 1.8500 ft 74.6130 cf 457.2500 ft 180.6420 c 1.9500 ft 76.5765 cf 457.3 00 ft 182.6055 c 2.0500 ft 78.5400 cf 457.4500 ft 184.690 c 452.1500 ft 80.5035 cf 457.5500 ft 186.5325 c 452.2500 ft 82.4670 cf 457.6500 ft 188.4960 c 452.3500 ft 84.4305 cf 457.7500 ft 190.4595 c 452.4500 ft 86.3940 cf 457.8500 ft 192.4230 c 452.5500 ft 88.3575 cf 457.9500 ft 194.3865 c 452.6500 ft 90.3210 cf 458.0500 ft 196.3500 c 452.7500 ft 92.2845 cf 4 8.1500 ft 198.3135 c 452.8500 ft 94.2480 cf 458.2500 ft 200.2770 ct 452.9500 ft 96.211 cf 4583500 ft 202.2405 ct 453.0500 ft 98.1750 cf 458.4500 ft 204.2040 ct 453.1500 ft 100.1385 c 458.5500 ft 206.1675 c 453.2500 ft 102.1020 c 458.6 00 ft 208.1310 c 458.8100 ft 211.2728 c Record Id: CB #5 Descri :Prototy e Record Increment 0.10 ft Start El.446.8000 ft Max E1. 457.9100 ft Classification Manhole Structure Type CB-TYPE 1-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflector Catch 1.5000 ft Bottom Area 19.6350 sf Condition Pro osed A-8 file:l!/Q:!2014I?140258/10_C[V/?ION_CAD/CALCSiConveyance'20140716%204%20Con... 7123!2014 Page 10 of 24 IStage Storage Rating Curve I 446.8000 ft 0.0000 cf 452.4000 ft 109.9560 c 446.9000 ft 1.9635 cf 452.5000 ft 111.9195 c 447.0000 ft 3.9270 cf 452.6000 ft 113.8830 c 447.1000 ft 5.8905 cf 452.7000 ft 115.8465 c 447.2000 ft 7.8540 cf 4 2.8000 ft 117.8100 c 447.3000 ft 9.8175 cf 452.9000 ft 119.7735 c 447.4000 ft 11 J810 cf 4 3.0000 ft 121.7370 c 447.5000 ft 13.7445 cf 4 3.1000 ft 123.7005 c 447.6000 ft 15.7080 cf 453.2000 ft 125.6640 c 447J000 ft 17.6715 cf 453.3000 ft 127.6275 c 447.8000 ft 19.6350 cf 453.4000 ft 129.5910 c 447.9000 ft 21.5985 cf 453.5000 ft 131.5545 c 448.0000 ft 23.5620 cf 453.6000 ft 133.5180 c 448.1000 ft 25.5255 cf 453.7000 ft 135.4815 c 448.2000 ft 27.4890 cf 453.8000 ft 137.4450 c 448.3000 ft 29.4525 cf 453.9000 ft 139.408 c 448.4000 ft 31.4160 cf 454.0000 ft 141.3720 c 448.5000 ft 33.3795 cf 454.1000 ft 143.3355 c 448.6000 ft 35.3430 cf 454.2000 ft 14.2990 c 448.7000 ft 37.3065 cf 454.3000 ft 147.2625 c 448.8000 ft 39.2700 cf 4 4.4000 ft 149.2260 c 448.9000 ft 41.2335 cf 4 4.000 ft 151.1895 c 449.0000 ft 43.1970 cf 454.6000 ft 153.1530 c 449.1000 ft 45.1605 cf 454.7000 ft 155.1165 c 449.2000 ft 47.1240 cf 454.8000 ft 157.0800 c 449.3000 ft 49.0875 cf 454.9000 ft 159.0435 c 449.4000 ft 51.0510 cf 455.0000 ft 161.0070 c 449.5000 ft 53.0145 cf 455.1000 ft 162.9705 c 449.6000 ft 54.9780 cf 455.2000 ft 164.9340 c 449.7000 ft 56.9415 cf 455.3000 ft 166.8975 c 449.8000 ft 58.9050 cf 455.4000 ft 168.8610 c 449.9000 ft 60.8685 cf 455.5000 ft 170.8245 c 450.0000 ft 62.8320 cf 455.6000 ft 172.7880 c 450.1000 ft 64.7955 cf 455.7000 ft 174.7515 c 450.2000 ft 66.7590 cf 455.8000 ft 176.7150 c 450.3000 ft 68.722 cf 4».9000 ft 178.6785 c 450.4000 fi 70.6860 cf 456.0000 ft 180.6420 c A-8 file:/.!IQ:I2014I21402 8I10_CIV/i]ON CAD!CALCS!Conveyance.20140716%20%20Con... 7!?3'2014 Page 1 1 of 24 u72.6495 cf 456.1000 ft 182.6055 c 450.6000 ft 74.6130 cf 456.2000 ft I 84.5690 c 450.7000 ft 76.5765 cf 456.3000 ft 186.5325 c 450.8000 ft 78.5400 cf 456.4000 ft 188.4960 c 450.9000 ft 80.5035 cf 456.5000 ft 190.459 c 451.0000 ft 82.4670 cf 456.6000 ft 192.4230 c 451.1000 ft 84.4305 cf 456.7000 ft 194.3865 c 451.2000 ft 863940 cf 456.8000 ft 196.3500 c 451.3000 ft 88.3575 cf 456.9000 ft 198.313 c 451.4000 ft 90.3210 cf 457.0000 ft 200.2770 c 451.5000 ft 92.2845 cf 457.1000 ft 202.240 c 451.6000 ft 94.2480 cf 457.2000 ft 204.2040 c 451.7000 ft 96.2115 cf 457.3000 ft 206.1675 c 451.8000 ft 98.1750 cf 457.4000 ft 208.1310 c 451.9000 ft 100.1385 c 457.5000 ft 210.0945 c 452.0000 ft 102.1020 c 457.6000 ft 212.0580 c 452.1000 ft 104.0655 c 457.7000 ft 214.0215 c 452.2000 ft 106.0290 c 457.8000 ft 215.9850 c 457.9100 ft 218.1452 c Record Id: CB #6 I Descri :Prototv e Record Increment 0.10 ft Start EI.443.7600 ft Max E1. 453.2100 ft Classification Manhole Structure Type CB-TYPE 1-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflector Catch I.5000 ft Bottom Area 19.6350 sf Condition Proposed Stage Stora e Ratin Curve 443.7600 ft 0.0000 cf 448.5600 ft 94.2480 cf 443.8600 ft 1.9635 cf 448.6600 ft 96.2115 cf 443.9600 ft 3.9270 cf 448.7600 ft 98.1750 cf 444.0600 ft 5.8905 cf 448.8600 ft 100.1385 c 444.1600 ft 7.8540 cf 448.9600 ft 102.1020 c 444.2600 ft 9.8175 cf 449.0600 ft 104.0655 c 444.3600 ft 11.7810 c 449.1600 ft 106.0290 c 444.4600 ft 13.7445 c 449.2600 ft 107.9925 c I- A_8 file:l//Q:12014!2140258,10_CIV/NON CADICALCS/Conveyance,'20140716%20%20Con... 7/23/2014 Pa e 1? of 2= 444.5600 ft 15.7080 c 449.3600 ft 109.9560 c 444.6600 ft 17.6715 c 449.4600 ft 1 1 1.9195 c 444J600 ft 19.6350 c 449.5600 ft 113.8830 c 444.8600 ft 21.5985 c 449.6600 ft 115.8465 c 444.9600 ft 23.5620 c 449.7600 ft 1 17.8100 c 445.0600 ft 25.5255 c 449.8600 ft 1 19.7735 c 445.1600 ft 27.4890 c 449.9600 ft 121.7370 c 445.2600 ft 29.4525 c 450.0600 ft 123.7005 c 445.3600 ft 31.4160 c 450.1600 ft 125.6640 c 445.4600 ft 33.3795 c 450.2600 ft 127.6275 c 445.5600 ft 35.3430 c 450.3600 ft 129.5910 c 445.6600 ft 37.3065 c 450.4600 ft 131.5545 c 445.7600 ft 392700 c 450.5600 ft 133.5180 c 445.8600 ft 41.2335 c 450.6600 ft 135.4815 c 445.9600 ft 43.1970 c 450J600 ft 137.4450 c 446.0600 ft 45.1605 c 450.8600 ft 139.4085 c i 446.1600 ft 47.1240 c 450.9600 ft 141.3720 c 4462600 ft 49.0875 c 451.0600 ft 143.3355 c 446.3600 ft 51.0510 c 451.1600 ft 145.2990 c 446.4600 ft 53.0145 c 451.2600 ft 147.262 c 446.5600 ft 54.9780 c 4 13600 ft 149.2260 c 446.6600 ft 56.9415 c 4 1.4600 ft 151.189 c 446.7600 ft 58.9050 c 451.600 ft 153.1530 c 446.8600 ft 60.8685 c 451.6600 ft 155.116 c 446.9600 ft 62.8320 c 451.7600 ft 157.0800 c 447.0600 ft 64.7955 c 451.8600 ft 159.0435 c 447.1600 ft 66.7590 c 451.9600 ft 161.0070 c 447.2600 ft 68.7225 c 452.0600 ft 162.9705 c 447.3600 ft 70.6860 c 452.1600 ft 164.9340 c 447.4600 ft 72.649 c 4522600 ft 166.8975 c 447.5600 ft 74.6130 c 452.3600 ft 168.8610 c 447.6600 ft 76.5765 c 4 2.4600 ft 170.8245 c 447.7600 ft 78.5400 c 452.5600 ft 172.7880 c 447.8600 ft 80.5035 c 452.6600 ft 174.7515 c 447.9600 ft 82.4670 c 452.7600 ft 176.7150 c 448.0600 ft 84.4305 c 452.8600 ft 178.6785 c 448.1600 ft 86.3940 c 452.9600 ft 180.6420 c 448.2600 ft 88.3575 c 453.0600 ft 182.6055 c r-t- A-8 file:///Q:I2014!2140258/l 0_CI V,'NON_CAD/CALCS/Conveyance/20140716%20%?OCon... 7/?3/2014 Paee 13 of 2 90.3210 c 453.1600 ft I 84.5690 c 453.2100 ft 185.5504 c Record Id: CB #7 Descri :Prototy e Record Increment 0.10 ft Start El.435.8500 ft Max El. 443.3500 ft Classification Manhole Structure Type CB-TYPE 1-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflector Catch 1.5000 ft Bottom Area 19.63 0 sf Condition Proposed Sta e Stora e Rating Curve 435.8500 ft 0.0001 cf 439.6500 ft 74.6131 cf 35.9500 ft 1.9636 cf 439.7500 ft 76.5766 cf 436.0500 ft 3.9271 cf 439.8500 ft 78.5401 cf 436.1500 ft 5.8906 cf 439.9500 ft 80.5036 cf 36.2500 ft 7.8541 cf 440A 00 ft 82.4671 cf 436.3500 ft 9.8176 cf 440.1500 ft 84.4306 cf 436.4500 ft 11 J811 c 440.2500 ft 86.3941 cf 436.5500 ft 13.7446 c 440.3500 ft 88.3576 cf 436.6500 ft 15.7081 c 440.4 00 ft 90.3211 cf 36.7500 ft 17.6716 c 440.5 00 ft 922846 cf 436.8500 ft 19.63 1 c 440.6500 ft 94.2481 cf 436.9500 ft 21.5986 c 440.7500 ft 96.2116 cf 437.0500 ft 23.5621 c 440.8 00 ft 98.1751 cf 37.1500 ft 2.5256 c 4409 00 ft 100.1386 c 37.2500 ft 27.4891 c 441.0500 ft 102.1021 c 437.3500 ft 29.4526 c 441.1500 ft 104.0656 c 437.4500 ft 31.4161 c 441.2500 ft 106.0291 c 437.5500 ft 33.3796 c 441.3 00 ft 107.9926 c 437.6500 ft 35.3431 c 441.4 00 ft 109.9561 c 437.7500 ft 37.3066 c 441.5500 ft 1119196 c 437.8500 ft 39.2701 c 441.6500 ft 113.8831 c 437.9500 ft 41.2336 c 441.7 00 ft 115.8466 c 438.0500 ft 43.1971 c 441.8500 ft 117.8101 c 438.1500 ft 45.1606 c 441.9500 ft 119.7736 c 438.2500 ft 47.1241 c 442.0500 ft 121.7371 c A-8 file:/'IQ:,2014,2140258/10_CIV,NON CAD/CALCS!Conveyance/20140716%20°/o20Con... 7123!2014 Page 14 of 24 438.3500 ft 49.0876 c 442.1500 ft 123.7006 c 438.4500 ft 51.051 1 c 442.2500 ft 125.6641 c 438.5500 ft 53.0146 c 442.3500 ft 127.6276 c 438.6500 ft 54.9781 c 442.4500 ft 129.5911 c 438.7500 ft 56.9416 c 442.5500 ft 131.5546 c 438.8500 ft 58.9051 c 442.6500 ft 133.5181 c 438.9500 ft 60.8686 c 442.7500 ft 135.4816 c 439.0500 ft 62.8321 c 442.8500 ft 137.4451 c 439.1500 ft 64.7956 c 442.9500 ft 139.4086 c 439.2500 ft 66.7591 c 443.0500 ft 141.3721 c 439.3500 ft 68.7226 c 443.1500 ft 143.3356 c 439.4500 ft 70.6861 c 443.2500 ft 145.2991 c 443.3500 ft 147.2625 c Record Id: EXISTING Descri :Protot e Record Increment 0.10 ft Start El.431.0800 ft Max E1. 438.0000 ft Classification Manhole Structure T e CB-TYPE 1-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflecto Catch 1.5000 ft Bottom Area 19.6350 sf Condition Proposed Stage Storage Rating Curve 431.0800 ft 0.0001 cf 434.5800 ft 68J226 cf 431.1800 ft 1.9636 cf 434.6800 ft 70.6861 cf 431.2800 ft 3.9271 cf 434.7800 ft 72.6496 cf 431.3800 ft 5.8906 cf 434.8800 ft 74.6131 cf 431.4800 ft 7.8541 cf 434.9800 ft 76.5766 cf 431.5800 ft 9.8176 cf 435.0800 ft 78.5401 cf 431.6800 ft 11.7811 c 435.1800 ft 80.5036 cf 431.7800 ft 13J446 c 435.2800 ft 82.4671 cf 431.8800 ft 15J081 c 435.3800 ft 84.4306 cf 431.9800 ft 17.6716 c 435.4800 ft 86.3941 cf 432.0800 ft 19.6351 c 435.5800 ft 88.3576 cf I 432.1800 ft 21.5986 c 435.6800 ft 90.3211 cf 432.2800 ft 23.5621 c 435.7800 ft 92.2846 cf I 432.3800 ft 25.5256 c 435.8800 ft 942481 cf A_8 file://IQ:!201412140?58/10_CIV/NON CAD,CALCS.!Conveyance120 1 407 1 6%20%20Con... 7,23/?014 Page 15 of 24 432.4800 ft 27.4891 c 435.9800 ft 96.2116 cf I 432.5800 ft 29.4526 c 436.0800 ft 98.1751 cf i 432.6800 ft 31.4161 c 436.1800 ft 100.1386 c 432.7800 ft 33.3796 c 436.2800 ft 102.1021 c 432.8800 ft 3.3431 ct 436.3800 ft 104.0656 c 432.9800 ft 37.3066 c 436.4800 ft 106.0291 c 433.0800 ft 39.2701 c 36.5800 ft 107.9926 c 433.1800 ft 41.2336 c 436.6800 ft 109.9561 c I 433.2800 ft 43.1971 c 436.7800 ft 1 l 1.9196 c 433.3800 ft 45.1606 c 436.8800 ft 113.8831 c 433.4800 ft 47.1241 c 436.9800 ft 1 15.8466 c 433.5800 ft 49.0876 c 437.0800 ft 117.8101 c 433.6800 ft 51.0511 c 437.1800 ft 119.7736 c 433.7800 ft 53.0146 c 437.2800 ft 121.7371 c I 433.8800 ft 54.9781 c 437.3800 ft 123.7006 c 433.9800 ft 56.9416 c 437.4800 ft 125.6641 ct 434.0800 ft 58.9051 c 437.5800 ft 127.6276 c 434.1800 ft 60.8686 c 437.6800 ft 129.5911 c 434.2800 ft 62.8321 c 437J800 ft 131.5546 c 434.3800 ft 64.7956 c 437.8800 ft 133.5181 c 438.0000 ft 135.8745 c p ys Record Id: JNCT #1 Descrip:Prototype Record Increment 0.10 ft Start El.453.8000 ft Max El. 463.8000 ft Classification Catch Basin Structure Ty e CB-TYPE 1-48 Ent Ke Groove End w/Headwall (ke=0.20} Channelization Curved or Deflecto Catch 1.5000 ft Bottom Area 19.6350 sf Condition Existin Stage Stora e Ratin Cur e 453.8000 ft 0.0000 cf 458.8000 ft 98.1750 cf 4 3.9000 ft 1.9635 cf 458.9000 ft 100.1385 c 454.0000 ft 3.9270 cf 459.0000 ft 102.1020 c 454.1000 ft 5.8905 cf 459.1000 ft 104.0655 c 454.2000 ft 7.8540 cf 459.2000 ft 106.0290 c I454.3000 ft 9.8175 cf 459.3000 ft 107.9925 c A-8 file:l//Q:i2014/21 0?58'l0 CIV%JON CAD/CALCS/Conveyance120140716°io20%20Con... 7/23I2014 Page 16 of 24 454.4000 ft 11.7810 c 459.4000 ft 109.9560 c 454.5000 ft 13.7445 c 459.000 ft 1 1 19195 c 454.6000 ft 1.7080 c 459.6000 ft 1 13.8830 c 4 4.7000 ft 17.6715 c 459.7000 ft 115.8465 c 454.8000 ft 19.6350 c 459.8000 ft 1 17.8100 c 454.9000 ft 21.5985 c 459.9000 ft 119.7735 c 455.0000 ft 23.5620 c 460.0000 ft 121.7370 c 455.1000 ft 2.5255 c 460.1000 ft 123.7005 c 455.2000 ft 27.4890 c 460.2000 ft 125.6640 c 455.3000 ft 29.452 c 460.3000 ft 127.6275 c 455.4000 ft 31.4160 c 460.4000 ft 129.910 c 455.5000 ft 33.3795 c 460.5000 ft 131.5 45 c 455.6000 ft 35.3430 c 460.6000 ft 133.5180 c 455.7000 ft 37.3065 c 460.7000 ft 13.4815 c 455.8000 ft 39.2700 c 460.8000 ft 137.4450 c 455.9000 ft 41.2335 c 460.9000 ft 139.4085 c 456.0000 ft 43.1970 c 461.0000 ft 141.3720 c 456.1000 ft 45.1605 c 461.1000 ft 143.3355 c 456.2000 ft 47.1240 c 461.2000 ft 1452990 c 456.3000 ft 49.0875 c 461.3000 ft 147.2625 c 456.4000 ft 51.OS 10 c 461.4000 ft 149.2260 c 456.5000 ft 53.0145 c 461.5000 ft 1 1.1895 c 456.6000 ft 54.9780 c 461.6000 ft 153.1530 c 456J000 ft 56.9415 c 461.7000 ft 155.1165 c 456.8000 ft 58.9050 c 461.8000 ft 157.0800 c 456.9000 ft 60.8685 c 461.9000 ft 159.0435 c 457.0000 ft 62.8320 c 462.0000 ft 161.0070 ct 457.1000 ft 64.7955 c 462.1000 ft 162.9705 ct 457.2000 ft 66.7590 c 462.2000 ft 164.9340 c 4573000 ft 68.7225 c 462.3000 ft 166.8975 ct 457.4000 ft 70.6860 c 462.4000 ft 168.8610 c 457.5000 ft 72.6495 c 462.5000 ft 170.8245 c 457.6000 ft 74.6130 c 462.6000 ft 172.7880 c 457.7000 ft 76.5765 c 462.7000 ft 174.7515 c 457.8000 ft 78.5400 c 462.8000 ft 176.7150 c 457.9000 ft 80.5035 c 462.9000 ft 178.6785 c 458.0000 ft 82.4670 c 463.0000 ft 180.6420 c 458.1000 ft 84.430 c 463.1000 ft 182.6055 c A-8 file:!.;'Q:!2014/21402 8!10 CIV/:ION CAD!CALCS/Conveyance'20140716°/o20%20Con... 7/23/2014 Page 17 of 24 86.3940 c 463.2000 ft 184.690 c 4 8.3000 ft 88.3575 c 463.3000 ft 186.5325 c 458.4000 ft 90.3210 c 463.4000 ft 188.4960 c 458.5000 ft 92.2845 c 463.5000 ft 190.4595 c 458.6000 ft 94.2480 c 463.6000 ft 192.4230 c 463.8000 ft 196.3500 c Record Id: JNCT #2 Descri :Prototy e Record Increment 0.10 ft Start El.453.5700 ft Max EI. 4 8.5700 ft Classification Catch Basin Structure Type CB-TYPE 1-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflector Catch 1.5000 ft Bottom Area 19.6350 sf Condition Existing Stage Stora e Ratin Curve 453.5700 ft 0.0001 cf 456.0700 ft 49.0876 c 453.6700 ft 1.9636 cf 456.1700 ft 1.0511 c 453.7700 ft 3.9271 cf 456.2700 ft 53.0146 c 453.8700 ft 5.8906 cf 456.3700 ft 54.9781 c 453.9700 ft 7.8541 cf 456.4700 ft 56.9416 c 454.0700 ft 9.8176 cf 456.5700 ft 58.9051 c 454.1700 ft 11.7811 c 456.6700 ft 60.8686 c 454.2700 ft 13.7446 c 456.7700 ft 62.8321 c 454.3700 ft 15.7081 c 456.8700 ft 64.79 6 c 454.4700 ft 17.6716 c 456.9700 ft 66.7591 c 454.5700 ft 19.6351 c 457.0700 ft 68.7226 c 454.6700 ft 21.5986 c 457.1700 ft 70.6861 c 454.7700 ft 23.5621 c 457.2700 ft 72.6496 c 454.8700 ft 25.5256 c 457.3700 ft 74.6131 c 454.9700 ft 27.4891 c 457.4700 ft 76.5766 c 455.0700 ft 29.4526 c 457.5700 ft 78.5401 c 455.1700 ft 31.4161 c 457.6700 ft 80.5036 c 455.2700 ft 33.3796 c 457.7700 ft 82.4671 c 455.3700 ft 35.3431 c 457.8700 ft 84.4306 c 455.4700 ft 37.3066 c 457.9700 ft 86.3941 c 455.5700 ft 39.2701 c 458.0700 ft 88.3576 c I I A-8 file:///Q:/2014/2140258/10_C[V/NON_CAD/CALCS/Conveyance/20140716%20%20Con... 7/23;2014 Page 18 of 24 455.6700 ft 41.2336 c 458.1700 ft 90.321 1 c 455.7700 ft 43.1971 c 458.2700 ft 92.2846 c 455.8700 ft 45.1606 c 458.3700 ft 94.2481 c 458.5700 ft 98.1750 c Record Id: JNCT #3 Descrip:Prototype Record Increment 0.10 ft Start EI.49.4700 ft Max EI. 459.1100 ft Classification Catch Basin Structure Tv e CB-TYPE 1-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflecto Catch 1.5000 ft Bottom Area 19.6350 sf Condition Pro osed Stage Storage Rating Curve 449.4700 ft 0.0000 cf 454.3700 ft 96.2115 cf 449.5700 ft 1.9635 cf 454.4700 ft 98.1750 cf 449.6700 ft 3.9270 cf 454.5700 ft 100.1385 c 449.7700 ft 5.8905 cf 454.6700 ft 102.1020 c 449.8700 ft 7.8540 cf 454.7700 ft ]04.0655 c 449.9700 ft 9.817 cf 454.8700 ft 106.0290 c 450.0700 ft 1 1 J810 c 454.9700 ft 107.9925 c 450.1700 ft 13.7445 c 455.0700 ft 109.9560 c 450.2700 ft 15.7080 c 455.1700 ft 1 1 1.9195 c 450.3700 ft 17.6715 c 455.2700 ft 1 13.8830 c 450.4700 ft 19.6350 c 455.3700 ft 1 15.8465 c 450.5700 ft 21.5985 c 455.4700 ft 1 17.8100 c I' 450.6700 ft 23.5620 c 455.5700 ft 1 19.7735 c 450.7700 ft 25.52 5 c 455.6700 ft 121 J370 c 450.8700 ft 27.4890 c 455.7700 ft 123.7005 c 450.9700 ft 29.4525 c 455.8700 ft 125.6640 c 451.0700 ft 31.4160 c 455.9700 ft 127.6275 c 451.1700 ft 33.379 c 456.0700 ft 129.5910 c 451.2700 ft 35.3430 c 456.1700 ft 131.5545 c 451.3700 ft 37.3065 c 456.2700 ft 133.5180 c 451.4700 ft 39.2700 c 456.3700 ft 135.4815 c 451.5700 ft 41.2335 c 456.4700 ft 137.4450 c 451.6700 ft 43.1970 c 456.5700 ft 139.4085 c A-8 file:!!!Q:'2014/2140?58,'10 CIV/NON_ CAD!CALCS'Com eyance/20140716%20%20Con... 7/23/2014 Page 19 of 24 451.7700 ft 45.1605 c 456.6700 ft 141.3720 c 451.8700 ft 47.1240 c 456.7700 ft 143.3355 c 451.9700 ft 49.0875 c 456.8700 ft 145.2990 c 452.0700 ft 51.0510 c 456.9700 ft 147.2625 c 452.1700 ft 53.0145 c 457.0700 ft 149.2260 c 452.2700 ft 54.9780 c 457.1700 ft 151.1895 c 452.3700 ft 56.9415 c 457.2700 ft 153.1530 c 452.4700 ft 58.9050 c 457.3700 ft 155.1165 c 452.5700 ft 60.8685 c 457.4700 ft 157.0800 c 452.6700 ft 62.8320 c 457.5700 ft 159.0435 c 452.7700 ft 64.795 c 457.6700 ft 161.0070 c 452.8700 ft 66.7590 c 457.7700 ft 162.9705 c 452.9700 ft 68.7225 c 457.8700 ft 164.9340 c 453.0700 ft 70.6860 c 457.9700 ft 166.8975 c 453.1700 ft 72.6495 c 458.0700 ft 168.8610 c 453.2700 ft 74.6130 c 4 8.1700 ft 170.8245 c 453.3700 ft 76.5765 c 458.2700 ft 172.7880 c 453.4700 ft 78.5400 c 458.3700 ft 174.7515 c 453.5700 ft 80.5035 c 458.4700 ft 176.7150 c 453.6700 ft 82.4670 c 458.5700 ft 178.6785 c 453.7700 ft 84.4305 c 458.6700 ft 180.6420 c 453.8700 ft 86.3940 c 458.7700 ft 182.6055 c 453.9700 ft 88.3575 c 458.8700 ft 184.5690 c 454.0700 ft 90.3210 c 458.9700 ft 186.5325 c 454.1700 ft 92.2845 c 459.0700 ft 188.4960 c 459.1100 ft 189.2811 c Record Id: P-001 Section Sha e: Circular Uniform Flow Method: Manning's Coefficient: 0.0100 Routing Method: Travel Time Translation DnNode JNCT#1 U Node CB #1 Material Plastic Size 8" Diam Ent Losses Groove End w/Headwall Len th 24.0000 ft Slo e 4.13% U [nvert 454.7900 ft Dn Invert 453.8000 ft Conduit Constraints A-8 file:/,'/Q:!2014i2140258I10 C[VINON CAD/CALCS/Conveyance!20140716%20%20Con... 71231?014 Page ?0 of 24 Min Vel Max Vel Min Slope Max Slope Min Cover 2.00 ft/s 15.00 ft/s 0.50% 2.00% 3.00 ft Dro across MH 0.0000 ft E Infil Rate 0.0000 in/hr Up [nvert 453.8000 ft Dn Invert 4 4.7900 ft Match inverts. DnNode JNCT#1 U Node CB #1 Record Id: P-002 Section Sha e: Circular Uniform Flow Method: Manning's Coefficient: 0.0100 Routing Method: Travel Time Translation DnNode JNCT #2 U Node JNCT#1 Material Plastic Size 8" Diam Ent Losses Groove End w/Headwall Length 14.0000 ft Slo e 1.64% U Invert 453.8000 ft Dn Invert 453.5700 ft Conduit Constraints Min Vel Max Vel Min Slo e Max Slo e Min Cover 2.00 ftls 15.00 fUs 0.50% 2.00°/a 3.00 ft Drop across MH 0.0000 ft Ex Infil Rate 0.0000 in,'hr U [nvert 453.5700 ft Dn Invert 453.8000 ft Match inverts. DnNode JNCT #2 UpNode JNC"I #1 Record Id: P-003 Section Shape: Circular Uniform Flow Method: Manning's Coefficient: 0.0130 Routin Method: Travel Time Translation DnNode CB #2 U Node JNC"I'#2 Material Conc-Spun Size 8" Diam Ent Losses Groove End w/Headwall Length 60.0000 ft Slo e 5.17% Up Im ert 4 3.5700 ft Dn Invert 450.4700 ft Conduit Constraints Min Vel Max Vel Min Slo e Max Slo e Min Cover A_8 file:/,IQ:!?01412140258!10_CIV-'I'ON CAD/CALCS!Conveyance/?0140716°rb20%?OCon... 7!23'2014 Page 2l of 24 I2.00 ft/s 15.00 ft/s 0.50% 2.00% 3.00 ft I I Dro across MH 0.0000 ft Ex/Infil Rate 0.0000 in/hr U Invert 450.4700 ft Dn [nvert 453.5700 ft Match inverts. DnNode CB #2 UpNode JNCT #2 Record Id: P-004 Section Sha e: Circular Uniform Flow Method: Mannin 's Coefficient: 0.0130 Routing Method: T'ravel Time Translation DnNode JNCT#3 UpNode CB #2 Material Conc-S un Size 15" Diam Ent Losses Groove End w/Headwall Length 85.0000 ft Slope 0.46% I U Invert 449.8600 ft Dn Invert 449.4700 ft Conduit Constraints Min Vel Max Vel Min Slope Max Slope Min Cover 2.00 ft/s 15.00 ftls 0.50% 2.00% 3.00 ft Dro across MH 0.0000 ft Ex/Infil Rate 0.0000 in/hr li Up Invert 449.4700 ft Dn Invert 449.8600 ft I Match inverts. DnNode JNCT#3 U Node CB #2 Record Id: P-005 Section Shape: Circular Uniform Flow Method: Manning's Coefficient: 0.0130 Routing Method: Travel Time Translation DnNode CB #3 U Node JNCT#3 Material Conc-S un Size 15" Diam Ent Losses Groove End w/Headwall Len th 85.0000 ft Slo e 0.67% I' U Invert 449.4700 ft Dn Invert 448.9000 ft Conduit Constraints Min Vel Max Vel Min Slope Max Slo e Min Cover 2.00 ft/s 15.00 ft/s 0.50% 2.00% 3.00 ft A-8 file://!Q:'2014I2140258/10 CIV/NON_CADICALCS!Conveyance/20140716%20°/o20Con... 7/?3/2014 Page 22 of 24 IDrop across MH I0.0000 ft I E Infil Rate 0.0000 in,hr U Invert 448.9000 ft Dn Invert 449.4700 ft Match inverts. DnNode CB #3 UpNode JNCT #3 Record Id: P-006 Section Shape: Circular Uniform Flow Method: Mannin 's Coefficient: 0.0130 Routin Method: Travel Time Translation DnNode CB #4 UpNode CB #3 Material Conc-Spun Size 15" Diam Ent Losses Groove End w/Headwall Len th 170.0000 ft Slo e 0.50°/a Up Im ert 448.9000 ft Dn Invert 448.0500 ft Conduit Constraints Min Vel Max Vel Min Slo e Max Slo e Min Cover 2.00 ft/s 1.00 ft/s 0.50% 2.00% 3.00 ft Dro across MH 0.0000 ft Ex/Infil Rate 0.0000 in/hr U Im-ert 448.0500 ft Dn Im-ert 448.9000 ft Match inverts. DnNode CB #4 U Node CB#3 i Record Id: P-007 Section Shape: Circular Uniform Flow Method: Mannin 's Coefficient: 0.0130 Routing Method: Travel Time Translation DnNode CB #5 UpNode CB #4 Material Conc-S un Size 15" Diam Ent Losses Groove End w/Headwall Length 125.0000 ft Slope 1.00% U Invert 448.0500 ft Dn Invert 446.8000 ft Conduit Constraints Min Vel Max Vel Min Slope Max Slope Min Cover 2.00 ft/s 15.00 fUs 0.50% 2.00% 3.00 ft Dro across MH 0.0000 ft Ex/Infil Rate 0.0000 in/hr Up Invert 446.8000 ft Dn Invert 448.0500 ft A-8 file://,'Q:/2014/2140258!10 CIV.'O:I CAD,CALCS,'Com eyance/20140716%20%20Con... 7!23!2014 Page 23 of 24 IMatch inverts. I DnNode CB #5 U Node CB #4 Record Id: P-008 Section Sha e: Circular CJniform Flow Method: Mannin 's Coefficient: 0.0130 Routing Method: Travel Time Translation DnNode CB #6 U Node CB #5 Material Conc-S un Size 15" Diam Ent Losses Groove End w/Headwall Length 200.0000 ft Slope 1.52% U Invert 446.8000 ft Dn Invert 443.7600 ft Conduit Constraints Min Vel Max Vel Min Slope Max Slope Min Cover 2.00 ft/s 15.00 ft/s 0.50% 2.00% 3.00 ft Dro across MH 0.0000 ft E Infil Rate 0.0000 in/hr II Up Invert 443.7600 ft Dn Invert 446.8000 ft Match inverts. DnNode CB #6 U Node CB #5 Record Id: P-009 Section Shape: Circular Uniform Flow Method: Manning's Coefficient: 0.0130 Routing Method: Travel Time Translation DnNode CB #7 U Node CB #6 Material Conc-Spun Size 15" Diam Ent Losses Groove End w/Headwall Len th 384.0000 ft Slo e 2.06°/a U Invert 443.7600 ft Dn Invert 435.8500 ft Conduit Constraints Min Vel Max Vel Min Slope Max Slo e Min Cover 2.00 ft/s 15.00 fUs 0.50% 2.00% 3.00 ft Drop across MH 0.0000 ft Ex/Infil Rate 0.0000 in/hr U Invert 435.8500 ft Dn Invert 443.7600 ft Match inverts. DnNode CB #7 UpNode CB #6 A-8 file:!//Q:/2014!?1402 8/10_CIV/NON CAD/CALCS!Conve}ance!20140716%20%?OCon... 7/23l?014 Page 24 of 24 Record Id: P-010 Section Shape: Circular Uniform Flow Method: Manning's Coefficient: 0.0130 Routin Method: Travel Time T'ranslation DnNode EXISTING U Node CB #7 Material Conc-Spun Size 18" Diam Ent Losses Groove End w/Headwall Len th 222.0000 ft Slo e 2.60% Up Invert 436.8500 ft Dn Invert 431.0800 ft Conduit Constraints iVlin Vel Max Vel Min Slo e Max Slo e Min Cover 2.00 ft/s 15.00 ft/s 0.50% 2.00% 3.00 ft Drop across MH 0.0000 ft E c/Infil Rate 0.0000 in/hr U Invert 431.0800 ft Dn Invert 436.8500 ft Match inverts. DnNode EXISTING UpNode CB #7 Licensed to: AHBL file:!!Q:I2014/2140258I10_CI V:`NON_CAD!CALCS'Convey ance/20140716%20%20Con... 7'?3'20l 4 Page 1 of 24 Proposed 25-year Storm Event History Cleared: 09:34:22 Wednesday,July 23, 2014 ROUTEHYD [] THRU [Untitled] USING KingCountyIr AND [25 yr] NOTZERO RELATIVE RATIONAL Reach Area TC Flow Full Q Full nDepth Size nVel fVel CBasin / ID ac) (m n) (cfs) (cfs) ratio (ft) ft/s) (ft/s) Hyd P-001 0.2336 6.36 0.4298 3.1992 0.13 0.1650 Dgam 6.3855 9.1650 BASIN 1 P-002 0.2336 6.41 0.4270 2.0190 0.21 0.2080 Dgam 4.5919 5.7839 P-003 0.2336 6.9 0.4248 2.7542 0.15 0.1768 g SJ310 7.8901Diam P-004 1.0022 6.99 2.1464 4.3874 0.49 0.6171 p,am 3.5556 3.5752 BASIN 2 P-005 1.0022 7.34 2.0661 5.3041 0.39 0.5417 p am 4.0530 4.3222 P-006 1.5350 8.05 2.9456 4.5801 0.64 0.7291 piam 3.9641 3.7322 BASIN 3 15"I P-007 2.0095 8.44 3.5347 6.4772 0.55 0.6583 Diam 5.3953 5.2781 BASIN 4 P-008 8.5890 30.31 5.1770 7.9856 0.65 •732 Diam 6.9250 6.5073 BASIN P-009 14.5625 31.05 8.70 0 9.2963 0.94 0.9598 piam 8.6095 7.5753 BASIN 6 P-010 23.6097 31.40 13.0058 16.9804 OJ7 0.9833 p,am 10.5931 9.6089 BASIN 7 From Rch Loss A Bend Junct Loss HW Loss Elev Max E1 Node To Node ft) ft)ft) ft) ft)ft) 431.5800 CB #7 EXISTING 439.5222 0.7813 0.0067 438.7475 443.3500 CB #6 CB #7 446.1414 0.2763 0.2771 446.1422 453.2100 CB #5 CB #6 448.2933 0.1288 0.0010 448.1655 457.9100 CB #4 CB #5 449.1865 0.2440 0.0018 448.9443 458.8100 CB #3 CB #4 449.9219 02551 0.0390 449.7058 458.8100 JNCT #3 CB #3 450.2811 0.1963 0.1340 450.2188 459.1 100 No approach losses at node JNCT#2 because inverts and/or crowns are offset. CB #2 JNCT#3 450.7126 ------ 450.7126 459.0000 JNCT #2 CB #2 453.9850 03274 0.0348 453.6924 458.5700 JNCT #1 JNCT #2 454.2280 0.6332 0.2470 453.8419 463.8000 CB #1 JNCT #1 455.21 l4 ------ 455.2114 457.6700 A-8 file:///Q:/20 1 4/2 1 4025 8/1 0_CI V/NON_CAD/CALC S/Conveyance/20140716%20%20Con... 7/23/2014 Page 2 of 24 Record Id: BASIN 1 Desi n Method Rational IDF Table: KingCount Ir Com osite C Calc Description SubArea Sub c Lawn (n=0.25) 0.08 ac 0.25 Pavement and roofs (n=0.90) 0.15 ac 0.90 Directly Connected TC Calc Type Description Length Slope Coeff Misc TT Fixed 6.30 min Directly Connected TC 6.30min Record Id: BASIN 2 Design Method Rational IDF Table: KingCountylr Composite C Calc Descri tion SubArea Sub c Lawn (n=0.25) 0.06 ac 0.25 Pavement and roofs (n=0.90) 0.71 ac 0.90 Directly Connected TC Calc Tv e Descri tion Len th Slo e Coeff Misc TT Fixed 6.30 min Directly Connected TC 6.30min Record Id: BASIN 3 Desi n Method Rational IDF Table: KingCountylr Com osite C Calc Description SubArea Sub c Lawn (n=0.25) 0.15 ac 0.25 Pavement and roofs (n=0.90) 0.38 ac 0.90 Directly Con ected TC Calc Type Description Length Slope Coeff Misc TT Fixed 6.30 min Directly Connected TC 6.30min Record Id: BASIN 4 A-8 file:///Q:,?014/21402 8/10_CIVINOI_CADICALCS!Conveyance/20140716%?0%20Con... 7/23!2014 Page 3 of 24 I Design Method I Rational I IDF Table: II KingCountylr I Com osite C Calc Descri tion SubArea Sub c Lawn (n=0.25) O.15 ac 0.25 i Pavement and roofs (n=0.90) 0.32 ac 0.90 I Directly Connected TC Calc Type Description Length Slope Coeff Misc TT Fixed 6.30 min Directly Connected TC 6.30min Record Id: BASIN 5 Desi n Method Rational IDF Table: Kin CountyIr Composite C Calc Description SubArea Sub c Lawn (n=0.25) 3.44 ac 0.25 Pavement and roofs (n=0.90) 3.14 ac 0.90 Directly Connected TC Calc Ty e Descri tion Len th Slope Coeff Misc TT Sheet Short rairie rass and lawns.: 0.15 393.00 ft 3.05% 0.1500 2.50 in 27.99 min Channel (interm) Concrete pipe (n=0Al2) 749.00 ft 2.56% 0.0120 1.84 min Directiv Connected TC 29.82min Record Id: BASIN 6 Desi n Method Rational IDF Table: KingCountyIr Com osite C Calc Description SubArea Sub c Lawn (n=0.25) 2.68 ac 0.25 Pavement and roofs (n=0.90) 3.30 ac 0.90 Directly Connected TC Calc Type Description Length Slope Coeff' Misc TT Sheet Short rairie rass and lawns.: 0.15 500.00 ft 3.20% 0.1500 2.50 in 3329 min Channel (interm) Concrete i e (n=0.012) 756.00 ft 1.47% 0.0120 2.45 min Directly Connected TC 35.74min Record Id: BASIN 7 A-8 file:///Q:/2014/21402 8/I 0_CIV/NON_CAD/CALCS/Conveyance!20140716%?0%20Con... 7/23/2014 Page 4 of 24 Design Method I Rational IDF Table: II KingCountylr I Com osite C Calc Descri tion SubArea Sub c Lawn (n=0.25) 5.49 ac 0.25 Pavement and roofs (n=0.90) 3.56 ac 0.90 Directiv Connected TC Calc Type Description Length Slope Coeff Misc TT Fixed 6.30 min Directiv Connected TC 6.30min Record Id: CB #1 Descri :Prototy e Record Increment 0.10 ft Start EI.4 4.7900 ft Max EL 457.6700 ft Classification Catch Basin Structure Type CB-TYPE 1-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflecto Catch 1.5000 ft Bottom Area 19.6350 sf Condition Existing Stage Storage Ratin Curve 454.7900 ft 0.0000 cf 4 6.2900 ft 29.4525 c 454.8900 ft 1.9635 cf 4 6.3900 ft 31.4160 c 454.9900 ft 3.9270 cf 456.4900 ft 33.3795 c 455.0900 ft .8905 cf 4 6.5900 ft 3.3430 c 455.1900 ft 7.8540 cf 456.6900 ft 37.3065 c 455.2900 ft 9.8175 cf 4 6.7900 ft 39.2700 c 455.3900 ft 11.7810 c 456.8900 ft 41.2335 c 455.4900 ft 13.7445 c 456.9900 ft 43.1970 c 455.5900 ft 15.7080 c 457.0900 ft 45.1605 c 455.6900 ft 17.6715 c 457.1900 ft 47.1240 c 455.7900 ft 19.6350 c 457.2900 ft 49.0875 c 455.8900 ft 21.5985 c 457.3900 ft 51.0 10 c 455.9900 ft 23.5620 c 457.4900 ft 53.0145 c 456.0900 ft 25.5255 c 457.5900 ft 4.9780 c 457.6700 ft 56.5489 c Record Id: CB #2 A-8 file:///Q:/2014/2140258/10_CNINON CAD!CALCS;Conveyance/20140716%20%20Con... 7!23/2014 Page 5 of 24 Descrip:IPrototype Record I[ncrement I0.10 ft I Start EI.449.8600 ft Max EI. 459.0000 ft Classification Catch Basin Structure T e CB-TYPE 1-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflecto Catch 1.5000 ft Bottom Area 19.6350 sf Condition Pro osed Stage Storage Rating Curve 449.8600 ft 0.0001 cf 454.4600 ft 90.321 1 cf 449.9600 ft 1.9636 cf 454.5600 ft 92.2846 cf 450.0600 ft 3.9271 cf 454.6600 ft 94.2481 cf 450.1600 ft 5.8906 cf 454.7600 fr 96.2116 cf 450.2600 ft 7.8541 cf 454.8600 ft 98.1751 cf 450.3600 ft 9.8176 cf 454.9600 ft 100.1386 c 450.4600 ft 11.781 1 c 455.0600 ft 102.1021 c 450.5600 ft 13.7446 c 4 5.1600 ft 104.0656 c 450.6600 ft 15.7081 c 45.2600 ft 106.0291 c 450.7600 ft 17.6716 c 455.3600 ft 107.9926 c 450.8600 ft 19.6351 c 455.4600 ft 109.9561 c 450.9600 ft 21.5986 c 455.5600 ft 1 11.9196 c 451.0600 ft 23.5621 c 455.6600 ft 113.8831 c 451.1600 ft 25.5256 c 455.7600 ft 115.8466 c 4 1.2600 ft 27.4891 c 455.8600 ft 117.8101 c 451.3600 ft 29.4526 c 455.9600 ft 119J736 c 451.4600 ft 31.4161 c 456.0600 ft 121.7371 c 451.5600 ft 33.3796 c 456.1600 ft 123.7006 c 451.6600 ft 35.3431 c 456.2600 ft 125.6641 c 451.7600 ft 37.3066 c 456.3600 ft 127.6276 c 451.8600 fi 39.2701 c 456.4600 ft 129.5911 c 451.9600 ft 41.2336 c 456.5600 ft 131.5546 c 452.0600 ft 43.1971 c 456.6600 ft 133.5181 c 452.1600 ft 45.1606 c }6.7600 ft 135.4816 c 452.2600 ft 47.1241 c 4 6.8600 ft 137.4451 c 452.3600 ft 49.0876 c 456.9600 ft 139.4086 c 452.4600 ft 51.0511 c 457.0600 ft 141.3721 c 452.5600 ft 53.0146 c 457.1600 ft 143.3356 c 452.6600 ft 54.9781 c 457.2600 ft 145.2991 c 452.7600 ft 56.9416 c 457.3600 ft 147.2626 c A-8 file:/I/Q:/?Ol!21402 8/10 CIVINON_CAD/CALCS!Conveyance/20140716%20%20Con... 7/23/2014 Page 6 of 24 452.8600 ft 58.9051 c 457.4600 ft 149.2261 c 452.9600 ft 60.8686 c 457.5600 ft 1 I.1896 c 453.0600 ft 62.8321 c 457.6600 ft 153.1531 c 453.1600 ft 64.7956 c 457.7600 fr 155.1166 c I 4 3.2600 ft 66.7591 c 457.8600 ft 157.0801 c 453.3600 ft 68.7??6 c 4 7.9600 ft 159.0436 c 4 3.4600 ft 70.6861 c 458.0600 ft 161.0071 c 453.5600 ft 72.6496 c 458.1600 ft 162.9706 c 453.6600 ft 74.6131 c 458.2600 ft 164.9341 c 453.7600 ft 76.5766 c 4 8.3600 ft 166.8976 c 453.8600 ft 78.5401 c 458.4600 ft 168.861 1 c 453.9600 ft 80.5036 c 4 8.5600 ft 170.8246 c 454.0600 ft 82.4671 c 458.6600 ft 172.7881 c 454.1600 ft 84.4306 c 458J600 ft 174J516 c 454.2600 ft 86.3941 c 458.8600 ft 176J151 c 459.0000 ft 179.4642 ct Record Id: CB #3 Descri :Protot e Record Increment 0.10 ft Start EI.448.9000 ft Max E1. 4 8.8100 ft Classification Catch Basin Structure Tvpe CB-TYPE 1-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflecto Catch I.5000 ft Bottom Area 19.6350 sf Condition Proposed Sta e Stora e Ratin Curve 448.9000 ft 0.0000 cf 4 3.9000 ft 98.1749 cf 449.0000 ft 1.9634 cf 454.0000 ft 100.1384 c 449.1000 ft 3.9269 cf 454.1000 ft 102.1019 c 449.2000 ft 5.8904 cf 454.2000 ft 104.0654 c 449.3000 ft 7.8539 cf 454.3000 ft 106.0289 c 449.4000 ft 9.8174 cf 454.4000 ft 107.9924 c 449.5000 ft 11.7809 c 454.5000 ft 109.9559 c 449.6000 ft 13.7444 c 454.6000 ft 111.9194 c 449.7000 ft 15.7079 c 454.7000 ft 113.8829 c 449.8000 ft 17.6714 c 454.8000 ft 115.8464 c 449.9000 ft 19.6349 c 454.9000 ft 117.8099 c A-8 file:,'!Q:/2014,2140?58!10_CIV/NON_CAD.!CALCS!Conveyance/20140716%?0%20Con... 7!23,'2014 i Page 7 of 24 Ui ;_450.0000 ft 21.5984 c 455.0000 ft 119.7734 c 4 0.1000 ft 23.5619 c 45.1000 ft 121.7369 c I ,- 00450.2000 ft 25.5254 c 455.2000 ft 123.7004 c 450.3000 ft 27.4889 c 455.3000 ft 125.6639 c 450.4000 ft 29.4524 c 455.4000 ft 127.6274 c I - ' 450.5000 ft 31.4159 c 455.5000 ft 129.5909 c I -- 450.6000 ft 33.3794 c 455.6000 ft 131.5544 c 0000i j 450.7000 ft 35.3429 c 455.7000 ft 133.5179 c 450.8000 ft 37.3064 c 4 5.8000 ft 135.4814 c j 450.9000 ft 39.2699 c 455.9000 ft 137.4449 c 451.0000 ft 41.2334 c 456.0000 ft 139.4084 c 451.1000 ft 43.1969 c 456.1000 ft 141.3719 c 451.2000 ft 45.1604 c 4 6.2000 ft 143.3354 c 451.3000 ft 47.1239 c 4563000 ft 145.2989 c i 451.4000 ft 49.0874 c 456.4000 ft 147.2624 c 451.5000 ft 51.0509 c 456.5000 ft 149.2259 c 451.6000 ft 53.0144 c 456.6000 ft 151.1894 c 451.7000 ft 54.9779 c 456.7000 ft 153.1529 c 451.8000 ft 56.9414 c 456.8000 ft 155.1164 c 451.9000 ft 58.9049 c 456.9000 ft 157.0799 c 452.0000 ft 60.8684 c 457.0000 ft 159.0434 c 0000452.1000 ft 62.8319 c 457.1000 ft 161.0069 c i 452.2000 ft 64.7954 c 457.2000 ft 162.9704 c 452.3000 ft 66.7589 c 457.3000 ft 164.9339 ck 452.4000 ft 68J224 c 457.4000 ft 166.8974 c 452.5000 ft 70.6859 c 457.5000 ft 168.8609 c II l_452.6000 ft 72.6494 c 457.6000 ft 170.8244 c I I _4 2.7000 ft 74.6129 c 457.7000 ft 172.7879 c 452.8000 ft 76.5764 c 457.8000 ft 174.7514 c I 452.9000 ft 78.5399 c 457.9000 ft 176.7149 c I 453.0000 ft 80.5034 c 458.0000 ft 178.6784 c I453.1000 ft 82.4669 c 458.1000 ft 180.6419 c 453.2000 ft 84.4304 c 458.2000 ft 182.6054 c 453.3000 ft 86.3939 c 458.3000 ft 184.5689 c 453.4000 ft 88.3574 c 458.4000 ft 186.5324 c 453.5000 ft 90.3209 c 458.5000 ft 188.4959 c 453.6000 ft 92.2844 c 458.6000 ft 190.4594 c 453.7000 ft 94.2479 c 458.7000 ft 192.4229 c A-8 file:l//Q:/201/2140258/10_C[V,INON_CADICALCS!Conveyance,20140716%20%20Con... 7/23/2014 Page S of 24 II I 458.8100 ft 194.5829 c I Record Id: CB #4 Descrip:Prototype Record Increment 0.10 ft Start EI.448.0500 ft Max El. 4 8.8100 ft Classification Catch Basin Structure T e CB-"TYPE 1-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflector Catch 1.5000 ft Bottom Area 19.6350 sf Condition Pro osed Stage Storage Rating Curve 448.0500 ft 0.0000 cf 4 3.4 00 ft 106.0290 c 448.1500 ft 1.9635 cf 453.5 00 ft 107.992 c 448.2500 ft 3.9270 cf 453.6500 ft 109.9560 c 448.3500 ft 5.8905 cf 453.7500 ft 1 1 1.9195 c 448.4500 ft 7.8540 cf 453.8500 ft 113.8830 c 448.5500 ft 9.8175 cf 453.9500 ft 115.8465 c 448.6500 ft 11.7810 cf 454.0500 ft 117.8100 c 448.7500 ft 13.7445 cf 454.1500 ft 119.7735 c I 448.8500 ft 15.7080 cf 454.2500 ft 121.7370 c 448.9500 ft 17.6715 cf 454.3500 ft 123.7005 c 449.0500 ft 19.6350 cf 454.4500 ft 125.6640 c I, 449.1500 ft 21.598 cf 454.5500 ft 127.6275 c I 449.2500 ft 23.5620 cf 454.6500 ft 129.5910 c i 449.3500 ft 25.5255 cf 454J500 ft 131.5545 c 449.4500 ft 27.4890 cf 454.8500 ft 133.5180 c 449.5500 ft 29.4525 cf 454.9500 ft 135.4815 c 449.6500 ft 31.4160 cf 455.0500 ft 137.4450 c 449.7500 ft 33.3795 cf 455.1500 ft 139.4085 c 449.8500 ft 35.3430 cf 455.2500 ft 141.3720 c0000 449.9500 ft 37.3065 cf 455.3500 ft 143.3355 c 450.0500 ft 39.2700 cf 455.4500 ft 145.2990 c 450.1500 ft 41.2335 cf 455.5500 ft 147.2625 c 450.2500 ft 43.1970 cf 455.6500 ft 149.2260 c 450.3500 ft 45.1605 cf 455.7500 ft 1 S l.l 895 c 450.4500 ft 47.1240 cf 455.8500 ft 153.1530 c 450.5500 ft 49.0875 cf 455.9500 ft 155.1165 c A-8 file://,'Q:I201412140258/]0_C[V/NON_CAD/CALCS!Conveyancel20140716%20%20Con... 7,'2312014 Page 9 of 24 450.6 00 ft 51.0 10 cf 456.0 00 ft 1 7.0800 c 450.7500 ft 53.0145 cf 456.1500 ft 1 9.0435 c 450.8500 ft 54.9780 cf 456.2500 ft 161.0070 c 4 09 00 ft 56.9415 cf 456.3500 ft 162.9705 c 4 1.0500 ft 58.9050 cf 456.4500 ft 164.9340 c 451.1500 ft 60.868 cf 456.5500 ft 166.8975 c 451.2500 ft 62.8320 cf 4 6.6500 ft 168.8610 c 451.3500 ft 64J955 cf 456.7500 ft 170.8245 c 451.4500 ft 66.7590 cf 4 6.8500 ft 172.7880 c 4 1.5500 ft 68.7225 cf 456.9500 ft 174.7515 c 451.6500 ft 70.6860 cf 457.0500 ft 176.7150 c 451.7500 ft 72.6495 cf 457.1500 ft 178.6785 c 451.8500 ft 74.6130 cf 457.2500 ft 180.6420 c 451.9500 ft 76.5765 cf 457.3500 ft 182.6055 c 452.0500 ft 78.5400 cf 457.4 00 ft 184.5690 c 452.1500 ft 80.5035 cf 457.5500 ft 186.5325 c 452.2500 ft 82.4670 cf 457.6500 ft 188.4960 c 452.3500 ft 84.4305 cf 457.7500 ft 190.4595 c 452.4500 ft 86.3940 cf 457.8500 ft 192.4230 c 452.5500 ft 88.3575 cf 4 7.9500 ft 194.3865 c 452.6500 ft 90.3210 cf 458.0500 ft 196.3500 c 452.7500 ft 92.2845 cf 458.1500 ft 1983135 c 452.8500 ft 94.2480 cf 458.2500 ft 200.2770 c 452.9500 ft 96.2115 cf 4 8.3500 ft 202,2405 c 453.0500 ft 98.1750 cf 458.4500 ft 204.2040 c 453.1500 ft 100.1385 c 458.5500 ft 206.1675 c 453.2500 ft 102.1020 c 458.6500 ft 208.1310 c 458.8100 ft 211.2728 c Record Id: CB #5 Descrip:Prototy e Record Increment 0.10 ft Start EI.446.8000 ft Max EL 457.9100 ft Classification Manhole Structure Type CB-TYPE 1-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflector Catch 1.5000 ft Bottom Area 19.6350 sf Condition Pro osed A-8 file:;l/QJ2014/?140258/10 CIV/NON_CAD/CALCS/Conve}'ance/20140716%20%20Con... 7/23/2014 Page 10 of 24 I Stage Storage Rating Curve I 446.8000 ft 0.0000 cf 452.4000 ft ]09.9560 c 446.9000 ft 1.9635 cf 4 2.000 ft 1 1 1.9195 c 447.0000 ft 3.9270 cf 4 2.6000 ft 1 13.8830 c 447.1000 ft 5.8905 cf 452.7000 ft 1 15.8465 c 447.2000 ft 7.8540 cf 452.8000 ft 1 17.8100 c 447.3000 ft 9.8175 cf 452.9000 ft 1 19.773 c 447.4000 ft 11.7810 cf 453.0000 ft 121.7370 c 447.5000 ft 13.7445 cf 453.1000 ft 123.7005 c 447.6000 ft 15.7080 cf 453.2000 ft 125.6640 c 1 ' 447.7000 ft 17.6715 cf 453.3000 ft 127.6275 c 447.8000 ft 19.6350 cf 453.4000 ft 129.5910 c 447.9000 ft 21.5985 cf 453.5000 ft 131.5545 c 448.0000 ft 23.5620 cf 453.6000 ft 133.5180 c 448.1000 ft 25.5255 cf 453.7000 ft 135.4815 c 448.2000 ft 27.4890 cf 453.8000 ft 137.44 0 c 448.3000 ft 29.4525 cf 453.9000 ft 139.4085 c 0000 I 448.4000 ft 31.4160 cf 454.0000 ft 141.3720 c 448.5000 ft 33.3795 cf 454.1000 ft 143.3355 c I 448.6000 ft 3.3430 cf 454.2000 ft 145.2990 c 448.7000 ft 37.3065 cf 454.3000 ft 147.2625 c 448.8000 ft 39.2700 cf 454.4000 ft 149.2260 c 448.9000 ft 41.2335 cf 454.5000 ft 151.1895 c 449.0000 ft 43.1970 cf 454.6000 ft 153.1 30 c 449.1000 ft 45.1605 cf 454.7000 ft I55.1 165 c 449.2000 ft 47.1240 cf 454.8000 ft 1 7.0800 c 449.3000 ft 49.087 cf 454.9000 ft 159.0435 c 449.4000 ft 51.0510 cf 455.0000 ft 161.0070 c 449.5000 ft 53.0145 cf 455.1000 ft 162.9705 c 449.6000 ft 54.9780 cf 455.2000 ft 164.9340 c 449.7000 ft 56.9415 cf 455.3000 ft 166.8975 c 449.8000 ft 58.9050 cf 455.4000 ft 168.8610 c 449.9000 ft 60.8685 cf 455.5000 ft 170.8245 c 450.0000 ft 62.8320 cf 455.6000 ft 172.7880 c 450.1000 ft 64J955 cf 455.7000 ft 174.7515 c 450.2000 ft 66.7590 cf 455.8000 ft 176.7150 c 450.3000 ft 68.7225 cf 455.9000 ft 178.6785 c 450.4000 ft 70.6860 cf 456.0000 ft 180.6420 c A-8 file:'!Q:!2014!21402 8'10_CI V/?ION_CAD!CALCS!Conveyancel20140716%20°/o20Con... 7l?3!201 Page 11 of 24 72.6495 cf 456.1000 ft 182.6055 c 450.6000 ft 74.6130 cf 456.2000 ft 184.5690 c 450.7000 ft 76.5765 cf 456.3000 ft 186.5325 c 450.8000 ft 78.400 cf 456.4000 ft 188.4960 c 450.9000 ft 80.5035 cf 456.5000 ft 190.4595 c 451.0000 ft 82.4670 cf 456.6000 ft 192.4230 c 451.1000 ft 84.4305 cf 456.7000 ft 194.3865 c 0000451.2000 ft 86.3940 cf 456.8000 ft 196.3500 c 451.3000 ft 88.3575 cf 4 6.9000 ft 198.3135 c 451.4000 ft 90.3210 cf 4 7.0000 ft 200.2770 c 451.5000 ft 92.2845 cf 457.1000 ft 202.2405 c 451.6000 ft 94.2480 cf 4572000 ft 204.2040 c 451.7000 ft 96.2115 cf 4 73000 ft 206.1675 c 451.8000 ft 98.1750 cf 457.4000 ft 208.1310 c 451.9000 ft 100.1385 c 457.5000 ft 210.0945 c 452.0000 ft 102.1020 c 457.6000 ft 212.0580 c 452.1000 ft 104.0655 c 457.7000 ft 214.0215 c 452.2000 ft 106.0290 c 457.8000 ft 215.9850 c 457.9100 ft 218.1452 c Record Id: CB #6 Descri :Prototy e Record Increment 0.10 ft Start E1.443.7600 ft Mati El. 453.2100 ft Classification Manhole Structure Type CB-TYPE 1-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflecto Catch 1.5000 ft Bottom Area 19.63 0 sf Condition Proposed Stage Storage Rating Curve 443.7600 ft 0.0000 cf 448.5600 ft 94.2480 cf 443.8600 ft 1.9635 cf 448.6600 ft 96.2115 cf 443.9600 ft 3.9270 cf 448.7600 ft 98.1750 cf 444.0600 ft 5.8905 cf 448.8600 ft 100.1385 c 444.1600 ft 7.8540 cf 448.9600 ft 102.1020 c 444.2600 ft 9.8175 cf 449.0600 ft 104.0655 c I444.3600 ft 11.7810 c 449.1600 ft 106.0290 c 444.4600 ft 13.7445 c 449.2600 ft 107.9925 c A-8 file:///Q:/2014/2140258/10_CI V/NON_CAD/CALCS/Conveyance/20140716°/a20%20Con... 7/23/20 l 4 Page 12 of 24 444.5600 ft 15.7080 c 4493600 ft 109.9560 c 444.6600 ft 17.6715 c 449.4600 ft 1119195 c 444.7600 ft 19.6350 c 449.5600 ft 113.8830 c i 444.8600 ft 21.5985 c 449.6600 ft 115.8465 c 444.9600 ft 23.5620 c 449.7600 ft 117.8100 c 0000 I445.0600 ft 5.255 c 449.8600 ft 1 19.7735 c 445.1600 ft 27.4890 c 449.9600 ft 121.7370 c 0000 I 445.2600 ft 29.4525 c 450.0600 ft 123.7005 c I 445.3600 ft 31.4160 c 450.1600 ft 125.6640 c 445.4600 ft 33.3795 c 450.2600 ft 127.6275 c 445.5600 ft 3.3430 c 4 0.3600 ft 129.5910 c 445.6600 ft 37.3065 c 450.4600 ft 131.5545 c 445.7600 ft 39.2700 c 450.5600 ft 133.5180 c 445.8600 ft 41.2335 c 450.6600 ft 135.4815 c 445.9600 ft 43.1970 c 450.7600 ft 137.4450 c 446.0600 ft 4.1605 c 450.8600 ft 139.4085 c 446.1600 ft 47.1240 c 450.9600 ft 141.3720 c 446.2600 ft 49.0875 c 451.0600 ft 143.3355 c 446.3600 ft 51.0510 c 451.1600 ft 1452990 c 446.4600 ft 53.0145 c 451.2600 ft 147.2625 c 446.5600 ft 54.9780 c 451.3600 ft 149.2260 c 446.6600 ft 56.9415 c 451.4600 ft 151.1895 c 446.7600 ft 8.90 0 c 451.5600 ft 1 3.1530 c 446.8600 ft 60.8685 c 451.6600 ft 155.1 165 c 0000 i 446.9600 ft 62.8320 c 451.7600 ft 157.0800 c 447.0600 ft 64.7955 c 451.8600 ft 159.0435 c 447.1600 ft 66.7590 c 4 1.9600 ft 161.0070 c 447.2600 ft 68.7225 c 452.0600 ft 162.9705 c 447.3600 ft 70.6860 c 452.1600 ft 164.9340 c 447.4600 ft 72.6495 c 452.2600 ft 166.8975 c 447.5600 ft 74.6130 c 452.3600 ft 168.8610 c 447.6600 ft 76.5765 c 452.4600 ft 170.8245 c 447.7600 ft 78.5400 c 452.5600 ft 172.7880 c 447.8600 ft 80.5035 c 452.6600 ft 174.7515 c 447.9600 ft 82.4670 c 452.7600 ft 176J 150 c 448.0600 ft 84.4305 c 452.8600 ft 178.6785 c 448.1600 ft 86.3940 c 452.9600 ft 180.6420 c 448.2600 ft 88.3575 c 453.0600 ft 182.6055 c A-8 file:/Q:/2014/21402 8/10 CIV,NON CAD!CALCS'Conveyance/20140716%20%20Con... 7/?3/?014 Page 13 of 24 u 90.3210 c 453.1600 ft 184.5690 c 453.2100 ft 185.5504 c Record Id: CB #7 Descri :Protot e Record Increment 0.10 ft Start EI.435.8500 ft Max El. 443.3500 ft Classification Manhole Structure T'ype CB-TYPE 1-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflecto Catch 1.5000 ft Bottom Area 19.6350 sf Condition Proposed Stage Stora e Ratin Curve 435.8500 ft 0.0001 cf 439.6 00 ft 74.6131 cf 135.9500 ft 1.9636 cf 439J500 ft 76.5766 cf 436.0500 ft 3.9271 cf 439.8500 ft 78.5401 cf 436.1500 ft 5.8906 cf 439.9500 ft 80.5036 cf 436.2500 ft 7.8541 cf 440.0500 ft 82.4671 cf 436.3500 ft 9.8176 cf 440.1500 ft 84.4306 cf 436.4500 ft 11 J811 c 440.2500 ft 86.3941 cf 436.5 00 ft 13.7446 c 440.3500 ft 88.3576 cf 436.6500 ft 15J081 c 440.4500 ft 90.3211 cf 436.7500 ft 17.6716 c 440.5500 ft 92.2846 cf 436.8500 ft 19.6351 c 440.6 00 ft 94.2481 cf 436.9500 ft 21.5986 c 440.7500 ft 96.2116 cf 437.0500 ft 23.5621 c 440.8500 ft 98.1751 cf 437.1500 ft 25.5256 c 440.9500 ft 100.1386 c 437.2500 ft 27.4891 c 441.0500 ft 102.1021 c 437.3500 ft 29.4526 c 441.1500 ft 104.0656 c 437.4500 ft 31.4161 c 441.2500 ft 106.0291 c 437.5500 ft 33.3796 c 441.3500 ft 107.9926 c 437.6500 ft 35.3431 c 441.4500 ft 109.9561 c I 437.7500 ft 37.3066 c 41.5500 ft 11 1.9196 c 437.8500 ft 39.2701 c 441.6500 ft 113.8831 c 437.9500 ft 41.2336 c 441.7500 ft 115.8466 c 438.0500 ft 43.1971 c 441.8500 ft 117.8101 c 438.1500 ft 45.1606 c 441.9500 ft 1 19.7736 c 4382500 ft 47.1241 c 442.0500 ft 121 J371 c I A-8 file:/IIQ:/?014/21402 8/10_CIV/NON CAD/CALCS/Conveyance/20140716%?0%20Con... 7!23I201 Page 14 of 24 438.3500 ft 49.0876 c 442.1500 ft 123.7006 c 438.4500 ft 51.0 1 1 c 4 2.2500 ft 125.6641 c 438.5500 ft 3.0146 c 442.3500 ft 127.6276 c 438.6500 ft 54.9781 c 442.4500 ft 129.591 1 c 438.7500 ft 56.9416 c 442.5500 ft 131.5546 c 438.8 00 ft 8.9051 c 442.6500 ft 133.5181 c 438.9500 ft 60.8686 c 442.7500 ft 135.4816 c 439.0500 ft 62.8321 c 442.8500 ft 137.4451 c 439.1500 ft 64.7956 c 442.9 00 ft 139.4086 c 439.2500 ft 66J591 c 443.0 00 ft 141.3721 c 439.3500 ft 68.7226 c 443.1500 ft 143.3356 c 439.4 00 ft 70.6861 c 443.2500 ft 14.2991 c 443.3500 ft 147.2625 c Record Id: EXISTING Descri :Prototv e Record Increment 0.10 ft Start EI.431.0800 ft Max EI. 438.0000 ft Classification Manhole Structure Ty e CB-TYPE 1-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflecto Catch 1.5000 ft Bottom Area 19.6350 sf Condition Proposed Stage Storage Rating Curve 431.0800 ft 0.0001 cf 434.5800 ft 68.7226 cf 431.1800 ft 1.9636 cf 434.6800 ft 70.6861 cf 431.2800 ft 3.9271 cf 434J800 ft 72.6496 cf 431.3800 ft 5.8906 cf 434.8800 ft 74.6131 cf 431.4800 ft 7.8541 cf 434.9800 ft 76.5766 cf 431.5800 ft 9.8176 cf 435.0800 ft 78.5401 cf 431.6800 ft 11.7811 c 435.1800 ft 80.5036 cf 431.7800 ft 13.7446 c 435.2800 ft 82.4671 cf 431.8800 ft 15.7081 c 435.3800 ft 84.4306 cf 431.9800 ft 17.6716 c 435.4800 ft 86.3941 cf 432.0800 ft 19.6351 c 435.5800 ft 88.3576 cf 432.1800 ft 21.5986 c 435.6800 ft 90.321 1 cf 432.2800 ft 23.5621 c 435.7800 ft 92.2846 cf 432.3800 ft 25.5256 c 435.8800 ft 942481 cf A-8 file:!!/Q:!014/2140258/10_CI V/NON_CAD!CALCS!Conveyance/20140716%?0%20Con... 7!23;'2014 Page 15 of 24 432.4800 ft 27.4891 c 435.9800 ft 96.2116 cf 432.5800 ft 29.4526 c 436.0800 ft 98.1751 cf 432.6800 ft 31.4161 c 436.1800 ft 100.1386 c 432.7800 ft 33.3796 c 436.2800 ft 102.1021 c 432.8800 ft 35.3431 c 436.3800 ft 104.0656 c 432.9800 ft 37.3066 c 436.4800 ft 106.0291 c 433.0800 ft 39.2701 c 436.800 ft 107.9926 c 433.1800 ft 41.2336 c 436.6800 ft ]09.9561 c 433.2800 ft 43.1971 c 436.7800 ft 111.9196 c 433.3800 ft 45.1606 c 436.8800 ft 113.8831 c 433.4800 ft 47.1241 c 436.9800 ft 115.8466 c 433.5800 ft 49.0876 c 437.0800 ft I 17.8101 c 433.6800 ft 51.0511 c 437.1800 ft 119.7736 c 433.7800 ft 53.0146 c 437.2800 ft 121.7371 c 433.8800 ft 54.9781 c 437.3800 ft 123.7006 c 433.9800 ft 56.9416 c 437.4800 ft 125.6641 c 434.0800 ft 58.9051 c 437.5800 ft 127.6276 c 434.1800 ft 60.8686 c 437.6800 ft 129.5911 c 434.2800 ft 62.8321 c 437.7800 ft 131.5546 c 434.3800 ft 64.7956 c 437.8800 ft 133.5181 c 438.0000 ft 135.8745 c Record Id: JNCT #1 Descrip:Prototype Record Increment 0.10 ft Start El.453.8000 ft Max El. 463.8000 ft Classification Catch Basin Structure Ty e CB-TYPE 1-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflecto Catch 1.5000 ft Bottom Area 19.6350 sf Condition Existing Stage Storage Ratin Cur e 453.8000 ft 0.0000 cf 458.8000 ft 98.1750 cf 453.9000 ft 1.9635 cf 458.9000 ft 100.1385 c 454.0000 ft 3.9270 cf 459.0000 ft 102.1020 c 454.1000 ft 5.8905 cf 459.1000 ft 104.0655 c 454.2000 ft 7.8540 cf 459.2000 ft 106.0290 c 454.3000 ft 9.8175 cf 4593000 ft 107.9925 c A-8 I' file:/,/Q:/2014/2140258/10 CIV/NON_CAD/CALCS/Com eyance/20140716%20%20Con... 7/23/2014 I Page 16 of 24 454.4000 ft 1 1.7810 c 459.4000 ft 1099 60 c 454.5000 ft 13.7445 c 459.5000 ft 111.9195 c 454.6000 ft 1.7080 c 459.6000 ft 113.8830 c 454.7000 ft 17.6715 c 459.7000 ft 115.8465 c 454.8000 ft 19.6350 c 459.8000 ft 117.8100 c 454.9000 ft 21.598 c 459.9000 ft 119.7735 c 455.0000 ft 23.5620 c 460.0000 ft 121.7370 c 455.1000 ft 25.5255 c 460.1000 fr 123J005 c 4 5.2000 ft 27.4890 c 460.2000 ft 125.6640 c 45.3000 ft 29.4525 c 460.3000 ft 127.6275 c 455.4000 ft 31.4160 c 460.4000 ft 129.5910 c 455.000 ft 33.3795 c 460.5000 ft 131.5545 c i 0000455.6000 ft 35.3430 c 460.6000 ft 133.5180 c 455J000 ft 37.306 c 460J000 ft 135.4815 c 455.8000 ft 39.?700 c 460.8000 ft 137.44 0 c II 455.9000 ft 41.233 c 460.9000 ft 139.408 c 456.0000 ft 43.1970 c 461.0000 ft 141.3720 c 456.1000 ft 45.1605 c 461.1000 ft 143.3355 c 00006.2000 ft 47.1240 c 461.2000 ft 145.2990 c I 456.3000 ft 49.0875 c 461.3000 ft 1472625 c 456.4000 ft 51.0510 c 461.4000 ft 149.2260 c 456.5000 ft 53A145 c 461.5000 ft 151.1895 c 456.6000 ft 54.9780 c 461.6000 ft 1 3.1530 c 456.7000 ft 56.9415 c 461 J000 ft 155.1 165 c 456.8000 ft 58.90 0 c 461.8000 ft 157.0800 c 456.9000 ft 60.868 c 461.9000 ft 159.0435 c 457.0000 ft 62.8320 c 462.0000 ft 161.0070 c 457.1000 ft 64.795 c 462.1000 ft 162.9705 c 457.2000 ft 66.7590 c 462.2000 ft 164.9340 c 457.3000 ft 68.7225 c 462.3000 ft 166.8975 c 457.4000 ft 70.6860 c 462.4000 ft 168.8610 c 457.5000 ft 72.6495 c 462.5000 ft 170.8245 c 457.6000 ft 74.6130 c 462.6000 ft 172.7880 c 457.7000 ft 76.5765 c 462.7000 ft 174.7515 c 4 7.8000 ft 78.5400 c 462.8000 ft 176.7150 c 457.9000 ft 80.5035 c 462.9000 ft 178.6785 c 458.0000 ft 82.4670 c 463.0000 ft 180.6420 c 458.1000 ft 84.4305 c 463.1000 ft 182.6055 c A-8 file:ll/Q:I201!21402 8/10_CIV/NON_CAD,CALCS!Conveyance/20140716%?0%20Con... 7!23!2014 Page 17 of 24 86.3940 c 463.2000 ft 184.5690 c 4 8.3000 ft 88.3575 c 463.3000 ft 186.5325 c 4 8.4000 ft 90.3210 c 463.4000 ft 188.4960 c 458.000 ft 92.2845 c 463.5000 ft 190.4595 c 458.6000 ft 94.2480 c 463.6000 ft 192.4230 c 463.8000 ft 196.3500 c Record Id: JNCT #2 Descri :Protot e Record Increment 0.10 ft Start EI.453.5700 ft Max El. 458.5700 ft Classification Catch Basin Structure Type CB-TYPE 1-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflector Catch l.5000 ft Bottom Area 19.6350 sf Condition Existing Stage Stora e Rating Curve 453.5700 ft 0.0001 cf 456.0700 ft 49.0876 c 453.6700 ft 1.9636 cf 456.1700 ft 51.0 11 c 453.7700 ft 3.9?71 cf 456.2700 ft 53.0146 c 453.8700 ft 5.8906 cf 456.3700 ft 54.9781 c 453.9700 ft 7.8541 cf 456.4700 ft 6.9416 c 454.0700 ft 9.8176 cf 456.5700 ft 58.9051 c 454.1700 ft 11.7811 c 456.6700 ft 60.8686 c 454.2700 ft 13.7446 c 456.7700 ft 62.8321 c 454.3700 ft 15.7081 c 456.8700 ft 64.7956 c 454.4700 ft 17.6716 c 456.9700 ft 66.7591 c 454.5700 ft 19.6351 c 457.0700 ft 68.7226 c 454.6700 ft 21.5986 c 457.1700 ft 70.6861 c 454.7700 ft 23.5621 c 457.2700 ft 72.6496 c 454.8700 ft 25.5256 c 4 7.3700 ft 74.6131 c 454.9700 ft 27.4891 c 457.4700 ft 76.5766 c 455.0700 ft 29.4526 c 457.5700 ft 78.5401 c 455.1700 ft 31.4161 c 457.6700 ft 80.5036 c 455.2700 ft 33.3796 c 457.7700 ft 82.4671 c 455.3700 ft 35.3431 c 457.8700 ft 84.4306 c 455.4700 ft 37.3066 c 457.9700 ft 86.3941 c 455.5700 ft 39.2701 c 458.0700 ft 883576 c A-8 I file:l,!Q:I2014,'?140258!10_CIV/I ON CADICALCS/Conveyance/20140716%20%20Con... 7/23/2014 Page 18 of 24 455.6700 ft 41.2336 c 458.1700 ft 90.321 1 c 455.7700 ft 43.1971 c 458.2700 ft 92.2846 c 455.8700 ft 45.1606 c 458.3700 ft 94.2481 c 458.5700 ft 98.1750 c Record Id: JNCT #3 Descrip:Prototype Record Increment 0.10 ft Start EI.449.4700 ft Max El. 459.1 100 ft Classification Catch Basin Structure T - e CB-TYPE 1-48 Ent Ke Groove End /Headwall (ke=0.20) Channelization Curved or Deflecto Catch 1.5000 ft Bottom Area 19.6350 sf Condition Pro osed Stage Storage Rating Curve 449.4700 ft 0.0000 cf 454.3700 ft 96.2115 cf 449.5700 ft 1.9635 cf 454.4700 ft 98.1750 cf 449.6700 ft 3.9270 cf 454.5700 ft 100.1385 c 449.7700 ft 5.8905 cf 454.6700 ft 102.1020 c 449.8700 ft 7.8540 cf 454.7700 ft 104.0655 c 449.9700 ft 9.817 cf 454.8700 ft 106.0290 c 4 0.0700 ft 11 J810 c 4 4.9700 ft 107.9925 c 450.1700 ft 13.7445 c 455.0700 ft 109.9560 c 450.2700 ft 15.7080 c 455.1700 ft 1 1 1.9195 c 450.3700 ft 17.6715 c 455.2700 ft 113.8830 c 450.4700 ft 19.6350 c 455.3700 ft 1 15.8465 c 450.5700 ft 21.5985 c 455.4700 ft 117.8100 c 450.6700 fi 23.5620 c 45.5700 ft 1 19.7735 c 450.7700 ft 25.5255 c 455.6700 ft 121.7370 c 450.8700 ft 27.4890 c 455.7700 ft 123.7005 c 450.9700 ft 29.4525 c 455.8700 ft 125.6640 c 451.0700 ft 31.4160 c 455.9700 ft 127.6275 c 451.1700 ft 33.3795 c 456.0700 ft 129.5910 c 451.2700 ft 35.3430 c 456.1700 ft 131.5545 c 451.3700 ft 37.3065 c 456.2700 ft 133.5180 c 451.4700 ft 39.2700 c 456.3700 ft 135.4815 c 451.5700 ft 41.2335 c 456.4700 ft 137.4450 c 451.6700 ft 43.1970 c 456.5700 ft 139.4085 c A-8 file:/.!Q:I20 1 4/2 1 402 8/10_CIVINON CAD,'CALCS!Con eyancel20140716%20%20Con... 7:'23!2014 Page 19 of 24 r 451.7700 ft 45.1605 c 456.6700 ft 141.3720 c 451.8700 ft 47.1240 c 456.7700 ft 143.3355 c 451.9700 ft 49.0875 c 4 6.8700 ft 145.2990 c 452.0700 ft 51.0510 c 4 6.9700 ft 147.2625 c 452.1700 ft 53.0145 c 457.0700 ft 149.2260 c 452.2700 ft 54.9780 c 457.1700 ft 151.189 c 452.3700 ft 56.9415 c 457.2700 ft 153.1530 c 452.4700 ft 8.90 0 c 457.3700 ft 155.1165 c 4 2.5700 ft 60.8685 c 457.4700 ft 1 7.0800 c f 452.6700 ft 62.8320 c 457.5700 ft 159.0435 c 452J700 ft 64.7955 c 457.6700 ft 161.0070 c 452.8700 ft 66.7590 c 457.7700 ft 162.9705 c 452.9700 ft 68.7225 c 457.8700 ft 164.9340 c 453.0700 ft 70.6860 c 457.9700 ft 166.8975 c I 0000453.1700 ft 72.6495 c 458.0700 ft 168.8610 c 453.2700 ft 74.6130 c 458.1700 ft 170.8245 c 453.3700 ft 76.5765 c 458.2700 ft 172.7880 c 453.4700 ft 78.5400 c 458.3700 ft 174.7515 c 453.5700 ft 80.5035 c 458.4700 ft 176.7150 c 453.6700 ft 82.4670 c 458.700 ft 178.6785 c 453.7700 ft 84.4305 c 458.6700 ft 180.6420 c 453.8700 ft 86.3940 c 458J700 ft 182.6055 c 453.9700 ft 88.3575 c 458.8700 ft 184.5690 c 454.0700 ft 90.3210 c 458.9700 ft 186.5325 c 454.1700 ft 92.2845 c 4 9.0700 ft 188.4960 c 459.1100 ft 1892811 c Record Id: P-001 Section Sha e: Circular Uniform Flo v Method: Manning's Coefficient: OA100 Routing Method: Travel Time Translation DnNode JNCT#1 U Node CB #1 Material Plastic Size 8" Diam i Ent Losses Groove End w/Headwall i Length 24.0000 ft Slope 4.13% U Invert 454.7900 ft Dn Invert 453.8000 ft Conduit Constraints r-- A-8 file:///Q:/2014/2140258/10_CIV/NON_CAD/CALCS/Conveyance/20140716%20°/a20Con... 7/23/2014 Page 20 of 24 Min Vel Max Vel Min Slope Max Slope Min Cover 2.00 ft/s 15.00 ft/s 0.50°/a 2.00% 3.00 ft Dro across MH 0.0000 ft E Infil Rate 0.0000 in/hr Up Invert 453.8000 ft Dn Invert 454.7900 ft Match inverts. DnNode JNCT #1 U Node CB #1 Record Id: P-002 Section Sha e: Circular Uniform Flow Method: Manning's Coefficient: 0.0100 Routing Method: Travel Time Translation DnNode JNCT#2 UpNode JNCT#1 I Material Plastic Size 8" Diam Ent Losses Groove End w/Headwall Len th 14.0000 ft Slope 1.64% Up Invert 453.8000 ft Dn Invert 453.5700 ft Conduit Constraints Min Vel Max Vel Min Slo e Max Slo e Min Cover 2.00 fUs 15.00 ft/s 0.50% 2.00% 3.00 ft Drop across MH 0.0000 ft Ex/Infil Rate 0.0000 in/hr U Invert 453.5700 ft Dn Invert 453.8000 ft Match inverts. DnNode JNCT#2 UpNode JNCT#1 Record Id: P-003 Section Shape: Circular Uniform Flow Method: Manning's Coefficient: 0.0130 Routin Method: Travel Time Translation DnNode CB #2 U Node JNCT #2 Material Conc-Spun Size 8" Diam Ent Losses Groove End w/Headwall Len h 60.0000 ft Slo e 5.17% Up Invert 453.5700 ft Dn Invert 450.4700 ft Conduit Constraints Min Vel Max Vel Min Slo e Max Slo e Min Cover A-8 file:,'!Q:l?014/2140258/10_C[V/NON_CAD/CALCS/Conve}ancel?0140716%20%20Con... 7/?3;2014 Page 21 of 24 2.00 ft's 1.00 ftls 0.50% ?.00% 3.00 ft IIi Dro across MH 0.0000 ft Eac/Infil Rate 0.0000 in/hr U Invert 450.4700 ft Dn Invert 453.5700 ft Match inverts. DnNode CB #2 U Node JNCT #2 Record Id: P-004 Section Sha e: Circular Uniform Flow Method: Manning's Coefficient: 0.0130 Routing Method: Travel Time Translation DnNode JNCT#3 UpNode CB #2 I Material Cono-S un Size 15" Diam I, Ent Losses Groove End w/Headwall Length 85.0000 ft Slope 0.46% U Invert 449.8600 ft Dn Invert 449.4700 ft Conduit Constraints Min Vel Max Vel Min Slope Max Slope Min Cover 2.00 ft/s 15.00 ft/s 0.50°/a 2.00% 3.00 ft Dro across MH 0.0000 ft Ex/Infil Rate 0.0000 in/hr Up Invert 449.4700 ft Dn Invert 449.8600 ft Match inverts- DnNode JNCT#3 U Node CB #2 Record Id: P-005 i Section Sha e: Circular Uniform Flow Method: Manning's Coefficient: 0.0130 i Routing Method: Travel Time Translation DnNode CB #3 U Node JNCT#3 I Material Conc-S un Size 15" Diam I Ent Losses Groove End w/Headwall Len th 85.0000 ft Slo e 0.67% U Invert 449.4700 ft Dn Invert 448.9000 ft Conduit Constraints Min Vel Max Vel Min Slo e Max Slo e Min Cover 2.00 ft/s 15.00 ft/s 0.50°/a 2.00% 3.00 ft A-8 file:/,/Q:!?014/21402 8/10 CIVINON CAD/CALCS!Conveyance!20140716%20%20Con... 7123!2014 Page 22 of 24 IDrop across MH II0.0000 ft Ex/Infil Rate 0.0000 in/hr U Invert 448.9000 ft Dn Invert 449.4700 ft Match inverts. DnNode CB #3 UpNode JNCT#3 Record Id: P-006 Section Shape: Circular Uniform Flow Method: Mannin 's Coefficient: 0.0130 Routin Method: Travel Time Translation DnNode CB #4 UpNode CB #3 Material Conc-Spun Size 15" Diam Ent Losses Groove End w/Headwall Len th 170.0000 ft Slo e 0.50% Up Invert 448.9000 ft Dn Invert 448.0500 ft Conduit Constraints Min Vel Max Vel Min Slo e Max Slo e Min Cover 2.00 ft/s 15.00 ft/s 0.50% 2.00% 3.00 ft Dro across MH 0.0000 ft Ex/Infil Rate 0.0000 in/hr U Invert 448.0500 ft Dn Invert 448.9000 ft Match inverts. DnNode CB #4 U Node CB #3 I, Record Id: P-007 Section Shape: Circular Uniform Flow Method: Manning's Coefficient: 0.0130 Routing Method: Travel Time Translation DnNode CB #5 UpNode CB #4 Material Conc-S un Size 15" Diam Ent Losses Groove End w/Headwall Length 125.0000 ft Slope 1.00% U Invert 448.0500 ft Dn Invert 446.8000 ft Conduit Constraints Min Vel MaY Vel Min Slope Max Slope Min Cover 2.00 ft s 15.00 ft/s 0.50% 2.00% 3.00 ft Dro across MH 0.0000 ft E Infil Rate 0.0000 in/hr Up Invert 446.8000 ft Dn Invert 448.0500 ft A-8 file:'!Q:/2014/2140258!10 CIV/I O I C.AD!CALCS;Conveyance/20140716%?0%?OCon... 7/23/?014 Page ?3 of 24 IMatch inverts. DnNode CB #5 U Node CB #4 Record Id: P-008 Section Sha e: Circular Uniform Flow Method: Mannin 's Coefficient: 0.0130 Routing Method: Travel Time Translation DnNode CB #6 U Node CB #5 Material Conc-S un Size 15" Diam Ent Losses Groove End w/Headwall Length 200.0000 ft Slope 1.52% U lnvert 446.8000 ft Dn Invert 443.7600 ft Conduit Constraints Min Vel Max Vel Min Slope Max Slope Min Cover 2.00 ft/s 15.00 ft/s 0.50% 2.00% 3.00 ft Dro across MH 0.0000 ft E Infil Rate 0.0000 in/hr Up Invert 443.7600 ft Dn Inver[ 446.8000 ft Match inverts. DnNode CB #6 U Node CB #5 Record Id: P-009 Section Sha e: Circular Uniform Flow Method: Manning's Coefficient: 0.0130 Routing Method: Travel Time Translation DnNode CB #7 U Node CB #6 Material Conc-Spun Size 15" Diam Ent Losses Groove End w/Headwall Len th 384.0000 ft Slo e 2.06% U Invert 443.7600 ft Dn Invert 435.8500 ft Conduit Constraints Min Vel Max Vel Min Slo e Max Slo e Min Cover 2.00 ft/s 15.00 ft/s 0.50% 2.00°/a 3.00 ft Drop across MH 0.0000 ft Ex/Infil Rate 0.0000 in/hr U Invert 435.8500 ft Dn [nvert 443.7600 ft Match im-erts. DnNode CB #7 UpNode CB #6 A-8 file:U/Q:/2014/2140258/10_CIV/NON CAD!CALCS!Conveyance/20140716%20%20Con... 7/23/2014 Page 24 of 24 Record Id: P-010 Section Sha e: Circular Uniform Flow Method: Manning's Coefficient: 0.0130 Routin Method: Travel Time Translation DnNode EXISTING U Node CB #7 Material Conc-Spun Size 18" Diam Ent Losses Groove End w/Headwall Len th 222.0000 ft Slo e 2.60% Up Invert 436.8500 ft Dn Invert 431.0800 ft Conduit Constraints Min Vel Max Vel Min Slope Max Slo e Min Cover 2.00 ft/s 15.00 ft/s 0.50°/a 2.00% 3.00 ft Drop across MH 0.0000 ft E[nfil Rate 0.0000 in/hr U Invert 431.0800 ft Dn Invert 436.8500 ft Match inverts. DnNode EXISTING UpNode CB #7 Licensed to: AHBL A-8 file:l.IQ:12014I21402 8/10_CI V/NON_CAD/CALCS/Conveyance,20140716%20%20Con... 7/23,'2014 City of Renton Print map Template egeN,o kSt es Q Inlet 3 _.... 7.- - _ . .;. :a — ManhWeF C ..,. Utifry vault r.+"`At 1 Unknown Strudure a Y K r Y r, _. . ..' y 1 7. 4 0 ntrol StructureCo i e r r i k, Pump Stationx, , : R k q',*,,,i intaE';. .,_..... . ' -- - d _ i T W., . t .....t•-- ,.. 3 D scha ge P k•0 t{ E f i s i Water Qualitys o- Detention Facilitiesf _ . . - t. s t,. f . j, '., - Pond M ' i ` s ,. u at... k.Tank I F 9,. .. 9; •.: _, yx ` yT`^, ' ",Y'='. l a„,L: _. k;, 35+t . 3ti' t' i4, vau t W tl de,.t, c'e anitiY f a 1 y'`.rs Pipe A vyM. I. d e ..: . .. . g _ i e.. _: . ... a"._. . f r 6 ^ 24" i Open Drains 24 CONCRETE UPSTREAM: 390.95 36" CONCRETE Faci ity out ine DOWNSTREAM: 386.59 Private Network StructuresUPSTREAM: 423.03 UPSTREAM: 363.64 y `-> r'= . DOWNSTREAM: 414.9 8•93% DOWNSTREAM: 363.27 o Iniet Manhole 2.32% 0.09%r a, k 24" CONCRETE yv Unknown SUucture w'`:, .: ._ j y T UPSTREAM: 404.15 F ,_ ,. , - _ r 5 Private Control Structure 24" CONCRETE DOWNSTREAM: 397.38 i=--' s Private Discharge Point UPSTREAM: 431.08 4.84°< 24" CONCRETE Private Water Quality DOWNSTREAM: 423.23 UPSTREAM: 374.08 o Private Detention Facilities 2.37/o DOWNSTREAM: 362.83 d w# . . ,y . 1- Pond tte.:` U.76 0 TankYr i V v. fk."s s VauN I . z Wetland 4 x,:, yf r ' t .. ' y,s q., z 3 w, ,r PipePnvate i_ . ; x - s 4 Private Culvert y` l.. .. ' . p E 4 CONCRETEr Pri ate Open DrainsF3 a, `, , 24" CONCRETE 24 C Private Facility OutlineUPSTREAM: 378.23ONCRETE DOWNSTREAM: 378.13UPSTREAM: 397.13 F ow Contro BnnPUPSTREAM: 414.73fi DOWNSTREAM: 404.61 DOWNSTREAM: 391.27 0.14°0 Fence o; 6 76°0 s e 'i { i .'+ i Facity Trans erds 11 t . 4° CONCRETE a:x..r.-s4 r___ w _ y _ tJPSTREAM 386 67 1 r -TREAM 378 7 Notes j SDOWN oq None361°/ i s s gY N P -.:... k e M' fa I . r ' I t l d rb.'`.. '-o q r:: y s w ' r.r:. E, r y., r FC f' ''1tEly ,. r,•4_ ' —. jf . S y't. w f .. f Ei - t.. - 4r eY ... . .a j- R - ' , .. f^-. er.,,,. ., f.t s.- Y' d M1i w . .. a' - a a. A` 1..a__ " i -...__ _—_ . Information Technology -GIS This map is a user generated static output from an Internet mapping site and is for reference only Data layers that appear on this map may or may not be Cl Of 512 0 256 512 Feet RentonMapSupport@Rentonwa.gov accurate. current or otherwise reliable. 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Z ; 7 i ...:'' a y,l 1 k / r1t m, I' 1 .: ' 1 ht 1 CF' A' FA S . a i ,, i This page left intentionally blank for double-sided printing. ng County Districts and Development Conditions for parcel number 2... http://ww5.kin county.go;%kceisreports,dd_report.aspx?PII`=282305903 HOME NEWS SERVICES DIRECTORY CONTACTSearch Terms: Searc KCGIS Center www.KingCounty.gov/GIS w._....__. KCGIS Parcel Reports King County Districts and Development Conditions for parcel Districts and Development r Conditions Report 2823059034 Parcel number 2823059034 Draina e Lower Cedar RiverFindYourCouncilDistnct9 Address 16022116TH Basin e , " Find Your Watershed AVE SE Lr4 t rsr:u Cedar River i Lake 5 111ash nqtott 4 ° a ' aKCGISCenterJurisdictionRenton1 Zipcode 98058 4?IA C clar-5arrsmarnish , , t Kroll Map page 602 PLSS NW-28-23-5 Thomas Guide 656 page Latitude 47.45749 I Longitude -122.18496 King County GIS Center King Street Center 201 S. Jackson St. Suite 706 Seattle.WA 98104 giscenter(c kingcounty.gov a.5s9os N Electoral Districts 122.33136 W i ;P;ct RNT 11-3590 Fire district does not apply 47° 35'56.72"Gi d:strict District 5,Qave Water district does not apply 122° 19'S2.90"U g£o g Sewer district does not apply206)477-1005 Water 8 Sewer Soos Creek Water 8 Sewer district District Congressional district 9 Parks&Recreation does not apply Legislative district 11 district School district Rentan#4D3 Hospital district Public Hospital District No. Seattle school board distrid does not apply(not in Seattle) Rural library district Rurel King County Library King County planning and cr ti al reas designations f;r:_C n+y ;ir:g NA,check with F '4 i.,;rEr xati r ar•a does not apply jurisdiction R r21 towr% No e'@IC•^v':"`:a'••i ccr:dit:o,s None Va e seryi e?^in r?, does not apply Gcr p e:ns.ve P{ar um a:fs F 1PS z>:e 335 r an G-vw#ArEa Urban Tra sp..rt r rcu ren.c.y does not apply 7m.r3.itx._erv;ce Area does not apply '`a e v t mmii 31#Y_P!^ning_,.fev Soos Creek Forest Production district? No Coal mine hazards? None mapped AgricuRural Production district? No Erosion hazards? None mapped C ,:_u j_ _;,^ r;,? None mapped Landslide hazards? No e mapped 100-year flood plain? None mapped v Seismic hazards? None mapped Wetlands at this parcel? None mapped t:?h€^:::a`a:a Sr rei>.er Non-Detect to 20.0 iurr32? PPm Estimaoed fvsenic Related resources A-11 of2 AM J King County Districts and Development Conditions for parcel number 2... http://www5.kingcounty.gov/kcgisreports/dd_report.aspx?PIN=282305903a King County Assessor:eReal Proaertv Report King County Assessor:Quarter Section Map (PDF format requires Acrobat) King County DPER: Perrnit Applications Report (for unincorporated areas onty) KioaCountvTreasucv._Qaerations:..PrQnertu.Tax.lnfnrmatinn_fQrlhi.s..Qrc as2v __.._... ......._._............._......_.... ....... Search Address or parcel number: Go Reset search by condo name exartple address:8621 426TH AVE SE e mple parcel number:0942000860 This report was generated on 6/11/2014 10:40:20 AM r, ?r:vac.y I Access.i:lit. " Searches__o._use5I .............. Contact us at y;sc rte:,•:^gcc nt..av. Links to external sites do not constitute endorsements by King County. By visiting this and other King County web pages,you expressly agree to be bound by terms and conditions of the site. 2013 King County A-11 2 of 2 6r'11!2014 10:40 AM ti zy o n so ay so CTy F r2OqY3CTqTS 9 ,' S' J' yC9S SE EDIvtOPJDS 1 9,p Cy 9F, C uRT tiF p FT APPROXIMATE SCALE IN FEET 9'T 0` 500 0 500 11 iH AVFNUE F, F, THE SOUTHEASI S5 q g'IH SOIJTHEAS7 6/TH STR[1 I SOUTH F s D 20TH 19TV1 STREET UC m m wI YF• C 4, T SF 15t3TH ,s S`Sr gfq pN m o' i °o L F acE o yA s°,'7HEasr m NATIONAL FLOOD INSURANCE PROGRAM m CITy oz, P 1 n S OF RFNT NpsEz,sr ° P P Tti , K N UNTSIHEET = CO Y SUUr SE z,T STFEE.T r N FI RMJ F s` N F100D INSURANCE RATE MAP I Q\, P Q\, P O N I d so KING COUNTY, G r n WASHINGTON AND z 2 INCORPORATED AREAS S a c mw160TH °' STREE7 y j PANEL 983 Of 1725 ISEE MAP INDE% Ofi i'ANCLS NOT PRINTfI]I PROJECT LOCATION Nrti S. COMMUNRr NUMBER PANEI SUFFiX KING COVNtt. UN flCVAPO P EU 4Afny fi]W91 OBtlB F I PENi0N.C11(Y" 6'p0l8 OBl9 f I MAP NUMBER 53033C0983 F K e=;,, MAP REVISEO: MAY 16,1995 I I Federal Emergency Management Agency I Thls is an olficial copy ofa portlon of the abo e referenced 11ood map. R was extracted usinp F-MIT On-Line. This map dces not reAect chanpes Ior amendments which may ha e been made subsequent to the date onthe title Wock. For the latent product iMormetlon about National Flood Ineurence Propram 11ood mape check the FEMA Flood Map Store at vnvw.msc.fema.pov A-12 I 1 This page left intentionally blank for double-sided printing. Site Im rovement Bond Quantit Worksheet II p Y Original bond computatlons prepared by: Name:William Fierst ate:une 12,2014 PE Registration Number: Tel.#:(253)383-2422 Firm Name: AHBL Address: 2215 N 30th St,Suite 300,Tacoma,WA 98403 Project No: 2140258.10 ROAD IMPROVEMENTS&DRAINAGE FACILITIES FINANCIAL GUARANTEE REQUIREMENTS PERFORMANCE BOND*," PUBLIC ROAD&DRAINAGE AMOUNT MAINTENANCE/DEFECT BOND',"" Stabilization/Erosion Sediment Control(ESC) A) $ Existing Right-of-Way Improvements B) $ Future Public Road Improvements 8 Drainage Facilities (C) $ Private Improvements D) $21,036.90 Construction Bond"Amount (A+g++D) = TOTAL (T) $21,036.90 Minimum bond'amount is$1000. g+C)x Maintenance/Defect Bond'Total 0.20= $ NAME OF PERSON PREPARING BOND'REDUCTION: Date. NOTE: The word"bond"as used in this document means any financial guarantee acceptable to the City of Renton. NOTE: All prices mclude labor,equipment,materials,overhead and profit. Prices are from RS Means data adjusted for the Seattle area or from local sources if not included in the RS Means database. DREQUIRED BOND"AMOUNTS ARE SUBJECT TO REVIEW AND MODIFICATION BY RDSD 1 Page 1 of 1 Unit prices updated:2/12/02 W Version:4/22/02 REF 8-H BOND QUANTITY WORKSHEET.xIs Report Date: 1/19/2010 This page left intentionally blank for double-sided printing. Site Improvement Bond Quantity Worksheet Existing Future Public Private Quantity Comp#eted II, Righf-of-Way Right of Way tmprovements Bond Reduction)' Draina e Facilities Qu2nt. Unit Price llnit Quant. Cost Quant Cost Quant Cost Complete Cost G N L!T'E fIS No. Backfill 8 Compaction-embankment GI- 1 $ 5.62 CY 0 0.00 0 0.00 0 0.00 0 0.00 Backfill&Compaction-trench GI-2 $ 8.53 CY 0 0.00 0 0.00 0 0.00 0 0.00 Clear/Remove Brush, by hand GI-3 $ 0.36 SY 0 0.00 0 0.00 0 0.00 0 0.00 ClearinglGrubbinglTree Removal GI-4 $ 8,876.16 Acre 0 0.00 0 0.00 0.17 1,508.95 0 0.00 Excavation-bulk GI-5 $ 1.50 CY 0 0.00 0 0.00 6.73 10.10 0 0.00 Excavation-Trench GI-6 $ 4.06 CY 0 0.00 0 0.00 110 446.60 0 0.00 Fencing, cedar, 6' high GI-7 $ 18.55 LF 0 0.00 0 0.00 0 0.00 0 0.00 Fencing, chain link, vinyl coated, 6'high GI-8 $ 13.44 LF 0 0.00 0 0.00 0 0.00 0 0.00 Fencing, chain link, gate, vinyl coated, 2 GI-9 $ 1,271.81 Each 0 0.0o 0 0.00 0 0.00 0 0.00 Fencing, split rail, 3' high GI- 10 $ 12.12 LF 0 0.00 0 0.00 0 0.00 0 0.00 Fill&compact-common barrow GI- 11 $ 22.57 CY 0 0.0 0 0.00 0 0.00 0 0.00 Fill 8 compact-gravel base GI- 12 $ 25.48 CY 0 0.00 0 0.00 16 407.68 0 0.00 Fill &compact-screened topsoil GI - 13 $ 37.85 CY 0 0.00 0 0.00 0 0.00 0 0.00 Gabion, 12"deep, stone filled mesh GI - 14 $ 54.31 SY o 0.00 0 0.00 0 0.00 0 0.00 Gabion, 18"deep, stone filled mesh GI- 15 $ 74.85 SY 0 0.00 0 0.00 0 0.00 0 0.0 Gabion, 36"deep, stone filled mesh GI- 16 $ 132.48 SY 0 0.00 0 0.0 0 0.00 0 0.00 Grading, fine, by hand GI- 17 $ 2.02 SY 0 0.00 0 0.00 0 0.00 0 0.00 Grading, fine,with grader GI-18 $ 0.95 SY 0 0.00 0 0.00 143 135.85 0 0.00 Monuments, 3' long GI-19 $ 135.13 Each 0 0.00 0 0.00 0 0.00 0 0.00 Sensitive Areas Sign GI-20 $ 2.88 Each 0 0.00 0 0.00 0 0.00 0 0.00 Sodding, 1"deep, sloped ground GI-21 $ 7.46 SY 0 0.00 0 0.00 24 179.04 0 0.00 Surveying, line&grade GI-22 $ 788.26 Day 0 0.00 0 0.00 0 0.00 0 0.00 Surveying, lot location/lines GI-23 $ 1,556.64 Acre 0 0.00 0 0.00 0 0.00 0 0.00 Traffic control crew(2 flaggers) GI-24 $ 85.18 HR 0 0.00 0 0.00 0 0.00 0 0.00 Trail, 4"chipped wood GI-25 $ 7.59 SY 0 0.00 0 0.00 0 0.00 0 0.00 Trail, 4"crushed cinder GI-26 $ 8.33 SY 0 0.00 0 0.00 0 0.00 0 0.00 Trail, 4"top course GI-27 $ 8.19 SY 0 0.00 0 0.00 0 0.00 0 0.00 Wall, retaining, concrete GI -28 $ 44.16 SF 0 0.00 0 0.00 0 0.00 0 0.00 Wall. rockery GI -29 $ 9.49 SF 0 0.00 0 0.00 0 0.00 0 0.00 Page 2 of 7 SUBTOTAL 0.00 0.00 2,68821 0.00 A-13 Unit prices updated: 2/12/02 Version:4/22/02 REF 8-H BOND QUANTITY WORKSHEET.xIs Report Date: 1/19/2010 Site Improvement Bond Quantity Worksheet Existing Future Public Private Band Reduction" Right-of-way Right of Way lmproveme ts 8 Drainage Facilities Quant. Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Complete Cost ROAOIMPROVEMENT No. AC Gnnding 4 ,Ide rachine < 1000sy RI - 1 S 23 00 SY 0 0 00 0 0 00 0 0 00 0 0 00 AC Grindin , 4'wide machine 1000-2000 RI-2 $ 5.75 SY 0 0.00 0 0.00 0 0.00 0 0.00 AC Grinding,4'wide machine>2000sy RI-3 $ 1.38 SY 0 0.00 0 0.00 0 0.00 0 0.00 AC Removal/Disposal/Repair RI-4 $ 41.14 SY 0 0.00 0 0.00 0 0.00 0 0.00 Barricade, pe I RI-5 $ 30.03 LF 0.00 0 0.00 0 0.00 0.00 Barricade,type III ( Permanent) RI-6 $ 45.05 LF 0 0.00 0 0.00 0 0.00 0 0.00 Curb&Gutter, rolled RI-7 $ 13.27 LF 0 0.00 0 0.00 0 0.00 0 0.00 Curb&Gutter, vertical RI-8 $ 9.69 LF 0 0.00 0 0.00 0 0.00 0 0.00 Curb and Gutter, demolition and disposal RI-9 $ 13.58 LF 0 0.00 0 0.00 0 0.00 0 0.00 Curb, extruded asphalt RI-10 $ 2.44 LF 0 0.00 0 0.00 0 0.00 0 0.00 Curb, extruded concrete RI- 11 $ 2.56 LF 0 0.00 0 0.00 0 0.00 0 0.00 Sawcut, as halt, 3"depth RI- 12 $ 1.85 LF 0 0.00 0 0.00 5 9.25 0 0.00 Sawcut, concrete, per 1"depth RI-13 $ 1.69 LF 0 0.00 0 0.00 35 59.15 0 0.00 Sealant, asphalt RI- 14 $ 0.99 LF 0 0.00 0 0.00 0 0.00 0 0.00 Shoulder,AC, (see AC road unit price) RI- 15 $ - SY 0 0.00 0 0.00 0 0.00 0 0.00 Shoulder, ravel, 4"thick RI- 16 $ 7.53 SY 0 0.00 0 0.00 0 0.00 0 0.00 Sidewalk, 4"thick RI- 17 $ 30.52 SY 0 0.00 0 0.00 143 4,364.36 0 0.00 Sidewalk, 4"thick, demolition and dispos RI- 18 $ 27.73 SY 0 0.00 0 0.00 0 0.00 0 0.00 Sidewalk, 5"thick RI- 19 $ 34.94 SY 0 0.00 0 0.00 0 0.00 0 0.00 Sidewalk, 5"thick, demolition and dispos RI-20 $ 34.65 SY 0 0.00 0 0.00 0 0.00 0 0.00 Si n, handicap RI -21 $ 85.28 Each 0 0.00 0 0.00 0 0.00 0 0.00 Stripin , per stall RI -22 $ 5.82 Each 0 0.00 0 0.00 0 0.00 0 0.00 Striping,thermoplastic, (for crosswalk) RI-23 $ 2.38 SF 0 0.00 0 0.00 0 0.00 0 0.00 Striping,4"reflectorized line RI-24 $ 0.25 LF 0 0.00 0 0.00 0 0.00 0 0.00 Page 3 of 7 SUBTOTAL 0.00 0.00 4,432.76 0.00 A-13 Unit prices updated: 2/12/02 Version:4/22/02 REF 8-H BOND QUANTITY WORKSHEET.xIs Report Date: 1/19/2010 Site Im rovement B i W II p ond Quant ty orksheet Exisfing Future Public Private Bond Reduction Right-of-way Right of Way improvements 8 Drainage Facilifies Quant. Unit Price Unit Quant. Cost Quant. Cosf Qu nt. Cost Compfete Cost ROAD SURFACING {4"Rack=2.5 base&1 5"top eourse) For'J3 KCRS{6.5" Rock=5"base& 7.5"top eaurse) For KCRS '93 (additional 2 5" basej add: RS- 1 S 3 60 SY 0 0 00 0 0 00 0 0 00 0 0.00 AC Overla , 1.5"AC RS-2 $ 7.39 SY 0 0.00 0 0.00 0 0.00 0 0.00 AC Overla , 2"AC RS-3 $ 8.75 SY 0 0.00 0 0.00 0 0.00 0 0.00 AC Road; 2", 4" rock, First 2500 SY RS-4 $ 17.24 SY 0 0.00 0 0.00 0 0.00 0 0.00 AC Road, 2",4"rock, Qty. over 2500SY RS-5 $ 13.36 SY 0 0.00 0 0.00 0 0.00 0 0.00 AC Road, 3",4"rock, First 2500 SY RS-6 $ 19.69 SY 0 0.00 0 0.00 0 0.00 0 0.00 AC Road, 3",4"rock, Qty. o er 2500 SY RS-7 $ 15.81 SY 0 0.00 0 0.00 0 0.00 0 0.00 AC Road, 5", First 2500 SY RS-8 $ 14.57 SY 0 0.00 0 0.00 0 0.00 0 0.00 AC Road, 5", Qty. Over 2500 SY RS-9 $ 13.94 SY 0 0.00 0 0.0 0 0.00 0 0.00 AC Road, 6", First 2500 SY RS- 1 $ 16.76 SY 0 0.40 0 0.00 0 0.00 0 0.00 AC Road, 6", Qty. Over 2500 SY RS- 11 $ 16.12 SY 0 0.00 0 0.0 0 0.00 0 0.00 Asphalt Treated Base, 4"thick RS- 1 $ 9.21 SY 0 0.00 0 0.00 0 0.00 0 0.00 Gravel Road, 4"rock, First 2500 SY S- 1 $ 11.41 SY 0 0.00 0 0.00 0 0.00 0 0.00 Gravel Road,4"rock, Qty. over 2500 SY RS- 1 $ 7.53 SY 0 0.00 0 0.00 0 0.00 0 0.00 PCC Road, 5", no base, over 2500 SY RS- 1 $ 21.51 SY 0 0.00 0 0.00 0 0.00 0 0.00 PCC Road, 6", no base, over 2500 SY RS- 1 $ 21.87 SY 0 0.00 0 0.00 0 0.00 0 0.00 Thickened Edge RS- 1 $ 6.89 LF 0 0.00 0 0.00 0 0.00 0 0.00 Page 4 of 7 SUBTOTAL 0.00 0.00 0.00 0.00 A- 13 Unit prices updated: 2/12/02 Version: 4/22/02 REF 8-H BOND QUANTITY WORKSHEET.xIs Report Date: 1/19/2010 Site Im rovement Bond Quantit WorksheetpY Existing Future Public Private Bond Reductian" Right-of-way Right of Way Improvements Drainage Facitities Quant. Unit Price Unit Quant. Cost Quant. Cost Quant Cost Complete Cost DRAINAGE {CPP=Corrugated Plastic Pipe.N12 or Eq ivalent) For Cutvert prices, Average o#4'caver was assumed.Assume per#oratsd PVC is same pnce as soiid pipe. Access Rcad R D D- 1 S 16 74 SY 0 0.00 0 0 00 0 0 00 0 0.00 Bollards-fixed D-2 $ 240.74 Each 0 0.00 0 0.00 0 0.00 0 0.00 Bollards-removable D-3 $ 452.34 Each 0 0.00 0 0.00 0 0.00 0 0.00 CBs include frame and lid) CB Type I D-4 $ 1,257.64 Each 0 0.00 0 0.00 3 3,772.92 0 0.00 CB Type IL D-5 $ 1,433.59 Each 0 0.00 0 0.00 0 0.00 0 0.00 CB Type II,48"diameter D-6 $ 2,033.57 Each 0 0.00 0 0.00 0 0.00 0 0.00 for additional depth over 4' D-7 $ 436.52 FT 0 0.00 0 0.00 0 0.00 0 0.00 CB Type II, 54"diameter D-8 $ 2,192.54 Each 0 0.00 0 0.00 0 0.00 0 0.00 f r additional depth over 4' D-9 $ 486.53 FT 0 0.00 0 O.DO 0 0.00 0 0.00 CB Type II, 60"diameter D- 10 $ 2,351.52 Each 0 0.00 0 0.0o 0 0.00 0 0.00 for additional depth over 4' D- 11 $ 536.54 FT 0 0.00 0 0.00 0 0.00 0 0.00 CB Type II, 72"diameter D- 12 $ 3,212.64 Each 0.00 0 0.00 0 0.00 0 0.00 for additional depth over 4' D- 13 $ 692.21 FT 0 0.00 0 0.00 0 0.00 0 0.00 Through-curb Inlet Framework(Add) D- 14 $ 366.09 Each 0 0.0 0 0.00 0 0.00 0 0.00 Cleanout, PVC, 4" D- 15 $ 130.55 Each 0 0.00 0 0.00 0 0.00 0 0.0o Cleanout, PVC, 6" D- 16 $ 174.90 Each 0 0.00 0 0.00 9 1,574.10 0 0.00 Cleanout, PVC, 8" D- 17 $ 224.19 Each 0 0.00 0 0.00 0 0.00 0 0.00 Culvert, PVC,4" D- 18 $ 8.64 LF 0 0.00 0 0.00 0 0.00 0 0.00 Culvert, PVC,6" D- 19 $ 12.60 LF 0 0.00 0 0.00 244 3,074.40 0 0.00 Culvert, PVC, 8" D-20 $ 13.33 LF 0 0.00 0 0.00 48 639.84 0 0.00 Culvert, PVC, 12" D-21 $ 21.77 LF 0 0.00 0 0.00 0 0.00 0 0.00 Culvert, CMP, 8" D-22 $ 17.25 LF 0 0.00 0 0.40 0 0.00 0 0.00 Culvert, CMP, 12" D-23 $ 26.45 LF 0 0.00 0 0.00 0 0.00 0 0.00 Culvert, CMP, 15" D-24 $ 32.73 LF 0 0.00 0 0.00 0 0.00 0 0.00 Culvert, CMP, 18" D-25 $ 37.74 LF 0 0.00 0 0.00 0 0.00 0 0.00 Culvert, CMP,24" D-26 $ 53.33 LF 0 0.00 0 0.00 0 0.00 0 0.00 Culvert, CMP, 30" D-27 $ 71.45 LF 0 0.00 0 a.00 0 0.00 0 0.00 Culvert, CMP, 36" D-28 $ 112.11 LF 0 0.00 0 0.0a 0 0.00 0 0.00 Culvert, CMP,48" D-29 $ 140.83 LF 0 0.00 0 0.00 0 0.00 0 0.00 Culvert, CMP,60" D-30 $ 235.45 LF 0 0.00 0 0.00 0 0.00 0 0.00 Culvert, CMP, 72" D-31 $ 302.58 LF 0 0.00 0 0.0 0 0.00 0 0.00 Page 5 of 7 SUBTOTAL 0.00 0.00 9,061.26 0.00 A-13 Unit prices updated: 2/12/02 Version:4/22/02 REF 8-H BOND QUANTITY WORKSHEET.xIs Report Date: 1/19/2010 Site Improvement Bond Quantity Worksheet Existing Future Public Private Bond Reduction* Right-of-way Right of Way improvements DRAINAGE CONTINUED Drainage Facilities Quant. No Uni#Price Unit Quant. Cost Quant. Cost Quant. Cost Complete Cost Culvert, Concrete, 8"D-32 S 21.02 LF 0 0 0 0 0 0 0 0 Culvert, Concrete, 12" D-33 $ 30.05 LF 0 0 0 0 0 0 0 0 Culvert, Concrete, 15" D-34 $ 37.34 LF 0 0 0 0 0 0 0 0 Culvert, Concrete, 18" D-35 $ 44.51 LF 0 0 0 0 0 0 0 0 Culve t, Concrete, 24" D-36 $ 61.07 LF 0 0 0 0 0 0 0 0 Culvert, Concrete, 30" D-37 $ 104.18 LF 0 0 0 0 0 0 0 0 Culvert, Concrete, 36" D-38 $ 137.63 LF 0 0 0 0 0 0 0 0 Culvert, Concrete, 42" D-39 $ 158.42 LF 0 0 0 0 0 0 0 0 Culvert, Concrete, 48" D-40 $ 175.94 LF 0 0 0 0 0 0 0 0 Culvert. CPP. 6" D-41 $ 10.70 LF 0 0 0 0 0 0 0 0 Culvert, CPP, 8" D-42 $ 16.10 LF 0 0 0 0 0 0 0 0 Culvert, CPP, 12" D-43 $ 20.70 LF 0 0 0 0 0 0 0 0 Culvert, CPP, 15" D-44 $ 23.00 LF 0 0 0 0 0 0 0 0 Culvert, CPP, 18" D-45 $ 27.60 LF 0 0 0 0 0 0 0 0 Culvert, CPP,24" D-46 $ 36.80 LF 0 0 0 0 0 0 0 0 Culvert, CPP, 30" D-47 $ 48.30 LF 0 0 0 0 0 0 0 0 Culvert, CPP, 36" D-48 $ 55.20 LF 0 0 0 0 0 0 0 0 Ditchin D-49 $ 8.08 CY 0 0 0 0 0 0 0 0 Flow Dispersal Trench (1,436 base+) D-50 $ 25.99 LF 0 0 0 0 0 0 0 0 French Drain (3'depth) D-51 $ 22.60 LF 0 0 0 0 0 0 0 0 Geotextile. laid in trench, polypropylene D-52 $ 2.40 SY 0 0 0 0 0 0 0 0 Infiltration pond testin D-53 $ 74.75 HR 0 0 0 0 0 0 0 0 Mid-tank Access Riser, 48"dia, 6'deep D-54 $ 1,605.40 Each 0 0 0 0 0 0 0 0 Pond Overflow Spillway D-55 $ 14.01 SY 0 0 0 0 0 0 0 0 Restrictor/Oil Separator, 12" D-56 $ 1,045.19 Each 0 0 0 0 0 0 0 0 Restrictor/Oil Separator, 15" D-57 $ 1,095.56 Each 0 0 0 0 0 0 0 0 Restrictor/Oil Separator, 18" D-58 $ 1,146.16 Each 0 0 0 0 0 0 0 0 Riprap, placed D-59 $ 39.08 CY 0 0 0 0 0 0 0 0 Tank End Reducer(36"diameter) D-60 $ 1,000.50 Each 0 0 0 0 0 0 0 0 Trash Rack, 12" D-61 $ 211.97 Each 0 0 0 0 0 0 0 0 Trash Rack, 15" D-62 $ 237.27 Each 0 0 0 0 0 0 0 0 Trash Rack, 18" D-63 $ 268.89 Each 0 0 0 0 0 0 0 0 Trash Rack. 21" D-64 $ 306.84 Each 0 0 0 0 0 0 0 0 Page 6 of 7 SUBTOTAL 0 0 0 0 A-13 Unit prices updated: 2/12/02 Version:4/22/02 REF 8-H BOND QUANTITY WORKSHEET.xIs Report Date: 1/19/2010 Site Improvement Bond Quantity Worksheet Existing Future Public Private Bond Reduction` Right-of-way Right of Way Improvements Drainage Facilities Quant. Untt Priee Unii Quant. Price Quant, Cosf Quant Cost Comptete Cost PARKING LOT SURFACING No. 2"AC,2"top course rock&4"borrow PL- 1 $ 15.84 SY 0 0 0 0 0 0 2"AC, 1.5" top course&2.5"base cour PL-2 $ 17.24 SY 0 0 0 0 0 0 4"select borrow PL-3 $ 4.55 SY 0 0 0 0 0 0 1.5"top course rock 8 2.5"base course PL-4 $ 11.41 SY 0 0 0 0 0 0 UTILITY POLES 8 STREET LIGHTING Utility pole€eloeatian costs must be accompanied by Franshise Utility's Gost Statement Utility Pole(s) Relocation UP-1 Lump Sum 0 0 Street Light Poles w/L minaires UP-2 Each 0 0 0.00 0.00 0 0.00 i zY 5 k. 3 { 5 :_ No. WI - 1 0 0.00 0.00 0.00 WI-2 0 0.00 0.00 0.00 WI-3 0 0.00 0.00 0.00 WI-4 0 0.00 0.00 0.00 WI-5 0 0.00 0.00 0.00 WI-6 0 0.00 0.00 0.00 WI-7 0 0.00 0.00 0.00 WI-8 0 0.00 0.00 0.00 WI-9 0 0.00 0.00 0.00 vw-io 0 0.00 0.00 0.00 SUBTOTAL 0.00 0.00 0.00 0.00 SUBTOTAL(SUM ALL PAGES):0.00 0.00 16,182.23 0.00 30%CONTINGENCY 8 MOBILIZATION:O.OQ 0.00 4.854.67 0.00 GRANDTOTAL:0.00 0.00 21.036.90 0.00 COLUMN:B C D E Page 7 of 7 A-13 Unit prices updated: 2/12/02 Version:4/22/02 REF 8-H BOND QUANTITY WORKSHEET.xis Report Date: 1/19/2010 KING COUNTY, WASHINGTON, SURFACE WA7'ER DESIGN MAVUAL APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES This appendix contains the maintenance requirements for the following typical stormwater control facilities and components: No. 1 —Detention Ponds(p.A-2) No.2—Infiltrarion Facilities(p.A-3) No. 3—Detention Tanks and Vaults(p.A-5) No.4—Control Structure/Flow Restrictor(p.A-7) No.5—Catch Basins and Manholes(p.A-9) No.6—Conveyance Pipes and Ditches(p.A-11) No. 7—Debris Barriers(e.g.,Trash Racks)(p. A-12) No. 8—Energy Dissipaters(p.A- 13) No.9—Fencing{p.A-14) No. 10—GatesBollards/Access Barriers(p.A-15) No. 11—Grounds(Landscaping)(p.A-16) No. 12—Access Roads(p.A-17) No. 13—Basic Biofiltration Swale(grass)(p.A-18) No. 14—Wet Biofiltration Swale(p.A-19) No. l 5—Filter Strip(p.A-20) No. 16—Wetpond(p.A-21) No. 17—Wetvault(p.A-23) No. 18—Stormwater Wetland(p.A-24) No. 19—Sand Filter Pond(p.A-26) No.20—Sand Filter Vault(p.A-28) No.21 —Stormfilter(Carnidge Type}(p.A-30) No.22—Baffle OiUWater Separator(p.A-32) No. 23—Coalescing Plate Oil/Water Separator(p.A-33) A-14 No. 24—Catch Basin Insert(p. A-35) 2009 Surface Water Design Manual—Appendix A 1/9/2009 A-1 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL,COi TVEYANCE,Ai ID WQ FACII,ITIES NO. 5-CATCH BASINS AND MANHOLES Maintenance Defect or Problem Condition When Malntenance is Needed Results Expected When Component Maintenance is Perfortned Structure Sediment Sediment exceeds 60°k of the depth from the Sump of catch basin contains no bottom ofthe catch basin to the invert of the sediment. lowest pipe into or out of the catch basin or is within 6 inches of the invert of the lowest pipe into or out of the catch basin. Trash and debris Trash or debris of mare than'/:cubic foot which No Trash or debris blocking or is located immediately in front of the catch basin potentially blocking entrance to opening or is blocking capaaty of the catch basin catch basin. by more than 10°. Trash or debris in the catch basin that exceeds No Vash or debris in the catch basin. the depth from the bottom of basin to invert the lowest pipe into or out of the basin. Dead animals or vegetation that could generate No dead animals or vegetation odors that could cause complaints or dangerous present within catch basin. gases(e.g.,methane). Deposfts of garbage exceeding 1 cubic foot in No condition present which would volume. attract or support the breeding of insects or rodents. Damage to frame Comer of frame extends more than'/.inch past Frame is even with curb. andlor top slab curb face iMo the street(If applipble). Top slab has hoies larger than 2 square inches or Top slab is free of holes and cracks. cracks wider than'/.inch. Frame not sitting flush on top slab,i.e., Frame is sitting flush on top slab. separation of more than'/.inch of the frame from the top slab. Cracks in walls or Cracks wider than Y:inch and longer than 3 feet, Catch basin is sealed and bottom any evidence of sal particles entering catch structurally sound. basin through cracks,or maintenance person judges that catch basin is unsound. Cracks wider than'/inch and longer than 1 foot No cracks more than'/d inch wide at at the joint of any inleUouUet pipe or any evidence the joint of inleUoutlet pipe. of soil particles entering catch basin through cradcs. SettlemenU Catch basin has settled more than 1 inch or has Basin replaced or repaired to design misalignment rotated more than 2 inches out of alignment standarcls. Damaged pipe joints Cracks wider than'/:-inch at the joint of the No cracks more than'/.-inch wide at inleUoutlet pipes or any evidence ofsoil entering the joint of inleUouUet pipes. the catch basin at the joint of the inlet/outlet pipes. Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of pollution as oil,gasdine,concrete slurties or paint. according to applicable regulations. 5ource control BMPs implemented if appropriate. No contaminants present other than a surface oil film. InIeUOutlet Pipe Sediment Sediment filling 20%or more of the pipe. Inlet/ouUet pipes Gear of sediment. accumuladon Trash and debris Trash and debris accumulated in inleUoutlet No trash or debris in pipes. pipes(indudes floatables and non-floatablesj. Damaged Cracks wider than'/rinch at the joint of the No cracks more than'/.-inch wide at inlet/ouUet pipes or any evidence of soil entering the joint of the inleUoutlet pipe. at the joints of the inleUoutlet pipes. A-14 2009 Surface Water Design Manual—Appendix A 1/9/2009 A-9 APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL,CONVEYANCE,AND WQ FACILI'TIES NO. 5-CATCH BASINS AND MANHOLES Maintenance Defect or Problem Condltion When Maintenance is Needed Results Expected When Component Maintenance is PerFormed Metal Grates Unsafe grate opening Grate with opening wider ihan'le inch. Grate opening meets design Catch Basins) standards. Trash and debris Trash and debris that is blocking more than 20% Grate free of trash and debris. of grate surface. footnote to guidelines for disposal Damaged or missing Grate missing or broken member(s)of the grate. Grate is in place and meets design My open structure requires urgern standards. maintenance. Manhole Cover/Lid Coverllid not in place CoverAid is missing or only partially in place.CoverAid protects opening to Any open structure requires urgent structure. maintenance. Lodcing mechanism Mechanism cannot be opened by one Mechanism opens with proper tools. Not Working maintenance person with proper tools.Bolts cannot be seated. Self-locking coverAid does not work. Coverllid difficutt to One maintenance person cannot remove CoverJlid can be removed and Remove cover/lid after applying SO Ibs.of lift.reinstalled by one maintenance person. A-14 1/9/2009 2009 Surface Water Design Manual—Appendix A A-]0 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL,CONVEYANCE,AND WQ FACII,ITIES NO. 6-CONVEYANCE PIPES AND DITCHES Mafntenance Defect or Problem Canditions When Malntenance Is Needed Results Expected When Component Maintenance is Performed Pipes Sediment 8 debris Accumulated sediment or debris that exceeds Water flows freely through pipes. accumulation 20%of the diameter of the pipe. Vegetation/roats Vegetationlroots that reduce free movement of Water flows freely through pipes. water through pipes. Contaminants and My evidence of contaminants or pollution such Materials removed and disposed of pollution as oil,gasoline,concrete slurries or paint. according to applicable regulations. Source conVol BMPs implemented if appropriate. No contaminants present other than a surtace oil film. Damage to protective Protective coatlng is damaged;rust or corrosion Pipe repaired or replaced. coating or corrosion is weakening the structural integrity of any part of pipe. Damaged Any dent that decreases the cross section area of Pipe repaired or replaced. pipe by more than 20%or is determined to have weakened structural integrity of the pipe. Ditches Trash and debris Trash and debris exceeds 1 cubic foot per 1,000 Trash and debris deared from square feet of ditch and slopes. ditches. Sediment Accumulated sediment that exceeds 20%of the Ditch deaned/flushed of all sediment accumulation design depth. and debris so that it matches design. Noxious weeds Any noxious or nuisance vegetation which may Noxious and nuisance vegetation constitute a hazard to County personnel or the removed according to applicable public. regulations. No danger of noxious vegetation where County personnel or the public might normally be. Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of pollution as oil,gasoline,concrete slurties or paint. according to applicabfe regulations. Source control BMPs implemented ff appropriate. No contaminants present other than a surface oil film. Vegetation Vegetation that reduces free movement of water Water flows freely through ditches. through ditches. Erosion damage to My erosion observed on a ditch slope. Slopes are not eroding. slopes Rodc lining out of One layer or less of rock exists above native soil Repiace rocks to design standards. place or missing(If area 5 square feet or more,any exposed native Applicable) soil. A-14 2009 Surface Water Design Manual—Appendix A 1/9/2009 A-1 I APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL,CONVEYANCE,AND WQ FACILITIES NO. 11 -GROUNDS (LANDSCAPING) Maintenance Defect or Probiem Conditions When Maintenance is Needed Results Expected When Component Maintenance is Perfortned Site Trash or litter My trash and debris which exceed 1 cubic foot Trash and debris deared from site, per 1,OQo square feet(this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Noxious weeds Any no ous or nuisance vegetation which may Noxious and n isance vegetation constitute a hazard to County personnel or the removed according to applicable public. regulations, No danger of naxious vegetation where County personnel or the public might normally be. Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of pollution as oil,gasoline,concrete slurries or paint. according to appiiqble regulations. Source controi BMPs implemented if appropriate. No conhaminants present other than a surface oil film. il Grasslgroundcover Grass or groundcover exceeds 18 inches in Grass or groundcover mowed to a I height height no greater than 6 inches. Trees and Shrubs Hazard Any tree or limb of a tree identfied as having a No hazard trees in facility. I potential to fall and cause property damage or threaten human IHe. A hazard tree identified by a qualified arbo ist must be removed as soon as possible. Damaged Limbs or parts of trees or shrubs that are split or Trees and shrubs with less than 5% broken which affect more than 25 0 of the total of total foliage with split or broken foliage ofthe tree or shrub. limbs. Trees or shrubs that have been blown down or No blown down vegeta6on or knodced over. knocked over vegetation. Trees or shn bs free of injury. Trees or shrubs which are not adequately Tree or shrub in place and supported or are leaning over,causing exposure adequately supported;dead or ofthe roots.diseased trees removed. II A-14 1/9/2009 2009 Surface Water Design Manual-Appendix A A-16 APPENDIX A MAIIVTENANCE REQUII2EMENTS FOR FLOW CONTROL,CONVEYANCE,AND WQ FACILITIES NO.24-CATCH BASIN INSERT Maintenance Defect.or Problem Conditions When Maintenance is Needed Resuks Expected When Component Maintenance is Performed Media lnsert sible Oil sible oil sheen passing through media Media inset replaced. Insert does not fit Flow gets into catch basin without going through All flow goes through media. catch basin properly media Filter media plugged Filter media plugged. Flow through fitter media is normal. Oil absorbent media Media oil saturated.Oil absorbent media replaced. saturated Water saturated Catc basin insert is saturated with water,which Insert replaced. no longer has the qpacity to absorb. Service life exceeded Regular interval replacement due to typical Media replaced at manufacturers average life of inedia insert product,typically one recommended interval. month. Seasonal When storms occur and during the wet season. Remove,clean and replace or install maintenance new insert after major storms, monthly during the wet season or at manufacturers recommended interval. A-14 2009 Surface Water Design Manual—Appendix A 1!9l2009 A-35 Appendix B Cascade Elementary Topographic Map Prepared by Townsend-Chastain &Assoc., Inc. October 6, 1992 Cascade Elementary School Site Drainage Plan Prepared by RoseWater Engineering, Inc. 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