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Home My WebLink AboutF_Lindbergh HS Parking Lot_Technical Information Report_170721.pdf Civil Engineers ● Structural Engineers ● Landscape Architects ● Community Planners ● Land Surveyors ● Neighbors Technical Information Report PREPARED FOR: Renton School District 403 300 SW 7th Street Renton, WA 98057 PROJECT: Lindbergh High School South Parking Lot Improvements 16740 128th Avenue SE Renton, WA 98058 2170057.10 PREPARED BY: Brian Schend, PE Project Engineer REVIEWED BY: William J. Fierst, PE Senior Project Manager Sean M. Comfort, PE Principal DATE: May 2017 Revised July 2017 SURFACE WATER UTILITY rstraka 07/21/2017 DEVELOPMENT ENGINEERING IFitz-James 07/21/2017 Technical Information Report PREPARED FOR: Renton School District 403 300 SW 7th Street Renton, WA 98057 PROJECT: Lindbergh High School South Parking Lot Improvements 16740 128th Avenue SE Renton, WA 98058 2170057.10 PREPARED BY: Brian Schend, PE Project Engineer REVIEWED BY: William J. Fierst, PE Senior Project Manager Sean M. Comfort, PE Principal DATE: May 2017 Revised July 2017 I hereby state that this Technical Information Report for the Lindbergh High School South Parking Lot Improvements project has been prepared by me or under my supervision, and meets the standard of care and expertise that is usual and customary in this community for professional engineers. I understand that City of Renton does not and will not assume liability for the sufficiency, suitability, or performance of drainage facilities prepared by me. Technical Information Report Lindbergh High School South Parking Lot Improvements 2170057.10 Table of Contents Section Page 1.0 Project Overview ............................................................................................................................ 1 1.1 Purpose and Scope............................................................................................................. 1 1.2 Existing Conditions.............................................................................................................. 1 1.3 Post-Development Conditions ............................................................................................ 1 1.4 Drainage Basins .................................................................................................................. 1 1.5 Soils .................................................................................................................................... 2 1.6 Sensitive Areas ................................................................................................................... 2 2.0 Conditions and Requirements Summary .................................................................................... 2 2.1 CR 1 – Discharge at the Natural Location .......................................................................... 2 2.2 CR 2 – Offsite Analysis ....................................................................................................... 2 2.3 CR 3 – Flow Control ............................................................................................................ 2 2.4 CR 4 – Conveyance System ............................................................................................... 3 2.5 CR 5 – Erosion and Sediment Control ................................................................................ 3 2.6 CR 6 – Maintenance and Operations.................................................................................. 3 2.7 CR 7 – Financial Guarantees and Liability ......................................................................... 3 2.8 CR 8 – Water Quality .......................................................................................................... 3 2.9 CR 9 – Onsite BMPs ........................................................................................................... 4 2.10 SR 1 – Other Adopted Requirements ................................................................................. 4 2.11 SR 2 – Flood Hazard Delineation ....................................................................................... 4 2.12 SR 3 – Flood Protection Facilities ....................................................................................... 5 2.13 SR 4 – Source Control ........................................................................................................ 5 2.14 SR 5 – Oil Control ............................................................................................................... 5 2.15 SR 6 – Aquifer Protection Area ........................................................................................... 5 3.0 Offsite Analysis .............................................................................................................................. 5 3.1 Task 1 – Study Area Definition and Maps........................................................................... 5 3.2 Task 2 – Resource Review ................................................................................................. 5 3.3 Task 3 – Field Inspection .................................................................................................... 6 3.4 Task 4 – Drainage System Description and Problem Descriptions .................................... 8 Technical Information Report Lindbergh High School South Parking Lot Improvements 2170057.10 4.0 Flow Control, Low Impact Development (LID) and Water Quality Facility Analysis and Design ............................................................................................................................................. 8 4.1 Existing Site Hydrology (Part A) .......................................................................................... 8 4.2 Developed Site Hydrology (Part B) ..................................................................................... 9 4.3 Performance Standards (Part C) ...................................................................................... 10 4.4 Flow Control System (Part D) ........................................................................................... 10 4.5 Water Quality System (Part E) .......................................................................................... 10 5.0 Conveyance System Analysis and Design ................................................................................ 11 6.0 Special Reports and Studies ...................................................................................................... 11 7.0 Other Permits ............................................................................................................................... 11 8.0 Construction Stormwater Pollution Prevention Plan (CSWPPP) Analysis and Design ....... 11 9.0 Bond Quantities, Facility Summaries, and Declaration of Covenant ..................................... 12 10.0 Operations and Maintenance Manual ........................................................................................ 12 11.0 Conclusion .................................................................................................................................... 12 Technical Information Report Lindbergh High School South Parking Lot Improvements 2170057.10 Appendices Appendix A Figures 1-1 ............. TIR Worksheet 1-2 ............. Vicinity Map 1-3 ............. Soil Map 3-1 ............. Downstream Analysis 3-2 ............. Off-Site Analysis Drainage System table 3-3 ............. Erosion Hazards Map 3-4 ............. Steep Slopes Map 3-5 ............. Slide Hazard Map 3-6 ............. Flood Hazard Map 3-7 ............. Coal Mine Hazard Map 3-8 ............. Aquifer Protection Map 3-9 ............. FIRM Rate Map 4-1 ............. Existing Basin Map 4-2 ............. Developed Basin Map 4-3 ............. Filterra GULD Approval 4-4 ............. Areas Requiring Treatment 4-5 ............. Areas Treated 5-1 ............. Conveyance Basin Map 9-1 ............. Bond Quantity Worksheet 9-2 ............. Flow Control and Water Quality Facility Summary Sheet and Sketch 9-3 ............. Declaration of Covenant Appendix B Geotechnical Report Appendix C WWHM Report Appendix D Conveyance Calculations Appendix E Operations and Maintenance Manual Technical Information Report Lindbergh High School South Parking Lot Improvements 1 2170057.10 1.0 Project Overview 1.1 Purpose and Scope This report accompanies the civil engineering plans and documents for the Renton School District’s Lindbergh Pool at Lindbergh High School located at 16740 128th Ave SE in Renton, Washington. The project site encompasses Tax Parcel 2823059004 in the city of Renton, King County, Washington. The parcel is located within the Northeast Quarter of Section 28, Township 23 North, Range 5 East, of the Willamette Meridian. See Figure 1-2 for a Site Vicinity Map. The Renton School District (RSD) proposes to replace a failing portion of the school’s parking lot. The project will remove the existing pavement and subgrade and construct new pavement. The project site is bounded by homes on SE 164th St on the north, homes on 132nd Pl SE to the east, Renton Park Elementary School and a church to the south, and 128th Ave SE to the west. The parking area to be replaced is located adjacent to the Lindbergh Pool. Most of the surrounding areas are single-family residential, but there are significant areas of open space nearby. The 2016 City of Renton Surface Water Design Manual (CORSWDM) establishes the methodology and design criteria used for the project. 1.2 Existing Conditions Existing improvements on the site include a high school building, athletic fields, pool, and parking areas. The area affected by the proposed work is a paved parking area, where a portion of the pavement has failed due to groundwater intrusion. The entire parcel is 22.7 acres, but the area of work is only 1.06 acres. The affected drainage basin is 1.35 acres, as some offsite areas will be directed to the new drainage facilities. 1.3 Post-Development Conditions RSD proposes to replace a portion of the existing parking lot. The area to be replaced is the bus loading area next to the pool building, the first row of parking to the west of it, and the south half of the access road leading to it. The entire pavement section, including subgrade, will be replaced. 1.4 Drainage Basins The site is located within the Lower Cedar River Drainage Basin, as delineated by the City of Renton Water Features Map. The area of work is 1.06 acres, the site drainage area is 1.35 acres, and the drainage area modeled is 1.05 acres. These areas are explained in detail in Section 4.0. Land Cover Areas Aimp (AC) Aperv (AC) Total (AC) Existing 1.20 0.15 1.35 Proposed 1.20 0.15 1.35 The engineered drainage system for the proposed site will not alter existing discharge locations from the site. Runoff travels through pipes around the north and east side of the high school track and exits the site to the east, discharging to Molasses Creek. Technical Information Report Lindbergh High School South Parking Lot Improvements 2 2170057.10 1.5 Soils The soils have been classified as Alderwood Gravelly Sandy Loam by the USDA Natural Resources Conservation Service. See Figure 1-4, Soil Map. Slopes vary from 0 to 10 percent. A Geotechnical Engineering Report was prepared in June 2017 by Associated Earth Sciences, Inc. The soil borings show the native soils to be Vashon Lodgement Till, with some areas having up to 6 feet of structural fill above the native soils . The existing pavement was laid directly on the fill or native soils, with no base or top course. The soil borings also found perched groundwater at shallow depths. Due to the high groundwater, infiltration is not feasible at this site. The Geotechnical Engineering Report is included in its entirety as Appendix B. 1.6 Sensitive Areas There are no known wetlands on or in the vicinity of the site. We reviewed maps provided by the city of Renton and concluded that this site is located in the Cedar Valley Sole Source Aquifer Review Area, but otherwise is not in any recognized sensitive area. These maps are discussed in more detail in Section 3.2. 2.0 Conditions and Requirements Summary The project triggers Full Drainage Review because it results in more than 7,000 square feet of land disturbing activity and over 2,000 square feet of new and/or replaced impervious surface. Below is a summary of how the proposed project will meet the Core Requirements (CR) and how it will meet applicable Special Requirements (SR). 2.1 CR 1 – Discharge at the Natural Location The proposed work site has a single discharge point to a catch basin northeast of the parking area, which is on high school property. This discharge point will be maintained by this project. See Section 3.0 for further description of the storm drainage system beyond the existing discharge location. 2.2 CR 2 – Offsite Analysis AHBL staff performed a Level One Downstream Analysis for the project on May 5, 2017. The analysis included:  Defining and mapping the study area.  Reviewing available information on the study area.  Field inspecting the study area.  Analyzing the existing drainage system, including its existing and predicted problems, if any. Please refer to Section 3.0 for the full offsite analysis. 2.3 CR 3 – Flow Control Because the existing parking lot will replace the entire subgrade, it qualifies as replaced impervious surface. The Western Washington Hydrology Model (WWHM) was used to model the existing stormwater conditions and design a detention system for the replaced parking area. Technical Information Report Lindbergh High School South Parking Lot Improvements 3 2170057.10 See the WWHM calculation results in Appendix C. According to the 2016 CORSWDM Reference 15-A, Flow Control Application Map, the site is subject to the Flow Control Duration Standard (Forested Conditions). This standard requires the post-development stream durations to match those of the forested condition from 50 percent of the 2-year storm through the 50-year storm, as well as matching 2-year and 10-year flows. Flow control will be provided through the use of buried detention pipes. WWHM is used to model the hydrologic conditions. Detention Pipe Sizing Results Detention Pipe Diameter (IN) Detention Pipe Length (LF) Storage Volume (CF) Detention Tank 60 885 17,400 2.4 CR 4 – Conveyance System The replaced parking areas will be collected in catch basins and conveyed in pipes to the detention and treatment facilities. Based on Section 1.2.4.1 of the CORSWDM, 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 will not overtop in the 100-year peak storm event, and there will be more than 6 inches of freeboard between the design water surface and structure grate during the 25-year peak storm event. No severe flooding problems or severe erosion problems will be created or aggravated in the 100-year storm event. See Appendix D for detailed calculations. 2.5 CR 5 – Erosion and Sediment Control Onsite land disturbance will consist of clearing the work site, demolition, and regrading. Erosion and sediment control will be provided with the use of temporary and permanent seeding within the work limits, silt fence or wattles, inlet sediment protection, stabilized construction entrance, and sedimentation ponds. See Section 8.0 for Construction Stormwater Pollution Prevention Plan (CSWPPP) analysis and design. 2.6 CR 6 – Maintenance and Operations Maintenance and operations of all drainage facilities will be maintained by the RSD. The project proposes a new detention facility, water quality facility, and new area drains and catch basins onsite. Operations and Maintenance are detailed Appendix D. 2.7 CR 7 – Financial Guarantees and Liability This project will provide financial guarantees and liability per City of Renton requirements. See the City of Renton Bond Quantities Worksheet in Figure 9-1. 2.8 CR 8 – Water Quality Because the existing parking lot pavement will be replaced to the existing subgrade, it qualifies as replaced impervious surface. The replaced parking lot will be pollution generating impervious surfaces (PGIS). Onsite flows will be treated to meet the performance standard of the Enhanced Basic Water Quality Menu by utilizing Contech Filterra structures. Technical Information Report Lindbergh High School South Parking Lot Improvements 4 2170057.10 Filterra structures will be provided for storm water treatment for pollution generating surfaces. See Figure 4-3 for the Filterra design guidelines per Department of Ecology approval. See Appendix C, WWHM Report, for sizing. 2.9 CR 9 – Onsite BMPs This project proposes work on a single site and the disturbed area exceeds 22,000 square feet; therefore, for CR 9, it must meet the requirements for Large Lot BMPs, as described in Section 1.2.9.2.2 in the CORSWDM. Due to the inability to infiltrate, meeting the LID performance requirement is not feasible. The onsite BMPs required by the City are addressed below: 1. Full Dispersion: This option is not feasible, as the project site and its surroundings are fully developed, and there are no forested areas to disperse to. 2. Full Infiltration of Roof Runoff: This does not apply, as no new roofs are proposed. 3. Full Infiltration, Limited Infiltration, Bioretention, or Permeable Pavement: High groundwater and till soils on this site make infiltration infeasible, which makes Full Infiltration, Limited Infiltration, Bioretention, and Permeable Pavement all infeasible. 4. Basic Dispersion: The CORSWDM lists four options for meeting Basic Dispersion. Splash Blocks do not apply, as no new roof areas are proposed. Rock Pads are infeasible, as this project has far more than 700 square feet of impervious surface. Gravel Filled Trenches are infeasible, as a 50-foot trench can only disperse 3,500 square feet, which would require this site to have more than ten such trenches, and there is not enough space on the site for the required vegetated flow paths for that number of trenches. Sheet Flow is infeasible, as the current layout of the site is not designed to allow this ; the site will not be reconfigured by this project and there is no vegetated area available to sheet flow to. 5. Reduced Impervious Surface Credit, Native Growth Retention Credit, or Tree Retention Credit: Restricted Footprint, Minimum Disturbance Foundation, and Open Grid Decking do not apply, as no buildings are proposed, while a Wheel Strip Driveway is not feasible for a driveway that serves busses, so the Reduced Impervious Surface Credit is not feasible. The Native Growth Retention Credit is not feasible, as there is no native growth to retain on this site. The Tree Retention Credit is not feasible, as there are not enough existing trees in the work area to meet the requirement. 6. Soil Moisture Holding Capacity: All pervious surfaces will be prepared in accordance with the soil amendment BMP described in Section C.2.13 of the CORSWDM. 7. Perforated Pipe Connection: This does not apply, as no new roofs are proposed. 2.10 SR 1 – Other Adopted Requirements The project is included in the Lower Cedar River Drainage Basin. City and County basin requirements will be followed where applicable. 2.11 SR 2 – Flood Hazard Delineation The proposed project is not in or adjacent to the 100-year floodplain. See Figure 3-9 for the FIRM Rate Map. Technical Information Report Lindbergh High School South Parking Lot Improvements 5 2170057.10 2.12 SR 3 – Flood Protection Facilities This project does not rely on existing flood protection facilities nor will it modify or construct new flood protection facilities. 2.13 SR 4 – Source Control The proposed project is a parking lot, while the site is a school. T herefore, it does not fit the definition of a commercial, industrial, or multi-family site for source control purposes. 2.14 SR 5 – Oil Control The site does not meet high use criteria and is not subject to oil control measures. 2.15 SR 6 – Aquifer Protection Area This project is located in the Cedar River Sole Source Aquifer zone. This area requires additional treatment before stormwater is infiltrated. Since infiltration is not possible for this project, this does not change the design. 3.0 Offsite Analysis 3.1 Task 1 – Study Area Definition and Maps RSD proposes to replace a portion of the existing parking lot at Lindbergh High School . The project site lies within the Lower Cedar River Drainage Basin, as delineated by the King County Water Features Map. There are upstream areas from other areas of the high school property that drain to the project site, but no areas on adjacent properties. The project has a single discharge point to an existing catch basin on high school property. From this discharge point, stormwater is conveyed through a series of catch basins and pipes through the high school property. The drainage runs east along the northwest side of the athletic track. From there, the drainage turns southeast along the northeast side of the track. The drainage exits the high school property, and the city of Renton, through a pipe that runs under a gravel walkway at the far southeast corner of the school. This point is approximately 0.25 mile downstream from the project discharge point. The stormwater enters the King County right-of-way on 132nd Pl SE at a catch basin at the low point of the road on the west side. It then crosses to a catch basin on the east side of the road that includes a control structure. Flow then continues east to discharge to Molasses Creek. Molasses Creek flows in a northerly direction through residential back yards before entering a culvert inlet north of SE 166th St. The stream travels through this pipe for approximately 1,000 feet and then discharges to a ravine. This ravine ultimately outfalls to the Cedar River. See Figure 3-1, Downstream Analysis, for a map of the downstream drainage. 3.2 Task 2 – Resource Review The following resources were reviewed to discover any existing or potential problems in the study area. All maps provided by the City of Renton extend into unincorporated King County. Technical Information Report Lindbergh High School South Parking Lot Improvements 6 2170057.10  Drainage system maps: We consulted the City of Renton online mapping system and an as-built map of the high school prepared by Patrick Harron & Associates, prepared in 2003. We found the City of Renton mapping to be accurate while the map prepared by Harron had numerous inaccuracies. The City of Renton mapping also extends into unincorporated King County, and we found it to be accurate there as well.  Adopted Basin Plans: The project site lies within the Lower Cedar River Drainage Basin. Requirements for the Lower Cedar River Basin Plan will be followed where applicable.  Offsite Analysis Reports: AHBL staff could not locate offsite analysis reports for projects near the Lindbergh High School project site.  FEMA Map: FEMA Flood Insurance Rate Map 53033C0983F, dated May 16, 1995 (see Figure 3-9), indicates that the project site lies outside the categorized flood zones.  City of Renton Sensitive Areas Landslide Hazard Map (see Figure 3-5): The project site is not located within the sensitive areas Landslide Hazard Area.  City of Renton Aquifer Protection Zone Map (see Figure 3-6): the project site is located in the Cedar Valley Sole Source Aquifer Review Area.  City of Renton Coal Mine Hazard Map (see Figure 3-7): The project site is located outside the coal mine hazard area.  City of Renton Erosion Hazard Map (see Figure 3-3): Molasses Creek, downstream from the site, is an erosion hazard area.  City of Renton Flood Hazard Map (see Figure 3-6): The project site is not within a flood hazard area.  City of Renton Steep Slopes Map (see Figure 3-4): The steep slopes map shows some areas of up to 25% slopes. However, most of the area is less than 15% slopes.  King County Drainage Complaint Records: King County maintains a log of drainage complaints they have received, accessible through their online mapping system. There is a history of complaints in the development east of the school. There have been several complaints of flooding throughout the years, m ost of them caused by clogged inlets. There have also been multiple sinkhole reports, in 2009, 2015, and an existing sinkhole that the county is currently repairing. There are also complaints of soggy yards.  Soils Information: Site soils have been classified by the Soil Survey of King County Area, Washington as Alderwood Gravelly Sandy Loam (AgV). Downstream areas also include Everett very gravelly sandy loam (EvC) and Seattle Muck (Sk). See Figure 1-4 for NRCS soil maps. See Appendix B for the Associated Earth Sciences Incorporated Geotechnical Report. 3.3 Task 3 – Field Inspection On May 5, 2017, AHBL staff performed a field visit of the downstream drainage system receiving stormwater runoff from the proposed Lindbergh High School parking replacement. 1. Investigate any problems reported or observed during the resource review: The City of Renton and King County maps identify Molasses Creek as an erosion hazard, and the King Technical Information Report Lindbergh High School South Parking Lot Improvements 7 2170057.10 County drainage complaints log shows a history of sinkholes. At the time of the site visit, a culvert inlet located north of SE 166th St had failed and caused a sinkhole of approximately 5 feet in diameter to open, and the creek was seen flowing into the sinkhole. We also confirmed the soggy yards reported to King County. Flooding was not present at the time of our visit. 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 : We found numerous problems with the downstream drainage on the site visit. The portion on high school property was found to be in need of maintenance, with several catch basin outlets submerged and full of debris, while others had TESC inserts, despite no sign of construction nearby. Along Molasses Creek, we observed that the surrounding ground was soaking wet at all areas near the creek, despite the fact that these areas were above the creek’s well-defined banks. As noted above, the creek entered a sinkhole north of SE 166th St where a culvert inlet had failed. On 132nd Pl SE, we noted several areas where groundwater was bubbling up through both sidewalks and private driveways. Most houses on this street had visible drainage pipes discharging onto the sidewalk, and one had flows of approximately 5 gallons per minute (gpm), despite the fact that there was no rain during the visit. These flows have visibly damaged the driveways and sidewalks by eroding away the concrete. 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 for the site: The uppermost section of the downstream path is on the high school site and is used as an athletic field and track. Upon leaving the high school, it enters an area of single-family housing. The study area ends at an open space area. Most of the site is flat, but there were areas of slopes, with a maximum slope of around 12 percent. 7. Collect information on pipe sizes, channel characteristics, drainage structures, and relevant critical areas (e.g., wetlands, stream, and steep slopes): Our observations found that most pipes were 12-inch in diameter. The culverts serving Molasses Creek were 36-inch pipes. We identified a control structure on the downstream path on 132 nd Place SE. The downstream path flows through Molasses Creek, which is approximately 5 feet wide. King County classifies the creek area as an erosion hazard area, but not as a wetland. 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): While onsite, we talked to two people about the downstream drainage system; a resident at 13214 SE 166th St and a King County worker at the sinkhole site. Both provided similar accounts on the state of downstream drainage in the residential development east of the high school. They stated that both surface water and groundwater flow down the bank on the east side of the high school into the yards of the homes on 132nd Pl SE. The resident told us this flow has Technical Information Report Lindbergh High School South Parking Lot Improvements 8 2170057.10 caused flooding and damage to the homes on the west side of the street, and at times the flows have crossed the street to flood driveways on the east side of the street. The resident also confirmed the 2009 sinkhole that happened in her backyard that is noted in King County records. The County worker stated that King County was attempting to pump waters from the creek around the sinkhole, but failing to keep up with flows from recent storms. He stated that the County engineering staff were currently designing a permanent repair. He also stated that the groundwater flows and wet conditions are year -round, and that it does not dry out in summer. 10. Note the date and weather conditions at the time of the inspection: The site visit occurred on May 5, 2017. The weather was partly cloudy and 50 degrees. There was no rain during the visit, but there was a severe thunderstorm the previous evening. 3.4 Task 4 – Drainage System Description and Problem Descriptions As noted above, several drainage problems were identified downstream. There have been three sinkholes reported near Molasses Creek in the past ten years. This caused damage to residential yards, but as far as is known, no building damage. King County records indicate that all three sinkholes were caused by failed drainage pipes. Two of the three have since been repaired by the County, while the third repair is in progress. As all of these sinkholes were pipe failures, the proposed project will not aggravate this problem. We also noted surface water and groundwater runoff from the high school to the adjacent houses. This has caused basement flooding, foundation damage, and damage to driveways and sidewalks. The flows that cause these problems appear to be constant year -round, regardless of season and weather conditions. Individual homeowners have installed footing drains that outlet to the sidewalks to mitigate this problem. The proposed project will install groundwater collection pipes and a stormwater detention system , which may reduce the amount of groundwater reaching these properties. King County has identified the area around Molasses Creek as an erosion hazard area. The CORSWDM calls this a Type 2 Drainage Problem. Under Table 1.2.3.A, a project meeting the Flow Control Duration Standard Matching Forested Conditions does not require any further mitigation. 4.0 Flow Control, Low Impact Development (LID) and Water Quality Facility Analysis and Design 4.1 Existing Site Hydrology (Part A) The existing site is occupied by a parking lot and some landscaping areas. The total area disturbed by construction is 1.06 acres, of which 0.90 acre is target surface requiring stormwater mitigation, while the remainder includes pavement replaced only for utility installation and areas that will be disturbed by construction, but replaced in kind. An additional 0.45 acre of undisturbed area will be routed to the proposed detention tank. The 0.90 acre of target surface plus the 0.45 acre of additional area routed to detention results in a total of 1.35 acres. However, this project proposes a mitigation trade of 0.30 acre, which is excluded from the model. This results in a total modeled area of 1.05 acres. The area described above is collected by catch basins onsite and routed through existing Catch Basin 1082 on the way to Molasses Creek. The total areas are summarized in the tables below. Technical Information Report Lindbergh High School South Parking Lot Improvements 9 2170057.10 Actual conditions: Area (AC) Peak Flow (CFS) Till Lawn Impervious Total 2-Year 10-Year 100-Year 0.12 0.93 1.05 0.362 0.527 0.750 As modeled for flow control design: Area (AC) Peak Flow (CFS) Forest Till Lawn Impervious Total 2-Year 10-Year 100-Year 0.90 0.02 0.13 1.05 0.066 0.106 0.166 See Figure 4-1, Existing Basin Map, for delineation of the existing drainage areas. 4.2 Developed Site Hydrology (Part B) The project proposes to remove the existing failed parking lot and replace it with a new parking area. The site areas after construction are summarized in the table below. Unmitigated flows: Area (AC) Unmitigated Peak Flow (CFS) Till Lawn Impervious Total 2-Year 10-Year 100-Year 0.14 0.91 1.05 0.356 0.519 0.739 Mitigated flows: Area (AC) Mitigated Peak Flow (CFS) Till Lawn Impervious Total 2-Year 10-Year 100-Year 0.14 0.91 1.05 0.033 0.058 0.106 A total of 45,825 square feet (1.05 acres) will be routed to the proposed detention pond. Of this area, only 39,391 square feet (0.90 acre) is target surface area that requires detention; this area is modeled as forested in the WWHM model. For areas that are not target area, the detention system has been designed to allow these areas to flow through the detention tank without detention; these areas are modeled in WWHM as actual existing conditions. Some of the target area cannot be directed to the detention system, so a mitigation trade is proposed, as shown in the table below. Area Detention Area Required Target Area Routed to Detention Mitigation Trade Area Routed to Detention Non-target Area Routed to Detention Not Detained SF AC SF AC SF AC SF AC SF AC Area 1 26,280 0.60 26,280 0.60 0 0 0 0 0 0 Area 2A 0 0 0 0 0 0 6,434 0.15 0 0 Area 2B 0 0 0 0 13,111 0.30 0 0 0 0 Area 3 3,207 0.07 0 0 0 0 0 0 3,207 0.07 Area 4 9,904 0.23 0 0 0 0 0 0 9,904 0.23 Total 39,391 0.90 26,280 0.60 13,111 0.30 6,434 0.15 13,111 0.30 Technical Information Report Lindbergh High School South Parking Lot Improvements 10 2170057.10 See Figure 4-2, Developed Basin Map, for delineation of the developed drainage areas and flow routes. 4.3 Performance Standards (Part C) According to the CORSWD Reference 15-A, Flow Control Application Map, the site is subject to the Flow Control Duration Standard (Forested Conditions). This standard requires the post- development stream durations to match the peak flow rates of the forested condition from 50 percent of the 2-year storm through the 50-year storm, as well as matching 2-year and 10-year flows. Flow control will be provided through the use of buried detention pipes. WWHM is used to model the hydrologic conditions. The CORSWD indicates that the entire city of Renton is a Basic Water Quality area. A school is considered a commercial site for stormwater regulations; therefore, the site requires Enhanced Basic Treatment. In accordance with the CORSWDM, onsite flows from the PGIS will be treated to meet the performance standards for the Enhanced Basic Water Quality Menu. The proposed Contech Filterra structures will exceed the performance standards of the Enhanced Basic Water Quality Menu. 4.4 Flow Control System (Part D) The proposed stormwater flow control system is designed to meet the requirements of the CORSWDM. Flow control will be provided through the use detention within buried detention pipe. WWHM was used to size the detention tank and outlet structures. Because of high groundwater, infiltration is not feasible onsite. In addition, the geotechnical report indicates the site soils are not conducive for infiltration. Therefore, a detention system is proposed for the project area. Flow control calculations were performed using WWHM. Calculations are provided as Appendix C. The tables in Sections 4.1 and 4.2 summarize the model inputs and resulting flow rates. 4.5 Water Quality System (Part E) The replaced parking area qualifies as replaced PGIS. In the city of Renton, the water quality standard is based solely on land use. Since a school is considered commercial development, Enhanced Basic is required. Due to grade, not all target areas can be directed to treatment. Therefore, several non-target areas will be treated, giving a total of 37,251 square feet (0.86 acre) of treated PGIS, which exceeds the 33,351 square feet (0.77 acre) target area shown in Figure 4-4. A series of Filterra devices will meet the treatment requirement. The Filterra devices will be modeled in WWHM to filter 91 percent of flows at a hydraulic loading rate of 24.82 inches per hour to meet the requirement for Enhanced Basic Treatment. See Figure 4-5 for the treatment basins. Area PGIS Treated Non-PGIS to Treatment Device Total Area to Treatment Device SF AC SF AC SF AC Filterra 1 16,927 0.39 4,004 0.09 20,931 0.48 Filterra 2 3,878 0.09 0 0 3,878 0.09 Filterra 3 16,446 0.38 2,182 0.05 18,628 0.43 Total 37,251 0.86 6,186 0.14 43,437 1.00 Technical Information Report Lindbergh High School South Parking Lot Improvements 11 2170057.10 5.0 Conveyance System Analysis and Design The project proposes collection of storm drainage from the buildings, field, landscaping area, and parking areas. Catch basins and pipe will be used to convey water to the detention pipe, where it will be detained before it is released to the discharge points. Conveyance drains will be Corrugated Polyethylene Pipe (CPEP). See Appendix D for detailed conveyance calculations. 6.0 Special Reports and Studies A Geotechnical Report dated April 2017, prepared by Associated Earth Sciences, Inc., can be found in Appendix B. 7.0 Other Permits Permits required include the National Pollutant Discharge Elimination System (NPDES) General Permit, and a site development permit. 8.0 Construction Stormwater Pollution Prevention Plan (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. A construction Stormwater Pollution Prevention Plan (CSWPPP) is provided in a separate document. The following measures will be 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 for 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.  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 conveya nce pipes will provide surface water collection.  Dewatering Control – Water from dewatering operations should be discharged to a well- vegetated area or to a temporary sediment control facility. Technical Information Report Lindbergh High School South Parking Lot Improvements 12 2170057.10  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 required for this project, as most existing surfaces are already 100 percent impervious. 9.0 Bond Quantities, Facility Summaries, and Declaration of Covenant Refer to Figure 9-1 for the Bond Quantity Worksheet, Figure 9-2 for the Flow Control and Water Quality Facility Summary Sheet and Sketch, and Figure 9-3 for the Declaration of Covenant. 10.0 Operations and Maintenance Manual Maintenance and operations of all drainage facilities will be maintained by the owner. The project proposes a detention system, water quality system, catch basins , and pipes. Maintenance and operations are detailed in Appendix D. 11.0 Conclusion This site has been designed to meet or exceed the requirements of the 2016 City of Renton Surface Water Design Manual (CORSWDM). 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. Brian Schend, PE Project Engineer BJS/lsk May 2017 Revised July 2017 Q:\2017\2170057\WORDPROC\Reports\20170707 Rpt (TIR) 2170057.10.docx Technical Information Report Lindbergh High School South Parking Lot Improvements 2170057.10 Appendix A Figures 1-1 .................... TIR Worksheet 1-2 .................... Vicinity Map 1-3 .................... Soil Map 3-1 .................... Downstream Analysis 3-2 .................... Off-Site Analysis Drainage System table 3-3 .................... Erosion Hazards Map 3-4 .................... Steep Slopes Map 3-5 .................... Slide Hazard Map 3-6 .................... Flood Hazard Map 3-7 .................... Coal Mine Hazard Map 3-8 .................... Aquifer Protection Map 3-9 .................... FIRM Rate Map 4-1 .................... Existing Basin Map 4-2 .................... Developed Basin Map 4-3 .................... Filterra GULD Approval 4-4 .................... Areas Requiring Treatment 4-5 .................... Areas Treated 5-1 .................... Conveyance Basin Map 9-1 .................... Bond Quantity Worksheet 9-2 .................... Flow Control and Water Quality Facility Summary Sheet and Sketch 9-3 .................... Declaration of Covenant CITY OF RENTON SURFACE WATER DESIGN MANUAL 2017 City of Renton Surface Water Design Manual 12/12/2016 8-A-1 REFERENCE 8-A TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 1 PROJECT OWNER AND PROJECT ENGINEER Part 2 PROJECT LOCATION AND DESCRIPTION Project Owner _____________________________ Phone ___________________________________ Address __________________________________ _________________________________________ Project Engineer ___________________________ Company _________________________________ Phone ___________________________________ Project Name __________________________ CED Permit # ________________________ Location Township ________________ Range __________________ Section _________________ Site Address __________________________ Renton, WA 98058 _____________ Part 3 TYPE OF PERMIT APPLICATION Part 4 OTHER REVIEWS AND PERMITS Land Use (e.g., Subdivision / Short Subd.) Building (e.g., M/F / Commercial / SFR) Grading Right-of-Way Use Other _______________________ DFW HPA COE 404 DOE Dam Safety FEMA Floodplain COE Wetlands Other ________ Shoreline Management Structural Rockery/Vault/_____ ESA Section 7 Part 5 PLAN AND REPORT INFORMATION Technical Information Report Site Improvement Plan (Engr. Plans) Type of Drainage Review (check one): Date (include revision dates): Date of Final: Full Targeted Simplified Large Project Directed __________________ __________________ __________________ Plan Type (check one): Date (include revision dates): Date of Final: Full Modified Simplified __________________ __________________ __________________ Renton School District 300 SW 7th St Renton, WA 98058 Brian Schend, PE AHBL, Inc. 253-383-2422 Lindbergh HS Parking Repair 23N 5E 28 16740 128th Ave SE 4 4 May 2017 4 May 2017 REFERENCE 8: PLAN REVIEW FORMS AND WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 12/12/2016 2017 City of Renton Surface Water Design Manual 8-A-2 Part 6 SWDM ADJUSTMENT APPROVALS Type (circle one): Standard / Blanket Description: (include conditions in TIR Section 2) ____________________________________________________________________________________ ____________________________________________________________________________________ ____________________________________________________________________________________ Approved Adjustment No. ______________________ Date of Approval: _______________________ Part 7 MONITORING REQUIREMENTS Monitoring Required: Yes / No Start Date: _______________________ Completion Date: _______________________ Describe: _________________________________ _________________________________________ _________________________________________ Re: SWDM Adjustment No. ________________ Part 8 SITE COMMUNITY AND DRAINAGE BASIN Community Plan: ____________________________________________________________________ Special District Overlays: ______________________________________________________________ Drainage Basin: _____________________________________________________________________ Stormwater Requirements: _____________________________________________________________ Part 9 ONSITE AND ADJACENT SENSITIVE AREAS River/Stream ________________________ Lake ______________________________ Wetlands ____________________________ Closed Depression ____________________ Floodplain ___________________________ Other _______________________________ _______________________________ Steep Slope __________________________ Erosion Hazard _______________________ Landslide Hazard ______________________ Coal Mine Hazard ______________________ Seismic Hazard _______________________ Habitat Protection ______________________ _____________________________________ None 4 Benson Cedar River Sole source aquifer area 4 None REFERENCE 8-A: TECHNICAL INFORMATION REPORT (TIR) WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2017 City of Renton Surface Water Design Manual 12/12/2016 Ref 8-A-3 Part 10 SOILS Soil Type ______________________ ______________________ ______________________ ______________________ Slopes ________________________ ________________________ ________________________ ________________________ Erosion Potential _________________________ _________________________ _________________________ _________________________ High Groundwater Table (within 5 feet) Other ________________________________ Sole Source Aquifer Seeps/Springs Additional Sheets Attached Part 11 DRAINAGE DESIGN LIMITATIONS REFERENCE Core 2 – Offsite Analysis_________________ Sensitive/Critical Areas__________________ SEPA________________________________ LID Infeasibility________________________ Other________________________________ _____________________________________ LIMITATION / SITE CONSTRAINT _______________________________________ _______________________________________ _______________________________________ _______________________________________ _______________________________________ _______________________________________ Additional Sheets Attached Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet per Threshold Discharge Area) Threshold Discharge Area: (name or description) Core Requirements (all 8 apply): Discharge at Natural Location Number of Natural Discharge Locations: Offsite Analysis Level: 1 2 3 dated:__________________ Flow Control (include facility summary sheet) Standard: _______________________________ or Exemption Number: ____________ On-site BMPs: _______________________________ Conveyance System Spill containment located at: _____________________________ Erosion and Sediment Control / Construction Stormwater Pollution Prevention CSWPP/CESCL/ESC Site Supervisor: _____________________ Contact Phone: _________________________ After Hours Phone: _________________________ Alderwood 8-15%Low 4 4 4 4 Downstream erosion hazard, Molasses Creek 4 Infiltration not possible Main 1 4 May 2017 Flow Control Duration Standard Matching Forested Detention Tank N/A To be determined REFERENCE 8: PLAN REVIEW FORMS AND WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 12/12/2016 2017 City of Renton Surface Water Design Manual 8-A-4 Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet per Threshold Discharge Area) Maintenance and Operation Responsibility (circle one): Private Public If Private, Maintenance Log Required: Yes No Financial Guarantees and Liability Provided: Yes No Water Quality (include facility summary sheet) Type (circle one): Basic Sens. Lake Enhanced Basic Bog or Exemption No. _______________________ Special Requirements (as applicable): Area Specific Drainage Requirements Type: SDO MDP BP Shared Fac. None Name: ________________________ Floodplain/Floodway Delineation Type (circle one): Major Minor Exemption None 100-year Base Flood Elevation (or range): _______________ Datum: Flood Protection Facilities Describe: Source Control (commercial / industrial land use) Describe land use: Describe any structural controls: Oil Control High-Use Site: Yes No Treatment BMP: _________________________________ Maintenance Agreement: Yes No with whom? _____________________________________ Other Drainage Structures Describe: 4 4 4 4 4 4 None Parking None 4 4 REFERENCE 8-A: TECHNICAL INFORMATION REPORT (TIR) WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2017 City of Renton Surface Water Design Manual 12/12/2016 Ref 8-A-5 Part 13 EROSION AND SEDIMENT CONTROL REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION Clearing Limits Cover Measures Perimeter Protection Traffic Area Stabilization Sediment Retention Surface Water Collection Dewatering Control Dust Control Flow Control Control Pollutants Protect Existing and Proposed BMPs/Facilities Maintain Protective BMPs / Manage Project MINIMUM ESC REQUIREMENTS AFTER CONSTRUCTION Stabilize exposed surfaces Remove and restore Temporary ESC Facilities Clean and remove all silt and debris, ensure operation of Permanent BMPs/Facilities, restore operation of BMPs/Facilities as necessary Flag limits of sensitive areas and open space preservation areas Other _______________________ Part 14 STORMWATER FACILITY DESCRIPTIONS (Note: Include Facility Summary and Sketch) Flow Control Type/Description Water Quality Type/Description Detention Infiltration Regional Facility Shared Facility On-site BMPs Other ________________ ________________ ________________ ________________ ________________ ________________ Vegetated Flowpath Wetpool Filtration Oil Control Spill Control On-site BMPs Other ________________ ________________ ________________ ________________ ________________ ________________ ________________ Part 15 EASEMENTS/TRACTS Part 16 STRUCTURAL ANALYSIS Drainage Easement Covenant Native Growth Protection Covenant Tract Other ____________________________ Cast in Place Vault Retaining Wall Rockery > 4ƍ High Structural on Steep Slope Other _______________________________ 4 4 4 4 4 4 4 4 4 4 4 4 Detention Tank 4 Contech Filterra REFERENCE 8: PLAN REVIEW FORMS AND WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 12/12/2016 2017 City of Renton Surface Water Design Manual 8-A-6 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. ____________________________________________________________________________________ Signed/Date Brian Schend, PE June 6, 2017 PROJECT AREA N Figure 1-2: Vicinity Map Soil Map—King County Area, Washington (Lindbergh High School, Renton, WA) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 5/8/2017 Page 1 of 352556005255700525580052559005256000525610052562005255700525580052559005256000525610052562005256300562400562500562600562700562800562900563000563100563200563300563400 562400 562500 562600 562700 562800 562900 563000 563100 563200 563300 563400 47° 27' 25'' N 122° 10' 21'' W47° 27' 25'' N122° 9' 29'' W47° 27' 2'' N 122° 10' 21'' W47° 27' 2'' N 122° 9' 29'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 10N WGS84 0 200 400 800 1200 Feet 0 50 100 200 300 Meters Map Scale: 1:4,970 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. Figure 1-3: Soil Map 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 12, Sep 8, 2016 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jul 8, 2014—Jul 15, 2014 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 (Lindbergh High School, Renton, WA) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 5/8/2017 Page 2 of 3 Figure 1-3: Soil Map Map Unit Legend King County Area, Washington (WA633) Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI AgC Alderwood gravelly sandy loam, 8 to 15 percent slopes 43.0 43.1% AgD Alderwood gravelly sandy loam, 15 to 30 percent slopes 18.2 18.2% AmC Arents, Alderwood material, 6 to 15 percent slopes 7.4 7.4% EvC Everett very gravelly sandy loam, 8 to 15 percent slopes 17.9 17.9% No Norma sandy loam 1.6 1.6% PITS Pits 0.3 0.3% Sk Seattle muck 4.4 4.4% Ur Urban land 7.0 7.0% Totals for Area of Interest 99.7 100.0% Soil Map—King County Area, Washington Lindbergh High School, Renton, WA Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 5/8/2017 Page 3 of 3 Figure 1-3: Soil Map POC 1 6 7 7 1/4 MILE DOWNSTREAM CONTROL STRUCTURE IN CATCH BASIN MOLASSES CREEK 36" CULVERT SINKHOLE PIPES AND CATCH BASINS 12" PIPE TYPICAL 1 2 3 4 5 2215 North 30th Street, Suite 300, Tacoma, WA 98403 253.383.2422 TEL 253.383.2572 FAX JOB NO: DATE: LINDBERGH HIGH SCHOOL PARKING LOT REPLACEMENT DOWNSTREAM DRAINAGE FIG 3-1 MAY 2017 2170057.10 N GRAPHIC SCALE 0 200 1" = 200 FEET 1000 CITY OF RENTON SURFACE WATER DESIGN MANUAL2017 City of Renton Surface WaterDesign Manual12/12/2016Ref 8-B-1 REFERENCE 8-B OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLECITY OFRENTON SURFACE WATER DESIGNMANUAL, CORE REQUIREMENT #2 Basin:Subbasin Name:Subbasin Number:DateSymbolDrainage Component Type, Name, and SizeDrainage Component DescriptionSlopeDistance from Site DischargeExisting ProblemsPotential ProblemsObservations of Field Inspector, Resource Reviewer,or ResidentSee mapType: sheet flow, swale, stream, channel, pipe, pond, flow control/treatment/on-site BMP/facilitySize: diameter, surface areadrainage basin, vegetation, cover, depth, type of sensitive area, volume%¼ ml = 1,320 ft.Constrictions,under capacity, ponding, overtopping, flooding, habitat or organism destruction, scouring, bank sloughing, sedimentation, incision, other erosionTributary area, likelihood of problem, overflow pathways, potential impacts k k k k k k k k k k k k k k k k k k k k k k k k k k k kk k k k k k k k k k k k k k k k k k k k HoquiamAveNEE Valley Hwy84thAveSNEParkD r SW 7th St SE 128th St SE 192nd StLindAveSWMainAveSS 132nd St Factory PlN Talbot Rd SN 3rd St RainierAveS 164thAveSETukwila Pk wy SPuget Dr NE 4th St S 3rd St S 1 2 9 th S t68thAveSSWSunsetBlvd SW 16th St 116thAveSEN 4th St I n t e r u r b a n Av e S WilliamsAveNBronsonW a y N NE7thSt 124thAveSES 7th St SERenton IssaquahRd Rai ni er AveNNewcastle Way CoalCr e e k PkwySESW 41st St T a ylor Pl N WNESunsetBlvdWellsAveNUnionAveNEN E 3 rd S tHa r die A v eSWS180th St Maple Valley Hwy 140thAveSES G rad yW ayS 2 1 s tSt BensonRdSRent o n AveS87thAveS128thAveSE148thAveSESW 43rd St SEC arrR d SE 168th St Beaco n A v e S 68thAveSLoganAveN108thAveSEForestDr SE S2ndSt 141 s t Ave SERainierAveS 156thAveSES E 183rdStBenson Dr SS 124th StS 43rd St Airport Way S W G ra dyW a y S E J o n e s RdSunsetBlvdN Puget Dr SES E 204th W aySW 34th StMo n ster RdSW S E 1 4 2 n d P lWestValleyHwySSEMayValleyRd SunsetBlvdNS C a r r RdHouserWayNNewcastle GolfClubRd S 133rd St WilliamsAveSWellsAveSEMercerWay154thPlSEDuvallAveNELoganAveSMonroeAveNESunsetBlvdNEEdmondsAveNEStevens AveNWRa i n i e r AveSTalbotRdSOakesdaleAveSWTaylorAveNW164thAveSERainierAveSWestVal l eyHwyWestValleyHwyParkAveN108thAveSE6 6 t h Av e SWMercerWayWMercer W ay Lakemont BlvdSE132ndAve SELakeWashingtonBlvdNE140thWaySE East Valley Rd68thAveS³City of RentonSensitive Areas 0 0.5 10.25 Miles Information Technology - GISmapsupport@rentonwa.govPrinted on: 11/12/2014 Data Sources: City of Renton, King County This document is a graphic representation, not guaranteedto survey accuracy, and is based on the best informationavailable as of the date shown. This map is intended forCity display purposes only. Renton City Limits k Education Fire Station K Valley Medical Center Erosion Hazard Severity High Coordinate System: NAD 1983 HARN StatePlane Washington North FIPS 4601 FeetProjection: Lambert Conformal ConicDatum: North American 1983 HARN Figure 3-3: Erosion Hazards LINDBERGH HIGH SCHOOL k k k k k k k k k k k k k k k k k k k k k k k k k k k kk k k k k k k k k k k k k k k k k k k k HoquiamAveNEE Valley Hwy84thAveSNEParkD r SW 7th St SE 128th St SE 192nd StLindAveSWMainAveSS 132nd St Factory PlN Talbot Rd SN 3rd St RainierAveS 164thAveSETukwila Pk wy SPuget Dr NE 4th St S 3rd St S 1 2 9 th S t68thAveSSWSunsetBlvd SW 16th St 116thAveSEN 4th St I n t e r u r b a n Av e S WilliamsAveNBronsonW a y N NE7thSt 124thAveSES 7th St SERenton IssaquahRd Rai ni er AveNNewcastle Way CoalCr e e k PkwySESW 41st St T a ylor Pl N WNESunsetBlvdWellsAveNUnionAveNEN E 3 rd S tHa r die A v eSWS180th St Maple Valley Hwy 140thAveSES G rad yW ayS 2 1 s tSt BensonRdSRent o n AveS87thAveS128thAveSE148thAveSESW 43rd St SEC arrR d SE 168th St Beaco n A v e S 68thAveSLoganAveN108thAveSEForestDr SE S2ndSt 141 s t Ave SERainierAveS 156thAveSES E 183rdStBenson Dr SS 124th StS 43rd St Airport Way S W G ra dyW a y S E J o n e s RdSunsetBlvdN Puget Dr SES E 204th W aySW 34th StMo n ster RdSW S E 1 4 2 n d P lWestValleyHwySSEMayValleyRd SunsetBlvdNS C a r r RdHouserWayNNewcastle GolfClubRd S 133rd St WilliamsAveSWellsAveSEMercerWay154thPlSEDuvallAveNELoganAveSMonroeAveNESunsetBlvdNEEdmondsAveNEStevens AveNWRa i n i e r AveSTalbotRdSOakesdaleAveSWTaylorAveNW164thAveSERainierAveSWestVal l eyHwyWestValleyHwyParkAveN108thAveSE6 6 t h Av e SWMercerWayWMercer W ay Lakemont BlvdSE132ndAve SELakeWashingtonBlvdNE140thWaySE East Valley Rd68thAveS³City of RentonSensitive Areas 0 0.5 10.25 Miles Information Technology - GISmapsupport@rentonwa.govPrinted on: 11/12/2014 Data Sources: City of Renton, King County This document is a graphic representation, not guaranteedto survey accuracy, and is based on the best informationavailable as of the date shown. This map is intended forCity display purposes only. Renton City Limits k Education Fire Station K Valley Medical Center Steep Slopes Percent Range >15% & <=25% >25% & <=40% >40% & <=90% >90%Coordinate System: NAD 1983 HARN StatePlane Washington North FIPS 4601 FeetProjection: Lambert Conformal ConicDatum: North American 1983 HARN Figure 3-4: Steep Slopes LINDBERGH HIGH SCHOOL k k k k k k k k k k k k k k k k k k k k k k k k k k k kk k k k k k k k k k k k k k k k k k k k HoquiamAveNEE Valley Hwy84thAveSNEParkD r SW 7th St SE 128th St SE 192nd StLindAveSWMainAveSS 132nd St Factory PlN Talbot Rd SN 3rd St RainierAveS 164thAveSETukwila Pk wy SPuget Dr NE 4th St S 3rd St S 1 2 9 th S t68thAveSSWSunsetBlvd SW 16th St 116thAveSEN 4th St I n t e r u r b a n Av e S WilliamsAveNBronsonW a y N NE7thSt 124thAveSES 7th St SERenton IssaquahRd Rai ni er AveNNewcastle Way CoalCr e e k PkwySESW 41st St T a ylor Pl N WNESunsetBlvdWellsAveNUnionAveNEN E 3 rd S tHa r die A v eSWS180th St Maple Valley Hwy 140thAveSES G rad yW ayS 2 1 s tSt BensonRdSRent o n AveS87thAveS128thAveSE148thAveSESW 43rd St SEC arrR d SE 168th St Beaco n A v e S 68thAveSLoganAveN108thAveSEForestDr SE S2ndSt 141 s t Ave SERainierAveS 156thAveSES E 183rdStBenson Dr SS 124th StS 43rd St Airport Way S W G ra dyW a y S E J o n e s RdSunsetBlvdN Puget Dr SES E 204th W aySW 34th StMo n ster RdSW S E 1 4 2 n d P lWestValleyHwySSEMayValleyRd SunsetBlvdNS C a r r RdHouserWayNNewcastle GolfClubRd S 133rd St WilliamsAveSWellsAveSEMercerWay154thPlSEDuvallAveNELoganAveSMonroeAveNESunsetBlvdNEEdmondsAveNEStevens AveNWRa i n i e r AveSTalbotRdSOakesdaleAveSWTaylorAveNW164thAveSERainierAveSWestVal l eyHwyWestValleyHwyParkAveN108thAveSE6 6 t h Av e SWMercerWayWMercer W ay Lakemont BlvdSE132ndAve SELakeWashingtonBlvdNE140thWaySE East Valley Rd68thAveS³City of RentonSensitive Areas 0 0.5 10.25 Miles Information Technology - GISmapsupport@rentonwa.govPrinted on: 11/12/2014 Data Sources: City of Renton, King County This document is a graphic representation, not guaranteedto survey accuracy, and is based on the best informationavailable as of the date shown. This map is intended forCity display purposes only. Renton City Limits k Education Fire Station K Valley Medical Center Landslide HazardSeverityVery HighHighModerateUnclassified Coordinate System: NAD 1983 HARN StatePlane Washington North FIPS 4601 FeetProjection: Lambert Conformal ConicDatum: North American 1983 HARN Figure 3-5: Slide Hazard LINDBERGH HIGH SCHOOL RentonKent Newcastle King CountyTukwilaMercer Island Bellevu e Lake Washington Lake Youngs Panther Lake Lake Boren Cedar RiverBlack River May Creek Springbrook Creek Cougar MountainCougar Mountain Coal Creek ParkCoal Creek Park Cedar River Natural ZoneCedar River Natural Zone May Creek ParkMay Creek Park Soos Creek Park and TrailSoos Creek Park and Trail Black River Riparian ForestBlack River Riparian Forest McGarvey Open SpaceMcGarvey Open Space Maplewood Community ParkMaplewood Community Park ValleyValley BensonBenson HighlandsHighlands West HillWest Hill East PlateauEast Plateau SE 192ND STTALBOT RD S140TH AVE SERAI N I E R A V E S EAST VALLEY RDSE 168TH ST RENTON A V E S116TH AVE SENE 12TH STE M ERCER WAY148TH AVE SENE 7TH S T84TH AVE SHOQUIAM AVE NENEWCASTLE W AY W M E RCER WAY S 128TH ST SW 41ST ST PARK AVE N128TH AVE SESE JONES R D E VALLEY HWYSE 72ND ST SE 164TH ST NILE AVE NEN 10TH S T SE 183RD S TUNION AVE NE156TH AVE SEUNION AVE SENE 2ND ST 148TH AVE SESE 164TH STLIND AVE SWUNION AVE NE116TH AVE SESW 7TH ST N 8TH ST EDMONDS AVE NEPUGET DR S E NE 27TH ST 156TH AVE SERENTON AVE S BENSON RD SMONROE AVE NE116TH AVE SENE 4TH ST SR 515 SUNS E T B LV D N E PARK AVE NM APLE VALLEY HWY SW 43RD ST NE 3RD STLOGAN AVE NSW SU NSET BLVD SW GRADY W A Y N 3RD STRAINIER AVE N140TH WAY SESR 167108TH AVE SEN 6TH ST S 2ND S T 108TH AVE SESR 515[^405 [^405 Effective FEMA FloodInsurance Rate Map µ Legend Renton City Limits Zone AE, A, AH, AO - Regulatory Zone X - Non Regulatory 0 0.5 10.25 Miles Public Works - Surface Water UtilityPrint Date: 11/05/2012 Data Sources: City of Renton, FEMA FIRM revised May 16, 1995.Cedar River flood hazard area updated with FEMA Cedar RiverLOMR (Case No. 06-10-B569P) approved December 4, 2006. This document is a graphic representation, not guaranteedto survey accuracy, and is based on the best informationavailable as of the date shown. This map is intended forCity display purposes only. Figure 3-6: Flood Hazard LINDBERGH HIGH SCHOOL k k k k k k k k k k k k k k k k k k k k k k k k k k k kk k k k k k k k k k k k k k k k k k k k HoquiamAveNEE Valley Hwy84thAveSNEParkD r SW 7th St SE 128th St SE 192nd StLindAveSWMainAveSS 132nd St Factory PlN Talbot Rd SN 3rd St RainierAveS 164thAveSETukwila Pk wy SPuget Dr NE 4th St S 3rd St S 1 2 9 th S t68thAveSSWSunsetBlvd SW 16th St 116thAveSEN 4th St I n t e r u r b a n Av e S WilliamsAveNBronsonW a y N NE7thSt 124thAveSES 7th St SERenton IssaquahRd Rai ni er AveNNewcastle Way CoalCr e e k PkwySESW 41st St T a ylor Pl N WNESunsetBlvdWellsAveNUnionAveNEN E 3 rd S tHa r die A v eSWS180th St Maple Valley Hwy 140thAveSES G rad yW ayS 2 1 s tSt BensonRdSRent o n AveS87thAveS128thAveSE148thAveSESW 43rd St SEC arrR d SE 168th St Beaco n A v e S 68thAveSLoganAveN108thAveSEForestDr SE S2ndSt 141 s t Ave SERainierAveS 156thAveSES E 183rdStBenson Dr SS 124th StS 43rd St Airport Way S W G ra dyW a y S E J o n e s RdSunsetBlvdN Puget Dr SES E 204th W aySW 34th StMo n ster RdSW S E 1 4 2 n d P lWestValleyHwySSEMayValleyRd SunsetBlvdNS C a r r RdHouserWayNNewcastle GolfClubRd S 133rd St WilliamsAveSWellsAveSEMercerWay154thPlSEDuvallAveNELoganAveSMonroeAveNESunsetBlvdNEEdmondsAveNEStevens AveNWRa i n i e r AveSTalbotRdSOakesdaleAveSWTaylorAveNW164thAveSERainierAveSWestVal l eyHwyWestValleyHwyParkAveN108thAveSE6 6 t h Av e SWMercerWayWMercer W ay Lakemont BlvdSE132ndAve SELakeWashingtonBlvdNE140thWaySE East Valley Rd68thAveS³City of RentonSensitive Areas 0 0.5 10.25 Miles Information Technology - GISmapsupport@rentonwa.govPrinted on: 11/12/2014 Data Sources: City of Renton, King County This document is a graphic representation, not guaranteedto survey accuracy, and is based on the best informationavailable as of the date shown. This map is intended forCity display purposes only. Renton City Limits k Education Fire Station K Valley Medical Center Coal Mine Hazards Severity HIGH MODERATE UNCLASSIFIED Coordinate System: NAD 1983 HARN StatePlane Washington North FIPS 4601 FeetProjection: Lambert Conformal ConicDatum: North American 1983 HARN Figure 3-7: Coal Mine Hazard LINDBERGH HIGH SCHOOL !!! ! ! !!!!! ! ! !! ! ! !! ! !! PW-12 PW-11PW-17 PW-4 PW-9 PW-8 RW-3 RW-2 EW-3 PW-5A PW-12 PW-10 ,§-405 ,§-405 115544tthhPPllSSEESW 34th StSW 34th St East Valley RdEast Valley Rd114488tthhAAvveeSSEE140th Ave SE140th Ave SE164th Ave SE164th Ave SETalbot Rd STalbot Rd S N 30th StN 30th St 68th Ave S68th Ave SRaini e r A v e S Raini e r A v e S SE 192nd StSE 192nd St SE May Valley R d SE May Valley R d E Valley HwyE Valley HwySE Petr o v i t s k y R d SE Petr o v i t s k y R d Forest Dr SEForest Dr SE S 128th StS 128th St 112th Ave SE112th Ave SE84th Ave S84th Ave SSE 168th StSE 168th St S 55th StS 55th St N 10th StN 10th St NE 2nd StNE 2nd St SW 41st StSW 41st St 116th Ave SE116th Ave SE140th Ave SE140th Ave SESE 192nd StSE 192nd St 148th Ave SE148th Ave SE114400tthhAAvveeSSEESW 27th StSW 27th St Benson Rd SBenson Rd SHouse r Wa y NHous e r Wa y NLind Ave SWLind Ave SWN 8th StN 8th St PP uu gg eettDDrrSSEERReennttoonnAAvv ee SS SW 7th StSW 7th St I-405 FWYI-405 FWYRain ier Ave NRain ier Ave N NNEEPPaa rrkkDDrr NE 4th StNE 4th St SW 43rd StSW 43rd St SE Carr RdSE Carr Rd NE 3rd StNE 3rd StLogan Ave NLogan Ave NDuvall Ave NEDuvall Ave NEI-405 FWYI-405 FWYI-405 FWYI-405 FWYI-405 FWYI-405 FWY I-405 FWYI-405 FWYNE 4th StNE 4th StI-405 FWYI-405 FWYII--440055FFWWYYI-405 FWYI-405 FWYI-405 FWYI-405 FWY I-405 FWYI-405 FWYI-405 FWYI-405 FWY NE 4th StNE 4th St BN IncBN IncBN I n c BN I n c BN IncBN Inc BN IncBN IncB N I n c B N I n c BN IncBN IncB N I n c B N I n c BN IncBN In c BB NN IInnccB N I n c B N I n c BN IncBN IncBN IncBN Inc BN IncBN IncCedar River Green River Black River May Creek Duwamish Waterway Springbrook Creek Lake Washington Lake Youngs Panther Lake Lake Boren Reference 15-B Wellfield Capture Zones One Year Capture Zone Five Year Capture Zone Ten Year Capture Zone Cedar Valley Sole SourceAquifer Project Review Area Streamflow Source Area Cedar Valley Sole Source Aquifer Aquifer Protection Area Zones Zone 1 Zone 1 Modified Zone 2 Network Structure !Production Well !Springbrook Springs Renton City Limits Potential Annexation Area Groundwater Protection Areas Date: 01/09/2014 µ0 1 2MilesDRAFT Figure 3-8: Aquifer Protection LINDBERGH HIGH SCHOOL LINDBERGH HIGH SCHOOL Figure 3-9: FIRM Rate Map 128TH AVENUE SOUTHEAST EXISTING BASIN45,828 SF 1.05 ACLANDSCAPED AREA5,511 SF 0.12 ACIMPERVIOUS AREA40,307 SF 0.93 ACMITIGATION TRADEEXCLUDEDFROM MODEL13,111 SF 0.30 ACCivil EngineersStructural EngineersLandscape ArchitectsCommunity PlannersLand SurveyorsNeighborsLINDBERGH HIGH SCHOOLPARKING LOT REPAIRNGRAPHIC SCALE0601" = 60 FEET30 128TH AVENUE SOUTHEAST AREA 2BMITIGATIONTRADE13,111 SF0.30 ACAREA 3TARGETNOT DETAINED3,207 SF 0.07 ACAREA 4TARGETNOT DETAINED9910 SF 0.23 ACLANDSCAPED AREA3,924 SF 0.09 ACIMPERVIOUS AREA22,356 SF 0.51 ACLANDSCAPED AREA1,128 SF 0.03 ACIMPERVIOUS AREA11,983 SF 0.27 ACAREA 1TARGETDETAINED26,280 SF0.60 ACAREA 2ANON-TARGETDETAINED6,434 SF0.15 ACLANDSCAPED AREA1,040 SF 0.02 ACIMPERVIOUS AREA5,394 SF 0.13 ACCivil EngineersStructural EngineersLandscape ArchitectsCommunity PlannersLand SurveyorsNeighborsLINDBERGH HIGH SCHOOLPARKING LOT REPAIRNGRAPHIC SCALE0601" = 60 FEET30LEGEND:PAVEMENTREPLACEMENTREQUIRING MITIGATIONPAVEMENTREPLACEMENT NOTREQUIRING MITIGATION 1 June 2016 GENERAL USE LEVEL DESIGNATION FOR BASIC (TSS), ENHANCED, PHOSPHORUS & OIL TREATMENT For Americast Filterra® Ecology’s Decision: Based on Americast’s submissions, including the Final Technical Evaluation Reports, dated March 27, 2014 and December 2009, and additional information provided to Ecology dated October 9, 2009, Ecology hereby issues the following use level designations: 1. A General Use Level Designation for Basic, Enhanced, Phosphorus, and Oil Treatment at the following water quality design hydraulic loading rates: Treatment Hydraulic Conductivity* (in/hr) for use in Western Washington Sizing Infiltration Rate (in/hr) for use in eastern Washington Sizing Basic 70.92 100 Phosphorus 70.92 100 Oil 35.46 50 Enhanced 24.82 35 *calculated based on listed infiltration rate and a hydraulic gradient of 1.41 inch/inch (2.55 ft head with 1.80 ft media). 2. The Filterra® unit is not appropriate for oil spill-control purposes. 3. Ecology approves the Filterra® units for treatment at the hydraulic loading rates listed above, to achieve the maximum water quality design flow rate. Calculate the water quality design flow rates using the following procedures:  Western Washington: for treatment installed upstream of detention or retention, the water quality design flow rate is the peak 15-minute flow rate as calculated using the sand filter module in the latest version of the Western Washington Hydrology Model or other Ecology-approved continuous runoff model. The model must indicate the unit is capable of processing 91 percent of the influent runoff file.  Eastern Washington: For treatment installed upstream of detention or retention, the water quality design flow rate is the peak 15-minute flow rate as calculated using one of the three flow rate based methods described in Chapter 2.2.5 of the Stormwater Management Manual for Eastern Washington (SWMMEW) or local manual. 2  Entire State: For treatment installed downstream of detention, the water quality design flow rate is the full 2-year release rate of the detention facility. 4. This General Use Level Designation has no expiration date but Ecology may revoke or amend the designation, and is subject to the conditions specified below. Ecology’s Conditions of Use: Filterra® units shall comply with these conditions shall comply with the following conditions: 1. Design, assemble, install, operate, and maintain the Filterra® units in accordance with applicable Americast Filterra® manuals, document, and the Ecology Decision. 2. Each site plan must undergo Americast Filterra® review before Ecology can approve the unit for site installation. This will ensure that site grading and slope are appropriate for use of a Filterra® unit. 3. Filterra® media shall conform to the specifications submitted to and approved by Ecology. 4. Maintenance includes removing trash, degraded mulch, and accumulated debris from the filter surface and replacing the mulch layer. Use inspections to determine the site-specific maintenance schedules and requirements. Follow maintenance procedures given in the most recent version of the Filterra® Operation and Maintenance Manual. 5. Maintenance: The required maintenance interval for stormwater treatment devices is often dependent upon the degree of pollutant loading from a particular drainage basin. Therefore, Ecology does not endorse or recommend a “one size fits all” maintenance cycle for a particular model/size of manufactured filter treatment device.  Filterra® designs their systems for a target maintenance interval of 6 months. Maintenance includes removing accumulated sediment and trash from the surface area of the media, removing the mulch above the media, replacing the mulch, providing plant health evaluation, and pruning the plant if deemed necessary.  Conduct maintenance following manufacturer’s guidelines. 6. Filterra® units come in standard sizes. 7. The minimum size filter surface-area for use in western Washington is determined by using the sand filter module in the latest version of WWHM or other Ecology approved continuous runoff model for western Washington. Model inputs include a) Filter media depth: 1.8 feet b) Effective Ponding Depth: 0.75 feet (This is equivalent to the 6-inch clear zone between the top of the mulch and the bottom of the slab plus 3-inches of mulch.) c) Side slopes: Vertical d) Riser height: 0.70 feet e) Filter Hydraulic Conductivity: Use the Hydraulic Conductivity as listed in the table above (use the lowest applicable hydraulic conductivity depending on the level of treatment required) under Ecology’s Decision, above. 3 8. The minimum size filter surface-area for use in eastern Washington is determined by using the design water quality flow rate (as determined in item 3, above) and the Infiltration Rate from the table above (use the lowest applicable Infiltration Rate depending on the level of treatment required). Calculate the required area by dividing the water quality design flow rate (cu-ft/sec) by the Infiltration Rate (converted to ft/sec) to obtain required surface area (sq ft) of the Filterra unit. 9. Discharges from the Filterra® units shall not cause or contribute to water quality standards violations in receiving waters. Approved Alternate Configurations Filterra® Internal Bypass - Pipe (FTIB-P) 1. The Filterra® Internal Bypass – Pipe allows for piped-in flow from area drains, grated inlets, trench drains, and/or roof drains. Design capture flows and peak flows enter the structure through an internal slotted pipe. Filterra® inverted the slotted pipe to allow design flows to drop through to a series of splash plates that then disperse the design flows over the top surface of the Filterra® planter area. Higher flows continue to bypass the slotted pipe and convey out the structure. 2. To select a FTIB-P unit, the designer must determine the size of the standard unit using the sizing guidance described above. Filterra® Internal Bypass – Curb (FTIB-C) 1. The Filterra® Internal Bypass –Curb model (FTIB-C) incorporates a curb inlet, biofiltration treatment chamber, and internal high flow bypass in one single structure. Filterra® designed the FTIB-C model for use in a “Sag” or “Sump” condition and will accept flows from both directions along a gutter line. An internal flume tray weir component directs treatment flows entering the unit through the curb inlet to the biofiltration treatment chamber. Flows in excess of the water quality treatment flow rise above the flume tray weir and discharge through a standpipe orifice; providing bypass of untreated peak flows. Americast manufactures the FTIB-C model in a variety of sizes and configurations and you may use the unit on a continuous grade when a single structure providing both treatment and high flow bypass is preferred. The FTIB-C model can also incorporate a separate junction box chamber to allow larger diameter discharge pipe connections to the structure. 2. To select a FTIB-C unit, the designer must determine the size of the standard unit using the sizing guidance described above. Filterra® Shallow 1. The Filterra® Shallow provides additional flexibility for design engineers and designers in situations where there is limited depth and various elevation constraints to applying a standard Filterra® configuration. Engineers can design this system up to six inches shallower than any of the previous Filterra unit configurations noted above. 4 2. Ecology requires that the Filterra® Shallow provide a contact time equivalent to that of the standard unit. This means that with a smaller depth of media, the surface area must increase. 3. To select a Filterra® Shallow System unit, the designer must first identify the size of the standard unit using the modeling guidance described above. 4. Once you establish the size of the standard Filterra® unit using the sizing technique described above, use information from the following table to select the appropriate size Filterra® Shallow System unit. Shallow Unit Basic, Enhanced, and Oil Treatment Sizing Standard Depth Equivalent Shallow Depth 4x4 4x6 or 6x4 4x6 or 6x4 6x6 4x8 or 8x4 6x8 or 8x6 6x6 6x10 or 10x6 6x8 or 8x6 6x12 or 12x6 6x10 or 10x6 13x7 Notes: 1. Shallow Depth Boxes are less than the standard depth of 3.5 feet but no less than 3.0 feet deep (TC to INV). Applicant: Filterra® Bioretention Systems, division of Contech Engineered Solutions, LLC. Applicant’s Address: 11815 NE Glenn Widing Drive Portland, OR 97220 Application Documents:  State of Washington Department of Ecology Application for Conditional Use Designation, Americast (September 2006)  Quality Assurance Project Plan Filterra® Bioretention Filtration System Performance Monitoring, Americast (April 2008)  Quality Assurance Project Plan Addendum Filterra® Bioretention Filtration System Performance Monitoring, Americast (June 2008)  Draft Technical Evaluation Report Filterra® Bioretention Filtration System Performance Monitoring, Americast (August 2009)  Final Technical Evaluation Report Filterra® Bioretention Filtration System Performance Monitoring, Americast (December 2009)  Technical Evaluation Report Appendices Filterra® Bioretention Filtration System Performance Monitoring, Americast, August 2009  Memorandum to Department of Ecology Dated October 9, 2009 from Americast, Inc. and Herrera Environmental Consultants 5  Quality Assurance Project Plan Filterra® Bioretention System Phosphorus treatment and Supplemental Basic and Enhanced Treatment Performance Monitoring, Americast (November 2011)  Filterra® letter August 24, 2012 regarding sizing for the Filterra® Shallow System.  University of Virginia Engineering Department Memo by Joanna Crowe Curran, Ph. D dated March 16, 2013 concerning capacity analysis of Filterra® internal weir inlet tray.  Terraphase Engineering letter to Jodi Mills, P.E. dated April 2, 2013 regarding Terraflume Hydraulic Test, Filterra® Bioretention System and attachments.  Technical Evaluation Report, Filterra® System Phosphorus Treatment and Supplemental Basic Treatment Performance Monitoring. March 27th, 2014. Applicant’s Use Level Request: General Level Use Desi gnation for Basic, Enhanced, Phosphorus, and Oil Treatment. Applicant’s Performance Claims: Field-testing and laboratory testing show that the Filterra® unit is promising as a stormwater treatment best management practice and can meet Ecology’s performance goals for basic, enhanced, phosphorus, and oil treatment. Findings of Fact: Field Testing 2013 1. Filterra® completed field-testing of a 6.5 ft x 4 ft. unit at one site in Bellingham, Washington. Continuous flow and rainfall data collected from January 1, 2013 through July 23, 2013 indicated that 59 storm events occurred. The monitoring obtained water quality data from 22 storm events. Not all the sampled storms produced information that met TAPE criteria for storm and/or water quality data. 2. The system treated 98.9 percent of the total 8-month runoff volume during the testing period. Consequently, the system achieved the goal of treating 91 percent of the volume from the site. Stormwater runoff bypassed during four of the 59 storm events. 3. Of the 22 sampled events, 18 qualified for TSS analysis (influent TSS concentrations ranged from 25 to 138 mg/L). The data were segregated into sample pairs with influent concentration greater than and less than 100 mg/L. The UCL95 mean effluent concentration for the data with influent less than 100 mg/L was 5.2 mg/L, below the 20- mg/L threshold. Although the TAPE guidelines do not require an evaluation of TSS removal efficiency for influent concentrations below 100 mg/L, the mean TSS removal for these samples was 90.1 percent. Average removal of influent TSS concentrations greater than 100 mg/L (three events) was 85 percent. In addition, the system consistently exhibited TSS removal greater than 80 percent at flow rates at a 100 inches per hour [in/hr] infiltration rate and was observed at 150 in/hr. 6 4. Ten of the 22 sampled events qualified for TP analysis. Americast augmented the dataset using two sample pairs from previous monitoring at the site. Influent TP concentrations ranged from 0.11 to 0.52 mg/L. The mean TP removal for these twelve events was 72.6 percent. The LCL95 mean percent removal was 66.0, well above the TAPE requirement of 50 percent. Treatment above 50 percent was evident at 100 in/hr infiltration rate and as high as 150 in/hr. Consequently, the Filterra® test system met the TAPE Phosphorus Treatment goal at 100 in/hr. Influent ortho-P concentrations ranged from 0.005 to 0.012 mg/L; effluent ortho-P concentrations ranged from 0.005 to 0.013 mg/L. The reporting limit/resolution for the ortho-P test method is 0.01 mg/L, therefore the influent and effluent ortho-P concentrations were both at and near non-detect concentrations. Field Testing 2008-2009 1. Filterra® completed field-testing at two sites at the Port of Tacoma. Continuous flow and rainfall data collected during the 2008-2009 monitoring period indicated that 89 storm events occurred. The monitoring obtained water quality data from 27 storm events. Not all the sampled storms produced information that met TAPE criteria for storm and/or water quality data. 2. During the testing at the Port of Tacoma, 98.96 to 99.89 percent of the annual influent runoff volume passed through the POT1 and POT2 test systems respectively. Stormwater runoff bypassed the POT1 test system during nine storm events and bypassed the POT2 test system during one storm event. Bypass volumes ranged from 0.13% to 15.3% of the influent storm volume. Both test systems achieved the 91 percent water quality treatment- goal over the 1-year monitoring period. 3. Consultants observed infiltration rates as high as 133 in/hr during the various storms. Filterra® did not provide any paired data that identified percent removal of TSS, metals, oil, or phosphorus at an instantaneous observed flow rate. 4. The maximum storm average hydraulic loading rate associated with water quality data is <40 in/hr, with the majority of flow rates < 25 in/hr. The average instantaneous hydraulic loading rate ranged from 8.6 to 53 inches per hour. 5. The field data showed a removal rate greater than 80% for TSS with an influent concentration greater than 20 mg/l at an average instantaneous hydraulic loading rate up to 53 in/hr (average influent concentration of 28.8 mg/l, average effluent concentration of 4.3 mg/l). 6. The field data showed a removal rate generally greater than 54% for dissolved zinc at an average instantaneous hydraulic loading rate up to 60 in/hr and an average influent concentration of 0.266 mg/l (average effluent concentration of 0.115 mg/l). 7. The field data showed a removal rate generally greater than 40% for dissolved copper at an average instantaneous hydraulic loading rate up to 35 in/hr and an average influent concentration of 0.0070 mg/l (average effluent concentration of 0.0036 mg/l). 8. The field data showed an average removal rate of 93% for total petroleum hydrocarbon (TPH) at an average instantaneous hydraulic loading rate up to 53 in/hr and an average influent concentration of 52 mg/l (average effluent concentration of 2.3 mg/l). The data 7 also shows achievement of less than 15 mg/l TPH for grab samples. Filterra® provided limited visible sheen data due to access limitations at the outlet monitoring location. 9. The field data showed low percentage removals of total phosphorus at all storm flows at an average influent concentration of 0.189 mg/l (average effluent concentration of 0.171 mg/l). We may relate the relatively poor treatment performance of the Filterra® system at this location to influent characteristics for total phosphorus that are unique to the Port of Tacoma site. It appears that the Filterra® system will not meet the 50 percent removal performance goal when you expect the majority of phosphorus in the runoff to be in the dissolved form. Laboratory Testing 1. Filterra® performed laboratory testing on a scaled down version of the Filterra® unit. The lab data showed an average removal from 83-91% for TSS with influents ranging from 21 to 320 mg/L, 82-84% for total copper with influents ranging from 0.94 to 2.3 mg/L, and 50-61% for orthophosphate with influents ranging from 2.46 to 14.37 mg/L. 2. Filterra® conducted permeability tests on the soil media. 3. Lab scale testing using Sil-Co-Sil 106 showed percent removals ranging from 70.1% to 95.5% with a median percent removal of 90.7%, for influent concentrations ranging from 8.3 to 260 mg/L. Filterra® ran these laboratory tests at an infiltration rate of 50 in/hr. 4. Supplemental lab testing conducted in September 2009 using Sil-Co-Sil 106 showed an average percent removal of 90.6%. These laboratory tests were run at infiltration rates ranging from 25 to 150 in/hr for influent concentrations ranging from 41.6 to 252.5 mg/l. Regression analysis results indicate that the Filterra® system’s TSS removal performance is independent of influent concentration in the concentration rage evaluated at hydraulic loading rates of up to 150 in/hr. Contact Information: Applicant: Sean Darcy Contech Engineered Solutions, LLC. 11815 Glenn Widing Dr Portland, OR 97220 (503) 258-3105 darcys@conteches.com Applicant’s Website: http://www.conteches.com Ecology web link: http://www.ecy.wa.gov/programs/wq/stormwater/newtech/index.html Ecology: Douglas C. Howie, P.E. Department of Ecology Water Quality Program (360) 407-6444 douglas.howie@ecy.wa.gov 8 Date Revision December 2009 GULD for Basic, Enhanced, and Oil granted, CULD for Phosphorus September 2011 Extended CULD for Phosphorus Treatment September 2012 Revised design storm discussion, added Shallow System. January 2013 Revised format to match Ecology standards, changed Filterra contact information February 2013 Added FTIB-P system March 2013 Added FTIB-C system April 2013 Modified requirements for identifying appropriate size of unit June 2013 Modified description of FTIB-C alternate configuration March 2014 GULD awarded for Phosphorus Treatment. GULD updated for a higher flow-rate for Basic Treatment. June 2014 Revised sizing calculation methods March 2015 Revised Contact Information June 2015 CULD for Basic and Enhanced at 100 in/hr infiltration rate November 2015 Removed information on CULD (created separate CULD document for 100 in/hr infiltration rate) June 2016 Revised text regarding Hydraulic conductivity value 128TH AVENUE SOUTHEAST POLLUTANT GENERATINGIMPERVIOUS SURFACEREQUIRING TREATMENT33,351 SF 0.77 ACCivil EngineersStructural EngineersLandscape ArchitectsCommunity PlannersLand SurveyorsNeighborsLINDBERGH HIGH SCHOOLPARKING LOT REPAIRNGRAPHIC SCALE0601" = 60 FEET30LEGEND:REPLACE POLLUTANTGENERATINGIMPERVIOUS SURFACEREQUIRING TREATMENTREPLACE POLLUTANTGENERATINGIMPERVIOUS SURFACENOT REQUIRINGTREATMENT 128TH AVENUE SOUTHEAST FILTERRA 2PGIS 3,878 SF 0.09 ACTOTAL 3,878 SF 0.09 ACFILTERRA 3PGIS 16,446 SF 0.38 ACTOTAL 18,628 SF 0.43 ACFILTERRA 1PGIS 16,927 SF 0.39 ACTOTAL 20,931 SF 0.48 ACCivil EngineersStructural EngineersLandscape ArchitectsCommunity PlannersLand SurveyorsNeighborsLINDBERGH HIGH SCHOOLPARKING LOT REPAIRNGRAPHIC SCALE0601" = 60 FEET30 128TH AVENUE SOUTHEAST 134815,950 SF0.37 AC13222,204 SF0.05 AC000112,137 SF0.28 AC134916,348 SF0.38 ACFILTERRA 318,628 SF0.43 ACFILTERRA 120,931 SF0.48 ACFILTERRA 23,878 SF0.09 AC108311,724 SF0.27 ACTOC FLOWPATHTYPICALCivil EngineersStructural EngineersLandscape ArchitectsCommunity PlannersLand SurveyorsNeighborsLINDBERGH HIGH SCHOOLPARKING LOT REPAIRNGRAPHIC SCALE0601" = 60 FEET30 Planning Division |1055 South Grady Way – 6 th Floor | Renton, WA 98057 (425) 430-7200 • • Section I: Project Information • • • Section II: Bond Quantities Worksheets • •Section II.a EROSION CONTROL (Stabilization/Erosion Sediment Control (ESC)) •Section II.b TRANSPORTATION (Street and Site Improvements) •Section II.c DRAINAGE (Drainage and Stormwater Facilities): •Section II.d WATER - ONLY APPLICABLE IF WATER SERVICE IS PROVIDED BY CITY OF RENTON •Section II.e SANITARY SEWER - ONLY APPLICABLE IF SEWER SERVICE IS PROVIDED BY CITY OF RENTON • • • • • • Section III. Bond Worksheet • BOND QUANTITY WORKSHEET INSTRUCTIONS This worksheet is intended to be a "working" copy of the bond quantity worksheet, which will be used throughout all phases of the project, from initial submittal to project close-out approval. Submit this workbook, in its entirety, as follows: The following forms are to be completed by the engineer/developer/applicant as applicable to the project: The Bond Worksheet form will auto-calculate and auto-populate from the information provided in Section I and Section II. This section includes all pertinent information for the project Section II contains a separate spreadsheet TAB for each of the following specialties: (1) electronic copy (.xlsx format) and (1) hard copy of the entire workbook for civil construction permit submittal. Hard copies are to be included as part of the Technical Information Report (TIR). (1) electronic copy (.xlsx format) and (1) hard copy of the entire workbook for final close-out submittal. This section must be completed in its entirety Information from this section auto-populates to all other relevant areas of the workbook This section calculates the required Permit Bond for construction permit issuance as well as the required Maintenance Bond for project close-out submittals to release the permit bond on a project. All unit prices include labor, equipment, materials, overhead and profit. Complete the 'Quantity' columns for each of the appropriate section(s). Include existing Right-of-Way (ROW), Future Public Improvements and Private Improvements. The 'Quantity Remaining' column is only to be used when a project is under construction. The City allows one (1) bond reduction during the life of the project with the exception of the maintenance period reduction. Excel will auto-calculate and auto-populate the relevant fields and subtotals throughout the document. Only the 'Quantity' columns should need completing. Additional items not included in the lists can be added under the "write-in" sections. Provide a complete description, cost estimate and unit of measure for each write-in item. Note: Private improvements, with the exception of stormwater facilities, are not included in the bond amount calculation, but must be entered on the form. Stormwater facilities (public and private) are required to be included in the bond amount. Page 1 of 14 Ref 8-H Bond Quantity Worksheet INSTRUCTIONS Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 7/7/2017 Planning Division |1055 South Grady Way – 6 th Floor | Renton, WA 98057 (425) 430-7200 Date 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:NO Water Service Provided by: If Yes, Provide Forest Practice Permit #:Sewer Service Provided by: N/AAbbreviated Legal Description: SE 1/4 OF NE 1/4 LESS E 500 FT OF N 1121 FT LESS E 330 FT OF S 216.47 FT M/L LESS S 250 FT OF E 523 FT OF W 553 FT LESS CO RD N/A 16740 128th Ave SE Renton, WA 98058 300 SW 7th St N/ASE 168th St 425-204-2300 6/6/2017 Revised 7/7/2017 Prepared by: FOR APPROVALProject Phase 1 scomfort@ahbl.com Sean M. Comfort, PE 29010 AHBL, Inc. 2215 N 30th St, Ste 300, Tacoma, WA 98403 253-383-2422 SITE IMPROVEMENT BOND QUANTITY WORKSHEET PROJECT INFORMATION CITY OF RENTON CITY OF RENTON 1 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 Submittal N/A Engineer Stamp Required (all cost estimates must have original wet stamp and signature) Clearing and Grading Utility Providers N/A Project Location and Description Project Owner Information Lindbergh HS South Parking Lot Improvements Renton, WA 98057 2823059004 Renton School District Page 2 of 14 Ref 8-H Bond Quantity Worksheet SECTION I PROJECT INFORMATION Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 7/7/2017 CED Permit #: Unit Reference #Price Unit Quantity Cost Backfill & compaction-embankment ESC-1 6.50$ CY Check dams, 4" minus rock ESC-2 SWDM 5.4.6.3 80.00$ Each Catch Basin Protection ESC-3 35.50$ Each 8 284.00 Crushed surfacing 1 1/4" minus ESC-4 WSDOT 9-03.9(3)95.00$ CY Ditching ESC-5 9.00$ CY Excavation-bulk ESC-6 2.00$ CY Fence, silt ESC-7 SWDM 5.4.3.1 1.50$ LF 600 900.00 Fence, Temporary (NGPE)ESC-8 1.50$ LF 1000 1,500.00 Geotextile Fabric ESC-9 2.50$ SY Hay Bale Silt Trap ESC-10 0.50$ Each Hydroseeding ESC-11 SWDM 5.4.2.4 0.80$ SY 900 720.00 Interceptor Swale / Dike ESC-12 1.00$ LF Jute Mesh ESC-13 SWDM 5.4.2.2 3.50$ SY Level Spreader ESC-14 1.75$ LF Mulch, by hand, straw, 3" deep ESC-15 SWDM 5.4.2.1 2.50$ SY Mulch, by machine, straw, 2" deep ESC-16 SWDM 5.4.2.1 2.00$ SY Piping, temporary, CPP, 6"ESC-17 12.00$ LF Piping, temporary, CPP, 8"ESC-18 14.00$ LF Piping, temporary, CPP, 12"ESC-19 18.00$ LF Plastic covering, 6mm thick, sandbagged ESC-20 SWDM 5.4.2.3 4.00$ SY Rip Rap, machine placed; slopes ESC-21 WSDOT 9-13.1(2)45.00$ CY Rock Construction Entrance, 50'x15'x1'ESC-22 SWDM 5.4.4.1 1,800.00$ Each Rock Construction Entrance, 100'x15'x1'ESC-23 SWDM 5.4.4.1 3,200.00$ Each 1 3,200.00 Sediment pond riser assembly ESC-24 SWDM 5.4.5.2 2,200.00$ Each Sediment trap, 5' high berm ESC-25 SWDM 5.4.5.1 19.00$ LF Sed. trap, 5' high, riprapped spillway berm section ESC-26 SWDM 5.4.5.1 70.00$ LF Seeding, by hand ESC-27 SWDM 5.4.2.4 1.00$ SY Sodding, 1" deep, level ground ESC-28 SWDM 5.4.2.5 8.00$ SY Sodding, 1" deep, sloped ground ESC-29 SWDM 5.4.2.5 10.00$ SY TESC Supervisor ESC-30 110.00$ HR 200 22,000.00 Water truck, dust control ESC-31 SWDM 5.4.7 140.00$ HR Unit Reference #Price Unit Quantity Cost EROSION/SEDIMENT SUBTOTAL:28,604.00 SALES TAX @ 10%2,860.40 EROSION/SEDIMENT TOTAL:31,464.40 (A) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR EROSION & SEDIMENT CONTROL Description No. (A) WRITE-IN-ITEMS Page 3 of 14 Ref 8-H Bond Quantity Worksheet SECTION II.a EROSION_CONTROL Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 7/7/2017 CED Permit #: Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost GENERAL ITEMS Backfill & Compaction- embankment GI-1 6.00$ CY Backfill & Compaction- trench GI-2 9.00$ CY 500 4,500.00 Clear/Remove Brush, by hand (SY)GI-3 1.00$ SY Bollards - fixed GI-4 240.74$ Each Bollards - removable GI-5 452.34$ Each Clearing/Grubbing/Tree Removal GI-6 10,000.00$ Acre Excavation - bulk GI-7 2.00$ CY 3300 6,600.00 Excavation - Trench GI-8 5.00$ CY 500 2,500.00 Fencing, cedar, 6' high GI-9 20.00$ LF Fencing, chain link, 4'GI-10 38.31$ LF Fencing, chain link, vinyl coated, 6' high GI-11 20.00$ LF Fencing, chain link, gate, vinyl coated, 20' GI-12 1,400.00$ Each Fill & compact - common barrow GI-13 25.00$ CY Fill & compact - gravel base GI-14 27.00$ CY 450 12,150.00 Fill & compact - screened topsoil GI-15 39.00$ CY Gabion, 12" deep, stone filled mesh GI-16 65.00$ SY Gabion, 18" deep, stone filled mesh GI-17 90.00$ SY Gabion, 36" deep, stone filled mesh GI-18 150.00$ SY Grading, fine, by hand GI-19 2.50$ SY Grading, fine, with grader GI-20 2.00$ SY Monuments, 3' Long GI-21 250.00$ Each Sensitive Areas Sign GI-22 7.00$ Each Sodding, 1" deep, sloped ground GI-23 8.00$ SY Surveying, line & grade GI-24 850.00$ Day 1 850.00 Surveying, lot location/lines GI-25 1,800.00$ Acre Topsoil Type A (imported)GI-26 28.50$ CY Traffic control crew ( 2 flaggers )GI-27 120.00$ HR Trail, 4" chipped wood GI-28 8.00$ SY Trail, 4" crushed cinder GI-29 9.00$ SY Trail, 4" top course GI-30 12.00$ SY Conduit, 2"GI-31 5.00$ LF Wall, retaining, concrete GI-32 55.00$ SF Wall, rockery GI-33 15.00$ SF SUBTOTAL THIS PAGE:26,600.00 (B)(C)(D)(E) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR STREET AND SITE IMPROVEMENTS Quantity Remaining (Bond Reduction) (B)(C) Page 4 of 14 Ref 8-H Bond Quantity Worksheet SECTION II.b TRANSPORTATION Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 7/7/2017 CED Permit #: Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR STREET AND SITE IMPROVEMENTS Quantity Remaining (Bond Reduction) (B)(C) ROAD IMPROVEMENT/PAVEMENT/SURFACING AC Grinding, 4' wide machine < 1000sy RI-1 30.00$ SY AC Grinding, 4' wide machine 1000-2000sy RI-2 16.00$ SY AC Grinding, 4' wide machine > 2000sy RI-3 10.00$ SY AC Removal/Disposal RI-4 35.00$ SY 4000 140,000.00 Barricade, Type III ( Permanent )RI-5 56.00$ LF Guard Rail RI-6 30.00$ LF Curb & Gutter, rolled RI-7 17.00$ LF Curb & Gutter, vertical RI-8 12.50$ LF Curb and Gutter, demolition and disposal RI-9 18.00$ LF Curb, extruded asphalt RI-10 5.50$ LF 1600 8,800.00 Curb, extruded concrete RI-11 7.00$ LF Sawcut, asphalt, 3" depth RI-12 1.85$ LF 600 1,110.00 Sawcut, concrete, per 1" depth RI-13 3.00$ LF Sealant, asphalt RI-14 2.00$ LF Shoulder, gravel, 4" thick RI-15 15.00$ SY Sidewalk, 4" thick RI-16 38.00$ SY 13 494.00 Sidewalk, 4" thick, demolition and disposal RI-17 32.00$ SY Sidewalk, 5" thick RI-18 41.00$ SY Sidewalk, 5" thick, demolition and disposal RI-19 40.00$ SY Sign, Handicap RI-20 85.00$ Each 5 425.00 Striping, per stall RI-21 7.00$ Each 45 315.00 Striping, thermoplastic, ( for crosswalk )RI-22 3.00$ SF 570 1,710.00 Striping, 4" reflectorized line RI-23 0.50$ LF 300 150.00 Additional 2.5" Crushed Surfacing RI-24 3.60$ SY HMA 1/2" Overlay 1.5" RI-25 14.00$ SY HMA 1/2" Overlay 2"RI-26 18.00$ SY HMA Road, 2", 4" rock, First 2500 SY RI-27 28.00$ SY HMA Road, 2", 4" rock, Qty. over 2500SY RI-28 21.00$ SY HMA Road, 4", 6" rock, First 2500 SY RI-29 45.00$ SY HMA Road, 4", 6" rock, Qty. over 2500 SY RI-30 37.00$ SY HMA Road, 4", 4.5" ATB RI-31 38.00$ SY Gravel Road, 4" rock, First 2500 SY RI-32 15.00$ SY Gravel Road, 4" rock, Qty. over 2500 SY RI-33 10.00$ SY Thickened Edge RI-34 8.60$ LF SUBTOTAL THIS PAGE:153,004.00 (B)(C)(D)(E) Page 5 of 14 Ref 8-H Bond Quantity Worksheet SECTION II.b TRANSPORTATION Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 7/7/2017 CED Permit #: Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR STREET AND SITE IMPROVEMENTS Quantity Remaining (Bond Reduction) (B)(C) PARKING LOT SURFACING No. 2" AC, 2" top course rock & 4" borrow PL-1 21.00$ SY 3800 79,800.00 2" AC, 1.5" top course & 2.5" base course PL-2 28.00$ SY 4" select borrow PL-3 5.00$ SY 1.5" top course rock & 2.5" base course PL-4 14.00$ SY SUBTOTAL PARKING LOT SURFACING:79,800.00 (B)(C)(D)(E) LANDSCAPING & VEGETATION No. Street Trees LA-1 Median Landscaping LA-2 Right-of-Way Landscaping LA-3 Wetland Landscaping LA-4 SUBTOTAL LANDSCAPING & VEGETATION: (B)(C)(D)(E) TRAFFIC & LIGHTING No. Signs TR-1 10 Street Light System ( # of Poles)TR-2 Traffic Signal TR-3 Traffic Signal Modification TR-4 SUBTOTAL TRAFFIC & LIGHTING: (B)(C)(D)(E) WRITE-IN-ITEMS SUBTOTAL WRITE-IN ITEMS: STREET AND SITE IMPROVEMENTS SUBTOTAL:179,604.00 SALES TAX @ 10%17,960.40 STREET AND SITE IMPROVEMENTS TOTAL:197,564.40 (B)(C)(D)(E) Page 6 of 14 Ref 8-H Bond Quantity Worksheet SECTION II.b TRANSPORTATION Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 7/7/2017 CED Permit #: Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost DRAINAGE (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/D D-1 26.00$ SY * (CBs include frame and lid) Beehive D-2 90.00$ Each Through-curb Inlet Framework D-3 400.00$ Each CB Type I D-4 1,500.00$ Each 2 3,000.00 CB Type IL D-5 1,750.00$ Each CB Type II, 48" diameter D-6 2,300.00$ Each 11 25,300.00 for additional depth over 4' D-7 480.00$ FT 42 20,160.00 CB Type II, 54" diameter D-8 2,500.00$ Each for additional depth over 4'D-9 495.00$ FT CB Type II, 60" diameter D-10 2,800.00$ Each 2 5,600.00 for additional depth over 4'D-11 600.00$ FT 7 4,200.00 CB Type II, 72" diameter D-12 6,000.00$ Each for additional depth over 4'D-13 850.00$ FT CB Type II, 96" diameter D-14 14,000.00$ Each for additional depth over 4'D-15 925.00$ FT Trash Rack, 12"D-16 350.00$ Each Trash Rack, 15"D-17 410.00$ Each Trash Rack, 18"D-18 480.00$ Each Trash Rack, 21"D-19 550.00$ Each Cleanout, PVC, 4"D-20 150.00$ Each Cleanout, PVC, 6"D-21 170.00$ Each Cleanout, PVC, 8"D-22 200.00$ Each Culvert, PVC, 4" D-23 10.00$ LF Culvert, PVC, 6" D-24 13.00$ LF 589 7,657.00 Culvert, PVC, 8" D-25 15.00$ LF Culvert, PVC, 12" D-26 23.00$ LF Culvert, PVC, 15" D-27 35.00$ LF Culvert, PVC, 18" D-28 41.00$ LF Culvert, PVC, 24"D-29 56.00$ LF Culvert, PVC, 30" D-30 78.00$ LF Culvert, PVC, 36" D-31 130.00$ LF Culvert, CMP, 8"D-32 19.00$ LF Culvert, CMP, 12"D-33 29.00$ LF 94 2,726.00 SUBTOTAL THIS PAGE:68,643.00 (B)(C)(D)(E) Quantity Remaining (Bond Reduction) (B)(C) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR DRAINAGE AND STORMWATER FACILITIES Page 7 of 14 Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 7/7/2017 CED Permit #: Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost Quantity Remaining (Bond Reduction) (B)(C) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR DRAINAGE AND STORMWATER FACILITIES DRAINAGE (Continued) Culvert, CMP, 15"D-34 35.00$ LF Culvert, CMP, 18"D-35 41.00$ LF Culvert, CMP, 24"D-36 56.00$ LF Culvert, CMP, 30"D-37 78.00$ LF Culvert, CMP, 36"D-38 130.00$ LF 24 3,120.00 Culvert, CMP, 48"D-39 190.00$ LF Culvert, CMP, 60"D-40 270.00$ LF 885 238,950.00 Culvert, CMP, 72"D-41 350.00$ LF Culvert, Concrete, 8"D-42 42.00$ LF Culvert, Concrete, 12"D-43 48.00$ LF Culvert, Concrete, 15"D-44 78.00$ LF Culvert, Concrete, 18"D-45 48.00$ LF Culvert, Concrete, 24"D-46 78.00$ LF Culvert, Concrete, 30"D-47 125.00$ LF Culvert, Concrete, 36"D-48 150.00$ LF Culvert, Concrete, 42"D-49 175.00$ LF Culvert, Concrete, 48"D-50 205.00$ LF Culvert, CPE Triple Wall, 6" D-51 14.00$ LF Culvert, CPE Triple Wall, 8" D-52 16.00$ LF Culvert, CPE Triple Wall, 12" D-53 24.00$ LF 430 10,320.00 Culvert, CPE Triple Wall, 15" D-54 35.00$ LF Culvert, CPE Triple Wall, 18" D-55 41.00$ LF Culvert, CPE Triple Wall, 24" D-56 56.00$ LF Culvert, CPE Triple Wall, 30" D-57 78.00$ LF Culvert, CPE Triple Wall, 36" D-58 130.00$ LF Culvert, LCPE, 6"D-59 60.00$ LF Culvert, LCPE, 8"D-60 72.00$ LF Culvert, LCPE, 12"D-61 84.00$ LF Culvert, LCPE, 15"D-62 96.00$ LF Culvert, LCPE, 18"D-63 108.00$ LF Culvert, LCPE, 24"D-64 120.00$ LF Culvert, LCPE, 30"D-65 132.00$ LF Culvert, LCPE, 36"D-66 144.00$ LF Culvert, LCPE, 48"D-67 156.00$ LF Culvert, LCPE, 54"D-68 168.00$ LF SUBTOTAL THIS PAGE:252,390.00 (B)(C)(D)(E) Page 8 of 14 Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 7/7/2017 CED Permit #: Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost Quantity Remaining (Bond Reduction) (B)(C) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR DRAINAGE AND STORMWATER FACILITIES DRAINAGE (Continued) Culvert, LCPE, 60"D-69 180.00$ LF Culvert, LCPE, 72"D-70 192.00$ LF Culvert, HDPE, 6"D-71 42.00$ LF Culvert, HDPE, 8"D-72 42.00$ LF Culvert, HDPE, 12"D-73 74.00$ LF Culvert, HDPE, 15"D-74 106.00$ LF Culvert, HDPE, 18"D-75 138.00$ LF Culvert, HDPE, 24"D-76 221.00$ LF Culvert, HDPE, 30"D-77 276.00$ LF Culvert, HDPE, 36"D-78 331.00$ LF Culvert, HDPE, 48"D-79 386.00$ LF Culvert, HDPE, 54"D-80 441.00$ LF Culvert, HDPE, 60"D-81 496.00$ LF Culvert, HDPE, 72"D-82 551.00$ LF Pipe, Polypropylene, 6"D-83 84.00$ LF Pipe, Polypropylene, 8"D-84 89.00$ LF Pipe, Polypropylene, 12"D-85 95.00$ LF Pipe, Polypropylene, 15"D-86 100.00$ LF Pipe, Polypropylene, 18"D-87 106.00$ LF Pipe, Polypropylene, 24"D-88 111.00$ LF Pipe, Polypropylene, 30"D-89 119.00$ LF Pipe, Polypropylene, 36"D-90 154.00$ LF Pipe, Polypropylene, 48"D-91 226.00$ LF Pipe, Polypropylene, 54"D-92 332.00$ LF Pipe, Polypropylene, 60"D-93 439.00$ LF Pipe, Polypropylene, 72"D-94 545.00$ LF Culvert, DI, 6"D-95 61.00$ LF Culvert, DI, 8"D-96 84.00$ LF Culvert, DI, 12"D-97 106.00$ LF Culvert, DI, 15"D-98 129.00$ LF Culvert, DI, 18"D-99 152.00$ LF Culvert, DI, 24"D-100 175.00$ LF Culvert, DI, 30"D-101 198.00$ LF Culvert, DI, 36"D-102 220.00$ LF Culvert, DI, 48"D-103 243.00$ LF Culvert, DI, 54"D-104 266.00$ LF Culvert, DI, 60"D-105 289.00$ LF Culvert, DI, 72"D-106 311.00$ LF SUBTOTAL THIS PAGE: (B)(C)(D)(E) Page 9 of 14 Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 7/7/2017 CED Permit #: Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost Quantity Remaining (Bond Reduction) (B)(C) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR DRAINAGE AND STORMWATER FACILITIES Specialty Drainage Items Ditching SD-1 9.50$ CY Flow Dispersal Trench (1,436 base+)SD-3 28.00$ LF French Drain (3' depth)SD-4 26.00$ LF Geotextile, laid in trench, polypropylene SD-5 3.00$ SY Mid-tank Access Riser, 48" dia, 6' deep SD-6 2,000.00$ Each Pond Overflow Spillway SD-7 16.00$ SY Restrictor/Oil Separator, 12"SD-8 1,150.00$ Each 1 1,150.00 Restrictor/Oil Separator, 15"SD-9 1,350.00$ Each Restrictor/Oil Separator, 18"SD-10 1,700.00$ Each Riprap, placed SD-11 42.00$ CY Tank End Reducer (36" diameter)SD-12 1,200.00$ Each Infiltration pond testing SD-13 125.00$ HR Permeable Pavement SD-14 Permeable Concrete Sidewalk SD-15 Culvert, Box __ ft x __ ft SD-16 SUBTOTAL SPECIALTY DRAINAGE ITEMS:1,150.00 (B)(C)(D)(E) STORMWATER FACILITIES (Include Flow Control and Water Quality Facility Summary Sheet and Sketch) Detention Pond SF-1 Each Detention Tank SF-2 Each 1 Detention Vault SF-3 Each Infiltration Pond SF-4 Each Infiltration Tank SF-5 Each Infiltration Vault SF-6 Each Infiltration Trenches SF-7 Each Basic Biofiltration Swale SF-8 Each Wet Biofiltration Swale SF-9 Each Wetpond SF-10 Each Wetvault SF-11 Each Sand Filter SF-12 Each Sand Filter Vault SF-13 Each Linear Sand Filter SF-14 Each Proprietary Facility SF-15 Each 3 Bioretention Facility SF-16 Each SUBTOTAL STORMWATER FACILITIES: (B)(C)(D)(E) Page 10 of 14 Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 7/7/2017 CED Permit #: Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost Quantity Remaining (Bond Reduction) (B)(C) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR DRAINAGE AND STORMWATER FACILITIES WRITE-IN-ITEMS (INCLUDE ON-SITE BMPs) WI-1 WI-2 WI-3 WI-4 WI-5 WI-6 WI-7 WI-8 WI-9 WI-10 WI-11 WI-12 WI-13 WI-14 WI-15 SUBTOTAL WRITE-IN ITEMS: DRAINAGE AND STORMWATER FACILITIES SUBTOTAL:322,183.00 SALES TAX @ 10%32,218.30 DRAINAGE AND STORMWATER FACILITIES TOTAL:354,401.30 (B)(C)(D)(E) Page 11 of 14 Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 7/7/2017 CED Permit #: Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost Connection to Existing Watermain W-1 2,000.00$ Each Ductile Iron Watermain, CL 52, 4 Inch Diameter W-2 50.00$ LF Ductile Iron Watermain, CL 52, 6 Inch Diameter W-3 56.00$ LF Ductile Iron Watermain, CL 52, 8 Inch Diameter W-4 60.00$ LF Ductile Iron Watermain, CL 52, 10 Inch Diameter W-5 70.00$ LF Ductile Iron Watermain, CL 52, 12 Inch Diameter W-6 80.00$ LF Gate Valve, 4 inch Diameter W-7 500.00$ Each Gate Valve, 6 inch Diameter W-8 700.00$ Each Gate Valve, 8 Inch Diameter W-9 800.00$ Each Gate Valve, 10 Inch Diameter W-10 1,000.00$ Each Gate Valve, 12 Inch Diameter W-11 1,200.00$ Each Fire Hydrant Assembly W-12 4,000.00$ Each Permanent Blow-Off Assembly W-13 1,800.00$ Each Air-Vac Assembly, 2-Inch Diameter W-14 2,000.00$ Each Air-Vac Assembly, 1-Inch Diameter W-15 1,500.00$ Each Compound Meter Assembly 3-inch Diameter W-16 8,000.00$ Each Compound Meter Assembly 4-inch Diameter W-17 9,000.00$ Each Compound Meter Assembly 6-inch Diameter W-18 10,000.00$ Each Pressure Reducing Valve Station 8-inch to 10-inch W-19 20,000.00$ Each WATER SUBTOTAL: SALES TAX @ 10% WATER TOTAL: (B)(C)(D)(E) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR WATER Quantity Remaining (Bond Reduction) (B)(C) Page 12 of 14 Ref 8-H Bond Quantity Worksheet SECTION II.d WATER Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 7/7/2017 CED Permit #: Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost Clean Outs SS-1 1,000.00$ Each Grease Interceptor, 500 gallon SS-2 8,000.00$ Each Grease Interceptor, 1000 gallon SS-3 10,000.00$ Each Grease Interceptor, 1500 gallon SS-4 15,000.00$ Each Side Sewer Pipe, PVC. 4 Inch Diameter SS-5 80.00$ LF Side Sewer Pipe, PVC. 6 Inch Diameter SS-6 95.00$ LF Sewer Pipe, PVC, 8 inch Diameter SS-7 105.00$ LF Sewer Pipe, PVC, 12 Inch Diameter SS-8 120.00$ LF Sewer Pipe, DI, 8 inch Diameter SS-9 115.00$ LF Sewer Pipe, DI, 12 Inch Diameter SS-10 130.00$ LF Manhole, 48 Inch Diameter SS-11 6,000.00$ Each Manhole, 54 Inch Diameter SS-13 6,500.00$ Each Manhole, 60 Inch Diameter SS-15 7,500.00$ Each Manhole, 72 Inch Diameter SS-17 8,500.00$ Each Manhole, 96 Inch Diameter SS-19 14,000.00$ Each Pipe, C-900, 12 Inch Diameter SS-21 180.00$ LF Outside Drop SS-24 1,500.00$ LS Inside Drop SS-25 1,000.00$ LS Sewer Pipe, PVC, ____ Inch Diameter SS-26 Lift Station (Entire System)SS-27 LS SANITARY SEWER SUBTOTAL: SALES TAX @ 10% SANITARY SEWER TOTAL: (B)(C)(D)(E) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR SANITARY SEWER Quantity Remaining (Bond Reduction) (B)(C) Page 13 of 14 Ref 8-H Bond Quantity Worksheet SECTION II.e SANITARY SEWER Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 7/7/2017 Planning Division |1055 South Grady Way – 6 th Floor | Renton, WA 98057 (425) 430-7200 Date: 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)354,401.30$ (e) (f) Site Restoration Civil Construction Permit Maintenance Bond 70,880.26$ Bond Reduction 2 Construction Permit Bond Amount 3 Minimum Bond Amount is $10,000.00 1 Estimate Only - May involve multiple and variable components, which will be established on an individual basis by Development Engineering. 2 The City of Renton allows one request only for bond reduction prior to the maintenance period. Reduction of not more than 70% of the original bond amount, provided that the remaining 30% will cover all remaining items to be constructed. 3 Required Bond Amounts are subject to review and modification by Development Engineering. * Note: The word BOND as used in this document means any financial guarantee acceptable to the City of Renton. ** Note: All prices include labor, equipment, materials, overhead and profit. EST1 ((b) + (c) + (d)) x 20% -$ MAINTENANCE BOND */** (after final acceptance of construction) 31,464.40$ -$ 354,401.30$ 31,464.40$ -$ 354,401.30$ -$ 385,865.70$ P (a) x 100% SITE IMPROVEMENT BOND QUANTITY WORKSHEET BOND CALCULATIONS 6/6/2017 Revised 7/7/2017 Sean M. Comfort, PE 29010 AHBL, Inc. R ((b x 150%) + (d x 100%)) S (e) x 150% + (f) x 100% Bond Reduction: Existing Right-of-Way Improvements (Quantity Remaining)2 Bond Reduction: Stormwater & Drainage Facilities (Quantity Remaining)2 T (P +R - S) Prepared by:Project Information CONSTRUCTION BOND AMOUNT */** (prior to permit issuance) 253-383-2422 scomfort@ahbl.com Lindbergh HS South Parking Lot Improvements 16740 128th Ave SE Renton, WA 98058 2823059004 FOR APPROVAL 2215 N 30th St, Ste 300, Tacoma, WA 98403 Page 14 of 14 Ref 8-H Bond Quantity Worksheet SECTION III. BOND WORKSHEET Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 7/7/2017 DETENTIONTANK SYSTEM60" CMP PIPESFLOW RESTRICTOR MANHOLEFILTERRA 1LINDBERGHPOOLFILTERRA 2FILTERRA 3LINDBERGH HIGH SCHOOLPARKING LOT REPAIRNGRAPHIC SCALE0401" = 40 FEET20 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 RENTON SCHOOL DISTRICT SEE ATTACHED 2823059004 C17-002606 C17-002606 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 Technical Information Report Lindbergh High School South Parking Lot Improvements 2170057.10 Appendix B Geotechnical Report a associat ed earth sciences Incorporat ed June 6, 2017 Project No. 170046E001 AHBL 1200 6th Avenue, Suite 1620 Seattle, Washington 98101 Attention: Subject: Mr. Bill Fierst Limited Pavement Remediation Recommendations Lindbergh High School Bus Loop 16426 128th Avenue SE King County, Washington Reference: Civil Plan Set Lindbergh High School Parking Lot Replacement Sheets C1.0, C2.0, C3.0, C3.2, C4.0, C5.5, C5.6 Prepared by AHBL Dated May 19, 2017 Dear Mr. Fierst: This report summarizes our recent subsurface explorations and pavement assessment at the referenced site. The purpose of our work was to evaluate the existing pavement section and subgrade at previously identified locations and provide recommendations for subgrade improvement, drainage, structural fill, temporary cut slopes, and suggested new pavement sections. Our services for this project have been completed in accordance with local standards of practice in the field of geotechnical engineering at the time they were completed. No other warranty, express or implied, is made. We were provided with the referenced plan sheets for preparation of this report. The site location is shown on the "Vicinity Map," Figure 1. The approximate locations of the hollow-stem auger explorations accomplished for our study are shown on the "Site and Exploration Plan," Figure 2. Logs of the exploration borings are also attached. Kirkland Office I 911 Fifth Avenue I Kirkland, WA 98033 P I 425.827.7701 Fl 425.827.5424 Everett Office I 2911Y2 Hewitt Avenue, Suite 2 I Everett, WA 98201 P I 425.259.0522 F I 425.827.5424 Tacoma Office I 1552 Commerce Street, Suite 102 I Tacoma, WA 98402 P I 253.722.2992 F I 253.722.2993 www.aesgeo.com Lindbergh High School Bus Loop Limited Pavement Remediation King County, Washington Recommendations SITE AND PROJECT DESCRIPTION The subject site consists of the bus/traffic loop and parking lot adjacent to the existing Lindbergh Pool at Lindbergh High School located at 16426 128th Avenue SE in King County, Washington. The paved traffic loop has access to 128th Avenue SE and is located south of the high school buildings and softball field near the southwest portion of the school campus. Portions of the existing paved bus loop and parking lot are currently showing signs of heavy pavement distress such as fatigue or "alligator" cracking, pavement and subgrade heave, and other forms of pavement deterioration. The worst portions are located near the east end of the bus loop and parking lot area. We understand that the project will consist of replacing the traffic loop as well as approximately one-fourth of the existing interior parking lot area. The project also proposes underground detention pipes for storm water control located near the northwest corner of the project area. Project plans propose nine, 60-inch corrugated metal pipe (CMP) detention pipes that range in length from approximately 60 to 100 feet. The bottom of the detention pipe bedding is proposed at elevation of 416 feet which will result in maximum excavation depths of approximately 11 feet. We are familiar with the Lindbergh High School site through the completion of several previous geotechnical studies that were completed in February 2010, April 2004, January 2003, and December 2000. These studies included subsurface explorations and geotechnical recommendations that aided in the design and construction of previous phases of the Lindbergh High School Improvement projects. SUBSURFACE EXPLORATION Subsurface conditions at the project site were observed during completion of seven shallow-auger borings (EB-101 through EB-107) completed with a track-mounted drill rig on March 30, 2017. The borings were completed by an experienced geologist from our firm, and interpretive logs of the subsurface conditions encountered at each exploration location are attached with this report. Descriptions contained in the exploration logs are based on visual classification of the soils encountered, difficulty of exploration, and previous experience with similar soils. Representative samples of the materials encountered in the exploration borings were collected, placed in sealed plastic bags, and returned to our office for further visual evaluation. The approximate exploration boring locations are shown relative to existing site features on Figure 2, attached with this report. Exploration borings labeled EB-6 and EB-7 completed December 2009 were in the vicinity of our 2017 exploration work and are shown on Figure 2. Exploration logs for these two previous exploration borings are included in the attachments of this document. The conclusions and recommendations presented in this report are based on the explorations completed for this study. The number, locations, and depths of our explorations were completed within site and budget constraints. Because of the nature of exploratory work June 6, 2017 ASSOCIATED EARTH SCIENCES, INC. AWR/Id - 170046E001-6 - Projects\20170046\KE\WP Page 2 Lindbergh High School Bus Loop Limited Pavement Remediation King County, Washington Recommendations below ground, extrapolation of subsurface conditions between field explorations is necessary. It should be noted that differing subsurface conditions may sometimes be present due to the random nature of deposition and the alteration of topography by past grading and/or filling. The nature and extent of any variations between the field explorations may not become fully evident until construction. If variations are observed at that time, it may be necessary to re-evaluate specific recommendations in this report and make appropriate changes. SUBSURFACE CONDITIONS Stratigraphy Existing Fill Existing fill was encountered in exploration EB-102 to a depth of 6.5 feet below the existing ground surface and in exploration EB-104 to a depth of 5 feet below the existing ground surface. No crushed surfacing base or top course material was encountered under the asphalt in either of these exploration locations. Existing fill was typically medium dense to dense, which is consistent with what would be expected for compacted granular structural fill. The fill material consisted of a light grey-brown silty sand with trace gravel and was similar to the underlying native soils. We did not observe large concentrations of construction materials or organics in our exploration borings. Based on our observations the existing fill appears suitable to support landscaping and lightly loaded site improvements, such as walkways and pavement with proper preparation. Excavated existing fill material appears suitable for reuse in structural fill applications. Excavated existing fill is very silty and is expected to be highly moisture- sensitive when used in structural fill applications. Lodgement Till In EB-104 below the surficial fill and in EB-101, EB-103, EB-105, EB-106, and EB-107 below the existing asphalt, we encountered dense to very dense light grey-brown silty sands with gravel interpreted to represent Vashon lodgement till. Lodgement till was deposited at the base of an active continental glacier and was compacted by the weight of the overlying glacial ice. Lodgement till is suitable for structural support when properly prepared. Excavated lodgement till material is suitable for use in structural fill applications if suitable moisture conditions are achieved prior to compaction, and if such reuse is specifically allowed by project plans and specifications. At the time of exploration, we estimate that most or all of the lodgement till soils that we observed were above optimum moisture content for compaction purposes, and therefore will require drying during favorable weather prior to compaction in structural fill applications. June 6,2017 ASSOCIATED EARTH SCIENCES, INC. AWR/Id - 170046E001-6 - Projects\20170046\KE\WP Page 3 Lindbergh High School Bus Loop Limited Pavement Remediation King County, Washington Recommendations Published Geologic Map Our interpretations of subsurface conditions onsite are generally consistent with a published geologic map of the area, as represented by The Geologic Map of the Renton Quadrangle, Washington, by D.R. Mullineaux, 1965, United States Geological Survey (USGS) Geologic Quadrangle Map GQ-405. The published map indicates that the site is in an area characterized by lodgement till sediments at the ground surface. Hydrology Ground water seepage was encountered in explorations EB-101 and EB-104 completed for this study. In EB-101 the seepage was observed below the asphalt and in EB-104 was observed at a depth of 3 feet below the surface. We interpreted the observed ground water as perched ground water. Perched ground water can occur where water has infiltrated into the subsurface and become perched on low-permeability soils, such as the unweathered till. Ground water levels could vary in response to changes in season, precipitation, on- and off-site land use, and other factors. CONCLUSIONS AND RECOMMENDATIONS Our explorations encountered 1 to 3 inches of asphalt placed directly on a silty native till or fill subgrade. With no drainage layer or conveyance system under the existing pavement, the perched ground water remains under the pavement and results in faster deterioration during traffic loading. In addition, the perched ground water undergoes freeze thaw action which results in further pavement deterioration and is likely the cause of areas where the asphalt and subgrade have heaved, resulting in mounds within the existing asphalt. The attached Figure 2 is an aerial photo which shows the locations of our explorations. Also visible in this figure is dark staining of the existing asphalt caused by the presence of ground water. The locations of the staining generally correlate with the observed locations of the heaviest asphalt deterioration. Shallow Infiltration Feasibility Our explorations indicate that, from a geotechnical standpoint, the subject site is not suitable for shallow storm water infiltration. Our explorations encountered dense to very dense relatively impermeable glacial till soils that generally consisted of fine sands and silts. In two of our explorations we encountered existing fill soils overlying the glacial till sediments. Due to the fine-grained nature and relative density of the glacial till soils these sediments have very low permeability and do not serve as a suitable infiltration receptor. In addition, the relatively impermeable lodgement till acts as a perching layer which will cause water that is infiltrated into the ground to "perch" and flow laterally, potentially impacting adjacent structures, subgrades, utilities, and/or properties. This has been corroborated through our site reconnaissance and subsurface explorations where we observed existing perched ground water on top of native lodgement till and under existing pavement causing accelerated deterioration June 6, 2017 ASSOCIATED EARTH SCIENCES, INC. AWR/Id - 170046E001-6 - Projects\20170046\KE\WP Page 4 Lindbergh High School Bus Loop Limited Pavement Remediation King County, Washington Recommendations of the existing pavement necessitating the proposed pavement section repair. Existing fill soils are also not considered as a suitable infiltration receptor due to its variable nature. Drainage Outside of the footprint of the underground detention pipe system a pavement drainage system should be installed at the time of construction to intercept and divert perched ground water before it has an opportunity to reach the locations where the heaviest pavement deterioration was observed. The drainage system should consist of a series of drain trenches with perforated pipe as well as crushed rock base course layers under the new asphalt. We recommend that the trenches for the drain be excavated to a depth of 18 to 24 inches below the crushed surfacing material. The drain system should consist of strategically located 4-inch-diameter, perforated PVC pipe surrounded by material meeting Washington State Department of Transportation (WSDOT) Standard Specification 9-03.12(4) for "Gravel Backfill for Drains." At least 6 inches of drainage fill should surround the pipes on all sides. The drain pipes should be graded to drain via gravity toward the storm water detention pipe system where they will tie into the underdrain system for the detention pipes. The drain trenches should then be backfilled with 2-inch clean crushed rock or a quarry spall product. The free-draining fill should be separated from the native and fill soils by a filter fabric, such as Mirafi 140N. A suitable location for this drainage system can be found in Figure 3 included in the attachments of this document. It is not necessary to continue the drain pipes over the footprint of the proposed detention pipes as the backfill for the detention pipe will serve to drain perched water in that location. Therefore, we recommend that the backfill for the detention pipes consist of permeable crushed rock meeting WSDOT Standard Specification 9-03.12(4) for "Gravel Backfill for Drains." Temporary Cut Slopes In our opinion, stable construction slopes should be the responsibility of the contractor and should be determined during construction. For estimating purposes, however, we anticipate that temporary, unsupported cut slopes in the existing fill or weathered lodgement till can be made at a maximum slope of 1.5H:1V (Horizontal:Vertical) or flatter. Temporary slopes in unsaturated, unweathered lodgement till sediments may be planned at 1H:1V. As is typical with earthwork operations, some sloughing and raveling may occur, and cut slopes may have to be adjusted in the field. If ground water seepage is encountered in cut slopes, or if surface water is not routed away from temporary cut slope faces, flatter slopes will be required. In addition, WISHA/OSHA regulations should be followed at all times. Structural Fill Structural fill may be placed to attain desired grades. Structural fill is defined as non-organic soil, acceptable to the geotechnical engineer, placed in maximum 8-inch loose lifts, with each June 6, 2017 ASSOCIATED EARTH SCIENCES, INC. AWR/Id - 170046E001-6 - Projects\20170046\KE\WP Page 5 Lindbergh High School Bus Loop Limited Pavement Remediation King County, Washington Recommendations lift being compacted to 95 percent of the modified Proctor maximum density using American Society for Testing and Materials (ASTM) D-1557 as the standard. Use of soils from the site in structural fill applications is acceptable if the material meets the project specifications for the intended use, and if specifically allowed by project specifications. In the case of roadway and utility trench filling, structural fill should be placed and compacted in accordance with current King County codes and standards. The top of the compacted fill should extend horizontally outward a minimum distance of 3 feet beyond the locations of the roadway edges before sloping down at an angle of 2H:1V. The contractor should note that any proposed fill soils must be evaluated by Associated Earth Sciences, Inc. (AESI) prior to their use in fills. This would require that we have a sample of the material 72 hours in advance to perform a Proctor test and determine its field compaction standard. Soils in which the amount of fine-grained material (smaller than the No. 200 sieve) is greater than approximately 5 percent (measured on the minus No. 4 sieve size) should be considered moisture-sensitive. Use of moisture-sensitive soil in structural fills should be limited to favorable dry weather conditions, and is only permitted if specifically allowed by project plans and specifications. The native and existing fill soils present onsite contained significant amounts of silt and are considered highly moisture-sensitive. Existing fill can contain construction/ demolition materials and/or significant organic content in which case they are not suitable for reuse in structural fill applications. If fill is placed during wet weather or if proper compaction cannot be obtained, a select import material consisting of a clean, free- draining gravel and/or sand should be used. Free-draining fill consists of non-organic soil with the amount of fine-grained material limited to 5 percent by weight when measured on the minus No. 4 sieve fraction with at least 25 percent retained on the No. 4 sieve. A representative from our firm should inspect the stripped subgrade and be present during placement of structural fill to observe the work and perform a representative number of in-place density tests. In this way, the adequacy of the earthwork may be evaluated as filling progresses, and any problem areas may be corrected at that time. It is important to understand that taking random compaction tests on a part-time basis will not assure uniformity or acceptable performance of a fill. As such, we are available to aid the school district in developing a suitable monitoring and testing program. Parking Lot The interior parking lot and aisles will be subject to light traffic loads from passenger vehicles driving and parking. We understand that the existing pavement will be removed and that new crushed surfacing material and asphalt will be placed. Once the existing pavement is removed, any soft or loose areas exposed should be overexcavated to expose suitable native soils. Structural fill may then be placed to restore planned pavement subgrade elevations. Structural fill should consist of granular, non-organic soil free of debris and acceptable to the geotechnical engineer compacted in 8-inch lifts to a firm and unyielding condition and at least 95 percent of the modified Proctor maximum dry density. Once the subgrade is compacted and firm and June 6, 2017 ASSOCIATED EARTH SCIENCES, INC. AWR/Id - 170046E001-6 - Projects\20170046\KE\WP Page 6 Lindbergh High School Bus Loop Limited Pavement Remediation King County, Washington Recommendations unyielding, we recommend the placement of 21/2 inches of asphalt concrete pavement (ACP) underlain by a 3-inch compacted layer of crushed surfacing top course (WSDOT 9-03.9(3)). The crushed rock will provide improved and consistent drainage which will extend the service life of the parking lot. Bus Loop Area The bus loop area to be repaired will encounter heavier loading from buses along with passenger vehicles. We understand that the existing pavement will be removed in this area and that new crushed surfacing material and asphalt will be placed. Once the existing pavement is removed, any soft or loose areas exposed should be overexcavated to expose suitable native soils. Structural fill may then be placed to restore planned pavement subgrade elevations. Structural fill should consist of granular, non-organic soil free of debris and acceptable to the geotechnical engineer compacted in 8-inch lifts to a firm and unyielding condition and at least 95 percent of the modified Proctor maximum dry density. For the pavement section in this area we recommend 3 inches of ACP underlain by 2 inches of crushed surfacing top course (WSDOT 9-03.9(3)) and 3 inches of crushed surfacing base course (WSDOT 9-03.9(3)). CLOSURE We appreciate the opportunity to be of service on this project. If you have any questions, please do not hesitate to call. Sincerely, ASSOCIATED EARTH SCIENCES, INC. Kirkland, Washington 6,r / Anthony W. Romanick, P.E. Kurt D. Merriman, P.E. Project Engineer Senior Principal Engineer Attachments: Figure 1: Vicinity Map Figure 2: Site and Exploration Plan Figure 3: Proposed Drainage Location Exploration Logs EB-101 through EB-107 (2017), EB-6 and EB-7 (2009) June 6,2017 ASSOCIATED EARTH SCIENCES, INC. AWR/Id - 170046E001-6 - Projects\20170046\KEIWP Page 7 5 ; • . Copyright:9-2pliej)Jational SoccieFil.eybeci associated earth sciences incorporated 1000 2000 FEET VICINITY MAP DATE: 4/17 PROJ NO 170046E001 DATA SOURCES / REFERENCES: USGS: 24K SERIES TOPOGRAPHIC MAPS KING CO: STREETS, CITY LIMITS, PARCELS 02/17 LOCATIONS AND DISTANCES SHOWN ARE APPROXIMATE NOTE: BLACK AND WHITE REPRODUCTION OF THIS COLOR ORIGINAL MAY REDUCE ITS EFFECTIVENESS AND LEAD TO INCORRECT INTERPRETATION LINDBERGH HIGH SCHOOL BUS LOOP RENTON, WASHINGTON FIGURE: associated earth sciences Incorpora ted NOTES: 1. BASE MAP REFERENCE: CITY OF RENTON 2012 BLACK AND WHITE REPRODUCTION OF THIS COLOR ORIGINAL MAY REDUCE ITS EFFECTIVENESS AND LEAD TO INCORRECT INTERPRETATION. LEGEND: o EB EXPLORATION BORING • EB EXPLORATION BORING - DECEMBER 2009 WET PAVEMENT FROM PERCHED GROUND WATER CONTOUR INTERVAL = N/A NOTE: LOCATION AND DISTANCES SHOWN ARE APPROXIMATE. SITE AND EXPLORATION PLAN LINDBERGH HIGH SCHOOL RENTON, WASHINGTON I DATE I FIGURE 170046E001 4/17 2 PROJ NO. 70046 Lindbergh HS \ 170046 F3 Prop Drain 5-17.00r CAP PIPE FCR FUTURE CONNECOOd 1E116.50 IP (3E) OLF IA1 CPEP 0 1 '4-450.55 LEGEND: • PROPOSED DRAIN PIPES - CONNECT TO THE UNDER DRAINS (NOT SHOWN) FOR DETENTION PIPES - LOCATION AND METHOD OF CONNECTION TO BE DETERMINED BY THE CIVIL CONTOUR INTERVAL = 1' NOTE: LOCATION AND DISTANCES SHOWN ARE APPROXIMATE. NOTES: I. BASE MAP REFERENCE: AHBL, LINDBERGH HIGH SCHOOL PARKING LOT REPLACEMENT, GRADING AND DRAINAGE PLAN, SHEET C3.0, 5119/17. LF1iCIFEPOl. LF Sr EPEPO 10.06% - 1=17GICR 111.13 AREA 60220% wit BLACKAND WHITE REPRODUCTION OF THIS COLOR ORIGINAL MAY REDUCE ITS EFFECTIVENESS AND LEAD TO INCORRECT INTERPRETATION. 0 a ssociated earth sciences o ii 0 r II 0 i a t ,. d PROPOSED DRAINAGE LOCATION LINDBERGH HIGH SCHOOL RENTON, WASHINGTON I DATE: I FIGURE: 170046E001 5/17 I 3 PROJ NO. 20 40 FEET blocks \ dwg \ log_key.dwg LAYOUT: Layout 4-2014 Qty Chng Coarse-Grained Soils - More than 50%(1)Retained on No. 200 Sieve Gravels - More than 50% (1)of Coarse Fractionl Retained on No. 4 Sieve it e re) mi t w GW Well-graded gravel and gravel with sand, little to no fines Terms Describing Relative Density and Consistency Density SPT(2) blows/foot Very Loose 0 to 4 Coarse- Coarse- Grained Soils Loose 4 to 10 Medium Dense 10 to 30 Test Symbols Dense 30 to 50 Very Dense >50 G = Grain Size M = Moisture Content Consistency SPT(2)blows/foot A = Atterberg Limits 0 0 0 0 0 0 0 ( 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 GP Poorly-graded gravel and gravel with sand, little to no fines — 'U i2 " 6\1 Ai "-2-„, `." (1," c:3 0 0 0' 0 0 GM Silty gravel and silty gravel with sand Very Soft 0 to 2 C = Chemical Fine- Soft 2 to 4 DD = Dry Density Grained Soils Medium Stiff 4 to 8 K = Permeability Stiff 8 to 15 Very Stiff 15 to 30 Hard >30 . ....-0.. .<•:?5- 1"GC Clayey gravel and clayey gravel with sand Component Definitions Descriptive Term Size Range and Sieve Number Sands - 50%(1)or More of Coarse Fraction Passes No. 4 Sieve 5% Fines (5) :•.•:•:•:- •:.:•:.:.: •...... SW Well-graded sand and sand with gravel, little to no fines Boulders Larger than 12" Cobbles 3" to 12" Gravel 3" to No. 4 (4.75 mm) Coarse Gravel 3" to 3/4" Fine Gravel 3/4" to No. 4 (4.75 mm) Sand No. 4 (4.75 mm) to No. 200 (0.075 mm) Coarse Sand No. 4 (4,75 mm) to No. 10 (2.00 mm) Medium Sand No. 10 (2.00 mm) to No. 40 (0.425 mm) Fine Sand No. 40 (0.425 mm) to No. 200 (0.075 mm) Silt and Clay Smaller than No. 200 (0.075 mm) • - SP Poorly-graded sand and sand with gravel, little to no fines 12% Fines (5) SM Silty sand and silty sand with gravel r SC Clayey sand and clayey sand with gravel (3) Estimated Percentage Component by Weight Moisture Content Dry - Absence of moisture, mercentage Trace <5 Some 5 to <12 Modifier 12 to <30 (silty, sandy, gravelly) ry modifier 30 to <50 Very (silty, sandy, gravelly) dusty, dry to the touch Slightly Moist - Perceptible moisture Moist - Damp but no visible water Very Moist - Water visible but not free draining Wet - Visible free water, usually from below water table Fine-Grained Soils - 50% Wor More Passes No. 200 Sieve Silts and Clays Liquid Limit Less than 50 _. 1" L Silt, sandy silt, gravelly silt, silt with sand or gravel j A CL Clay of low to medium plasticity; silty, sandy, or gravelly clay, lean clay _—_—_ 0 L Organic clay or silt of low plasticity Symbols Blows/6" or Sampler portion of 6" Type / 2 T OD Sampler Type . 10 Cement Cement grout surface seal i . Silts and Clays Liquid Limit 50 or More jj . MH Elastic silt, clayey silt, silt with micaceous or diatomaceous fine sand or silt Split-Spoon m Description (4) sBeearnite Sampler (SPT) Bulk sample Grab Sample M 20 Il 3.0" OD Split-Spoon Sampler - I 3.25" OD Split-Spoon Ring Sampler (4) al 3.0" OD Thin-Wall Tube Sampler (including Shelby tube) LAPIP 0 Portion not recovered 2-.•,_.-.- :. :-. •-• = ..-_— • —.• • — • __-- .-.- Filter pack with ::' blank casing section -•• Screened casing •. or Hydrotip - with filter pack End cap 4 CH Clay of high plasticity, sandy or gravelly clay, fat clay with sand or gravel i/;// ..."///,;, ;///;/ /i/ /% 'i//// // ) OH Organic clay or silt of medium to high plasticity (1) Percentage by dry weight (4) Depth of ground water (2) (SPT) Standard Penetration Test M AID = At time of drilling (ASTM D-1586) Static water level (date) (31 In General Accordance with Standard Practice for Description 151 Combined USCS symbols used for . and Identification of Soils (ASTM D-2488) fines between 5% and 12% >, 2 PT Peat, muck and other highly organic Soils ............. -I-i-x-÷-, Classifications of soils in this report are based on visual field and/or aboratory observations, which include density/consistency, moisture condition, grain size, and plasticity estimates and should not be construed to imply field or laboratory testing unless presented herein. Visual-manual and/or laboratory classification methods of ASTM D-2487 and D-2488 were used as an identification guide for the Unified Soil Classification System. associated earth sciences EXPLORATION LOG KEY 000 r r2 FIGURE Al 0- cO 0 0 0 0 .....w -,jj associated earth sciences incorporated Exploration Log Project Number 170046E001 Exploration Number EB-101 Sheet 1 of 1 Project Name Location Driller/Equipment Hammer Weight/Drop Lindbergh HS Ground Surface Elevation Start/Finish Diameter (in) (ft) N/A Renton. WA Datum Boretec / Mini-Track Date 3130/17,3/30/17 140# / 30" Hole 6 inches Depth (ft) cn Samples Graphic Symbol DESCRIPTION Well Completion Water Level Blows/6" Blows/Foot 10 20 30 40 Other Tests - 5 -10 - 15 _ S-1 S-2 — S-3 _ Asphalt - 2 inches - 6 21 41 33 50/4" 38 50/3' £62 £50/4" A50/3" Vashon Lodgement Till Very dense, moist, light gray-brown, silty, fine SAND, trace gravel; unsorted; some oxidation (SM). Very dense, moist, light gray-brown, silty, fine SAND, trace gravel; unsorted; no oxidation (SM). As above. Bottom of exploration boring at 6 feet Moderate seepage below asphalt layer. No visible seepage in native soils. Sampler _ Type (ST): 2" OD Split Spoon Sampler (SPT) I 3" OD Split Spoon Sampler (D n Grab Sample — No Recovery M - Moisture Logged by: TAG Water Level 0 Approved by: JHS Water Level at time of drilling (ATD) & M) I Ring Sample V Shelby Tube Sample T < >, associated earth sciences incorporated Exploration Log Project Number 170046E001 Exploration Number EB-102 Sheet 1 of 1 Project Name Location Driller/Equipment Hammer Weight/Drop Lindbergh HS Ground Surface Start/Finish Diameter (in) Elevation (ft) N/A Renton. WA Datum Boretec / Mini-Track Date 3/30/17,3/30/17 140# / 30" Hole 6 inches Depth (ft) —Q) Samples Graphic Symbol DESCRIPTION Well Completion Water Level Blows/6" Blows/Foot 10 20 30 40 Other Tests - 5 - 10 - 15 _ S-1 — S-2 _ ..- Asphalt - 3 inches 25 50/6" 34 22 19 A41 A50/6" Fill Very dense, moist, light gray-brown, very silty, fine SAND, trace gravel; dark brown inclusion (SM). Dense, moist, light gray-brown, very silty, fine SAND, trace gravel (SM). Bottom of exploration boring at 6.5 feet No visible seepage. Sampler Type (ST): 2" OD Split Spoon Sampler (SPT) No Recovery M - Moisture Logged by: TAG 111 3" OD Split Spoon Sampler (D & M) U Ring Sample V Water Level () Approved by: JHS Grab Sample Shelby Tube Sample T Water Level at time of drilling (ATD) <- > associated earth sciences incorporated Exploration Log Project Number 170046E001 Exploration Number EB-103 Sheet 1 of 1 Project Name Location Driller/Equipment Hammer Weight/Drop Lindbergh HS Ground Surface Start/Finish Diameter (in) Elevation (ft) N/A Renton. WA Datum Boretec / Mini-Track Date 3/30/17,3/30/17 140# / 30" Hole 6 inches Depth (ft) ct Samples Graphic Symbol DESCRIPTION Well Completion Water Level Blows/6" Blows/Foot 10 20 30 40 Other Tests — 5 — 10 — 15 — S-1 — — S-2 .._, Asphalt - 3 inches 16 22 25 34 50/5 A47 A50/5" Vashon Lodgement Till Dense, moist, light gray-brown, very silty, fine SAND, trace gravel; unsorted; some oxidation; low recovery (SM). Very dense, moist, light gray-brown, very silty, fine SAND, trace gravel; unsorted; no oxidation; low recovery (SM). Bottom of exploration boring at 6 feet No visible seepage. Sampler Type (ST): 2" OD Split Spoon Sampler (SPT) No Recovery M - Moisture Logged by: TAG I 3" OD Split Spoon Sampler (D & M) Ripg Sample Water Level () Approved by: JHS 15 Grab Sample I Shelby Tube Sample T Water Level at time of drilling (ATD) < ..> associated earth sciences incorporated Exploration Log Project Number 170046E001 Exploration Number EB-104 Sheet 1 of 1 Project Name Location Driller/Equipment Hammer Weight/Drop Lindbergh HS Ground Surface Start/Finish Diameter (in) Elevation (ft) N/A Renton WA Datum Boretec / Mini-Track Date 3/30/17,3/30/17 140# / 30" Hole 6 inches Depth (ft) -10) Samples Graphic Symbol DESCRIPTION Well Completion Water Level Blows/6" Blows/Foot 10 20 30 40 Other Tests - 5 - - 10 - 15 S-1 — S-2 _ f. \ Asphalt - 1 inch /- 13 10 9 14 28 30 A19 Fill ., Medium dense, very moist, light gray-brown, silty, fine to medium SAND, trace gravel (SM). 4168 Vashon Lodgement Till Very dense, moist, light gray-brown, very silty, fine SAND, trace gravel; unsorted; some oxidation (SM). Bottom of exploration boring at 6.5 feet Moderate seepage from 3 feet to bottom of boring. Sampler Type (ST): 2" OD Split Spoon Sampler (SPT) 11 3" OD Split Spoon Sampler (D .6 Grab Sample No Recovery M - Moisture Logged by: TAG Water Level () Approved by: JHS Water Level at time of drilling (ATD) & M) I Ring Sample V E Shelby Tube Sample T ‹. > associated earth sciences incorporated Exploration Log Project Number 170046E001 Exploration Number EB-105 Sheet 1 of 1 Project Name Location Driller/Equipment Hammer Weight/Drop Lindbergh HS Ground Surface Start/Finish Diameter (in) Elevation (ft) N/A Renton WA Datum Boretec / Mini-Track Date 3/30/17,3/30/17 140# / 30" Hole 6 inches Depth (ft) -IC!) Samples Graphic Symbol DESCRIPTION Well Completion Water Level Blows/6" Blows/Foot 10 20 30 40 Other Tests — 5 _ — 10 — 15 S-1 I S-2 — S-3 _ Asphalt - 2 inches .7 22 31 50/5 35 50/5" 4 '..53 A50/5" A50/5" , Vashon Lodgement Till Very dense, moist, light gray-brown, very silty, fine SAND, trace gravel; unsorted; some oxidation (SM). •Very dense, moist, light gray-brown, very silty, fine SAND, trace gravel; unsorted, no oxidation; low recovery (SM). As above. Bottom of exploration boring at 6 feet No visible seepage. Sampler I I Type (ST): 2" OD Split Spoon Sampler (SPT) — No Recovery M - Moisture Logged by: TAG 3" OD Split Spoon Sampler (D & M) U Ring Sample Water Level 0 Approved by: JHS Grab Sample Shelby Tube Sample T Water Level at time of drilling (ATD) 7104 ‹. > associated earth sciences incorporated Exploration Log Project Number 170046E001 Exploration Number EB-106 Sheet 1 of 1 Project Name Location Driller/Equipment Hammer Weight/Drop Lindbergh HS - Ground Surface Start/Finish Diameter (in) Elevation (ft) N/A Renton. WA Datum Boretec / Mini-Track Date 3/30/17,3/30/17 140# / 30" Hole 6 inches Depth (ft) Samples Graphic Symbol DESCRIPTION Well Completion Water Level Blows/6" Blows/Foot 10 20 30 40 Other Tests - - 5 - 10 - 15 S-1 S-2 — S-3 — Asphalt - 2 inches - 12 22 32 30 b014" 16 33 &Ye" A54 A50/4" A83 Vashon Lodgement Till Very dense, moist, light gray-brown, very silty, fine SAND, trace gravel; unsorted (SM). As above. As above. Bottom of exploration boring at 6.5 feet No visible seepage. I Sampler Type (ST): 2" OD Split Spoon Sampler (SPT) _ No Recovery M - Moisture Logged by: TAG 3" OD Split Spoon Sampler (D & M) U Ring Sample V Water Level () Approved by: JFis Grab Sample I Shelby Tube Sample T- Water Level at time of drilling (ATD) ie. > associated earth sciences in co r p or a t ed Exploration Log Project Number 170046E001 Exploration Number EB-107 Sheet 1 of 1 Project Name Location Driller/Equipment Hammer Weight/Drop Lindbergh HS Ground Surface Elevation Start/Finish Diameter (in) (ft) N/A Renton. WA Datum Boretec / Mini-Track Date 3/30/17,3/30/17 140# / 30" Hole 6 inches \ Depth (ft) Samples Graphic Symbol DESCRIPTION Well Completion Tu > = a),D —I cn tu g Blows/Foot 10 20 30 40 Other Tests — 5 — 10 - 15 — S-1 — S-2 — Asphalt - 2 inches - 19 26 31 39 50/5" A57 A50/5.' Vashon Lodgement Till Very dense, moist, light gray-brown, very silty, fine SAND, trace gravel; unsorted (SM). As above. Bottom of exploration boring at 6 feet No visible seepage. Sampler Type (ST): 2" OD Split Spoon Sampler (SPT) No Recovery M - Moisture Logged by: TAG 3" OD Split Spoon Sampler (D & M) 11 Ring Sample Water Level () Approved by: JHS Grab Sample Shelby Tube Sample T Water Level at time of drilling (ATD) II - -6 Technical Information Report Lindbergh High School South Parking Lot Improvements 2170057.10 Appendix C WWHM Report WWHM2012 PROJECT REPORT DETENTION DESIGN 2170057 7/7/2017 10:08:46 AM Page 2 General Model Information Project Name:2170057 Site Name: Site Address: City: Report Date:7/7/2017 Gage:Seatac Data Start:1948/10/01 Data End:2009/09/30 Timestep:15 Minute Precip Scale:1.00 Version Date:2016/03/03 Version:4.2.12 POC Thresholds Low Flow Threshold for POC1:50 Percent of the 2 Year High Flow Threshold for POC1:50 Year Low Flow Threshold for POC2:50 Percent of the 2 Year High Flow Threshold for POC2:50 Year 2170057 7/7/2017 10:08:46 AM Page 3 Landuse Basin Data Predeveloped Land Use Target Surface Bypass:No GroundWater:No Pervious Land Use acre C, Forest, Flat 0.9 Pervious Total 0.9 Impervious Land Use acre Impervious Total 0 Basin Total 0.9 Element Flows To: Surface Interflow Groundwater 2170057 7/7/2017 10:08:46 AM Page 4 Area 2A Bypass:No GroundWater:No Pervious Land Use acre C, Lawn, Flat 0.02 Pervious Total 0.02 Impervious Land Use acre PARKING FLAT 0.13 Impervious Total 0.13 Basin Total 0.15 Element Flows To: Surface Interflow Groundwater 2170057 7/7/2017 10:08:46 AM Page 5 Actual existing condition Bypass:No GroundWater:No Pervious Land Use acre C, Lawn, Flat 0.12 Pervious Total 0.12 Impervious Land Use acre PARKING FLAT 0.93 Impervious Total 0.93 Basin Total 1.05 Element Flows To: Surface Interflow Groundwater 2170057 7/7/2017 10:08:46 AM Page 6 Mitigated Land Use Area 2A Bypass:No GroundWater:No Pervious Land Use acre C, Lawn, Flat 0.02 Pervious Total 0.02 Impervious Land Use acre PARKING FLAT 0.13 Impervious Total 0.13 Basin Total 0.15 Element Flows To: Surface Interflow Groundwater Tank 1 Tank 1 2170057 7/7/2017 10:08:46 AM Page 7 Area 1 Bypass:No GroundWater:No Pervious Land Use acre C, Lawn, Flat 0.09 Pervious Total 0.09 Impervious Land Use acre PARKING FLAT 0.51 Impervious Total 0.51 Basin Total 0.6 Element Flows To: Surface Interflow Groundwater Tank 1 Tank 1 2170057 7/7/2017 10:08:46 AM Page 8 Area 2B Bypass:No GroundWater:No Pervious Land Use acre C, Lawn, Flat 0.03 Pervious Total 0.03 Impervious Land Use acre PARKING FLAT 0.27 Impervious Total 0.27 Basin Total 0.3 Element Flows To: Surface Interflow Groundwater Tank 1 Tank 1 2170057 7/7/2017 10:08:46 AM Page 9 Routing Elements Predeveloped Routing 2170057 7/7/2017 10:08:46 AM Page 10 Mitigated Routing Tank 1 Dimensions Depth:5 ft. Tank Type:Circular Diameter:5 ft. Length:885 ft. Discharge Structure Riser Height:4 ft. Riser Diameter:12 in. Orifice 1 Diameter:0.9375 in.Elevation:0.5 ft. Orifice 2 Diameter:0.5 in.Elevation:2.3 ft. Orifice 3 Diameter:1.125 in.Elevation:3 ft. Element Flows To: Outlet 1 Outlet 2 Tank Hydraulic Table Stage(feet)Area(ac.)Volume(ac-ft.)Discharge(cfs)Infilt(cfs) 0.0000 0.000 0.000 0.000 0.000 0.0556 0.021 0.000 0.000 0.000 0.1111 0.029 0.002 0.000 0.000 0.1667 0.036 0.004 0.000 0.000 0.2222 0.041 0.006 0.000 0.000 0.2778 0.046 0.008 0.000 0.000 0.3333 0.050 0.011 0.000 0.000 0.3889 0.054 0.014 0.000 0.000 0.4444 0.057 0.017 0.000 0.000 0.5000 0.061 0.020 0.000 0.000 0.5556 0.063 0.024 0.005 0.000 0.6111 0.066 0.027 0.008 0.000 0.6667 0.069 0.031 0.009 0.000 0.7222 0.071 0.035 0.011 0.000 0.7778 0.073 0.039 0.012 0.000 0.8333 0.075 0.043 0.013 0.000 0.8889 0.077 0.048 0.014 0.000 0.9444 0.079 0.052 0.015 0.000 1.0000 0.081 0.056 0.016 0.000 1.0556 0.082 0.061 0.017 0.000 1.1111 0.084 0.066 0.018 0.000 1.1667 0.085 0.070 0.019 0.000 1.2222 0.087 0.075 0.020 0.000 1.2778 0.088 0.080 0.021 0.000 1.3333 0.089 0.085 0.021 0.000 1.3889 0.091 0.090 0.022 0.000 1.4444 0.092 0.095 0.023 0.000 1.5000 0.093 0.100 0.023 0.000 1.5556 0.094 0.105 0.024 0.000 1.6111 0.094 0.111 0.025 0.000 1.6667 0.095 0.116 0.025 0.000 1.7222 0.096 0.121 0.026 0.000 1.7778 0.097 0.127 0.027 0.000 1.8333 0.097 0.132 0.027 0.000 1.8889 0.098 0.138 0.028 0.000 1.9444 0.099 0.143 0.028 0.000 2170057 7/7/2017 10:08:46 AM Page 11 2.0000 0.099 0.149 0.029 0.000 2.0556 0.100 0.154 0.029 0.000 2.1111 0.100 0.160 0.030 0.000 2.1667 0.100 0.165 0.030 0.000 2.2222 0.101 0.171 0.031 0.000 2.2778 0.101 0.176 0.031 0.000 2.3333 0.101 0.182 0.033 0.000 2.3889 0.101 0.188 0.034 0.000 2.4444 0.101 0.193 0.035 0.000 2.5000 0.101 0.199 0.036 0.000 2.5556 0.101 0.205 0.037 0.000 2.6111 0.101 0.210 0.038 0.000 2.6667 0.101 0.216 0.039 0.000 2.7222 0.101 0.222 0.040 0.000 2.7778 0.101 0.227 0.040 0.000 2.8333 0.100 0.233 0.041 0.000 2.8889 0.100 0.238 0.042 0.000 2.9444 0.100 0.244 0.042 0.000 3.0000 0.099 0.249 0.043 0.000 3.0556 0.099 0.255 0.052 0.000 3.1111 0.098 0.260 0.056 0.000 3.1667 0.097 0.266 0.059 0.000 3.2222 0.097 0.271 0.062 0.000 3.2778 0.096 0.277 0.064 0.000 3.3333 0.095 0.282 0.066 0.000 3.3889 0.094 0.287 0.069 0.000 3.4444 0.094 0.293 0.071 0.000 3.5000 0.093 0.298 0.073 0.000 3.5556 0.092 0.303 0.074 0.000 3.6111 0.091 0.308 0.076 0.000 3.6667 0.089 0.313 0.078 0.000 3.7222 0.088 0.318 0.080 0.000 3.7778 0.087 0.323 0.081 0.000 3.8333 0.085 0.328 0.083 0.000 3.8889 0.084 0.332 0.084 0.000 3.9444 0.082 0.337 0.086 0.000 4.0000 0.081 0.342 0.087 0.000 4.0556 0.079 0.346 0.228 0.000 4.1111 0.077 0.351 0.480 0.000 4.1667 0.075 0.355 0.795 0.000 4.2222 0.073 0.359 1.139 0.000 4.2778 0.071 0.363 1.478 0.000 4.3333 0.069 0.367 1.779 0.000 4.3889 0.066 0.371 2.018 0.000 4.4444 0.063 0.374 2.186 0.000 4.5000 0.061 0.378 2.303 0.000 4.5556 0.057 0.381 2.448 0.000 4.6111 0.054 0.384 2.564 0.000 4.6667 0.050 0.387 2.675 0.000 4.7222 0.046 0.390 2.781 0.000 4.7778 0.041 0.392 2.883 0.000 4.8333 0.036 0.394 2.982 0.000 4.8889 0.029 0.396 3.077 0.000 4.9444 0.021 0.398 3.170 0.000 5.0000 0.000 0.398 3.259 0.000 5.0556 0.000 0.000 3.347 0.000 2170057 7/7/2017 10:08:46 AM Page 12 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area:0.92 Total Impervious Area:0.13 Mitigated Landuse Totals for POC #1 Total Pervious Area:0.14 Total Impervious Area:0.91 Flow Frequency Method:Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.066203 5 year 0.089619 10 year 0.106398 25 year 0.129094 50 year 0.147114 100 year 0.16611 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.033229 5 year 0.047109 10 year 0.058294 25 year 0.074953 50 year 0.08938 100 year 0.105696 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.093 0.027 1950 0.088 0.031 1951 0.085 0.071 1952 0.049 0.025 1953 0.042 0.027 1954 0.055 0.030 1955 0.067 0.034 1956 0.064 0.034 1957 0.075 0.030 1958 0.050 0.029 2170057 7/7/2017 10:09:17 AM Page 13 1959 0.046 0.029 1960 0.083 0.064 1961 0.061 0.030 1962 0.039 0.023 1963 0.058 0.029 1964 0.055 0.028 1965 0.068 0.030 1966 0.050 0.027 1967 0.092 0.031 1968 0.071 0.027 1969 0.061 0.028 1970 0.062 0.028 1971 0.067 0.031 1972 0.080 0.040 1973 0.046 0.028 1974 0.063 0.029 1975 0.082 0.032 1976 0.061 0.030 1977 0.042 0.026 1978 0.054 0.030 1979 0.071 0.024 1980 0.106 0.049 1981 0.059 0.026 1982 0.105 0.055 1983 0.060 0.032 1984 0.047 0.025 1985 0.054 0.028 1986 0.081 0.042 1987 0.081 0.055 1988 0.042 0.026 1989 0.052 0.026 1990 0.181 0.057 1991 0.121 0.066 1992 0.054 0.028 1993 0.041 0.028 1994 0.035 0.023 1995 0.057 0.032 1996 0.109 0.070 1997 0.084 0.064 1998 0.052 0.028 1999 0.115 0.041 2000 0.064 0.032 2001 0.055 0.025 2002 0.074 0.047 2003 0.080 0.027 2004 0.098 0.084 2005 0.070 0.031 2006 0.066 0.030 2007 0.147 0.141 2008 0.139 0.084 2009 0.090 0.040 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.1807 0.1408 2 0.1468 0.0842 3 0.1387 0.0835 2170057 7/7/2017 10:09:17 AM Page 14 4 0.1207 0.0711 5 0.1147 0.0699 6 0.1087 0.0656 7 0.1056 0.0641 8 0.1047 0.0639 9 0.0984 0.0571 10 0.0927 0.0554 11 0.0918 0.0547 12 0.0901 0.0492 13 0.0876 0.0468 14 0.0852 0.0416 15 0.0840 0.0414 16 0.0825 0.0401 17 0.0821 0.0397 18 0.0813 0.0344 19 0.0808 0.0337 20 0.0797 0.0323 21 0.0796 0.0323 22 0.0750 0.0318 23 0.0738 0.0315 24 0.0710 0.0315 25 0.0707 0.0314 26 0.0700 0.0312 27 0.0680 0.0310 28 0.0669 0.0305 29 0.0667 0.0304 30 0.0661 0.0302 31 0.0639 0.0300 32 0.0635 0.0298 33 0.0629 0.0297 34 0.0625 0.0295 35 0.0614 0.0294 36 0.0608 0.0294 37 0.0606 0.0294 38 0.0604 0.0292 39 0.0590 0.0284 40 0.0576 0.0284 41 0.0571 0.0283 42 0.0554 0.0283 43 0.0549 0.0283 44 0.0548 0.0282 45 0.0539 0.0277 46 0.0537 0.0277 47 0.0536 0.0274 48 0.0525 0.0274 49 0.0517 0.0270 50 0.0502 0.0270 51 0.0499 0.0267 52 0.0488 0.0264 53 0.0475 0.0264 54 0.0464 0.0261 55 0.0456 0.0256 56 0.0424 0.0250 57 0.0420 0.0249 58 0.0416 0.0248 59 0.0410 0.0237 60 0.0388 0.0235 61 0.0350 0.0226 2170057 7/7/2017 10:09:17 AM Page 15 2170057 7/7/2017 10:09:17 AM Page 16 Duration Flows The Facility PASSED Flow(cfs)Predev Mit Percentage Pass/Fail 0.0331 4725 4605 97 Pass 0.0343 4261 4241 99 Pass 0.0354 3865 3835 99 Pass 0.0366 3493 3467 99 Pass 0.0377 3157 3035 96 Pass 0.0389 2858 2520 88 Pass 0.0400 2601 2072 79 Pass 0.0412 2363 1724 72 Pass 0.0423 2160 1344 62 Pass 0.0435 1959 997 50 Pass 0.0446 1790 959 53 Pass 0.0458 1618 933 57 Pass 0.0469 1484 888 59 Pass 0.0481 1355 866 63 Pass 0.0492 1249 843 67 Pass 0.0504 1135 828 72 Pass 0.0515 1038 807 77 Pass 0.0527 955 784 82 Pass 0.0538 879 738 83 Pass 0.0550 799 698 87 Pass 0.0561 726 649 89 Pass 0.0573 672 590 87 Pass 0.0584 604 558 92 Pass 0.0596 553 520 94 Pass 0.0607 498 476 95 Pass 0.0619 460 438 95 Pass 0.0630 418 399 95 Pass 0.0642 391 354 90 Pass 0.0653 362 331 91 Pass 0.0665 336 300 89 Pass 0.0677 308 277 89 Pass 0.0688 275 257 93 Pass 0.0700 254 230 90 Pass 0.0711 231 201 87 Pass 0.0723 208 182 87 Pass 0.0734 196 167 85 Pass 0.0746 175 154 88 Pass 0.0757 161 141 87 Pass 0.0769 149 129 86 Pass 0.0780 141 115 81 Pass 0.0792 129 105 81 Pass 0.0803 117 95 81 Pass 0.0815 103 83 80 Pass 0.0826 94 72 76 Pass 0.0838 83 46 55 Pass 0.0849 76 24 31 Pass 0.0861 73 20 27 Pass 0.0872 66 14 21 Pass 0.0884 61 7 11 Pass 0.0895 55 7 12 Pass 0.0907 52 7 13 Pass 0.0918 47 6 12 Pass 0.0930 41 6 14 Pass 2170057 7/7/2017 10:09:17 AM Page 17 0.0941 37 6 16 Pass 0.0953 35 6 17 Pass 0.0964 34 6 17 Pass 0.0976 30 6 20 Pass 0.0987 25 6 24 Pass 0.0999 25 6 24 Pass 0.1010 22 6 27 Pass 0.1022 22 6 27 Pass 0.1034 20 6 30 Pass 0.1045 19 5 26 Pass 0.1057 18 5 27 Pass 0.1068 16 5 31 Pass 0.1080 15 4 26 Pass 0.1091 13 4 30 Pass 0.1103 13 4 30 Pass 0.1114 13 4 30 Pass 0.1126 13 4 30 Pass 0.1137 12 4 33 Pass 0.1149 10 4 40 Pass 0.1160 8 4 50 Pass 0.1172 8 4 50 Pass 0.1183 8 4 50 Pass 0.1195 7 4 57 Pass 0.1206 7 4 57 Pass 0.1218 6 3 50 Pass 0.1229 6 3 50 Pass 0.1241 6 3 50 Pass 0.1252 6 3 50 Pass 0.1264 6 3 50 Pass 0.1275 6 3 50 Pass 0.1287 6 3 50 Pass 0.1298 6 3 50 Pass 0.1310 6 3 50 Pass 0.1321 5 3 60 Pass 0.1333 5 3 60 Pass 0.1344 5 2 40 Pass 0.1356 5 1 20 Pass 0.1367 4 1 25 Pass 0.1379 4 1 25 Pass 0.1391 3 1 33 Pass 0.1402 3 1 33 Pass 0.1414 3 0 0 Pass 0.1425 3 0 0 Pass 0.1437 2 0 0 Pass 0.1448 2 0 0 Pass 0.1460 2 0 0 Pass 0.1471 1 0 0 Pass 2170057 7/7/2017 10:09:26 AM Page 21 Model Default Modifications Total of 0 changes have been made. PERLND Changes No PERLND changes have been made. IMPLND Changes No IMPLND changes have been made. 2170057 7/7/2017 10:09:26 AM Page 22 Appendix Predeveloped Schematic 2170057 7/7/2017 10:09:26 AM Page 23 Mitigated Schematic WWHM2012 PROJECT REPORT WATER QUALITY DESIGN 2170057 6/6/2017 11:35:59 AM Page 2 General Model Information Project Name:2170057 Site Name: Site Address: City: Report Date:6/6/2017 Gage:Seatac Data Start:1948/10/01 Data End:2009/09/30 Timestep:15 Minute Precip Scale:1.00 Version Date:2016/03/03 Version:4.2.12 POC Thresholds 2170057 6/6/2017 11:35:59 AM Page 4 Mitigated Land Use Filterra 1 Bypass:No GroundWater:No Pervious Land Use acre Pervious Total 0 Impervious Land Use acre PARKING FLAT 0.48 Impervious Total 0.48 Basin Total 0.48 Element Flows To: Surface Interflow Groundwater Filterra 1 Filterra 1 2170057 6/6/2017 11:35:59 AM Page 5 Filterra 2 Bypass:No GroundWater:No Pervious Land Use acre Pervious Total 0 Impervious Land Use acre PARKING FLAT 0.09 Impervious Total 0.09 Basin Total 0.09 Element Flows To: Surface Interflow Groundwater Filterra 2 Filterra 2 2170057 6/6/2017 11:35:59 AM Page 6 Filterra 3 Bypass:No GroundWater:No Pervious Land Use acre Pervious Total 0 Impervious Land Use acre PARKING FLAT 0.43 Impervious Total 0.43 Basin Total 0.43 Element Flows To: Surface Interflow Groundwater Filterra 3 Filterra 3 2170057 6/6/2017 11:35:59 AM Page 8 Mitigated Routing Filterra 1 Bottom Length:10.00 ft. Bottom Width:6.00 ft. Depth:0.75 ft. Side slope 1:0 To 1 Side slope 2:0 To 1 Side slope 3:0 To 1 Side slope 4:0 To 1 Filtration On Hydraulic conductivity:24.82 Depth of filter medium:1.8 Total Volume Infiltrated (ac-ft.):129.841 Total Volume Through Riser (ac-ft.):10.854 Total Volume Through Facility (ac-ft.):140.695 Percent Infiltrated:92.29 Total Precip Applied to Facility:0 Total Evap From Facility:0 Discharge Structure Riser Height:0.7 ft. Riser Diameter:48 in. Element Flows To: Outlet 1 Outlet 2 Sand Filter Hydraulic Table Stage(feet)Area(ac.)Volume(ac-ft.)Discharge(cfs)Infilt(cfs) 0.0000 0.001 0.000 0.000 0.000 0.0083 0.001 0.000 0.000 0.034 0.0167 0.001 0.000 0.000 0.034 0.0250 0.001 0.000 0.000 0.035 0.0333 0.001 0.000 0.000 0.035 0.0417 0.001 0.000 0.000 0.035 0.0500 0.001 0.000 0.000 0.035 0.0583 0.001 0.000 0.000 0.035 0.0667 0.001 0.000 0.000 0.035 0.0750 0.001 0.000 0.000 0.035 0.0833 0.001 0.000 0.000 0.036 0.0917 0.001 0.000 0.000 0.036 0.1000 0.001 0.000 0.000 0.036 0.1083 0.001 0.000 0.000 0.036 0.1167 0.001 0.000 0.000 0.036 0.1250 0.001 0.000 0.000 0.036 0.1333 0.001 0.000 0.000 0.037 0.1417 0.001 0.000 0.000 0.037 0.1500 0.001 0.000 0.000 0.037 0.1583 0.001 0.000 0.000 0.037 0.1667 0.001 0.000 0.000 0.037 0.1750 0.001 0.000 0.000 0.037 0.1833 0.001 0.000 0.000 0.038 0.1917 0.001 0.000 0.000 0.038 0.2000 0.001 0.000 0.000 0.038 0.2083 0.001 0.000 0.000 0.038 0.2167 0.001 0.000 0.000 0.038 0.2250 0.001 0.000 0.000 0.038 EXCEEDS 91% MINIMUM 2170057 6/6/2017 11:35:59 AM Page 9 0.2333 0.001 0.000 0.000 0.038 0.2417 0.001 0.000 0.000 0.039 0.2500 0.001 0.000 0.000 0.039 0.2583 0.001 0.000 0.000 0.039 0.2667 0.001 0.000 0.000 0.039 0.2750 0.001 0.000 0.000 0.039 0.2833 0.001 0.000 0.000 0.039 0.2917 0.001 0.000 0.000 0.040 0.3000 0.001 0.000 0.000 0.040 0.3083 0.001 0.000 0.000 0.040 0.3167 0.001 0.000 0.000 0.040 0.3250 0.001 0.000 0.000 0.040 0.3333 0.001 0.000 0.000 0.040 0.3417 0.001 0.000 0.000 0.041 0.3500 0.001 0.000 0.000 0.041 0.3583 0.001 0.000 0.000 0.041 0.3667 0.001 0.000 0.000 0.041 0.3750 0.001 0.000 0.000 0.041 0.3833 0.001 0.000 0.000 0.041 0.3917 0.001 0.000 0.000 0.042 0.4000 0.001 0.000 0.000 0.042 0.4083 0.001 0.000 0.000 0.042 0.4167 0.001 0.000 0.000 0.042 0.4250 0.001 0.000 0.000 0.042 0.4333 0.001 0.000 0.000 0.042 0.4417 0.001 0.000 0.000 0.042 0.4500 0.001 0.000 0.000 0.043 0.4583 0.001 0.000 0.000 0.043 0.4667 0.001 0.000 0.000 0.043 0.4750 0.001 0.000 0.000 0.043 0.4833 0.001 0.000 0.000 0.043 0.4917 0.001 0.000 0.000 0.043 0.5000 0.001 0.000 0.000 0.044 0.5083 0.001 0.000 0.000 0.044 0.5167 0.001 0.000 0.000 0.044 0.5250 0.001 0.000 0.000 0.044 0.5333 0.001 0.000 0.000 0.044 0.5417 0.001 0.000 0.000 0.044 0.5500 0.001 0.000 0.000 0.045 0.5583 0.001 0.000 0.000 0.045 0.5667 0.001 0.000 0.000 0.045 0.5750 0.001 0.000 0.000 0.045 0.5833 0.001 0.000 0.000 0.045 0.5917 0.001 0.000 0.000 0.045 0.6000 0.001 0.000 0.000 0.046 0.6083 0.001 0.000 0.000 0.046 0.6167 0.001 0.000 0.000 0.046 0.6250 0.001 0.000 0.000 0.046 0.6333 0.001 0.000 0.000 0.046 0.6417 0.001 0.000 0.000 0.046 0.6500 0.001 0.000 0.000 0.046 0.6583 0.001 0.000 0.000 0.047 0.6667 0.001 0.000 0.000 0.047 0.6750 0.001 0.000 0.000 0.047 0.6833 0.001 0.000 0.000 0.047 0.6917 0.001 0.001 0.000 0.047 0.7000 0.001 0.001 0.000 0.047 0.7083 0.001 0.001 0.032 0.048 2170057 6/6/2017 11:35:59 AM Page 10 0.7167 0.001 0.001 0.091 0.048 0.7250 0.001 0.001 0.167 0.048 0.7333 0.001 0.001 0.258 0.048 0.7417 0.001 0.001 0.361 0.048 0.7500 0.001 0.001 0.474 0.048 0.7583 0.001 0.001 0.598 0.049 2170057 6/6/2017 11:35:59 AM Page 11 Filterra 2 Bottom Length:4.00 ft. Bottom Width:4.00 ft. Depth:0.75 ft. Side slope 1:0 To 1 Side slope 2:0 To 1 Side slope 3:0 To 1 Side slope 4:0 To 1 Filtration On Hydraulic conductivity:24.82 Depth of filter medium:1.8 Total Volume Infiltrated (ac-ft.):12.669 Total Volume Through Riser (ac-ft.):0.385 Total Volume Through Facility (ac-ft.):13.053 Percent Infiltrated:97.06 Total Precip Applied to Facility:0 Total Evap From Facility:0 Discharge Structure Riser Height:0.7 ft. Riser Diameter:48 in. Element Flows To: Outlet 1 Outlet 2 Sand Filter Hydraulic Table Stage(feet)Area(ac.)Volume(ac-ft.)Discharge(cfs)Infilt(cfs) 0.0000 0.000 0.000 0.000 0.000 0.0083 0.000 0.000 0.000 0.009 0.0167 0.000 0.000 0.000 0.009 0.0250 0.000 0.000 0.000 0.009 0.0333 0.000 0.000 0.000 0.009 0.0417 0.000 0.000 0.000 0.009 0.0500 0.000 0.000 0.000 0.009 0.0583 0.000 0.000 0.000 0.009 0.0667 0.000 0.000 0.000 0.009 0.0750 0.000 0.000 0.000 0.009 0.0833 0.000 0.000 0.000 0.009 0.0917 0.000 0.000 0.000 0.009 0.1000 0.000 0.000 0.000 0.009 0.1083 0.000 0.000 0.000 0.009 0.1167 0.000 0.000 0.000 0.009 0.1250 0.000 0.000 0.000 0.009 0.1333 0.000 0.000 0.000 0.009 0.1417 0.000 0.000 0.000 0.009 0.1500 0.000 0.000 0.000 0.010 0.1583 0.000 0.000 0.000 0.010 0.1667 0.000 0.000 0.000 0.010 0.1750 0.000 0.000 0.000 0.010 0.1833 0.000 0.000 0.000 0.010 0.1917 0.000 0.000 0.000 0.010 0.2000 0.000 0.000 0.000 0.010 0.2083 0.000 0.000 0.000 0.010 0.2167 0.000 0.000 0.000 0.010 0.2250 0.000 0.000 0.000 0.010 0.2333 0.000 0.000 0.000 0.010 0.2417 0.000 0.000 0.000 0.010 EXCEEDS 91% MINIMUM 2170057 6/6/2017 11:35:59 AM Page 12 0.2500 0.000 0.000 0.000 0.010 0.2583 0.000 0.000 0.000 0.010 0.2667 0.000 0.000 0.000 0.010 0.2750 0.000 0.000 0.000 0.010 0.2833 0.000 0.000 0.000 0.010 0.2917 0.000 0.000 0.000 0.010 0.3000 0.000 0.000 0.000 0.010 0.3083 0.000 0.000 0.000 0.010 0.3167 0.000 0.000 0.000 0.010 0.3250 0.000 0.000 0.000 0.010 0.3333 0.000 0.000 0.000 0.010 0.3417 0.000 0.000 0.000 0.010 0.3500 0.000 0.000 0.000 0.011 0.3583 0.000 0.000 0.000 0.011 0.3667 0.000 0.000 0.000 0.011 0.3750 0.000 0.000 0.000 0.011 0.3833 0.000 0.000 0.000 0.011 0.3917 0.000 0.000 0.000 0.011 0.4000 0.000 0.000 0.000 0.011 0.4083 0.000 0.000 0.000 0.011 0.4167 0.000 0.000 0.000 0.011 0.4250 0.000 0.000 0.000 0.011 0.4333 0.000 0.000 0.000 0.011 0.4417 0.000 0.000 0.000 0.011 0.4500 0.000 0.000 0.000 0.011 0.4583 0.000 0.000 0.000 0.011 0.4667 0.000 0.000 0.000 0.011 0.4750 0.000 0.000 0.000 0.011 0.4833 0.000 0.000 0.000 0.011 0.4917 0.000 0.000 0.000 0.011 0.5000 0.000 0.000 0.000 0.011 0.5083 0.000 0.000 0.000 0.011 0.5167 0.000 0.000 0.000 0.011 0.5250 0.000 0.000 0.000 0.011 0.5333 0.000 0.000 0.000 0.011 0.5417 0.000 0.000 0.000 0.012 0.5500 0.000 0.000 0.000 0.012 0.5583 0.000 0.000 0.000 0.012 0.5667 0.000 0.000 0.000 0.012 0.5750 0.000 0.000 0.000 0.012 0.5833 0.000 0.000 0.000 0.012 0.5917 0.000 0.000 0.000 0.012 0.6000 0.000 0.000 0.000 0.012 0.6083 0.000 0.000 0.000 0.012 0.6167 0.000 0.000 0.000 0.012 0.6250 0.000 0.000 0.000 0.012 0.6333 0.000 0.000 0.000 0.012 0.6417 0.000 0.000 0.000 0.012 0.6500 0.000 0.000 0.000 0.012 0.6583 0.000 0.000 0.000 0.012 0.6667 0.000 0.000 0.000 0.012 0.6750 0.000 0.000 0.000 0.012 0.6833 0.000 0.000 0.000 0.012 0.6917 0.000 0.000 0.000 0.012 0.7000 0.000 0.000 0.000 0.012 0.7083 0.000 0.000 0.032 0.012 0.7167 0.000 0.000 0.091 0.012 0.7250 0.000 0.000 0.167 0.012 2170057 6/6/2017 11:35:59 AM Page 13 0.7333 0.000 0.000 0.258 0.012 0.7417 0.000 0.000 0.361 0.013 0.7500 0.000 0.000 0.474 0.013 0.7583 0.000 0.000 0.598 0.013 2170057 6/6/2017 11:35:59 AM Page 14 Filterra 3 Bottom Length:12.00 ft. Bottom Width:4.00 ft. Depth:0.75 ft. Side slope 1:0 To 1 Side slope 2:0 To 1 Side slope 3:0 To 1 Side slope 4:0 To 1 Filtration On Hydraulic conductivity:24.82 Depth of filter medium:1.8 Total Volume Infiltrated (ac-ft.):129.841 Total Volume Through Riser (ac-ft.):10.854 Total Volume Through Facility (ac-ft.):140.695 Percent Infiltrated:92.29 Total Precip Applied to Facility:0 Total Evap From Facility:0 Discharge Structure Riser Height:0.7 ft. Riser Diameter:48 in. Element Flows To: Outlet 1 Outlet 2 Sand Filter Hydraulic Table Stage(feet)Area(ac.)Volume(ac-ft.)Discharge(cfs)Infilt(cfs) 0.0000 0.001 0.000 0.000 0.000 0.0083 0.001 0.000 0.000 0.027 0.0167 0.001 0.000 0.000 0.027 0.0250 0.001 0.000 0.000 0.028 0.0333 0.001 0.000 0.000 0.028 0.0417 0.001 0.000 0.000 0.028 0.0500 0.001 0.000 0.000 0.028 0.0583 0.001 0.000 0.000 0.028 0.0667 0.001 0.000 0.000 0.028 0.0750 0.001 0.000 0.000 0.028 0.0833 0.001 0.000 0.000 0.028 0.0917 0.001 0.000 0.000 0.029 0.1000 0.001 0.000 0.000 0.029 0.1083 0.001 0.000 0.000 0.029 0.1167 0.001 0.000 0.000 0.029 0.1250 0.001 0.000 0.000 0.029 0.1333 0.001 0.000 0.000 0.029 0.1417 0.001 0.000 0.000 0.029 0.1500 0.001 0.000 0.000 0.029 0.1583 0.001 0.000 0.000 0.030 0.1667 0.001 0.000 0.000 0.030 0.1750 0.001 0.000 0.000 0.030 0.1833 0.001 0.000 0.000 0.030 0.1917 0.001 0.000 0.000 0.030 0.2000 0.001 0.000 0.000 0.030 0.2083 0.001 0.000 0.000 0.030 0.2167 0.001 0.000 0.000 0.030 0.2250 0.001 0.000 0.000 0.031 0.2333 0.001 0.000 0.000 0.031 0.2417 0.001 0.000 0.000 0.031 EXCEEDS 91% MINIMUM 2170057 6/6/2017 11:35:59 AM Page 15 0.2500 0.001 0.000 0.000 0.031 0.2583 0.001 0.000 0.000 0.031 0.2667 0.001 0.000 0.000 0.031 0.2750 0.001 0.000 0.000 0.031 0.2833 0.001 0.000 0.000 0.031 0.2917 0.001 0.000 0.000 0.032 0.3000 0.001 0.000 0.000 0.032 0.3083 0.001 0.000 0.000 0.032 0.3167 0.001 0.000 0.000 0.032 0.3250 0.001 0.000 0.000 0.032 0.3333 0.001 0.000 0.000 0.032 0.3417 0.001 0.000 0.000 0.032 0.3500 0.001 0.000 0.000 0.032 0.3583 0.001 0.000 0.000 0.033 0.3667 0.001 0.000 0.000 0.033 0.3750 0.001 0.000 0.000 0.033 0.3833 0.001 0.000 0.000 0.033 0.3917 0.001 0.000 0.000 0.033 0.4000 0.001 0.000 0.000 0.033 0.4083 0.001 0.000 0.000 0.033 0.4167 0.001 0.000 0.000 0.034 0.4250 0.001 0.000 0.000 0.034 0.4333 0.001 0.000 0.000 0.034 0.4417 0.001 0.000 0.000 0.034 0.4500 0.001 0.000 0.000 0.034 0.4583 0.001 0.000 0.000 0.034 0.4667 0.001 0.000 0.000 0.034 0.4750 0.001 0.000 0.000 0.034 0.4833 0.001 0.000 0.000 0.035 0.4917 0.001 0.000 0.000 0.035 0.5000 0.001 0.000 0.000 0.035 0.5083 0.001 0.000 0.000 0.035 0.5167 0.001 0.000 0.000 0.035 0.5250 0.001 0.000 0.000 0.035 0.5333 0.001 0.000 0.000 0.035 0.5417 0.001 0.000 0.000 0.035 0.5500 0.001 0.000 0.000 0.036 0.5583 0.001 0.000 0.000 0.036 0.5667 0.001 0.000 0.000 0.036 0.5750 0.001 0.000 0.000 0.036 0.5833 0.001 0.000 0.000 0.036 0.5917 0.001 0.000 0.000 0.036 0.6000 0.001 0.000 0.000 0.036 0.6083 0.001 0.000 0.000 0.036 0.6167 0.001 0.000 0.000 0.037 0.6250 0.001 0.000 0.000 0.037 0.6333 0.001 0.000 0.000 0.037 0.6417 0.001 0.000 0.000 0.037 0.6500 0.001 0.000 0.000 0.037 0.6583 0.001 0.000 0.000 0.037 0.6667 0.001 0.000 0.000 0.037 0.6750 0.001 0.000 0.000 0.037 0.6833 0.001 0.000 0.000 0.038 0.6917 0.001 0.000 0.000 0.038 0.7000 0.001 0.000 0.000 0.038 0.7083 0.001 0.000 0.032 0.038 0.7167 0.001 0.000 0.091 0.038 0.7250 0.001 0.000 0.167 0.038 2170057 6/6/2017 11:35:59 AM Page 16 0.7333 0.001 0.000 0.258 0.038 0.7417 0.001 0.000 0.361 0.038 0.7500 0.001 0.000 0.474 0.039 0.7583 0.001 0.000 0.598 0.039 2170057 6/6/2017 11:35:59 AM Page 18 Model Default Modifications Total of 0 changes have been made. PERLND Changes No PERLND changes have been made. IMPLND Changes No IMPLND changes have been made. 2170057 6/6/2017 11:35:59 AM Page 20 Mitigated Schematic 2170057 6/6/2017 11:35:59 AM Page 32 Disclaimer Legal Notice This program and accompanying documentation are provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by End User. Clear Creek Solutions Inc. and the governmental licensee or sublicensees disclaim all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions Inc. be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions Inc. or their authorized representatives have been advised of the possibility of such damages. Software Copyright © by : Clear Creek Solutions, Inc. 2005-2017; All Rights Reserved. Clear Creek Solutions, Inc. 6200 Capitol Blvd. Ste F Olympia, WA. 98501 Toll Free 1(866)943-0304 Local (360)943-0304 www.clearcreeksolutions.com Technical Information Report Lindbergh High School South Parking Lot Improvements 2170057.10 Appendix D Conveyance Calculations Page 1 of 18 Project: Lindbergh High School South Parking Lot Improvements Project Number: 2170057.10 Task: Conveyance Calculations Date: 5/31/2017, revised July 7, 2017 Performed By: Brian Schend, P.E. Reference: 2016 City of Renton Surface Water Design Manual Design Requirements: Rational Method Convey and Contain 25-Year Peak Flow with 6 Inches Freeboard Convey and Contain 100-Year Peak Flow without creating or aggravating a severe flooding problem. Assumptions: The detention tank is treated as a single node point with no outlet. The tank outlet was modeled using a dummy basin that was sized to match the WWHM outlet flow frequency peaks as closely as possible. All pipes modeled as CMP with Manning’s n=0.022 Software Used: StormSHED2G, Release 7,0,0,13 SBUH modeling Summary: Proposed conveyance system maintains 6 inches freeboard in the 25-year design event and the 100-year design event. Page 2 of 18 Conveyance Layout Layout Report: Lindbergh HS Event Precip (in) 2 year 2.0000 10 year 2.9000 25 year 3.4000 100 year 3.9000 Page 3 of 18 Reach Records Record Id: 1 to 14 Section Shape: Circular Uniform Flow Method: Manning's Coefficient: 0.0220 Routing Method: Travel Time Translation DnNode 0014 UpNode 0001 Material Plastic Size 12" Diam Ent Losses Beveled ring, 33.7 deg bevels Length 86.4800 ft Slope 4.23% Up Invert 421.4000 ft Dn Invert 417.7400 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 Drop across MH 0.0000 ft Ex/Infil Rate 0.0000 in/hr Up Invert 417.7400 ft Dn Invert 421.4000 ft Match inverts. DnNode 0014 UpNode 0001 Record Id: 1083 to 0014 Section Shape: Circular Uniform Flow Method: Manning's Coefficient: 0.0220 Routing Method: Travel Time Translation DnNode 0014 UpNode 1083 Material Conc-Spun Size 12" Diam Ent Losses Groove End w/Headwall Length 12.8000 ft Slope 1.17% Up Invert 417.9300 ft Dn Invert 417.7800 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 Drop across MH 0.0000 ft Ex/Infil Rate 0.0000 in/hr Page 4 of 18 Up Invert 417.7800 ft Dn Invert 417.9300 ft Match inverts. DnNode 0014 UpNode 1083 Record Id: 12 to 13 Section Shape: Circular Uniform Flow Method: Manning's Coefficient: 0.0220 Routing Method: Travel Time Translation DnNode 0013 UpNode 0012 Material Conc-Spun Size 12" Diam Ent Losses Groove End w/Headwall Length 17.3800 ft Slope 10.07% Up Invert 416.5000 ft Dn Invert 414.7500 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 Drop across MH 0.0000 ft Ex/Infil Rate 0.0000 in/hr Up Invert 414.7500 ft Dn Invert 416.5000 ft Match inverts. DnNode 0013 UpNode 0012 Record Id: 13 to 14 Section Shape: Circular Uniform Flow Method: Manning's Coefficient: 0.0220 Routing Method: Travel Time Translation DnNode 0014 UpNode 0013 Material Conc-Spun Size 12" Diam Ent Losses Groove End w/Headwall Length 30.5500 ft Slope 2.03% Up Invert 414.7500 ft Dn Invert 414.1300 ft Conduit Constraints Page 5 of 18 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 Drop across MH 0.0000 ft Ex/Infil Rate 0.0000 in/hr Up Invert 414.1300 ft Dn Invert 414.7500 ft Match inverts. DnNode 0014 UpNode 0013 Record Id: 1322 to 1348 Section Shape: Circular Uniform Flow Method: Manning's Coefficient: 0.0220 Routing Method: Travel Time Translation DnNode 1348 UpNode 1322 Material Plastic Size 12" Diam Ent Losses Beveled ring, 33.7 deg bevels Length 61.0000 ft Slope 1.03% Up Invert 426.7100 ft Dn Invert 426.0800 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 Drop across MH 0.0000 ft Ex/Infil Rate 0.0000 in/hr Up Invert 426.0800 ft Dn Invert 426.7100 ft Match inverts. DnNode 1348 UpNode 1322 Record Id: 1348 to 1349 Section Shape: Circular Uniform Flow Method: Manning's Coefficient: 0.0220 Routing Method: Travel Time Translation DnNode 1349 UpNode 1348 Material Plastic Size 12" Diam Ent Losses Beveled ring, 33.7 deg bevels Page 6 of 18 Length 76.6900 ft Slope 1.03% Up Invert 426.0600 ft Dn Invert 425.2679 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 Drop across MH 0.0000 ft Ex/Infil Rate 0.0000 in/hr Up Invert 425.2679 ft Dn Invert 426.0600 ft Match inverts. DnNode 1349 UpNode 1348 Record Id: 1349 to 1 Section Shape: Circular Uniform Flow Method: Manning's Coefficient: 0.0220 Routing Method: Travel Time Translation DnNode 0001 UpNode 1349 Material Plastic Size 12" Diam Ent Losses Beveled ring, 33.7 deg bevels Length 110.4100 ft Slope 3.51% Up Invert 425.2700 ft Dn Invert 421.4000 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 Drop across MH 0.0000 ft Ex/Infil Rate 0.0000 in/hr Up Invert 421.4000 ft Dn Invert 425.2700 ft Match inverts. DnNode 0001 UpNode 1349 Record Id: 14 to 15 Section Shape: Circular Uniform Flow Method: Manning's Coefficient: 0.0220 Routing Method: Travel Time Translation Page 7 of 18 DnNode 0015 UpNode 0014 Material Conc-Spun Size 12" Diam Ent Losses Groove End w/Headwall Length 62.4800 ft Slope 0.99% Up Invert 414.1300 ft Dn Invert 413.5100 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 Drop across MH 0.0000 ft Ex/Infil Rate 0.0000 in/hr Up Invert 413.5100 ft Dn Invert 414.1300 ft Match inverts. DnNode 0015 UpNode 0014 Record Id: 15 to 16 Section Shape: Circular Uniform Flow Method: Manning's Coefficient: 0.0220 Routing Method: Travel Time Translation DnNode 0016 UpNode 0015 Material Conc-Spun Size 12" Diam Ent Losses Groove End w/Headwall Length 35.0000 ft Slope 1.51% Up Invert 413.5100 ft Dn Invert 412.9800 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 Drop across MH 0.0000 ft Ex/Infil Rate 0.0000 in/hr Up Invert 412.9800 ft Dn Invert 413.5100 ft Match inverts. DnNode 0016 UpNode 0015 Record Id: 16 to 1362 Page 8 of 18 Section Shape: Circular Uniform Flow Method: Manning's Coefficient: 0.0220 Routing Method: Travel Time Translation DnNode 1362 UpNode 0016 Material Conc-Spun Size 12" Diam Ent Losses Groove End w/Headwall Length 170.4500 ft Slope 10.98% Up Invert 412.9800 ft Dn Invert 394.2700 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 Drop across MH 0.0000 ft Ex/Infil Rate 0.0000 in/hr Up Invert 394.2700 ft Dn Invert 412.9800 ft Match inverts. DnNode 1362 UpNode 0016 Page 9 of 18 Node Records Record Id: 0001 Descrip: Prototype Record Increment 0.10 ft Start El. 421.4000 ft Max El. 424.4000 ft Classification Catch Basin Structure Type CB-TYPE 1 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflector Catch 1.4160 ft Bottom Area 3.9700 sf Condition Existing Record Id: 0012 Descrip: Prototype Record Increment 0.10 ft Start El. 416.5000 ft Max El. 423.2700 ft Classification Catch Basin Structure Type CB-TYPE 2-60 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflector Catch 2.0000 ft Bottom Area 19.6340 sf Condition Existing Record Id: 0013 Descrip: Prototype Record Increment 0.10 ft Start El. 414.7500 ft Max El. 422.5000 ft Classification Catch Basin Structure Type CB-TYPE 2-96 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflector Catch 2.0000 ft Bottom Area 50.2650 sf Condition Existing Record Id: 0014 Descrip: Prototype Record Increment 0.10 ft Start El. 414.1300 ft Max El. 421.3000 ft Classification Catch Basin Structure Type CB-TYPE 2-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflector Page 10 of 18 Catch 2.0000 ft Bottom Area 12.5664 sf Condition Existing Record Id: 0015 Descrip: Prototype Record Increment 0.10 ft Start El. 413.5100 ft Max El. 419.9800 ft Classification Catch Basin Structure Type CB-TYPE 2-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflector Catch 2.0000 ft Bottom Area 12.5664 sf Condition Existing Record Id: 0016 Descrip: Prototype Record Increment 0.10 ft Start El. 412.9800 ft Max El. 416.9800 ft Classification Catch Basin Structure Type CB-TYPE 2-48 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflector Catch 2.0000 ft Bottom Area 12.5664 sf Condition Existing Record Id: 1083 Descrip: Prototype Record Increment 0.10 ft Start El. 417.9300 ft Max El. 421.7400 ft Classification Catch Basin Structure Type CB-TYPE 1 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflector Catch 1.4160 ft Bottom Area 3.9700 sf Condition Proposed Record Id: 1322 Descrip: Prototype Record Increment 0.10 ft Start El. 426.7100 ft Max El. 429.6900 ft Page 11 of 18 Classification Catch Basin Structure Type CB-TYPE 1 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflector Catch 1.4160 ft Bottom Area 3.9700 sf Condition Proposed Record Id: 1348 Descrip: Prototype Record Increment 0.10 ft Start El. 426.0600 ft Max El. 430.2500 ft Classification Catch Basin Structure Type CB-TYPE 1 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflector Catch 1.4160 ft Bottom Area 3.9700 sf Condition Proposed Record Id: 1349 Descrip: Prototype Record Increment 0.10 ft Start El. 425.2700 ft Max El. 428.6200 ft Classification Catch Basin Structure Type CB-TYPE 1 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflector Catch 1.4160 ft Bottom Area 3.9700 sf Condition Proposed Record Id: 1362 Descrip: Prototype Record Increment 0.10 ft Start El. 394.2700 ft Max El. 397.8000 ft Classification Catch Basin Structure Type CB-TYPE 1 Ent Ke Groove End w/Headwall (ke=0.20) Channelization Curved or Deflector Catch 1.4160 ft Bottom Area 3.9700 sf Condition Proposed Page 12 of 18 Contributing Drainage Areas Record Id: 0001 Design Method SBUH Rainfall type TYPE1A Hyd Intv 10.00 min Peaking Factor 484.00 Abstraction Coeff 0.20 Pervious Area (AMC 2) 0.28 ac DCIA 0.00 ac Pervious CN 98.00 DC CN 0.00 Pervious TC 2.18 min DC TC 0.00 min Pervious CN Calc Description SubArea Sub cn Paved parking 0.28 ac 100.00 Pervious Composited CN (AMC 2) 100.00 Pervious TC Calc Type Description Length Slope Coeff Misc TT Sheet Smooth Surfaces.: 0.011 230.00 ft 3.30% 0.0110 2.50 in 2.18 min Pervious TC 2.18 min Record Id: 1083 Design Method SBUH Rainfall type TYPE1A Hyd Intv 10.00 min Peaking Factor 484.00 Abstraction Coeff 0.20 Pervious Area (AMC 2) 0.27 ac DCIA 0.00 ac Pervious CN 98.00 DC CN 0.00 Pervious TC 1.87 min DC TC 0.00 min Pervious CN Calc Description SubArea Sub cn Paved parking 0.27 ac 100.00 Pervious Composited CN (AMC 2) 100.00 Pervious TC Calc Type Description Length Slope Coeff Misc TT Sheet Smooth Surfaces.: 0.011 200.00 ft 3.70% 0.0110 2.50 in 1.87 min Page 13 of 18 Pervious TC 1.87 min Record Id: 1322 Design Method SBUH Rainfall type TYPE1A Hyd Intv 10.00 min Peaking Factor 484.00 Abstraction Coeff 0.20 Pervious Area (AMC 2) 0.05 ac DCIA 0.00 ac Pervious CN 98.00 DC CN 0.00 Pervious TC 1.70 min DC TC 0.00 min Pervious CN Calc Description SubArea Sub cn Paved parking 0.05 ac 100.00 Pervious Composited CN (AMC 2) 100.00 Pervious TC Calc Type Description Length Slope Coeff Misc TT Sheet Smooth Surfaces.: 0.011 80.00 ft 0.75% 0.0110 2.50 in 1.70 min Pervious TC 1.70 min Record Id: 1348 Design Method SBUH Rainfall type TYPE1A Hyd Intv 10.00 min Peaking Factor 484.00 Abstraction Coeff 0.20 Pervious Area (AMC 2) 0.37 ac DCIA 0.00 ac Pervious CN 98.00 DC CN 0.00 Pervious TC 2.92 min DC TC 0.00 min Pervious CN Calc Description SubArea Sub cn Paved parking 0.37 ac 100.00 Pervious Composited CN (AMC 2) 100.00 Pervious TC Calc Page 14 of 18 Type Description Length Slope Coeff Misc TT Sheet Smooth Surfaces.: 0.011 280.00 ft 2.36% 0.0110 2.50 in 2.92 min Pervious TC 2.92 min Record Id: 1349 Design Method SBUH Rainfall type TYPE1A Hyd Intv 10.00 min Peaking Factor 484.00 Abstraction Coeff 0.20 Pervious Area (AMC 2) 0.38 ac DCIA 0.00 ac Pervious CN 98.00 DC CN 0.00 Pervious TC 2.93 min DC TC 0.00 min Pervious CN Calc Description SubArea Sub cn Paved parking 0.38 ac 100.00 Pervious Composited CN (AMC 2) 100.00 Pervious TC Calc Type Description Length Slope Coeff Misc TT Sheet Smooth Surfaces.: 0.011 310.00 ft 2.87% 0.0110 2.50 in 2.93 min Pervious TC 2.93 min Layout Hydrographs Hydrograph ID: 1362 - 100 year Area 1.6700 ac Hyd Int 10.00 min Base Flow Pending tt translation 3.24 min Peak flow 1.5378 cfs Peak Time 7.83 hrs Hyd Vol 0.4930 acft Time (hr) Flow (cfs) Time (hr) Flow (cfs) Time (hr) Flow (cfs) 0.67 0.0048 8.67 0.5603 16.33 0.1946 0.83 0.0186 8.83 0.4941 16.50 0.1945 1.00 0.0333 9.00 0.5166 16.67 0.1945 1.17 0.0501 9.17 0.4235 16.83 0.1945 1.33 0.0654 9.33 0.3707 17.00 0.1946 Page 15 of 18 1.50 0.0747 9.50 0.3890 17.17 0.1859 1.67 0.0877 9.67 0.3569 17.33 0.1802 1.83 0.0981 9.83 0.3428 17.50 0.1822 2.00 0.1050 10.00 0.3477 17.67 0.1815 2.17 0.1178 10.17 0.3203 17.83 0.1818 2.33 0.1280 10.33 0.3043 18.00 0.1817 2.50 0.1332 10.50 0.3099 18.17 0.1730 2.67 0.1390 10.67 0.2908 18.33 0.1674 2.83 0.1437 10.83 0.2804 18.50 0.1693 3.00 0.1481 11.00 0.2841 18.67 0.1686 3.17 0.1519 11.17 0.2742 18.83 0.1689 3.33 0.1554 11.33 0.2692 19.00 0.1688 3.50 0.1585 11.50 0.2710 19.17 0.1601 3.67 0.1682 11.67 0.2618 19.33 0.1545 3.83 0.1755 11.83 0.2565 19.50 0.1564 4.00 0.1767 12.00 0.2584 19.67 0.1557 4.17 0.1940 12.17 0.2492 19.83 0.1560 4.33 0.2057 12.33 0.2438 20.00 0.1559 4.50 0.2052 12.50 0.2457 20.17 0.1560 4.67 0.2234 12.67 0.2365 20.33 0.1560 4.83 0.2351 12.83 0.2311 20.50 0.1560 5.00 0.2343 13.00 0.2330 20.67 0.1560 5.17 0.2528 13.17 0.2324 20.83 0.1560 5.33 0.2646 13.33 0.2327 21.00 0.1560 5.50 0.2636 13.50 0.2327 21.17 0.1560 5.67 0.2823 13.67 0.2240 21.33 0.1560 5.83 0.2941 13.83 0.2184 21.50 0.1561 6.00 0.2928 14.00 0.2204 21.67 0.1561 6.17 0.3276 14.17 0.2197 21.83 0.1561 6.33 0.3500 14.33 0.2201 22.00 0.1561 6.50 0.3452 14.50 0.2200 22.17 0.1473 6.67 0.3981 14.67 0.2114 22.33 0.1417 6.83 0.4311 14.83 0.2057 22.50 0.1436 7.00 0.4230 15.00 0.2077 22.67 0.1429 7.17 0.4863 15.17 0.2070 22.83 0.1432 Page 16 of 18 7.33 0.5248 15.33 0.2073 23.00 0.1431 7.50 0.5150 15.50 0.2073 23.17 0.1432 7.67 1.1331 15.67 0.1986 23.33 0.1431 7.83 1.5378 15.83 0.1930 23.50 0.1432 8.00 1.4148 16.00 0.1949 23.67 0.1432 8.17 0.9577 16.17 0.1943 23.83 0.1432 8.33 0.6100 16.33 0.1946 24.00 0.1432 8.50 0.7312 16.50 0.1945 24.17 0.0468 Page 17 of 18 ROUTEHYD [] THRU [Lindbergh HS] USING TYPE1A AND [100 year] NOTZERO RELATIVE SCS/SBUH Reach ID Area (ac) Flow (cfs) Full Q (cfs) Full ratio nDepth (ft) Size nVel (ft/s) fVel (ft/s) CBasin / Hyd 1083 to 0014 0.2700 0.2587 2.2852 0.11 0.2271 12" Diam 1.9307 2.9096 1083 12 to 13 0.1300 0.1042 6.6984 0.02 0.0874 12" Diam 3.1082 8.5287 Control structure discharge 13 to 14 0.1300 0.1042 3.0073 0.03 0.1274 12" Diam 1.7883 3.8290 1322 to 1348 0.0500 0.0479 2.1453 0.02 0.1030 12" Diam 1.1223 2.7315 1322 1348 to 1349 0.4200 0.3968 2.1454 0.18 0.2915 12" Diam 2.0838 2.7316 1348 1349 to 1 0.8000 0.7550 3.9521 0.19 0.2964 12" Diam 3.8745 5.0320 1349 1 to 14 1.0800 1.0225 4.3427 0.24 0.3306 12" Diam 4.5132 5.5293 0001 14 to 15 1.4800 1.3855 2.1028 0.66 0.5923 12" Diam 2.8598 2.6774 15 to 16 1.4800 1.3855 2.5977 0.53 0.5195 12" Diam 3.3609 3.3075 16 to 1362 1.4800 1.3855 6.9939 0.20 0.3022 12" Diam 6.9193 8.9049 From Node To Node Rch Loss (ft) App (ft) Bend (ft) Junct Loss (ft) HW Loss Elev (ft) Max El (ft) 396.0000 0016 1362 413.6426 0.1754 0.0022 ------ 413.4695 416.9800 0015 0016 414.2400 0.1270 0.0073 ------ 414.1203 419.9800 No approach losses at node 0001 because inverts and/or crowns are offset. 0014 0015 414.8751 ------ ------ ------ 414.8751 421.3000 1083 0014 418.2265 ------ ------ ------ 418.2265 421.7400 0013 0014 414.9370 0.1500 0.0014 ------ 414.7884 422.5000 0012 0013 416.6273 ------ ------ ------ 416.6273 423.2700 0001 0014 421.9679 0.2331 0.0364 ------ 421.7712 424.4000 1349 0001 425.7506 0.0674 0.0053 ------ 425.6885 428.6200 Page 18 of 18 1348 1349 426.4324 0.0196 0.0134 ------ 426.4263 430.2500 1322 1348 426.8365 ------ ------ ------ 426.8365 429.6900 Technical Information Report Lindbergh High School South Parking Lot Improvements 2170057.10 Appendix E Operations and Maintenance Manual C I T Y O F R E N T O N S U R F A C E W A T E R D E S I G N M A N U A L 2017 City of Renton Surface Water Design Manual 12/12/2016 A-1 MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS This appendix contains the maintenance requirements for the following typical stormwater flow control and water quality facilities and on-site BMPs (ctrl/click the title to follow the link): No. 3 – Detention Tanks and Vaults No. 4 – Control Structure/Flow Restrictor No. 5 – Catch Basins and Manholes No. 6 – Conveyance Pipes and Ditches No. 11 – Grounds (landscaping) APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-6 NO. 3 – DETENTION TANKS AND VAULTS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash and debris which exceed 1 cubic foot per 1,000 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. Trash and debris cleared from site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations.No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations.Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive growth of grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Tank or Vault Storage Area Trash and debris Any trash and debris accumulated in vault or tank (includes floatables and non- floatables). No trash or debris in vault. Sediment accumulation Accumulated sediment depth exceeds 10% of the diameter of the storage area for ½ length of storage vault or any point depth exceeds 15% of diameter.Example: 72-inch storage tank would require cleaning when sediment reaches depth of 7 inches for more than ½ length of tank. All sediment removed from storage area. Tank Structure Plugged air vent Any blockage of the vent.Tank or vault freely vents. Tank bent out of shape Any part of tank/pipe is bent out of shape more than 10% of its design shape. Tank repaired or replaced to design. Gaps between sections, damaged joints or cracks or tears in wall A gap wider than ½-inch at the joint of any tank sections or any evidence of soil particles entering the tank at a joint or through a wall. No water or soil entering tank through joints or walls. Vault Structure Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch, any evidence of soil entering the structure through cracks or qualified inspection personnel determines that the vault is not structurally sound. Vault is sealed and structurally sound. Inlet/Outlet Pipes Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipes Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Access Manhole Cover/lid not in place Cover/lid is missing or only partially in place.An y open manhole requires immediate maintenance. Manhole access covered. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2017 City of Renton Surface Water Design Manual 12/12/2016 A-7 NO. 3 – DETENTION TANKS AND VAULTS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Access Manhole (cont.) Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated.Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. Large access doors/plate Damaged or difficult to open Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat; covers access opening completely. Lifting rings missing, rusted Lifting rings not capable of lifting weight of door or plate. Lifting rings sufficient to lift or remove door or plate. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-8 NO. 4 – CONTROL STRUCTURE/FLOW RESTRICTOR MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Structure Trash and debris Trash or debris of more than ½ cubic foot which is located immediately in front of the structure opening or is blocking capacity of the structure by more than 10%. No Trash or debris blocking or potentially blocking entrance to structure. Trash or debris in the structure that exceeds 1/3 the depth from the bottom of basin to invert the lowest pipe into or out of the basin. No trash or debris in the structure. Deposits of garbage exceeding 1 cubic foot in volume. No condition present which would attract or support the breeding of insects or rodents. Sediment accumulation Sediment exceeds 60% of the depth from the bottom of the structure to the invert of the lowest pipe into or out of the structure or the bottom of the FROP-T section or is within 6 inches of the invert of the lowest pipe into or out of the structure or the bottom of the FROP-T section. Sump of structure contains no sediment. Damage to frame and/or top slab Corner of frame extends more than ¾ inch past curb face into the street (If applicable). Frame is even with curb. Top slab has holes larger than 2 square inches or cracks wider than ¼ inch. Top slab is free of holes and cracks. Frame not sitting flush on top slab, i.e., separation of more than ¾ inch of the frame from the top slab. Frame is sitting flush on top slab. Cracks in walls or bottom Cracks wider than ½ inch and longer than 3 feet, any evidence of soil particles entering structure through cracks, or maintenance person judges that structure is unsound. Structure is sealed and structurally sound. Cracks wider than ½ inch and longer than 1 foot at the joint of any inlet/outlet pipe or any evidence of soil particles entering structure through cracks. No cracks more than 1/4 inch wide at the joint of inlet/outlet pipe. Settlement/ misalignment Structure has settled more than 1 inch or has rotated more than 2 inches out of alignment. Basin replaced or repaired to design standards. Damaged pipe joints Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering the structure at the joint of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of inlet/outlet pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations.Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Ladder rungs missing or unsafe Ladder is unsafe due to missing rungs, misalignment, rust, cracks, or sharp edges. Ladder meets design standards and allows maintenance person safe access. FROP-T Section Damaged FROP-T T section is not securely attached to structure wall and outlet pipe structure should support at least 1,000 lbs of up or down pressure. T section securely attached to wall and outlet pipe. Structure is not in upright position (allow up to 10% from plumb). Structure in correct position. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2017 City of Renton Surface Water Design Manual 12/12/2016 A-9 NO. 4 – CONTROL STRUCTURE/FLOW RESTRICTOR MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED FROP-T Section (cont.) Damaged FROP-T (cont.) Connections to outlet pipe are not watertight or show signs of deteriorated grout. Connections to outlet pipe are water tight; structure repaired or replaced and works as designed. Any holes—other than designed holes—in the structure. Structure has no holes other than designed holes. Cleanout Gate Damaged or missing cleanout gate Cleanout gate is missing.Replace cleanout gate. Cleanout gate is not watertight.Gate is watertight and works as designed. Gate cannot be moved up and down by one maintenance person. Gate moves up and down easily and is watertight. Chain/rod leading to gate is missing or damaged. Chain is in place and works as designed. Orifice Plate Damaged or missing orifice plate Control device is not working properly due to missing, out of place, or bent orifice plate. Plate is in place and works as designed. Obstructions to orifice plate Any trash, debris, sediment, or vegetation blocking the plate. Plate is free of all obstructions and works as designed. Overflow Pipe Obstructions to overflow pipe Any trash or debris blocking (or having the potential of blocking) the overflow pipe. Pipe is free of all obstructions and works as designed. Deformed or damaged lip of overflow pipe Lip of overflow pipe is bent or deformed.Overflow pipe does not allow overflow at an elevation lower than design Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Metal Grates (If applicable) Unsafe grate opening Grate with opening wider than 7/8 inch.Grate opening meets design standards. Trash and debris Trash and debris that is blocking more than 20% of grate surface. Grate free of trash and debris.footnote to guidelines for disposal Damaged or missing grate Grate missing or broken member(s) of the grate. Grate is in place and meets design standards. Manhole Cover/Lid Cover/lid not in place Cover/lid is missing or only partially in place.An y open structure requires urgent maintenance. Cover/lid protects opening to structure. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated.Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs. of lift. Cover/lid can be removed and reinstalled by one maintenance person. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-10 NO. 5 – CATCH BASINS AND MANHOLES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Structure Sediment accumulation Sediment exceeds 60% of the depth from the bottom of the catch basin to the invert of the 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. Sump of catch basin contains no sediment. Trash and debris Trash or debris of more than ½ cubic foot which is located immediately in front of the catch basin opening or is blocking capacity of the catch basin by more than 10%. No Trash or debris blocking or potentially blocking entrance to catch basin. Trash or debris in the catch basin that exceeds 1/3 the depth from the bottom of basin to invert the lowest pipe into or out of the basin. No trash or debris in the catch basin. Dead animals or vegetation that could generate odors that could cause complaints or dangerous gases (e.g., methane). No dead animals or vegetation present within catch basin. Deposits of garbage exceeding 1 cubic foot in volume. No condition present which would attract or support the breeding of insects or rodents. Damage to frame and/or top slab Corner of frame extends more than ¾ inch past curb face into the street (If applicable). Frame is even with curb. Top slab has holes larger than 2 square inches or cracks wider than ¼ inch. Top slab is free of holes and cracks. Frame not sitting flush on top slab, i.e., separation of more than ¾ inch of the frame from the top slab. Frame is sitting flush on top slab. Cracks in walls or bottom Cracks wider than ½ inch and longer than 3 feet, any evidence of soil particles entering catch basin through cracks, or maintenance person judges that catch basin is unsound. Catch basin is sealed and is structurally sound. Cracks wider than ½ inch and longer than 1 foot at the joint of any inlet/outlet pipe or any evidence of soil particles entering catch basin through cracks. No cracks more than 1/4 inch wide at the joint of inlet/outlet pipe. Settlement/ misalignment Catch basin has settled more than 1 inch or has rotated more than 2 inches out of alignment. Basin replaced or repaired to design standards. Damaged pipe joints Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering the catch basin at the joint of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of inlet/outlet pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations.Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2017 City of Renton Surface Water Design Manual 12/12/2016 A-11 NO. 5 – CATCH BASINS AND MANHOLES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Inlet/Outlet Pipe (cont.) Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Metal Grates (Catch Basins) Unsafe grate opening Grate with opening wider than 7/8 inch.Grate opening meets design standards. Trash and debris Trash and debris that is blocking more than 20% of grate surface. Grate free of trash and debris.footnote to guidelines for disposal Damaged or missing grate Grate missing or broken member(s) of the grate. Any open structure requires urgent maintenance. Grate is in place and meets design standards. Manhole Cover/Lid Cover/lid not in place Cover/lid is missing or only partially in place.An y open structure requires urgent maintenance. Cover/lid protects opening to structure. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated.Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs. of lift. Cover/lid can be removed and reinstalled by one maintenance person. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-12 NO. 6 – CONVEYANCE PIPES AND DITCHES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Pipes Sediment & debris accumulation Accumulated sediment or debris that exceeds 20% of the diameter of the pipe. Water flows freely through pipes. Vegetation/root growth in pipe Vegetation/roots that reduce free movement of water through pipes. Water flows freely through pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations.Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Damage to protective coating or corrosion Protective coating is damaged; rust or corrosion is weakening the structural integrity of any part of pipe. Pipe repaired or replaced. Damaged pipes Any dent that decreases the cross section area of pipe by more than 20% or is determined to have weakened structural integrity of the pipe. Pipe repaired or replaced. Ditches Trash and debris Trash and debris exceeds 1 cubic foot per 1,000 square feet of ditch and slopes. Trash and debris cleared from ditches. Sediment accumulation Accumulated sediment that exceeds 20% of the design depth. Ditch cleaned/flushed of all sediment and debris so that it matches design. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations.No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations.Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive vegetation growth Vegetation that reduces free movement of water through ditches. Water flows freely through ditches. Erosion damage to slopes Any erosion observed on a ditch slope.Slopes are not eroding. Rock lining out of place or missing (If applicable) One layer or less of rock exists above native soil area 5 square feet or more, any exposed native soil. Replace rocks to design standards. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2017 City of Renton Surface Water Design Manual 12/12/2016 A-17 NO. 11 – GROUNDS (LANDSCAPING) MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash and debris which exceed 1 cubic foot per 1,000 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. Trash and debris cleared from site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations.No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations.Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive growth of grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Trees and Shrubs Hazard tree identified Any tree or limb of a tree identified as having a potential to fall and cause property damage or threaten human life.A hazard tree identified by a qualified arborist must be removed as soon as possible. No hazard trees in facility. Damaged tree or shrub identified Limbs or parts of trees or shrubs that are split or broken which affect more than 25% of the total foliage of the tree or shrub. Trees and shrubs with less than 5% of total foliage with split or broken limbs. Trees or shrubs that have been blown down or knocked over. No blown down vegetation or knocked over vegetation.Trees or shrubs free of injury. Trees or shrubs which are not adequately supported or are leaning over, causing exposure of the roots. Tree or shrub in place and adequately supported; dead or diseased trees removed. Operation & Maintenance (OM) Manual v01 ® Bioretention Systems ENGINEERED SOLUTIONS www.ContechES.com/filterra | 800-338-1122 Table of Contents Overview • Filterra General Description • Filterra Schematic • Basic Operations • Design Maintenance • Maintenance Overview »Why Maintain? »When to Maintain? • Exclusion of Services • Maintenance Visit Summary • Maintenance Tools, Safety Equipment and Supplies • Maintenance Visit Procedure • Maintenance Checklist Resources • Example Filterra Project Maintenance Report Sheet • Example Filterra Structure Maintenance Report Sheet • Filterra Warranty • Drawing FTST-2: Filterra Standard Configuration Detail • Drawing FTNL-3: Filterra Narrow Length Configuration Detail • Drawing FTNW-3: Filterra Narrow Width Configuration Detail ® Bioretention Systems ENGINEERED SOLUTIONS www.ContechES.com/filterra | 800-338-1122 General Description The following general specifications describe the general operations and maintenance requirements for the Contech Engineered Solutions LLC stormwater bioretention filtration system, the Filterra. The system utilizes physical, chemical and biological mechanisms of a soil, plant and microbe complex to remove pollutants typically found in urban stormwater runoff. The treatment system is a fully equipped, pre-constructed drop-in place unit designed for applications in the urban landscape to treat contaminated runoff. Stormwater flows through a specially designed filter media mixture contained in a landscaped concrete container. The mixture immobilizes pollutants which are then decomposed, volatilized and incorporated into the biomass of the Filterra system’s micro/ macro fauna and flora. Stormwater runoff flows through the media and into an underdrain system at the bottom of the container, where the treated water is discharged. Higher flows bypass the Filterra to a downstream inlet or outfall. Maintenance is a simple, inexpensive and safe operation that does not require confined space access, pumping or vacuum equipment or specialized tools. Properly trained landscape personnel can effectively maintain Filterra Stormwater systems by following instructions in this manual. www.ContechES.com/filterra | 800-338-1122 Basic Operations Filterra is a bioretention system in a concrete box. Contaminated stormwater runoff enters the filter box through the curb inlet spreading over the 3-inch layer of mulch on the surface of the filter media. As the water passes through the mulch layer, most of the larger sediment particles and heavy metals are removed through sedimentation and chemical reactions with the organic material in the mulch. Water passes through the soil media where the finer particles are removed and other chemical reactions take place to immobilize and capture pollutants in the soil media. The cleansed water passes into an underdrain and flows to a pipe system or other appropriate discharge point. Once the pollutants are in the soil, the bacteria begin to break down and metabolize the materials and the plants begin to uptake and metabolize the pollutants. Some pollutants such as heavy metals, which are chemically bound to organic particles in the mulch, are released over time as the organic matter decomposes to release the metals to the feeder roots of the plants and the cells of the bacteria in the soil where they remain and are recycled. Other pollutants such as phosphorus are chemically bound to the soil particles and released slowly back to the plants and bacteria and used in their metabolic processes. Nitrogen goes through a very complex variety of biochemical processes where it can ultimately end up in the plant/bacteria biomass, turned to nitrogen gas or dissolves back into the water column as nitrates depending on soil temperature, pH and the availability of oxygen. The pollutants ultimately are retained in the mulch, soil and biomass with some passing out of the system into the air or back into the water. Design and Installation Each project presents different scopes for the use of Filterra systems. To ensure the safe and specified function of the stormwater BMP, Contech reviews each application before supply. Information and help may be provided to the design engineer during the planning process. Correct Filterra box sizing (by rainfall region) is essential to predict pollutant removal rates for a given area. The engineer shall submit calculations for approval by the local jurisdiction. The contractor is responsible for the correct installation of Filterra units as shown in approved plans. A comprehensive installation manual is available at www.conteches.com. Maintenance Why Maintain? All stormwater treatment systems require maintenance for effective operation. This necessity is often incorporated in your property’s permitting process as a legally binding BMP maintenance agreement. • Avoid legal challenges from your jurisdiction’s maintenance enforcement program. • Prolong the expected lifespan of your Filterra media. • Avoid more costly media replacement. • Help reduce pollutant loads leaving your property. Simple maintenance of the Filterra is required to continue effective pollutant removal from stormwater runoff before discharge into downstream waters. This procedure will also extend the longevity of the living biofilter system. The unit will recycle and accumulate pollutants within the biomass, but is also subjected to other materials entering the throat. This may include trash, silt and leaves etc. which will be contained within the void below the top grate and above the mulch layer. Too much silt may inhibit the Filterra’s® flow rate, which is the reason for site stabilization before activation. Regular replacement of the mulch stops accumulation of such sediment. When to Maintain? Contech includes a 1-year maintenance plan with each system purchase. Annual included maintenance consists of a maximum of two (2) scheduled visits. Additional maintenance may be necessary depending on sediment and trash loading (by Owner or at additional cost). The start of the maintenance plan begins when the system is activated for full operation. Full operation is defined as the unit installed, curb and gutter and transitions in place and activation (by Supplier) when mulch and plant are added and temporary throat protection removed. Activation cannot be carried out until the site is fully stabilized (full landscaping, grass cover, final paving and street sweeping completed). Maintenance visits are scheduled seasonally; the spring visit aims to clean up after winter loads including salts and sands while the fall visit helps the system by removing excessive leaf litter. It has been found that in regions which receive between 30-50 inches of annual rainfall, (2) two visits are generally required; regions with less rainfall often only require (1) one visit per annum. Varying land uses can affect maintenance frequency; e.g. some fast food restaurants require more frequent trash removal. Contributing drainage areas which are subject to new development wherein the recommended erosion and sediment control measures have not been implemented may require additional maintenance visits. Some sites may be subjected to extreme sediment or trash loads, requiring more frequent maintenance visits. This is the reason for detailed notes of maintenance actions per unit, helping the Supplier and Owner predict future maintenance frequencies, reflecting individual site conditions. Owners must promptly notify the (maintenance) Supplier of any damage to the plant(s), which constitute(s) an integral part of the bioretention technology. Owners should also advise other landscape or maintenance contractors to leave all maintenance to the Supplier (i.e. no pruning or fertilizing). www.ContechES.com/filterra | 800-338-1122 Exclusion of Services It is the responsibility of the owner to provide adequate irrigation when necessary to the plant of the Filterra system. Clean up due to major contamination such as oils, chemicals, toxic spills, etc. will result in additional costs and are not covered under the Supplier maintenance contract. Should a major contamination event occur the Owner must block off the outlet pipe of the Filterra (where the cleaned runoff drains to, such as drop inlet) and block off the throat of the Filterra. The Supplier should be informed immediately. Maintenance Visit Summary Each maintenance visit consists of the following simple tasks (detailed instructions below). 1. Inspection of Filterra and surrounding area 2. Removal of tree grate and erosion control stones 3. Removal of debris, trash and mulch 4. Mulch replacement 5. Plant health evaluation and pruning or replacement as necessary 6. Clean area around Filterra 7. Complete paperwork Maintenance Tools, Safety Equipment and Supplies Ideal tools include: camera, bucket, shovel, broom, pruners, hoe/rake, and tape measure. Appropriate Personal Protective Equipment (PPE) should be used in accordance with local or company procedures. This may include impervious gloves where the type of trash is unknown, high visibility clothing and barricades when working in close proximity to traffic and also safety hats and shoes. A T-Bar or crowbar should be used for moving the tree grates (up to 170 lbs ea.). Most visits require minor trash removal and a full replacement of mulch. See below for actual number of bagged mulch that is required in each unit size. Mulch should be a double shredded, hardwood variety; do not use colored or dyed mulch. Some visits may require additional Filterra engineered soil media available from the Supplier. Box Length Box Width Filter Surface Area (ft²)Volume at 3” (ft³)# of 2 ft³ Mulch Bags 4 4 4 4 2 6 4 6 6 3 8 4 8 8 4 6 6 9 9 5 8 6 12 12 6 10 6 15 15 8 12 6 18 18 9 13 7 23 23 12 www.ContechES.com/filterra | 800-338-1122 Maintenance Visit Procedure Keep sufficient documentation of maintenance actions to predict location specific maintenance frequencies and needs. An example Maintenance Report is included in this manual. 1. Inspection of Filterra and surrounding area • Record individual unit before maintenance with photograph (numbered). Record on Maintenance Report (see example in this document) the following: 2. Removal of tree grate and erosion control stones • Remove cast iron grates for access into Filterra box. • Dig out silt (if any) and mulch and remove trash & foreign items. 3. Removal of debris, trash and mulch • After removal of mulch and debris, measure distance from the top of the Filterra engineered media soil to the bottom of the top slab. If this distance is greater than 12”, add Filterra media (not top soil or other) to recharge to a 9” distance Record on Maintenance Report the following: Standing Water yes | no Damage to Box Structure yes | no Damage to Grate yes | no Is Bypass Clear yes | no If yes answered to any of these observations, record with close-up photograph (numbered). Record on Maintenance Report the following: Silt/Clay yes | no Cups/ Bags yes | no Leaves yes | no # of Buckets Removed ________ Record on Maintenance Report the following: Distance of Bottom of Top Slab (inches) ________ # of Buckets of Media Added ________ www.ContechES.com/filterra | 800-338-1122 4. Mulch replacement • Please see mulch specifications. • Add double shredded mulch evenly across the entire unit to a depth of 3”. • Ensure correct repositioning of erosion control stones by the Filterra inlet to allow for entry of trash during a storm event. • Replace Filterra grates correctly using appropriate lifting or moving tools, taking care not to damage the plant. 5. Plant health evaluation and pruning or replacement as necessary • Examine the plant’s health and replace if dead. • Prune as necessary to encourage growth in the correct directions 6. Clean area around Filterra • Clean area around unit and remove all refuse to be disposed of appropriately. 7. Complete paperwork • Deliver Maintenance Report and photographs to appropriate location (normally Contech during maintenance contract period). • Some jurisdictions may require submission of maintenance reports in accordance with approvals. It is the responsibility of the Owner to comply with local regulations. Record on Maintenance Report the following: Height above Grate (Feet) Width at Widest Point (feet) Health alive | dead Damage to Plant yes | no Plant Replaced yes | no www.ContechES.com/filterra | 800-338-1122 Maintenance Checklist Drainage System Failure Problem Conditions to Check Condition that Should Exist Actions Inlet Excessive sediment or trash accumulation. Accumulated sediments or trash impair free flow of water into Filterra. Inlet should be free of obstructions allowing free distributed flow of water into Filterra. Sediments and/or trash should be removed. Mulch Cover Trash and floatable debris accumulation. Excessive trash and/or debris accumulation. Minimal trash or other debris on mulch cover. Trash and debris should be removed and mulch cover raked level. Ensure bark nugget mulch is not used. Mulch Cover “Ponding” of water on mulch cover. “Ponding” in unit could be indicative of clogging due to excessive fine sediment accumulation or spill of petroleum oils. Stormwater should drain freely and evenly through mulch cover. Recommend contact manufacturer and replace mulch as a minimum. Vegetation Plants not growing or in poor condition. Soil/mulch too wet, evidence of spill. Incorrect plant selection. Pest infestation. Vandalism to plants. Plants should be healthy and pest free. Contact manufacturer for advice. Vegetation Plant growth excessive. Plants should be appropriate to the species and location of Filterra. Trim/prune plants in accordance with typical landscaping and safety needs. Structure Structure has visible cracks. Cracks wider than 1/2 inch or evidence of soil particles entering the structure through the cracks. Vault should be repaired. Maintenance is ideally to be performed twice annually. ENGINEERED SOLUTIONS © 2015 Contech Engineered Solutions LLC Revised 3/2/2016