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21-104847_preliminary TIR_11-16-2021_v3
Redondo Heights: Site C Land Use Permit Preliminary Technical Information Report November 2021 Redondo Heights: Site C – City of Federal Way i Technical Information Report November 2021 Prepared for: City of Federal Way Land Use Permit Prepared by: Jeremy Febus, PE Tom Jones Meghan Martella KPFF Consulting Engineers 1601 Fifth Avenue, Suite 1600 Seattle, WA 98101 (206) 622-5822 KPFF Project No. 2000638 11/12/2021 KPFF Consulting Engineers ii This page intentionally left blank. Redondo Heights: Site C – City of Federal Way iii Table of Contents 1. Project Overview ........................................................................................................................................... 1 2. Conditions and Requirements Summary ................................................................................................... 2 Core Requirement No. 1 – Discharge at the Natural Location ................................................................. 2 Core Requirement No. 2 – Off-Site Analysis ............................................................................................ 2 Core Requirement No. 3 – Flow Control Facilities ................................................................................... 2 Core Requirement No. 4 – Conveyance System ..................................................................................... 2 Core Requirement No. 5 – Construction Stormwater Pollution Prevention ............................................. 2 Core Requirement No. 6 – Maintenance and Operations ........................................................................ 2 Core Requirement No. 7 – Financial Guarantees and Liability ................................................................ 3 Core Requirement No. 8 – Water Quality ................................................................................................ 3 Core Requirement No. 9 – Flow Control BMPS ....................................................................................... 3 Special Requirement No. 1 – Other Adopted Area-Specific Requirements ............................................. 3 Special Requirement No. 2 – Flood Hazard Area Delineation ................................................................. 3 Special Requirement No. 3 – Flood Protection Facilities ......................................................................... 4 Special Requirement No. 4 – Source Controls ........................................................................................ 4 Special Requirement No. 5 – Oil Control ................................................................................................. 4 3. Off-site Analysis ............................................................................................................................................ 4 Task 1: Study Area Definition and Maps ................................................................................................. 4 Task 2: Resource Review ....................................................................................................................... 4 Task 3: Field Inspection .......................................................................................................................... 4 Task 4: Drainage System Description ..................................................................................................... 4 List of Figures Figure 1: Vicinity Map ............................................................................................................................................ 1 Appendices Appendix A – TIR Worksheet Appendix B – Existing Site Conditions Exhibit Appendix C – Downstream Drainage Map Appendix D – Proposed Site Conditions Exhibit Appendix E – Flow Control Calculations Appendix F – Water Quality BioPod Detail and WADOE GULD Documentation KPFF Consulting Engineers iv This page intentionally left blank. Redondo Heights – City of Federal Way 1 1. Project Overview The project proposes to construct multi-family residential units on parcel numbers 720480-0188 and 720480- 0190 totaling approximately 1.4263 acres located in Federal Way, Washington. The site improvements will include six multifamily residential buildings with associated drive aisles, parking, sidewalks, residential open space, drainage infrastructure and site utility services. The project site is bounded by existing multifamily residential units to the east and north; a muffler shop to the south, and Pacific Highway South to the west (See Figure 1 – Vicinity Map). The project site is currently undeveloped and is heavily vegetated with trees and various underbrush. Stormwater runoff generally sheet flows to a catch basin located within the northern portion of the site and discharges to the existing storm drain system located in Pacific Highway South. See Appendix B for existing conditions exhibit and Appendix C for downstream drainage exhibits The proposed drainage improvements include onsite conveyance system, water quality treatment facilities and a detention vault with flow control structure. The project proposes to outfall to an existing City drainage catch basin to the west that connects to the existing storm drain main in Pacific Highway South. See Appendix D for proposed conditions exhibit. This report is being prepared to for the City of Federal Way land use permit. The project is subject to the requirements of the 2016 King County Surface Water Design Manual (KCSWDM) and the City of Federal Way Addendum requirements. Figure 1: Vicinity Map KPFF Consulting Engineers 2 2. Conditions and Requirements Summary The project proposes greater than 2,000 square feet of new plus replaced impervious surface; therefore, a Full Drainage Review is required, that includes complying with all nine core requirements and all five special requirements. CORE REQUIREMENT NO. 1 – DISCHARGE AT THE NATURAL LOCATION The project site currently sheet flows to a catch basin located within the northern portion of the site and discharges to the existing storm drain system located in Pacific Highway South. The project proposes to outfall to an existing City drainage catch basin to the west that connects to the existing storm drain main in Pacific Highway South. CORE REQUIREMENT NO. 2 – OFF-SITE ANALYSIS A Level 1 downstream analysis is provided in Section 3. CORE REQUIREMENT NO. 3 – FLOW CONTROL FACILITIES The project is located in a Level 3 Flood Problem Flow Control area; therefore, the project is required to match historic site condition durations for 50% of the 2-year through the 50-year peak flows and match existing site condition 100-year peak flows for the post development discharge. Existing conditions are modeled as forested. The project is proposing a detention vault with flow control structure to meet the Level 3 flow control standard. See Appendix E for preliminary detention vault MGSFlood calculations demonstrating that the project meets the Level 3 Flow Control requirements. CORE REQUIREMENT NO. 4 – CONVEYANCE SYSTEM The project is providing a new conveyance system to collect and route the onsite runoff to the proposed detention system. The conveyance system will be designed to convey and contain the 25-year peak flow rates and meet requirements of the KCSWDM. CORE REQUIREMENT NO. 5 – CONSTRUCTION STORMWATER POLLUTION PREVENTION Temporary erosion and sediment control (TESC) measures will be implemented during construction. A preliminary TESC plan is provided for this project submittal. It is anticipated that a construction stormwater pollution prevention plan (CSWPPP) will be required for duration of construction activities. The preliminary TESC measures include but will not be limited to silt fence, inlet protection systems, interceptor swales and silt dikes, and portable sediment treatment tanks to manage erosion during construction activities. CORE REQUIREMENT NO. 6 – MAINTENANCE AND OPERATIONS The Owner will be responsible for the onsite drainage facility maintenance and operation. Onsite drainage facilities include catch basins, manholes, storm drain pipe, water quality facilities, and the detention vault and associated flow control structure. Coordination for maintenance responsibilities for the outfall pipe connection to the existing City drainage infrastructure will be determined prior to construction. Redondo Heights – City of Federal Way 3 CORE REQUIREMENT NO. 7 – FINANCIAL GUARANTEES AND LIABILITY All drainage facilities constructed or modified for this project will comply with the City’s financial guarantee requirements. CORE REQUIREMENT NO. 8 – WATER QUALITY The project is required to provide water quality facilities and meet the enhanced water quality treatment standard. The Oldcastle BioPod enhanced treatment system (or an approved equal) is being proposed to meet the enhanced water quality treatment requirements. This treatment facility has a general use level designation (GULD) by the Washington State Department of Ecology (WADOE) for enhanced treatment application. The treatment facilities are located upstream of the detention vault and have been preliminarily sized to meet KCSWDM requirements. See Appendix F for the BioPod general detail and WADOE GULD documentation. The final system decision will be made during construction document design and permitting. CORE REQUIREMENT NO. 9 – FLOW CONTROL BMPS This project is required to evaluate flow control Best Management Practice (BMP) to the maximum extent feasible and is subject to Large Lot BMP Requirements, as the project site is greater than 22,000 square feet. The evaluation of Flow Control BMPs is based on the requirements per KCSWDM, Section 1.2.9.2.2 and Appendix C.2. The following is the evaluation of the BMP categories and summary of implementation of BMPs where feasible: Full Dispersion: Full dispersion is not feasible, as the proposed improvements do not allow for sufficient on-site native vegetated flow paths for full dispersion. Full infiltration of roof runoff: Full infiltration is not feasible as the project is underlain with a glacial till soils that have limited infiltration. Full Infiltration, Partial Infiltration, Bioretention or Permeable Pavement: Infiltration is not feasible as the project is underlain with a glacial till soils that have limited infiltration. Basic Dispersion: Basic dispersion will be applied to roof downspouts use splash blocks and vegetated flows paths where feasible. Native Growth Retention: Native growth retention will be evaluated and retained where possible. Proposed improvements and grading activities may limit the available native growth retention areas onsite Post Amended Soils: Post Amended soils will be applied to landscape areas onsite. Perforated Pipe Connection: Perforated pipe connection are not recommended due to restrictive infiltration glacial till soils onsite. SPECIAL REQUIREMENT NO. 1 – OTHER ADOPTED AREA-SPECIFIC REQUIREMENTS This project does not fall under any area-specific requirements. SPECIAL REQUIREMENT NO. 2 – FLOOD HAZARD AREA DELINEATION No flood hazard areas are located within the proposed site. KPFF Consulting Engineers 4 SPECIAL REQUIREMENT NO. 3 – FLOOD PROTECTION FACILITIES The project does not contain a stream that has an existing flood protection facility. The project also does not propose to construct new or to modify an existing flood protection facility. SPECIAL REQUIREMENT NO. 4 – SOURCE CONTROLS Source control BMPs are anticipated to be implemented during construction activities. The contractor shall be responsible for monitoring stormwater runoff during construction activities and implement appropriate source control BMPs to prevent illicit discharges. It is not anticipated that permanent Source Control BMPs will be required for this project. SPECIAL REQUIREMENT NO. 5 – OIL CONTROL This project does not qualify as a high-use site; therefore, no oil controls are required. 3. Off-site Analysis TASK 1: STUDY AREA DEFINITION AND MAPS A Level 1 downstream analysis has been performed for this project in accordance with the KCSWDM. The analysis consists of a project mapping investigation, a field investigation of the site, and a verification of the downstream conveyance path. The study area extends to a point approximately a quarter mile downstream of the project site. Refer to Appendix C for the downstream drainage map. TASK 2: RESOURCE REVIEW The following resources were reviewed for this project: City of Federal Way record drawings and inspection documents. City of Federal Way GIS maps. Project Site Survey TASK 3: FIELD INSPECTION A field inspection was conducted during the process of surveying the project site. The downstream system consists of the proposed connection point to the existing catch basin and downstream piped conveyance system. Generally, the system was observed to be consistent with the City of Federal Way drainage information. There were no drainage concerns documented at the time of the field inspection. TASK 4: DRAINAGE SYSTEM DESCRIPTION Upstream Analysis The project is proposing to tie in to the existing 12” storm drain main in Pacific Highway South. The existing storm drain main flows to the north. Within the southern right-of-way area, runoff is collected in the gutter and discharged to existing catch basins along the curb line. There is an existing detention vault within the southern sidewalk area of the project site that detains right-of-way runoff before it re-enters the storm drain main. Redondo Heights – City of Federal Way 5 Downstream Analysis The existing 12” storm drain main Pacific Highway South flows north and runoff continues to be collected n catch basins along the curb line. Redondo Heights: Site C – City of Federal Way Appendix A Appendix A TIR Worksheet KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 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 _________________________ DPER Permit # ________________________ Location Township ______________ Range ________________ Section ________________ Site Address __________________________ _____________________________________ Part 3 TYPE OF PERMIT APPLICATION Part 4 OTHER REVIEWS AND PERMITS Landuse (e.g.,Subdivision / Short Subd. / UPD) Building (e.g.,M/F / Commercial / SFR) Clearing and 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 __________________ __________________ __________________ Part 6 SWDM ADJUSTMENT APPROVALS Type (circle one): Standard / Experimental / Blanket Description: (include conditions in TIR Section 2) ____________________________________________________________________________________ ____________________________________________________________________________________ ____________________________________________________________________________________ Approved Adjustment No. ______________________ Date of Approval: ______________________ 2016 Surface Water Design Manual 4/24/2016 1 22 4 33 Redondo Heights: Site CCity of Krikland 425-587-3828 123 5th Ave Tom Jones KPFF Consulting Engineers 206-622-5822 Kirkland, WA 98033 No Address Parcels 720480-0188 and -0190 11/15/2021 NA Lakehaven Water & Sewer 11/15/2021 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 7 MONITORING REQUIREMENTS Monitoring Required: Yes / No Start Date: _______________________ Completion Date: _______________________ Describe: _________________________________ _________________________________________ _________________________________________ Re: KCSWDM 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 ______________________ _____________________________________ Part 10 SOILS Soil Type _________________ _________________ _________________ _________________ Slopes _________________ _________________ _________________ _________________ Erosion Potential _________________ _________________ _________________ _________________ High Groundwater Table (within 5 feet) Other ________________________________ Sole Source Aquifer Seeps/Springs Additional Sheets Attached 2016 Surface Water Design Manual 4/24/2016 2 Fill soils over glacial till Erosion potential during construction to be addressed with ESC measures. Level 3 Flood Problem Flow Control and Enhanced WQ Treatment exist slopes are generally with 5%-15%, and slope from north to south KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 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) Level: 1 / 2 / 3 or Exemption Number ____________ Flow Control 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: _________________________ 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. ______________________ Landscape Management Plan: Yes / No Special Requirements (as applicable): Area Specific Drainage Requirements Type: CDA / SDO / MDP / BP / LMP / 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: 2016 Surface Water Design Manual 4/24/2016 3 onsite area 1.4263 acres 1 Detention Vault None. Flow Control BMPs glacial till soils limiting infiltration BMPs TBD TO BE PROVIDED KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet per Threshold Discharge Area) Source Control (comm ercial / 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: 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 Protection of Flow Control BMP Facilities (existing and proposed) Maintain 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 Facilities, restore operation of Flow Control BMP Facilities as necessary Flag limits of SAO 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 Flow Control BMPs Other ________________ ________________ ________________ ________________ ________________ ________________ Vegetated Flowpath Wetpool Filtration Oil Control Spill Control Flow Control BMPs Other ________________ ________________ ________________ ________________ ________________ ________________ ________________ 2016 Surface Water Design Manual 4/24/2016 4 Detention Vault Old Castle BioPod basic dispersion downspout splash block N/A Redondo Heights: Site C – City of Federal Way Appendix B Appendix B Existing Site Conditions Map VISITOR PARKINGVISITOR PARKING1601 5th Avenue, Suite 1600 Seattle, WA 98101 206.622.5822 www.kpff.com Redondo Heights: Site C – City of Federal Way Appendix C Appendix C Downstream Drainage Map VISITOR PARKINGVISITOR PARKING1601 5th Avenue, Suite 1600 Seattle, WA 98101 206.622.5822 www.kpff.com PROJECT SITE CITY OF FEDERAL WAY STORMWATER GIS MAP Redondo Heights: Site C – City of Federal Way Appendix D Appendix D Proposed Site Conditions Map VISITOR PARKINGVISITOR PARKING1601 5th Avenue, Suite 1600 Seattle, WA 98101 206.622.5822 www.kpff.com Redondo Heights: Site C – City of Federal Way Appendix E Appendix E Flow Control Calculations ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.52 Program License Number: 200410007 Project Simulation Performed on: 11/10/2021 11:03 AM Report Generation Date: 11/10/2021 11:03 AM ————————————————————————————————— Input File Name: Site C.fld Project Name: Redondo Frontage Analysis Title: Comments: ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 15 Full Period of Record Available used for Routing Precipitation Station : 96004005 Puget East 40 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961040 Puget East 40 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 1.559 1.559 Area of Links that Include Precip/Evap (acres) 0.000 0.000 Total (acres) 1.559 1.559 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Subbasin 1 ---------- -------Area (Acres) -------- Till Forest 1.559 ---------------------------------------------- Subbasin Total 1.559 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 ---------- Subbasin : Subbasin 1 ---------- -------Area (Acres) -------- Till Grass 0.259 Impervious 1.167 ---------------------------------------------- Subbasin Total 1.426 ---------- Subbasin : Subbasin 2 ---------- -------Area (Acres) -------- Till Grass 0.021 Impervious 0.112 ---------------------------------------------- Subbasin Total 0.132 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 2 ------------------------------------------ Link Name: New Structure Lnk1 Link Type: Structure Downstream Link Name: New Copy Lnk2 Prismatic Pond Option Used Pond Floor Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 110.50 Max Pond Elevation (ft) : 111.50 Storage Depth (ft) : 10.50 Pond Bottom Length (ft) : 45.0 Pond Bottom Width (ft) : 50.0 Pond Side Slopes (ft/ft) : L1= 0.00 L2= 0.00 W1= 0.00 W2= 0.00 Bottom Area (sq-ft) : 2250. Area at Riser Crest El (sq-ft) : 2,250. (acres) : 0.052 Volume at Riser Crest (cu-ft) : 23,625. (ac-ft) : 0.542 Area at Max Elevation (sq-ft) : 2250. (acres) : 0.052 Vol at Max Elevation (cu-ft) : 25,875. (ac-ft) : 0.594 PROPOSED SITE CONDITIONS REQUIRED VAULT VOLUME PROPOSED STORAGE DEPTH PROPOSED VAULT FOOTPRINT Hydraulic Conductivity (in/hr) : 0.00 Massmann Regression Used to Estimate Hydralic Gradient Depth to Water Table (ft) : 100.00 Bio-Fouling Potential : Low Maintenance : Average or Better Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 18.00 Common Length (ft) : 0.000 Riser Crest Elevation : 110.50 ft Hydraulic Structure Geometry Number of Devices: 3 ---Device Number 1 --- Device Type : Circular Orifice Control Elevation (ft) : 100.00 Diameter (in) : 0.50 Orientation : Horizontal Elbow : No ---Device Number 2 --- Device Type : Circular Orifice Control Elevation (ft) : 108.00 Diameter (in) : 0.50 Orientation : Horizontal Elbow : Yes ---Device Number 3 --- Device Type : Circular Orifice Control Elevation (ft) : 109.00 Diameter (in) : 1.50 Orientation : Horizontal Elbow : Yes ------------------------------------------ Link Name: New Copy Lnk2 Link Type: Copy Downstream Link: None **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 Number of Links: 2 ORIFICE DESIGN ********** Link: New Structure Lnk1 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 103.609 1.11-Year 104.000 1.25-Year 104.440 2.00-Year 105.966 3.33-Year 107.057 5-Year 108.297 10-Year 109.449 25-Year 110.111 50-Year 110.357 100-Year 110.487 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Subbasin 1 268.765 _____________________________________ Total: 268.765 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Subbasin 1 31.653 Subbasin: Subbasin 2 2.542 Link: New Structure Lnk1 0.000 Link: New Copy Lnk2 Not Applicable _____________________________________ Total: 34.195 Total Predevelopment Recharge is Greater than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 1.701 ac-ft/year, Post Developed: 0.216 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Links: 2 ********** Link: New Structure Lnk1 ********** Basic Wet Pond Volume (91% Exceedance): 5436. cu-ft Computed Large Wet Pond Volume, 1.5*Basic Volume: 8154. cu-ft Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 575.44 Inflow Volume Including PPT-Evap (ac-ft): 575.44 Total Runoff Infiltrated (ac-ft): 0.00, 0.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 575.33 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 0.00% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Subbasin 1 Scenario Postdeveloped Compliance Link: New Structure Lnk1 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 3.322E-02 2-Year 1.629E-02 5-Year 5.413E-02 5-Year 2.266E-02 10-Year 7.294E-02 10-Year 6.624E-02 25-Year 9.248E-02 25-Year 9.053E-02 50-Year 0.118 50-Year 9.762E-02 100-Year 0.128 100-Year 0.101 200-Year 0.199 200-Year 0.224 500-Year 0.295 500-Year 0.389 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals **** Flow Duration Performance **** Excursion at Predeveloped 50%Q2 (Must be Less Than or Equal to 0%): -5.8% PASS Maximum Excursion from 50%Q2 to Q2 (Must be Less Than or Equal to 0%): -5.8% PASS Maximum Excursion from Q2 to Q50 (Must be less than 10%): 900.0% FAIL Percent Excursion from Q2 to Q50 (Must be less than 50%): 74.0% FAIL ------------------------------------------------------------------------------------------------- FLOW DURATION DESIGN CRITERIA: FAIL ------------------------------------------------------------------------------------------------- **** LID Duration Performance **** Excursion at Predeveloped 8%Q2 (Must be Less Than 0%): 375.7% FAIL Maximum Excursion from 8%Q2 to 50%Q2 (Must be Less Than 0%): 553.5% FAIL ------------------------------------------------------------------------------------------------- LID DURATION DESIGN CRITERIA: FAIL ------------------------------------------------------------------------------------------------- ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.52 Program License Number: 200410007 Project Simulation Performed on: 11/10/2021 11:05 AM Report Generation Date: 11/10/2021 11:05 AM ————————————————————————————————— Input File Name: 100 year.fld Project Name: Redondo Frontage Analysis Title: Comments: ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 15 Full Period of Record Available used for Routing Precipitation Station : 96004005 Puget East 40 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961040 Puget East 40 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 1.559 1.559 Area of Links that Include Precip/Evap (acres) 0.000 0.000 Total (acres) 1.559 1.559 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Subbasin 1 ---------- -------Area (Acres) -------- Till Forest 1.426 Till Grass 0.021 Impervious 0.112 ---------------------------------------------- PER SECTION 1.2.3 OF THE KING COUNTY 2016 SURFACE WATER DESIGN MANUAL (CORE REQUIREMENT #3: FLOW CONTROL FACILITIES): Any required application of the Flood Problem Flow Control Areas facility requirement to replaced impervious surface may assume existing site conditions as the predeveloped condition for the purposes of matching the developed 100-year peak discharge rate to the predeveloped 100-year peak discharge rate. Subbasin Total 1.559 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 ---------- Subbasin : Subbasin 1 ---------- -------Area (Acres) -------- Till Grass 0.259 Impervious 1.167 ---------------------------------------------- Subbasin Total 1.426 ---------- Subbasin : Subbasin 2 ---------- -------Area (Acres) -------- Till Grass 0.021 Impervious 0.112 ---------------------------------------------- Subbasin Total 0.132 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 2 ------------------------------------------ Link Name: New Structure Lnk1 Link Type: Structure Downstream Link Name: New Copy Lnk2 Prismatic Pond Option Used Pond Floor Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 110.50 Max Pond Elevation (ft) : 111.50 Storage Depth (ft) : 10.50 Pond Bottom Length (ft) : 45.0 Pond Bottom Width (ft) : 50.0 Pond Side Slopes (ft/ft) : L1= 0.00 L2= 0.00 W1= 0.00 W2= 0.00 Bottom Area (sq-ft) : 2250. Area at Riser Crest El (sq-ft) : 2,250. (acres) : 0.052 Volume at Riser Crest (cu-ft) : 23,625. (ac-ft) : 0.542 Area at Max Elevation (sq-ft) : 2250. (acres) : 0.052 Vol at Max Elevation (cu-ft) : 25,875. REDEVELOPMENT BYPASS AREA (ac-ft) : 0.594 Hydraulic Conductivity (in/hr) : 0.00 Massmann Regression Used to Estimate Hydralic Gradient Depth to Water Table (ft) : 100.00 Bio-Fouling Potential : Low Maintenance : Average or Better Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 18.00 Common Length (ft) : 0.000 Riser Crest Elevation : 110.50 ft Hydraulic Structure Geometry Number of Devices: 3 ---Device Number 1 --- Device Type : Circular Orifice Control Elevation (ft) : 100.00 Diameter (in) : 0.50 Orientation : Horizontal Elbow : No ---Device Number 2 --- Device Type : Circular Orifice Control Elevation (ft) : 108.00 Diameter (in) : 0.50 Orientation : Horizontal Elbow : Yes ---Device Number 3 --- Device Type : Circular Orifice Control Elevation (ft) : 109.00 Diameter (in) : 1.50 Orientation : Horizontal Elbow : Yes ------------------------------------------ Link Name: New Copy Lnk2 Link Type: Copy Downstream Link: None **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 Number of Links: 2 ********** Link: New Structure Lnk1 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 103.609 1.11-Year 104.000 1.25-Year 104.440 2.00-Year 105.966 3.33-Year 107.057 5-Year 108.297 10-Year 109.449 25-Year 110.111 50-Year 110.357 100-Year 110.487 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Subbasin 1 248.477 _____________________________________ Total: 248.477 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Subbasin 1 31.653 Subbasin: Subbasin 2 2.542 Link: New Structure Lnk1 0.000 Link: New Copy Lnk2 Not Applicable _____________________________________ Total: 34.195 Total Predevelopment Recharge is Greater than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 1.573 ac-ft/year, Post Developed: 0.216 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Links: 2 ********** Link: New Structure Lnk1 ********** Basic Wet Pond Volume (91% Exceedance): 5436. cu-ft Computed Large Wet Pond Volume, 1.5*Basic Volume: 8154. cu-ft Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 575.44 Inflow Volume Including PPT-Evap (ac-ft): 575.44 Total Runoff Infiltrated (ac-ft): 0.00, 0.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 575.33 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 0.00% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Subbasin 1 Scenario Postdeveloped Compliance Link: New Structure Lnk1 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 5.948E-02 2-Year 1.629E-02 5-Year 8.925E-02 5-Year 2.266E-02 10-Year 0.115 10-Year 6.624E-02 25-Year 0.143 25-Year 9.053E-02 50-Year 0.175 50-Year 9.762E-02 100-Year 0.197 100-Year 0.101 200-Year 0.268 200-Year 0.224 500-Year 0.364 500-Year 0.389 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals **** Flow Duration Performance **** Excursion at Predeveloped 50%Q2 (Must be Less Than or Equal to 0%): -85.6% PASS Maximum Excursion from 50%Q2 to Q2 (Must be Less Than or Equal to 0%): -24.2% PASS Maximum Excursion from Q2 to Q50 (Must be less than 10%): 168.8% FAIL Percent Excursion from Q2 to Q50 (Must be less than 50%): 36.4% PASS ------------------------------------------------------------------------------------------------- FLOW DURATION DESIGN CRITERIA: FAIL ------------------------------------------------------------------------------------------------- **** LID Duration Performance **** Excursion at Predeveloped 8%Q2 (Must be Less Than 0%): 366.9% FAIL Maximum Excursion from 8%Q2 to 50%Q2 (Must be Less Than 0%): 396.6% FAIL ------------------------------------------------------------------------------------------------- LID DURATION DESIGN CRITERIA: FAIL ------------------------------------------------------------------------------------------------- Redondo Heights: Site C – City of Federal Way Appendix F Appendix F Water Quality BioPod Detail and WADOE GULD Documentation October 2019 GENERAL USE LEVEL DESIGNATION FOR BASIC (TSS), DISSOLVED METALS (ENHANCED), AND PHOSPHORUS TREATMENT For Oldcastle Infrastructure, Inc.’s The BioPod™ Biofilter (Formerly the TreePod Biofilter) Ecology’s Decision: Based on Oldcastle Infrastructure, Inc. application submissions for the The BioPod™ Biofilter (BioPod), Ecology hereby issues the following use level designation: 1. General Use Level Designation (GULD) for Basic, Enhanced, and Phosphorus Treatment: Sized at a hydraulic loading rate of 1.6 gallons per minute (gpm) per square foot (sq ft) of media surface area. Constructed with a minimum media thickness of 18-inches (1.5-feet). 2. Ecology approves the BioPod at the hydraulic loading rate listed above, to achieve the maximum water quality design flow rate. The water quality design flow rates are calculated 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 latest version of the Western Washington Hydrology Model or other Ecology- approved continuous runoff model. 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 methods described in Chapter 2.2.5 of the Stormwater Management Manual for Eastern Washington (SWMMEW) or local manual. 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. 3. The GULD has no expiration date, but may be amended or revoked by Ecology. Ecology’s Conditions of Use: The BioPod shall comply with these conditions: 1) Applicants shall design, assemble, install, operate, and maintain the BioPod installations in accordance with Oldcastle Infrastructure, Inc.’s applicable manuals and the Ecology Decision. 2) The minimum size filter surface-area for use in Washington is determined by using the design water quality flow rate (as determined in Ecology Decision, Item 3, above) and the Infiltration Rate (as identified in Ecology Decision, Item 1, above). 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 BioPod unit 3) BioPod media shall conform to the specifications submitted to and approved by Ecology 4) Maintenance: The required inspection/maintenance interval for stormwater treatment devices is often dependent on the efficiency of the device and 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. The BioPod is designed for a target maintenance interval of 1 year. Maintenance includes replacing the mulch, assessing plant health, removal of trash, and raking the top few inches of engineered media. A BioPod system tested at the Lake Union Ship Canal Test Facility in Seattle, WA required maintenance after 1.5 months, or 6.3% of a water year. Monitoring personnel observed similar maintenance issues with other systems evaluated at the Test Facility. The runoff from the Test Facility may be unusual and maintenance requirements of systems installed at the Test Facility may not be indicative of maintenance requirements for all sites. Test results provided to Ecology from a BioPod System evaluated in a lab following New Jersey Department of Environmental Protection Laboratory Protocol for Filtration MTDs have indicated the BioPod System is capable of longer maintenance intervals. Owners/operators must inspect BioPod systems for a minimum of twelve months from the start of post-construction operation to determine site-specific inspection/maintenance schedules and requirements. Owners/operators must conduct inspections monthly during the wet season, and every other month during the dry season. (According to the SWMMWW, the wet season in western Washington is October 1 to April 30. According to the SWMMEW, the wet season in eastern Washington is October 1 to June 30.) After the first year of operation, owners/operators must conduct inspections based on the findings during the first year of inspections. Conduct inspections by qualified personnel, follow manufacturer’s guidelines, and use methods capable of determining either a decrease in treated effluent flow rate and/or a decrease in pollutant removal ability. 5) Install the BioPod in such a manner that you bypass flows exceeding the maximum operating rate and you will not resuspend captured sediment. 6) Discharges from the BioPod shall not cause or contribute to water quality standards violations in receiving waters. Approved Alternate Configurations BioPod Internal Bypass 1) The BioPod Internal Bypass configuration may be combined with a Curb Inlet, Grated Inlet, and Piped-In Inlet. Water quality flows and peak flows are directed from the curb, overhead grate, or piped inlet to a contoured inlet rack. The inlet rack disperses water quality flows over the top surface of the biofiltration chamber. Excess flows are diverted over an curved bypass weir to the outlet area without passing through the treatment area. Both water quality flows and bypass flows are combined in the outlet area prior to being discharged out of the system. 2) To select a BioPod Internal Bypass unit, the designer must determine the size of the standard unit using the sizing guidance described above. Systems that have an internal bypass, may use the off-line water quality design flow rate. 3) The internal bypass configuration has a maximum flow rate of 900 gallons per minute. Sites where the anticipated flow rate at the treatment device is larger than 900 gpm must use an external bypass, or size the treatment device for the on-line water quality design flow rate. Applicant: Oldcastle Infrastructure, Inc. Applicant’s Address: 7100 Longe St, Suite 100 Stockton, CA 95206 Application Documents: Technical Evaluation Report TreePod™ BioFilter System Performance Certification Project, Prepared for Oldcastle, Inc., Prepared by Herrera Environmental Consultants, Inc. February 2018 Technical Memorandum: Response to Board of External Reviewers’ Comments on the Technical Evaluation Report for the TreePod™ Biofilter System Performance Certification Project, Oldcastle, Inc. and Herrera Environmental Consultants, Inc., February 2018 Technical Memorandum: Response to Board of External Reviewers’ Comments on the Technical Evaluation Report for the TreePod™ Biofilter System Performance Certification Project, Oldcastle, Inc. and Herrera Environmental Consultants, Inc., January 2018 Application for Pilot Use Level Designation, TreePod™ Biofilter – Stormwater Treatment System, Oldcastle Stormwater Solutions, May 2016 Emerging Stormwater Treatment Technologies Application for Certification: The TreePod™ Biofilter, Oldcastle Stormwater Solutions, April 2016 Applicant’s Use Level Request: General Use Level Designation as a Basic, Enhanced, and Phosphorus Treatment device in accordance with Ecology’s Stormwater Management Manual for Western Washington Applicant’s Performance Claims: Based on results from laboratory and field-testing, the applicant claims the BioPod™ Biofilter operating at a hydraulic loading rate of 153 inches per hour is able to remove: 80% of Total Suspended Solids (TSS) for influent concentrations greater than 100 mg/L and achieve a 20 mg/L effluent for influent concentrations less than 100 mg/L. 60% dissolved zinc for influent concentrations 0.02 to 0.3 mg/L. 30% dissolved copper for influent concentrations 0.005 to 0.02 mg/L. 50% or greater total phosphorus for influent concentrations 0.1 to 0.5 mg/L. Ecology’s Recommendations: Ecology finds that: Oldcastle Infrastructure, Inc. has shown Ecology, through laboratory and field testing, that the BioPod™ Biofilter is capable of attaining Ecology’s Basic, Total Phosphorus, and Enhanced treatment goals. Findings of Fact: Field Testing 1. Herrera Environmental Consultants, Inc. conducted monitoring of the BioPod™ Biofilter at the Lake Union Ship Canal Test Facility in Seattle Washington between November 2016 and April 2018. Herrera collected flow-weight composite samples during 14 separate storm events and peak flow grab samples during 3 separate storm events. The system was sized at an infiltration rate of 153 inches per hour or a hydraulic loading rate of 1.6 gpm/ft2. 2. The D50 of the influent PSD ranged from 3 to 292 microns, with an average D50 of 28 microns. 3. Influent TSS concentrations ranged from 17 mg/L to 666 mg/L, with a mean concentration of 98 mg/L. For all samples (influent concentrations above and below 100 mg/L) the bootstrap estimate of the lower 95 percent confidence limit (LCL 95) of the mean TSS reduction was 84% and the bootstrap estimate of the upper 95 percent confidence limit (UCL95) of the mean TSS effluent concentration was 8.2 mg/L. 4. Dissolved copper influent concentrations from the 17 events ranged from 9.0 µg/L to 21.1 µg/L. The 21.1 µg/L data point was reduced to 20.0 µg/L, the upper limit to the TAPE allowed influent concentration range, prior to calculating the pollutant removal. A bootstrap estimate of the LCL95 of the mean dissolved copper reduction was 35%. 5. Dissolved zinc influent concentrations from the 17 events ranged from 26.1 µg/L to 43.3 µg/L. A bootstrap estimate of the LCL95 of the mean dissolved zinc reduction was 71%. 6. Total phosphorus influent concentrations from the 17 events ranged from 0.064 mg/L to 1.56 mg/L. All influent data greater than 0.5 mg/L were reduced to 0.5 mg/L, the upper limit to the TAPE allowed influent concentration range, prior to calculating the pollutant removal. A bootstrap estimate of the LCL95 of the mean total phosphorus reduction was 64%. 7. The system experienced rapid sediment loading and needed to be maintained after 1.5 months. Monitoring personnel observed similar sediment loading issues with other systems evaluated at the Test Facility. The runoff from the Test Facility may not be indicative of maintenance requirements for all sites. Laboratory Testing 1. Good Harbour Laboratories (GHL) conducted laboratory testing at their site in Mississauga, Ontario in October 2017 following the New Jersey Department of Environmental Protection Laboratory Protocol for Filtration MTDs. The testing evaluated a 4-foot by 6-foot standard biofiltration chamber and inlet contour rack with bypass weir. The test sediment used during the testing was custom blended by GHL using various commercially available silica sands, which had an average d50 of 69 µm. Based on the lab test results: a. GHL evaluated removal efficiency over 15 events at a Maximum Treatment Flow Rate (MTFR) of 37.6 gpm, which corresponds to a MTFR to effective filtration treatment area ratio of 1.80 gpm/ft2. The system, operating at 100% of the MTFR with an average influent concentration of 201.3 mg/L, had an average removal efficiency of 99 percent. b. GHL evaluated sediment mass loading capacity over an additional 16 events using an influent SSC concentration of 400 mg/L. The first 11 runs were evaluated at 100% of the MTFR. The BioPod began to bypass, so the remaining 5 runs were evaluated at 90% of the MTFR. The total mass of the sediment captured was 245.0 lbs and the cumulative mass removal efficiency was 96.3%. 2. Herrera Environmental Consultants Inc. conducted laboratory testing in September 2014 at the Seattle University Engineering Laboratory. The testing evaluated the flushing characteristics, hydraulic conductivity, and pollutant removal ability of twelve different media blends. Based on this testing, Oldcastle Infrastructure, Inc. selected one media blend, Mix 8, for inclusion in their TAPE evaluation of the BioPod™ Biofilter. a. Herrera evaluated Mix 8 in an 8-inch diameter by 36-inch tall polyvinyl chloride (PVC) column. The column contained 18-inches of Mix 8 on top of 6-inches of pea gravel. The BioPod will normally include a 3-inch mulch layer on top of the media layer; however, this was not included in the laboratory testing. b. Mix 8 has a hydraulic conductivity of 218 inches per hour; however, evaluation of the pollutant removal ability of the media was based on an infiltration rate of 115 inches per hour. The media was tested at 75%, 100%, and 125% of the infiltration rate. Based on the lab test results: The system was evaluated using natural stormwater. The dissolved copper and dissolved zinc concentrations in the natural stormwater were lower than the TAPE influent standards; therefore, the stormwater was spiked with 66.4 mL of 100 mg/L Cu solution and 113.6 mL of 1,000 mg/L Zn solution. The BioPod removed an average of 81% of TSS, with a mean influent concentration of 48.4 mg/L and a mean effluent concentration of 9.8 mg/L. The BioPod removed an average of 94% of dissolved copper, with a mean influent concentration of 10.6 µg/L and a mean effluent concentration of 0.6 µg/L. The BioPod removed an average of 97% of dissolved zinc, with a mean influent concentration of 117 µg/L and a mean effluent concentration of 4 µg/L. The BioPod removed an average of 97% of total phosphorus, with a mean influent concentration of 2.52 mg/L and a mean effluent concentration of 0.066 mg/L. When total phosphorus influent concentrations were capped at the TAPE upper limit of 0.5 mg/L, calculations showed an average removal of 87%. Other BioPod Related Issues to be Addressed By the Company: 1. Conduct hydraulic testing to obtain information about maintenance requirements on a site with runoff that is more typical of the Pacific Northwest. Technology Description: Download at https://oldcastleprecast.com/stormwater/bioretention- biofiltration-applications/bioretention-biofiltration- solutions/ Contact Information: Applicant: Chris Demarest Oldcastle Infrastructure, Inc. (925) 667-7100 Chris.demarest@oldcastle.com Applicant website: https://oldcastleprecast.com/stormwater/ Ecology web link: https://ecology.wa.gov/Regulations-Permits/Guidance-technical- assistance/Stormwater-permittee-guidance-resources/Emerging-stormwater-treatment- technologies Ecology: Douglas C. Howie, P.E. Department of Ecology Water Quality Program (360) 407-6444 douglas.howie@ecy.wa.gov Revision History Date Revision March 2018 GULD granted for Basic Treatment March 2018 Provisional GULD granted for Enhanced and Phosphorus Treatment June 2016 PULD Granted April 2018 GULD for Basic and Provisional GULD for Enhanced and Phosphorus granted, changed name to BioPod from TreePod July 2018 GULD for Enhanced and Phosphorus granted September 2018 Changed Address for Oldcastle December 2018 Added minimum media thickness requirement May 2019 Changed language on who must Install and maintain the device from Oldcastle to Applicants August 2019 Added text on sizing using infiltration rate and water quality design flow rate October 2019 Added text describing ability to use off-line design water quality flow rate for sizing due to internal bypass ISOMETRIC VIEW BPU-IB C US Patents Pending THIS DOCUMENT IS THE PROPERTY OF OLDCASTLE INFRASTRUCTURE, INC. IT IS SUBMITTED FOR REFERENCE PURPOSES ONLY AND SHALL NOT BE USED IN ANY WAY INJURIOUS TO THE INTERESTS OF SAID COMPANY. COPYRIGHT © 2020 OLDCASTLE INFRASTRUCTURE, INC. ALL RIGHTS RESERVED. BioPod f Biofilter Underground Vault with Internal Bypass dOldcastle dOldcastle dOldcastle Bioretention/ Biofiltration A PLAN VIEW A SECTION A-A BPU-IB C US Patents PendingSAUDFI1325-0510USAXXXXTHIS DOCUMENT IS THE PROPERTY OF OLDCASTLE INFRASTRUCTURE, INC. IT IS SUBMITTED FOR REFERENCE PURPOSES ONLY AND SHALL NOT BE USED IN ANY WAY INJURIOUS TO THE INTERESTS OF SAID COMPANY. COPYRIGHT © 2020 OLDCASTLE INFRASTRUCTURE, INC. ALL RIGHTS RESERVED. MODEL VAULT SIZE 1 (ID) VAULT FOOTPRINT 1 (OD) TREATMENT FLOW CAPACITY (GPM/CFS) A DIM B DIM C DIM A1 DIM B1 DIM 1.6 GPM/SF (WA GULD2) 1.8 GPM/SF (NJCAT3) BPU-46IB 4'6'1.5'5'7'25.6 / 0.057 28.8 / 0.064 BPU-48IB 4'8'1.5'5'9'38.4 / 0.086 43.2 / 0.096 BPU-412IB 4'12'1.5'5'13'64.0 / 0.143 72.0 / 0.160 BPU-66IB 6'6'1.5'7'7'38.4 / 0.086 43.2 / 0.096 BPU-68IB 6'8'1.5'7'9'57.6 / 0.128 64.8 / 0.144 BPU-612IB 6'12'2'7'13'91.2 / 0.203 102.6 / 0.229 BPU-812IB 8'12'2'9'13'121.6 / 0.271 136.9 / 0.305 BPU-816IB 8'16'2'9'17'172.8 / 0.385 194.4 / 0.433 BioPod f Biofilter Underground Vault with Internal Bypass fFIDSAUXXXXUSADFI11540010FIDSAUXXXXUSADFI11540010 SITE SPECIFIC DATA Structure ID Model Size Orientation (Left or Right) Treatment Flow Rate (cfs) Peak Flow Rate (cfs) Rim Elevation Pipe Data Pipe Location (Front or Side)Pipe Size Pipe Type Invert Elevation Inlet Outlet Notes: 1 All Dimensions are nominal, ID=Inside Dimension, OD=Outside Dimension. 2 Treartment flow capacity at 1.6 gpm/sf media surface area based on an WA Ecology GULD Approval for Basic, Enhanced & Phosphorus. 3 Treatment flow capacity at 1.8 gpm/sf media surface area based on an NJCAT Verification & NJ DEP Certification. Bioretention/ Biofiltration BPU-48IB LEFT 0.190 3.95 TBD FRONT 12" PER PLAN TBD BACK 12" PER PLAN TBD