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HomeMy WebLinkAboutEx_11_RS_Drainage_Report_210804_v1 Prepared for: Zarnoor Associates, LLC Nazim Karmali 19515 North Creek Parkway Suite 314 Bothell, WA 98011 Prepared by: CPH Consultants 11321-B NE 120th Street Kirkland, WA 98034 Jamie Schroeder, PE Adrian Smith, EIT June 25, 2021 Technical Information Report Harrington Redevelopment CPH Project No. 0192-20-002 Renton, WA EXHIBIT 11 RECEIVED 08/30/2021 jding PLANNING DIVISION DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Harrington Redevelopment Preliminary Technical Information Report CPH Project No. 0192-20-002 June 25, 2021 C|P|H CONSULTANTS Page 1 Preliminary Technical Information Report FOR HARRINGTON REDEVELOPMENT RENTON, WA TABLE OF CONTENTS SECTION 1 – PROJECT OVERVIEW 2 FIGURE 1 – VICINITY MAP FIGURE 2 – DRAINAGE INFORMATION SUMMARY FORM SECTION 2 – CONDITIONS AND REQUIREMENTS SUMMARY 5 SECTION 3 – EXISTING SITE CONDITIONS 6 SECTION 4 – UPSTREAM SITE CONDITIONS 7 SECTION 5 – SWPPP 8 SECTION 6 – DEVELOPED SITE CONDITIONS 10 SECTION 7 – DOWNSTREAM ANALYSIS 13 SECTION 8 – OPERATIONS AND MAINTENANCE MANUAL 15 SECTION 9 – BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT 20 FIGURES FIGURE 3 – EXISTING SITE CONDITIONS FIGURE 4 – DEVELOPED SITE CONDITIONS FIGURE 5 – EXISTING DRAINAGE BASINS FIGURE 6 – DEVELOPED DRAINAGE BASINS APPENDICES APPENDIX A – NRCS SOILS DATA & GEOTECHNICAL REPORT APPENDIX B – ARBORIST REPORT APPENDIX C – WWHM REPORTS APPENDIX D – DOWNSTREAM ANALYSIS & OFFSITE PHOTOS APPENDIX E – PRELIMINARY WATER QUALITY DATA DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Harrington Redevelopment Preliminary Technical Information Report CPH Project No. 0192-20-002 June 25, 2021 C|P|H CONSULTANTS Page 2 SECTION 1 – PROJECT OVERVIEW This Technical Information Report (TIR) is provided to describe the stormwater conditions and proposed drainage improvements for the Harrington Redevelopment project. The project proposes to redevelop one existing property into a five-story building with 54 residential units with retail, parking, and infrastructure improvements within Renton, Washington. This report is provided to identify the applicable storm drainage standards and to summarize the analyses and design provisions proposed for the project to comply with City of Renton surface water standards. The information provided within this TIR represents the basis of design for the storm drainage systems and surface water conditions for the project. The vicinity map provided below as Figure 1 illustrates the general location of the project site. The site is located at 960 Harrington Ave NE, Renton, WA 98056 in King County (KC tax parcel no. 7227801025). More generally the site is located in a portion of the NW ¼, Section 9, Township 23 North, Range 5 East, King County, Washington. (See Vicinity Map below). Figure 1 – Vicinity Map DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Harrington Redevelopment Preliminary Technical Information Report CPH Project No. 0192-20-002 June 25, 2021 C|P|H CONSULTANTS Page 3 The project site is comprised of one parcel with an area of approximately 0.67 acres. It currently consists of 2 one-story restaurants, several small structures, and parking. Several trees of varying type, age, and health conditions exist on site. The site and surrounding parcels are zoned CV (Center Village). Figure 3 displays the existing site conditions. The proposed development will create a five-story building with 54 residential units along with retail and parking. In addition, the project will construct half street frontage improvements along NE Sunset Blvd and Harrington Ave NE including pavement narrowing, concrete curb, gutter, and sidewalk. The project will create and/or replace a total of approximately 0.67 acres of impervious surfaces. Total site impervious coverage for proposed individual lots is limited to 75% by the zoning designation. The proposed site plan is shown in Figure 4. The developed site is required to provide Enhanced Basic Water Quality treatment in addition to meeting the Peak Rate Flow Control Standard (May 1979 Conditions) per current City of Renton surface water standards. Water quality storm volumes are proposed to be treated with a biofilter prior to entering the city’s storm drainage mains. A series of catch basin inlets and underground pipes will collect and convey surface water runoff from the rooftop and pervious and impervious surfaces to the existing stormwater system. Existing catch basins exist on the north side of the site on NE Sunset Blvd and on the south side of the site on Harrington Ave NE. Storm drainage controls for this project are proposed in accordance with the 2017 City of Renton Surface Water Design Manual (CORSWDM), which is based on the 2016 King County Surface Water Design Manual (KCSWDM) with some modifications to reflect City of Renton specific requirements. On-site Soil Conditions The soils of the area are characterized generally by the Natural Resource Conservation Services (NRCS) as Ragnar-Indianola (RdC) with slopes ranging from 2% to 15%. A site-specific investigation of the existing site geotechnical conditions was performed by Earth Solutions NW, LLC. A copy of the NRCS report is provided in Appendix A for reference. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Harrington Redevelopment Preliminary Technical Information Report CPH Project No. 0192-20-002 June 25, 2021 C|P|H CONSULTANTS Page 4 Figure 2 – Technical Information Report (TIR) Worksheet, 2017 Surface Water Design Manual Part 1 PROJECT OWNER AND PROJECT ENGINEER Part 2 PROJECT LOCATION AND DESCRIPTION Project Owner: Zarnoor Associates Project Name: Harrington Redevelopment Phone: 206-788-5644 DDES Permit #: ______________________ Address: 19515 North Creek Parkway Suite 314 Location: Township: 23 N Bellevue, WA 98005 Range: 5 E Project Engineer: Company: Jamie Schroeder, PE CPH Consultants Section: 9 Phone: (425) 285-2390 Site Address: 960 Harrington Ave NE Renton, WA 98056 Part 3 TYPE OF PERMIT APPLICATION Part 4 OTHER REVIEWS AND PERMITS ◼ Landuse Services  DFW HPA  Shoreline Subdivision / Short Subd. / UPD  COE 404 Management  Building Services  DOE Dam Safety  Structural M/F / Commercial / SFR  FEMA Floodplain Rockery/Vault/ ____  Clearing and Grading  COE Wetlands  ESA Section 7  Right-of-Way Use  Other _______________________________  Other: Part 5 PLAN AND REPORT INFORMATION Technical Information Report Site Improvement Plan (Engr. Plans) Type of Drainage Full / Targeted / Type (circle one): Full / Modified / Review (circle): Simplified / Large Project Simplified Directed Date (include revision Date (include revision dates): 6/14/2021 dates): 6/14/2021 Date of Final: Date of Final: Part 6 ADJUSTMENT APPROVALS Type (circle one): Standard / Complex / Preapplication / Experimental / Blanket Description: (include conditions in TIR Section 2) Date of Approval: _____________________________ DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Harrington Redevelopment Preliminary Technical Information Report CPH Project No. 0192-20-002 June 25, 2021 C|P|H CONSULTANTS Page 5 Figure 2 – Technical Information Report (TIR) Worksheet, 2017 Surface Water Design Manual (cont’d.) Part 7 MONITORING REQUIREMENTS Monitoring Required: Yes / No Describe: Start Date: Completion Date: Part 8 SITE COMMUNITY AND DRAINAGE BASIN Community Plan: Highlands Special District Overlays: Drainage Basin: East Lake Washington – Renton Drainage Basin Stormwater Requirements: Enhanced Basic Water Quality, Peak Rate Flow Control Part 9 ONSITE AND ADJACENT SENSITIVE AREAS  River/Stream  Steep Slope  Lake  Erosion Hazard  Wetlands  Landslide Hazard  Closed Depression  Coal Mine Hazard  Floodplain  Seismic Hazard  Other  Habitat Protection Part 10 SOILS Soil Type Slopes Erosion Potential RdC 2% - 15% Ur 2% - 15%  High Groundwater Table (within 5 feet)  Sole Source Aquifer  Other __________________  Seeps/Springs  Additional Sheets Attached DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Harrington Redevelopment Preliminary Technical Information Report CPH Project No. 0192-20-002 June 25, 2021 C|P|H CONSULTANTS Page 6 Figure 2 – Technical Information Report (TIR) Worksheet, 2017 Surface Water Design Manual (cont’d.) Part 11 DRAINAGE DESIGN LIMITATIONS REFERENCE LIMITATION / SITE CONSTRAINT  Core 2 – Off-site Analysis  Sensitive/Critical Areas  LID Infeasibility  SEPA   Additional Sheets Attached Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet per Threshold Discharge Area) Threshold Discharge Area: (name or description) 24-in Surface Water Main, No. 126578 Core Requirements (all 8 apply) Discharge at Natural Location Number of Natural Discharge Locations: 2 Offsite Analysis Level: 1 / 2 / 3 Dated: June 8, 2021 Flow Control Level: 1 / 2 / 3 or Exemption Number: (include a facility summary sheet) Small Site BMP’s: _____________________ Conveyance System Spill containment located at: Erosion and Sediment Control ESC Site Supervisor: TBD Contact Phone: After Hours Phone: Maintenance and Operation Responsibility: Private / Public If Private, Maintenance Log Required: Yes / No Financial Guarantees and Liability Provided: Yes / No Water Quality Type: Basic / Sens. Lake / Enhanced Basic / Bog (include facility summary sheet) or Exemption No. Landscape Management Plan: Yes / No Special Requirements (as applicable) Area Specific Drainage Type: CDA / SDO / MDP / BP / LMP / Shared Fac / None Requirements Name: ________________________________ Floodplain/Floodway Delineation Type: Major / Minor / Exemption / None 100-year Base Flood Elevation (or range): _______________ Datum: Flood Protection Facilities Description: N/A Source Control Describe landuse: Commercial Mixed Use (comm./industrial landuse) Describe any structural controls: N/A Oil Control High-use Site: Yes / No Treatment BMP: __________________________________ Maintenance Agreement: Yes / No with whom?: Other Drainage Structures Describe: DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Harrington Redevelopment Preliminary Technical Information Report CPH Project No. 0192-20-002 June 25, 2021 C|P|H CONSULTANTS Page 7 Figure 2 – Technical Information Report (TIR) Worksheet, 2017 Surface Water Design Manual (cont’d.) Part 13 EROSION AND SEDIMNET CONTROL REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION MINIMUM ESC REQUIREMENTS AFTER CONSTRUCTION ■ Clearing Limits ■ Stabilize Exposed Surfaces ■ Cover Measures ■ Remove and restore Temporary ESC facilities ■ Perimeter Protection ■ Traffic Area Stabilization ■ Clean and remove all silt and debris, ensure ■ Sediment Retention operation of permanent facilities, restore operation of Flow Control BMP Facilities as necessary ■ Surface Water Collection ■ Flag Limits of SAO and open space ■ ■ ■ Dewatering Control Dust Control Flow Control preservation areas ■ ■ Protection of Flow Control BMP Facilities (existing and proposed) Maintain BMPs/Manage Project  Other _____________________________ Part 14 STORMWATER FACILITY DESCRIPTIONS (Note: Include Facility Summary and Sketch) Flow Control Type/Description Water Quality Type/Description  Detention ◼ Biofiltration Biofilter Vault  Infiltration  Wetpool  Regional Facility  Media Filtration  Shared Facility ◼ Oil Control Oil/water Separator  Small Site BMP’s  Spill Control  Other  Small Site BMP’s  Other Part 15 EASEMENTS / TRACTS Part 16 STRUCTURAL ANALYSIS ◼ Drainage Easement  Cast in Place Vault  Access Easement  Retaining Wall ◼ Native Growth Protection Covenant  Rockery > 4’ High  Tract  Structural on Steep Slope  Other  Other Part 17 SIGNATURE OF PROFESSIONAL ENGINEER I, or a civil engineer under my supervision, have visited the site. Actual site conditions as observed were incorporated into this worksheet and the attached technical Information Report. To the best of my knowledge the information provided here is accurate. June 14, 2021 Signed Date DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Harrington Redevelopment Preliminary Technical Information Report CPH Project No. 0192-20-002 June 25, 2021 C|P|H CONSULTANTS Page 8 SECTION 2 – CONDITIONS AND REQUIREMENTS SUMMARY Compliance with Project Drainage Requirements The storm drainage and temporary erosion control standards for the project are established by the 2017 City of Renton Surface Water Design Manual (CORSWDM). The project must comply with all minimum requirements 1 through 9 as it proposes more than 5,000 square feet of new impervious surface coverage. The CORSWDM specifies nine minimum requirements that are to be met for this project. Compliance and/or applicability of each of these design standards are summarized below: CORSWDM Core Requirements 1. Discharge at Natural Location: The project site currently slopes and drains to two different discharge points at catch basins whose flows converge within ¼ mile downstream. On-site stormwater will maintain this existing drainage pattern and ultimate downstream discharge in accordance with current flow control standards. 2. Off-site Analysis: Summarized in Section 3 – Off-Site Analysis. 3. Flow Control: The project requires Peak Rate Flow Control. This standard will be achieved by comparing the proposed and existing site conditions. Descriptions of the proposed flow control facilities are provided in Section 4 – Flow Control and Water Quality Facility Analysis and Design. 4. Conveyance System: The project proposes to collect stormwater runoff and convey it to existing catch basins and storm pipes. These improvements are shown in Figure 4 and described further in Section 5 – Conveyance System Analysis and Design. 5. Erosion and Sediment Control: Temporary erosion and sediment controls are as described in Section 8 – CSWPPP Analysis and Design. 6. Maintenance and Operations: The on-site storm drainage facilities are proposed to be privately maintained and have been designed in accordance with city of Renton surface water standards. As such, Operations and Maintenance Manual will be provided with final engineering. 7. Financial Guarantees and Liability: A Bond Quantity Worksheet will be prepared and provided for review and approval prior to issuance of any site work permits with the final Technical Information Report (TIR). Approval and all financial guarantees will be provided by the developer. 8. Water Quality: Enhanced Basic Water Quality treatment is required for the proposed project. This treatment level will be achieved by means of one biofiltration vault as shown on Figure 4 and as described in Section 4 – Flow Control and Water Quality Facility Analysis and Design. 9. On-site BMPs: On-site BMPs are required for the proposed project. This is described further in Section 4. CORSWDM Special Requirements 1. Other Adopted Area-Specific Requirements: No area-specific requirements apply to this project site. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Harrington Redevelopment Preliminary Technical Information Report CPH Project No. 0192-20-002 June 25, 2021 C|P|H CONSULTANTS Page 9 2. Flood Hazard Area Delineation: The limits of this project are not located within or in proximity to a 100-year floodplain. 3. Flood Protection Facilities: N/A. 4. Source Control: No additional source control is proposed or expected to be necessary. 5. Oil Control: The project is considered a high-use area and proposes an oil/water separator for the parking garage. The water separated will then flow to the sanitary sewer system. 6. Aquifer Protection Area: The limits of this project are not located within an Aquifer Protection Area (AFA). DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Harrington Redevelopment Preliminary Technical Information Report CPH Project No. 0192-20-002 June 25, 2021 C|P|H CONSULTANTS Page 10 SECTION 3 – OFF-SITE ANALYSIS Task 1: Study Area Definition and Maps The proposed project site is located at 960 Harrington Ave NE in Renton, WA and is currently developed with two one-story restaurants, utility structures, and a parking lot. Existing ground cover consists mostly of grass with several trees of varying age and health. The existing site topography consists of slopes ranging from 0% to 15%. The existing site conditions are shown in Figure 3. Task 2: Resource Review King County iMAP and the City of Renton (COR) Maps and GIS Data were reviewed to identify any potential sensitive areas in the proximity of the project site. • Wetlands: iMap does not identify any wetlands on the project site. • Streams and 100-year Floodplain: The project site is not located in the 100-year floodplain. • Erosion Hazard Areas: COR Maps identifies no erosion hazard areas on the project site. • Seismic Hazard Areas: COR Maps identifies no seismic hazard areas on the project site. • Landslide Hazard Areas: COR Maps identifies no landslide hazard area on the project site. • Coal Mine Hazard Areas: COR Maps identifies no coal mine hazard area on the project site. • Critical Aquifer Recharge Area: The project site is not located within a critical aquifer recharge area per iMAP records. • Basin Condition: iMap does not indicate any basin conditions. • Areas Susceptible to Groundwater Contamination: iMap does not show the project site as being susceptible to groundwater contamination. King County iMAP was also reviewed for downstream drainage complaints. No relevant complaints were identified. Task 3: Field Inspection A field inspection was performed on June 8, 2021, on a sunny day with a temperature of approximately 65 degrees. Onsite Drainage Basin The existing topography of the site has slopes ranging from 0% to 15%. The project site is comprised of a single drainage basin with surface runoff traveling primarily as sheet flow over impervious areas towards the northwest and southwest corner. The project site currently drains to two different discharge points at catch basins whose flows converge within ¼ mile downstream. The drainage basin is comprised mostly of impervious building and parking area, along with a small area of grass and trees. Based on visual inspection during the site visit and survey contour data there are low points where runoff can collect on site. Low points will remain similar to the existing low points to ensure proposed drainage patterns remain similar to existing drainage patterns. Task 4: Drainage System Description Downstream Basin Runoff from the project site sheet flows northwesterly and southwesterly before entering existing stormwater infrastructures via off-site catch basins. The northwestern catch basin connects to the storm main located on the south side of NE Sunset Blvd and flows west. Approximately 480 feet downstream, the main turns southwest, DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Harrington Redevelopment Preliminary Technical Information Report CPH Project No. 0192-20-002 June 25, 2021 C|P|H CONSULTANTS Page 11 runs 397 feet under 3 properties and NE 9th Place until it reaches Ferndale Circle NE. The southwestern catch basin connects to the storm main located on the east side of Harrington Avenue NE and flows south. Approximately 470 feet downstream of the site at the intersection of Harrington Ave NE and NE 9th St, the main turns to the west and runs 900 feet down NE 9th St, turns north, and runs 293 feet up Ferndale Cir NE where it reunites with the flow from the northwest catch basin. The outlet pipe flows 233 feet west through two properties to Edmonds Ave NE, where it joins with another surface water main. The outlet pipe runs 212 feet west under two properties to Dayton Ave NE, past the quarter mile mark. The collected runoff generally continues to flow northwest to Lake Washington. A downstream map and photos are attached in Appendix D. Upstream Basin The project site is bordered by a large grocery store to the east, apartment buildings to the south, NE Sunset Blvd to the north, and Harrington Ave Ne to the west. Surface flow from NE Sunset Blvd and the grocery store flow southwest along the edge of the road towards the site, entering the storm system on the south side of NE Sunset Blvd. A portion of the east property slopes towards the site. This upstream flow-through basin has been accounted for in the design. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Harrington Redevelopment Preliminary Technical Information Report CPH Project No. 0192-20-002 June 25, 2021 C|P|H CONSULTANTS Page 12 SECTION 4 – FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN The hydrologic analysis of the runoff conditions for this project is based on drainage characteristics such as basin area, soil type, and land use (i.e., pervious vs. impervious) in accordance with the City of Renton Surface Water Design Manual. The Western Washington Hydraulic Model (WWHM) software was used to evaluate the storm water runoff conditions for the project site and to design the on-site flow control facilities. The following is a summary of the results of the analysis and the proposed drainage facility improvements for this project. Existing Site Hydrology The existing site conditions are shown in Figure 3 and summarized in Table 4.1 below. Table 4.1 – Land Use Cover, Existing Site Conditions (prior to development) Basin ID Total Area (AC) Land Cover (AC) Impervious Till Forest Pasture North Basin 0.27 0.22 0.00 0.05 North Frontage 0.07 0.03 0.00 0.03 South Basin 0.40 0.38 0.00 0.02 South Frontage 0.12 0.11 0.00 0.01 Upstream Flow-Through 0.09 0.09 0.00 0.00 Project Basin 0.95 0.83 0.00 0.12 The Western Washington Hydraulic Model (WWHM) software was used to model the existing site hydrology and calculate runoff peak rates. The results of the existing site runoff analysis are provided in Appendix C. Existing site conditions were modeled as historic site (i.e., fully forested) conditions in the analysis of the pre- developed conditions for all on-site targeted developed surfaces in accordance with CORSWDM standards for Flow Control. The project basin area totals 0.95 acres and consists of 0.67 acres of on-site improvements and 0.19 acres of frontage improvements. The northern portion of the site flows to a catch basin on NE Sunset Blvd, while the southern portion flows to a catch basin on Harrington Ave NE. For more information regarding basin areas see Figure 5. The site’s runoff flows will need to match its existing conditions since there will be no detention for this project. The overall flow control model was modeled in WWHM. Input and output parameters for this model are provided in Appendix C of this report. Developed Site Hydrology The site is planned to be improved with roadway, storm drainage, and utility infrastructure in support of the mixed-use development. Frontage improvements on NE Sunset Blvd and Harrington Ave NE will be completed in accordance with city road standards as conditions with the preliminary plat approval. These improvements include road narrowing for side parking, 8-foot planter strip, and 5-foot sidewalk. The developed site drainage is contained within one threshold basin that contains two natural discharge areas. These two discharges converge within ¼ mile. The offsite drainage map can be seen in Appendix D. The developed conditions of the site were modeled using the WWHM modeling software. All the roadway, on-site paved surfaces, and landscape areas on the site are collected and directed to the city stormwater DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Harrington Redevelopment Preliminary Technical Information Report CPH Project No. 0192-20-002 June 25, 2021 C|P|H CONSULTANTS Page 13 system, with the exception of the parking garage. The parking garage will be treated with an oil/water separator and discharged to the sewer system. Fully developed conditions were modeled assuming coverage as shown on the current plans. The impervious and pervious areas for all other areas were calculated directly by measuring the new rooftops, roadways, and sidewalks as impervious, and grass areas as pervious. The results of the developed site runoff analysis for the project site are summarized in Table 4.2 and more detailed land use summaries are provided in Figure 5. Table 4.2 – Land Use Cover, Developed Site Conditions Basin ID Total Area (AC) Land Cover (AC) Impervious Till Forest Till Grass North Basin 0.27 0.23 0.00 0.05 North Frontage 0.07 0.04 0.00 0.03 South Basin 0.40 0.34 0.00 0.06 South Frontage 0.12 0.06 0.00 0.06 Upstream Flow-Through 0.09 0.09 0.00 0.00 Project Basin 0.95 0.76 0.00 0.19 Flow Control Compliance with the Peak Rate Control Duration Standard (Existing Conditions) is proposed for this project. The site has been designed to have release durations match the peak flows from the 2-year and 10-year, and 100-year event as required by Section 1.2.3 of Chapter 1 of the CORSWDM. Table 4.3 shows the pre- developed and developed peak flows for 2-year, 10-year, and 100-year storm events. Table 4.3 – Peak Flow Summary Structure Land-Use Condition Peak Flow Rates (cfs) 2-year 10-year 100-year Project Runoff Pre- Developed 0.3208 0.4637 0.6554 Developed 0.2982 0.4318 0.6111 The full WWHM results are provided in the WWHM Total Basin Peak Flows Report. Because the developed peak flows are less than the existing peak flows, an on-site flow control facility is not required to meet the Peak Rate Control Duration Standard. Water Quality Design The CORSWDM requires that all proposed projects assess the requirement to provide water quality facilities to treat runoff of pollution-generating impervious surfaces. Storm drainage runoff from pollution generating impervious surfaces (PGIS) will require Enhanced Water Quality treatment prior to discharge to the downstream, off-site system. This treatment level is proposed to be achieved with a BioPod Biofilter located in the southeast corner of the site, upstream of the off-site stormwater system. Runoff from the pollution-generating parking area and a portion of the roof runoff will be collected and treated using the BioPod Biofilter. Given these parameters the off-line water quality facility flow rate was determined to be 0.0229 cfs. Table 4.8 below shows the land use conditions used for determining the water quality flowrate for the Biopod Biofilter and the WWHM results are provided in Appendix E of this report. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Harrington Redevelopment Preliminary Technical Information Report CPH Project No. 0192-20-002 June 25, 2021 C|P|H CONSULTANTS Page 14 Table 4.8 – Land Use Cover, Developed Conditions for Determining the Water Quality Flowrate Basin ID Total Area (AC) Land Cover (AC) Impervious Till Forest Till Grass WQ Basin (Total) 0.27 0.25 0.00 0.02 The BioPod Biofilter consists of an inlet chamber for high-flow bypass and removal of gross pollutants, a treatment chamber for filtration through StormMix engineered media, and an outlet chamber for flow collection and discharge. A standard detail has been provided by OldCastle and can be found in Appendix E. On-Site BMPs Core requirement #9 requires that all proposed projects provide on-site BMPs to mitigate the hydrologic impacts generated by new impervious and pervious surface, existing impervious surfaces, and replaced impervious surface. The on-site BMPs are methods to disperse, infiltrate, or otherwise reduce or prevent development related increases in runoff at or near the sources of those increases. On-site BMPs shall be incorporated to the maximum extent feasible per the CORSWDM. The feasibility and applicability of full dispersion must be evaluated for all target impervious surfaces. Full dispersion has been determined to be infeasible due to insufficient flow paths on-site. Where full dispersion of target impervious areas is not feasible or applicable, or will cause flooding or erosion impacts, the feasibility and applicability of full infiltration must be evaluated. Full infiltration has been determined to be infeasible, due to the infiltration rate of 0.5, given by the geotechnical report. All target impervious surfaces not mitigated by full dispersion or full infiltration must be mitigated to the maximum extent feasible using one or more BMPs from the following: limited infiltration, rain gardens, bioretention, and permeable pavement. Limited infiltration facilities, rain gardens, and bioretention do not appear to be feasible at this time due to the available areas to place the systems and meet required setbacks. Permeable pavement has been determined to be feasible. Permeable pavement can be used for sidewalks. A Geotech shall complete testing to confirm if subgrade meets minimum organic matter content and minimum cation exchange capacity requirements or a 6” sand layer may be included in the design beneath the permeable pavement in areas of pollution generating impervious. All target impervious surfaces not mitigated by an aforementioned BMP must be mitigated to the maximum extent feasible using the Basic Dispersion BMP. Basic dispersion has been determined to be infeasible due to the available areas to place systems and meet required setbacks. For an impervious area greater than 65% on the buildable portion of the site/lot, on-site BMPs must be applied to 20% of the target impervious surfaces or to an impervious area equal to at least 10% of the site/lot, whichever is less. BMPs must be implemented, at minimum, for an impervious area equal to at least 10% of the lot for lot sizes up to 11,000 square feet and at least 20% of the lot for lot sizes between 11,000 and 22,000 square feet. If these minimum areas are not mitigated using feasible BMPs from above, one or more BMPs from the following list are required to be implemented to achieve compliance: Reduced Impervious Surface Credit, Native Growth Retention Credit and Tree Retention Credit. Native Growth Retention Credit has been determined to be infeasible for the project due to existing site topography and lack of potential donor areas. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Harrington Redevelopment Preliminary Technical Information Report CPH Project No. 0192-20-002 June 25, 2021 C|P|H CONSULTANTS Page 15 Tree Retention Credit has been determined to be infeasible for the project due to no trees meeting the minimum design requirements. The soil moisture holding capacity of new pervious surfaces shall be protected in accordance with the soil amendment standards as detailed in Section C.2.13 of the CORSWDM. Any proposed connection of roof downspouts to the local drainage system shall be via a perforated pipe connection as detailed in Section C.2.11 of the CORSWDM. Both of these BMPs will be implemented with the final construction plans for the project. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Harrington Redevelopment Preliminary Technical Information Report CPH Project No. 0192-20-002 June 25, 2021 C|P|H CONSULTANTS Page 16 SECTION 5 – CONVEYANCE SYSTEM AND ANALYSIS AND DESIGN Surface water collection and conveyance for the project is proposed by means of grading, grated inlets, and below grade pipes. Building roof drains, on-site paved surfaces and landscape areas on the site are collected and directed to the existing public stormwater system. Conveyance analysis for the project will be performed in accordance with Chapter 4 of the CORSWDM which requires that new and existing pipe systems be designed with sufficient capacity to convey and contain at minimum the 25-year peak flow. The design flow rate for conveyance/backwater analysis is based on peak 100-year peak flow rates using the rational method. Developed conditions for improved tributary areas and existing conditions for any off-site tributary areas were used for input parameters. The storm drainage conveyance systems are illustrated in Figure 4. Conveyance backwater analysis will be provided with final engineering. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Harrington Redevelopment Preliminary Technical Information Report CPH Project No. 0192-20-002 June 25, 2021 C|P|H CONSULTANTS Page 17 SECTION 6 – SPECIAL REPORTS AND STUDIES Geotechnical Engineering Study – Draft, by Earth Solutions NW, LLC, March 31, 2021 Arborist Report, by Layton Tree Consulting, LLC, April 19, 2021 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Harrington Redevelopment Preliminary Technical Information Report CPH Project No. 0192-20-002 June 25, 2021 C|P|H CONSULTANTS Page 18 SECTION 7 – OTHER PERMITS Construction and Grading Permits will be obtained from the City of Renton for roadway, storm drainage, and utility improvements proposed for the infrastructure serving the development. Design Review Approval will be obtained from the City of Renton to establish the layout of the site plan and to ensure the proposed plat is in accordance with COR adopted standards. A Construction Permit will be required to construct the access and utility infrastructure to serve the development. A general Stormwater Permit from Department of Ecology is not required since the disturbed area is less than 1 acre. The individual building permit will be required for the building structure. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Harrington Redevelopment Preliminary Technical Information Report CPH Project No. 0192-20-002 June 25, 2021 C|P|H CONSULTANTS Page 19 SECTION 8 – CSWPPP ANALYSIS AND DESIGN Site specific details and provisions for the temporary erosion and sediment control (ESC) facilities are provided with the improvement plans that accompany this TIR. The proposed facilities have been selected and sized in accordance with the recommendations provided in the CORSWDM standards. In addition to the site-specific ESC measures, the following general Best Management Practices (BMPs) for sediment control shall also be implemented in accordance with the provisions of the CORSWDM: 1. Clearing Limits Construction clearing limits fence or silt fence will be installed by the contractor along the entire project corridor to prevent disturbance of project areas not designated for construction. These fences will be installed prior to clearing and grading activities where appropriate. 2. Cover Measures Temporary and permanent cover measures will be provided by the contractor to protect disturbed areas. Disturbed areas will be seeded and mulched to provide permanent cover measure and to reduce erosion within seven days if those areas not scheduled for immediate work. 3. Perimeter Protection The contractor will install silt fences as indicated on the drawings prior to any up-slope clearing, grading and trenching activities in order to reduce the transport of sediment offsite. 4. Traffic Area Stabilization Stabilized pads of quarry spalls will be installed by the contractor at all egress points from the project site as required to reduce the amount of sediment transported onto paved roads or other offsite areas by motor vehicles. 5. Sediment Retention Sediment retention will be provided by silt fencing and catch basin inlet protection at the locations and dimensions shown on the project drawings. 6. Surface Water Control Surface water control will include ditches, temporary culverts, check dams, and/or other inlet and outlet protection at the locations and dimensions shown on the drawings. 7. Dust Control Water and/or street sweeping equipment will be used by the contractor to control dust emissions during construction operations. 8. Wet Season Requirements If soils are exposed during the period of October 1 to March 31, the contractor will mulch and seed or otherwise cover as much disturbed area as possible by the first week of October, in order to provide protective ground cover for the wet season. The contractor will also conform to the following wet season special provisions: A. Apply cover measures to disturbed areas that are to remain unworked for more than two days. B. Protect stockpiles that are to remain unworked for more than 12 hours. No area is to be left uncovered/denuded longer than 12 hours during the winter months. C. Provide onsite stockpiles of cover materials sufficient to cover all disturbed areas. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Harrington Redevelopment Preliminary Technical Information Report CPH Project No. 0192-20-002 June 25, 2021 C|P|H CONSULTANTS Page 20 D. Seed all areas that are to be unworked during the wet season by the end of the first week of October. E. Apply mulch to all seeded areas for protection. F. Provide onsite storage of 50 linear feet of silt fence (and the necessary stakes) for every acre of disturbed area. Straw bales are to be stockpiled onsite for use in an emergency. G. Provide construction road and parking lot stabilization areas for all sites. H. Provide additional sediment retention as required by the City of Renton Engineer. I. Provide additional surface water controls as required by the City of Renton Engineer. J. Implement construction phasing and more conservative BMPs for construction activity near surface waters (to be evaluated). K. Review and maintain TESC measures on a weekly basis and within 24-hours after any runoff-producing event. 9. Sensitive Areas Restrictions No sensitive areas are located on-site. 10. Maintenance Requirements All ESC measures will be maintained and reviewed on a regular basis following the standard maintenance requirements identified in the project drawings. An ESC supervisor will be designated by the contractor and the name, address and phone number of the ESC supervisor will be given to the City prior to the start of construction. A sign will be posted at the primary entrance to the project site identifying the ESC supervisor and his/her phone number. The ESC supervisor will inspect the site at least once a month during the dry season, weekly during the wet season, and within 24 hours of each runoff-producing storm. A standard ESC maintenance report will be used as a written record of all maintenance. The contractor will be responsible for phasing of erosion and sediment controls during construction so that they are coordinated with construction activities. The contractor will also be responsible for maintenance of temporary controls during construction, including removal of accumulated sediment, and for the removal of the controls and remaining accumulated sediment at the completion of construction. 11. Final Stabilization Prior to obtaining final construction approval, the site shall be stabilized, the structural ESC measures removed, and drainage facilities cleaned. To obtain final construction approval, the following conditions must be met: • All disturbed areas of the site should be vegetated or otherwise permanently stabilized in accordance with project BMPs. At a minimum, disturbed areas should be seeded and mulched to provide a high likelihood that sufficient cover will develop shortly after final approval. The plans include erosion control notes and specifications for hydro-seeding and mulching disturbed areas. • Structural measures such as silt fences, pipe slope drains, storm drain inlet protection and sediment traps and ponds shall be removed once the proposed improvements are complete and vegetated areas are stabilized. All permanent surface water facilities shall be cleaned completely and restored to working order prior to removal of ESC facilities. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Harrington Redevelopment Preliminary Technical Information Report CPH Project No. 0192-20-002 June 25, 2021 C|P|H CONSULTANTS Page 21 SECTION 9 – BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT All required bonds, facility summaries, and covenants will be provided prior to final approval. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Harrington Redevelopment Preliminary Technical Information Report CPH Project No. 0192-20-002 June 25, 2021 C|P|H CONSULTANTS Page 22 SECTION 10 – OPERATIONS AND MAINTENANCE MANUAL The on-site storm drainage conveyance facilities for this project will be privately maintained by the property owner. The required BMP facilities will be privately maintained and designed in accordance with CORSWDM. A site-specific maintenance manual for the private BMPs will be completed prior to final recording. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Site Planning Civil Engineering Landscape Architecture Project Management Land Use Consulting FIGURES DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB NE SUNSET BLVDHARRINGTON AVE NEΔFIGURE 3 - EXISTING SITE CONDITIONS IN FEETPLAN 0 N 50 100101 South Wenatchee Avenue, Suite C3 Wenatchee, WA 98801 • (509) 293-7731 Site Planning • Civil Engineering Landscape Architecture • Land Use Consulting 11321-B NE 120th Street Kirkland, WA 98034 • (425) 285-2390 www.cphconsultants.com DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB NE SUNSET BLVDHARRINGTON AVE NEΔFIGURE 4 - DEVELOPED SITE CONDITIONS IN FEETPLAN 0 N 50 100101 South Wenatchee Avenue, Suite C3 Wenatchee, WA 98801 • (509) 293-7731 Site Planning • Civil Engineering Landscape Architecture • Land Use Consulting 11321-B NE 120th Street Kirkland, WA 98034 • (425) 285-2390 www.cphconsultants.com DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB NE SUNSET BLVDHARRINGTON AVE NEΔUPSTREAM FLOW-THROUGH 0.09 AC IMP. NORTH FRONTAGE 0.03 AC IMP 0.03 AC LAWN SOUTH FRONTAGE 0.11 AC IMP. 0.01 AC LAWN NORTH BASIN 0.22 AC IMP. 0.05 AC LAWN SOUTH BASIN 0.38 AC IMP. 0.02 AC LAWN FIGURE 5 - EXISTING DRAINAGE BASINS IN FEETPLAN 0 N 50 100101 South Wenatchee Avenue, Suite C3 Wenatchee, WA 98801 • (509) 293-7731 Site Planning • Civil Engineering Landscape Architecture • Land Use Consulting 11321-B NE 120th Street Kirkland, WA 98034 • (425) 285-2390 www.cphconsultants.com DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB NE SUNSET BLVDHARRINGTON AVE NEΔUPSTREAM FLOW-THROUGH 0.09 AC IMP. NORTH FRONTAGE 0.04 AC IMP. 0.03 AC LAWN SOUTH FRONTAGE 0.06 AC IMP. 0.06 AC LAWN SOUTH BASIN 0.35 AC IMP. 0.05 AC LAWN NORTH BASIN 0.23 AC IMP. 0.05 AC LAWN FIGURE 6 - DEVELOPED DRAINAGE BASINS IN FEETPLAN 0 N 50 100101 South Wenatchee Avenue, Suite C3 Wenatchee, WA 98801 • (509) 293-7731 Site Planning • Civil Engineering Landscape Architecture • Land Use Consulting 11321-B NE 120th Street Kirkland, WA 98034 • (425) 285-2390 www.cphconsultants.com DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Site Planning Civil Engineering Landscape Architecture Project Management Land Use Consulting APPENDIX A GEOTECHNICAL REPORT, NRCS SOILS REPORT DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB PREPARED FOR ZARNOOR ASSOCIATES, LLC C/O MR. KARIM KARMALI March 31, 2021 _________________________ Chase G. Halsen, L.G. Project Geologist _________________________ Keven D. Hoffmann, P.E. Senior Project Manager GEOTECHNICAL ENGINEERING STUDY HARRINGTON REDEVELOPMENT 960 HARRINGTON AVENUE NORTHEAST RENTON, WASHINGTON ES-7282 Earth Solutions NW, LLC 15365 Northeast 90th Street, Suite 100 Redmond, Washington 98052 Phone: 425-449-4704 | Fax: 425-449-4711 www.earthsolutionsnw.comDRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB March 31, 2021 ES-7282 Zarnoor Associates, LLC c/o Mr. Karim Karmali 19515 North Creek Parkway, Suite 314 Bothell, Washington 98011 Attention: Mr. Nazim Karmali Dear Mr. Karmali: Earth Solutions NW, LLC (ESNW) is pleased to present this geotechnical report to support the design and construction of the proposed mixed-use development, currently known as the Harrington Redevelopment. Based on the results of our investigation, the proposed redevelopment is feasible from a geotechnical standpoint. Our study indicates the site is underlain primarily by dense to very dense glacial till. Based on our findings, the proposed mixed-use structure may be constructed on a conventional continuous and spread footing foundations bearing upon competent native soil, recompacted native soil, or new structural fill placed directly on competent native soil. Competent native soil suitable for support of the proposed building will likely be encountered beginning at depths of about two-and-one-half to five feet below existing grades across most of the site. Soil in the northwest site corner was characterized as loose to medium dense during the field exploration; accordingly, areas of native soil may need to be either mechanically recompacted or overexcavated and replaced with suitable structural fill to establish competent and uniform soil bearing conditions. In general, where loose or unsuitable soil conditions are exposed at foundation subgrade elevations, compaction of the soil to the specifications of structural fill or overexcavation and replacement with suitable structural fill will be necessary. Full infiltration is not recommended from a geotechnical standpoint given the predominance of dense silty sand encountered across most of the site. Sandier soils encountered near the northwest site corner may prove feasible for limited, targeted infiltration. However, any design would need to incorporate provisions for overflow. If infiltration is pursued, ESNW should be contacted to provide supplementary consulting and testing services. Pertinent geotechnical recommendations are provided in this study. We appreciate the opportunity to be of service to you on this project. If you have any questions regarding the content of this geotechnical engineering study, please call. Sincerely, EARTH SOLUTIONS NW, LLC Chase G. Halsen, L.G. Project Geologist DRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Earth Solutions NW, LLC Table of Contents ES-7282 PAGE INTRODUCTION ................................................................................. 1 General .................................................................................... 1 Project Description ................................................................. 2 SITE CONDITIONS ............................................................................. 2 Surface ..................................................................................... 2 Subsurface .............................................................................. 2 Topsoil and Fill ............................................................. 3 Native Soil ..................................................................... 3 Geologic Setting ........................................................... 3 Groundwater ................................................................. 3 Critical Areas Review ............................................................. 4 DISCUSSION AND RECOMMENDATIONS ....................................... 4 General .................................................................................... 4 Site Preparation and Earthwork ............................................. 4 Temporary Erosion Control ......................................... 4 Excavations and Slopes .............................................. 5 In-situ and Imported Soil ............................................. 5 Subgrade Preparation .................................................. 6 Wet Season Grading…………………………………...... 6 Structural Fill ................................................................ 6 Foundations ............................................................................ 7 Seismic Design ....................................................................... 7 Slab-on-Grade Floors ............................................................. 8 Retaining Walls ....................................................................... 8 Drainage................................................................................... 9 Preliminary Infiltration Feasibility ............................... 9 Utility Support and Trench Backfill ....................................... 9 LIMITATIONS ...................................................................................... 10 Additional Services ................................................................. 10 DRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Earth Solutions NW, LLC Table of Contents Cont’d ES-7282 GRAPHICS Plate 1 Vicinity Map Plate 2 Boring Location Plan Plate 3 Retaining Wall Drainage Detail Plate 4 Footing Drain Detail APPENDICES Appendix A Subsurface Exploration Boring Logs Appendix B Laboratory Test Results DRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Earth Solutions NW, LLC GEOTECHNICAL ENGINEERING STUDY HARRINGTON REDEVELOPMENT 960 HARRINGTON AVENUE NORTHEAST RENTON, WASHINGTON ES-7282 INTRODUCTION General This geotechnical engineering study (study) was prepared for the proposed mixed-use project (currently referred to as the Harrington Redevelopment), to be constructed directly southeast of the intersection between Northeast Sunset Boulevard and Harrington Avenue Northeast, in Renton, Washington. This study was prepared to provide geotechnical recommendations for currently proposed development plans and included the following geotechnical services: Borings to characterize soil and groundwater conditions. Laboratory testing of representative soil samples collected at the boring locations. Engineering analyses. The following documents and maps were reviewed as part of our study preparation: Feasibility Study for Revised Options – Surface Parking, prepared by Grouparchitect, dated August 10, 2020. Conceptual Site Plan for 25% Schematic Design, prepared by Grouparchitect, dated February 4, 2021. ALTA/NSPS Land Title Survey, prepared by Axis Survey & Mapping, Inc., dated January 7, 2020. Online Web Soil Survey (WSS) resource, maintained by the Natural Resources Conservation Service (NRCS) under the United States Department of Agriculture (USDA). Geologic Map of the Renton Quadrangle, Washington, prepared by D.R. Mullineaux, 1965. Chapter 3, Title IV of the Renton Municipal Code.DRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Zarnoor Associates, LLC ES-7282 c/o Mr. Karim Karmali Page 2 March 31, 2021 Earth Solutions NW, LLC Project Description We understand the project is pursing construction of a six-story, mixed-use structure and associated site improvements. The at-grade level will include a parking garage, retail space, and residential accessories, and levels two through six will be apartments. Site ingress and egress will be provided by Northeast Sunset Boulevard. At the time of report submission, specific building load plans were not available for review. Based on our experience with similar developments, the proposed structure will utilize a concrete podium for at-grade level construction, with lightly loaded wood farming above. Perimeter footing loads will likely be about 5 to 6 kips per lineal foot. Slab-on-grade loading is anticipated to be approximately 150 pounds per square foot (psf). We anticipate grade modifications (cuts or fills) of less than five feet will be necessary to establish design elevations. If the above design assumptions either change or are incorrect, ESNW should be contacted to review the recommendations provided in this report. ESNW should review final designs to confirm that appropriate geotechnical recommendations have been incorporated into the plans. SITE CONDITIONS Surface The subject site is located at the southeast corner of the Northeast Sunset Boulevard and Harrington Avenue Northeast intersection, in Renton, Washington. The approximate site location is depicted on Plate 1 (Vicinity Map). The irregularly shaped site consists of King County Parcel No. 722780-1025, totaling about 0.67 acres. The site is bordered to the north by Northeast Sunset Boulevard, to the east by a Safeway grocery store and parking lot, to the south by an apartment building, and to the west by Harrington Avenue Northeast. The existing topography descends to the southwest, with about six to eight feet of elevation change across the subject site. The site is currently developed with two restaurants (Subway and Pizza Hut) and associated improvements. Most of the site is surfaced with asphalt. Subsurface An ESNW representative observed, logged, and sampled the advancement of three soil borings on February 12, 2021. The borings were completed within accessible areas of the property using a drill rig and operators retained by our firm. The approximate locations of the borings are depicted on Plate 2 (Boring Location Plan). Please refer to the boring logs provided in Appendix A for a more detailed description of subsurface conditions. Representative soil samples collected at the boring locations were analyzed in general accordance with both Unified Soil Classification System (USCS) and USDA methods and procedures. DRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Zarnoor Associates, LLC ES-7282 c/o Mr. Karim Karmali Page 3 March 31, 2021 Earth Solutions NW, LLC Topsoil and Fill Topsoil was not encountered at the boring locations. Given the existing level of development, significant amount of topsoil are not expected across the site. Silty sand fill was encountered at B-2, extending to a depth of about four-and-one-half feet below the existing ground surface (bgs). The fill was characterized as very loose and moist. As stated above, asphalt covers most of the ground surface across the site. Asphalt thicknesses were about one to two inches at the boring locations. Native Soil Native site soil encountered at the boring locations consisted primarily of silty sand (USCS: SM). Localized areas of poorly graded sand with silt and well-graded sand with silt (USCS: SP-SM and SW-SM) were encountered at B-3. Native soils were primarily observed in a medium dense to very dense and moist condition and generally exhibited an increasingly dense condition with depth. However, the approximate upper 10 feet of soil encountered at B-3 was characterized as loose to medium dense. Each boring location was terminated in very dense native soil and extended to a maximum exploration depth of about 26.5 feet bgs. Geologic Setting The referenced geologic map resource identifies ground moraine deposits (Qgt) as underlying the site and adjacent areas. Ground moraine deposits, otherwise known as glacial till, are considered an unsorted mixture of sand, silt, clay, and gravel. The referenced WSS resource identifies soils of the Ragnar-Indianola association and Urban land designations across the site and immediately adjacent areas. The Ragnar-Indianola associations is representative of kame, terrace, and eskers landforms, while designations of Urban land suggest historic earthwork activities and grade modifications in the area. Based on the encountered conditions, native soils are generally considered representative of ground moraine (glacial till) deposits in accordance with local geologic mapping. Groundwater Minor perched groundwater seepage was exposed at a depth of about 10 feet bgs within B-1. Zones of perched groundwater seepage should be expected during general earthwork activities and will likely develop within the soil substratum depending on the time of year. Seepage rates and elevations fluctuate depending on many factors, including precipitation duration and intensity, the time of year, and soil conditions. In general, groundwater flow rates are higher during the winter, spring, and early summer months. DRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Zarnoor Associates, LLC ES-7282 c/o Mr. Karim Karmali Page 4 March 31, 2021 Earth Solutions NW, LLC Critical Areas Review The City of Renton GIS mapping application and Chapter 3, Title IV of the Renton Municipal Code were reviewed to evaluate the presence of jurisdictionally recognized geologic hazards on site or on immediately adjacent parcels. Review of these applications did not indicate the presence of any jurisdictionally recognized geologic hazards in the area. In addition, we did not observe any obvious indication of the presence of these hazards at surface grades or within the boring locations. DISCUSSION AND RECOMMENDATIONS General Based on the results of our investigation, construction of the proposed residential development is feasible from a geotechnical standpoint. The primary geotechnical considerations for the proposal are in reference to structural fill placement and compaction, established a suitable subgrade to support the proposed mixed-use structure, foundation design, and stormwater management recommendations. Site Preparation and Earthwork Initial site preparation activities will consist of installing temporary erosion control measures, establishing grading limits, and demolishing existing improvements. Subsequent earthwork activities will involve site grading activities, foundation preparation, and installation of infrastructure improvements. Temporary Erosion Control The following temporary erosion and sediment control (TESC) Best Management Practices (BMPs) are offered: Temporary construction entrances and drive lanes should be constructed with at least six inches of quarry spalls to both minimize off-site soil tracking and provide a stable access entrance surface. A woven geotextile fabric can be placed beneath the quarry spalls to provide greater stability, if needed. Silt fencing should be placed around the site perimeter. When not in use, soil stockpiles should be covered or otherwise protected. Stockpiles should never be placed at the top of slopes, whether the slopes are native or created through grading. Temporary measures for controlling surface water runoff, such as interceptor trenches, sumps, or interceptor swales, should be installed prior to beginning earthwork activities. Dry soils disturbed during construction should be wetted to reduce dust. When appropriate, permanent planting or hydroseeding will help to stabilize site soils.DRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Zarnoor Associates, LLC ES-7282 c/o Mr. Karim Karmali Page 5 March 31, 2021 Earth Solutions NW, LLC Additional TESC BMPs, as specified by the project civil engineer and/or as indicated on the TESC plans, should be incorporated into construction activities. TESC measures must be upkept and may require modification during construction to ensure proper function. Excavations and Slopes Based on the soil conditions observed at the boring locations, the following allowable temporary slope inclinations, as a function of horizontal to vertical (H:V) inclination, may be used. The applicable Federal Occupation Safety and Health Administration (OSHA) and Washington Industrial Safety and Health Act (WISHA) soil classifications are also provided:  Loose to medium dense soil 1.5H:1V (Type C)  Areas exposing groundwater seepage 1.5H:1V (Type C)  Dense to very dense, undisturbed native soil 0.75H:1V (Type A) Steeper temporary slope inclinations within undisturbed, very dense native soil may be feasible based on the soil and groundwater conditions exposed within the excavations. ESNW can evaluate the feasibility of utilizing steeper temporary slopes at the time of construction, on a case- by-case basis. In any event, an ESNW representative should observe temporary slopes to confirm inclinations are suitable for the exposed soil conditions and to provide additional excavation and slope stability recommendations, as necessary. If the recommended temporary slope inclinations cannot be achieved, temporary shoring may be necessary to support excavations. Permanent slopes should be graded to 2H:1V (or flatter) and planted with vegetation to enhance stability and minimize erosion potential. Permanent slopes should be observed by ESNW prior to vegetation and landscaping. In-situ and Imported Soil Successful use of the on-site soil as structural fill will largely be dictated by the moisture content at the time of placement and compaction. Based on the conditions observed during our subsurface exploration, the on-site soil is highly moisture sensitive. Depending on the time of year construction occurs, remedial measures (such as soil aeration) may be necessary as part of site grading and earthwork activities. If the on-site soil cannot be successfully compacted, the use of an imported soil may be necessary. In our opinion, a contingency should be provided in the project budget for export of soil that cannot be successfully compacted as structural fill, particularly if grading activities take place during periods of extended rainfall activity. In general, soils with fines contents greater than 5 percent typically degrade rapidly when exposed to periods of rainfall. DRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Zarnoor Associates, LLC ES-7282 c/o Mr. Karim Karmali Page 6 March 31, 2021 Earth Solutions NW, LLC Imported structural fill soil should consist of a well-graded, granular soil that can achieve a suitable working moisture content. During wet weather conditions, imported soil intended for use as structural fill should consist of a well-graded, granular soil with a fines content of 5 percent or less (where the fines content is defined as the percent passing the Number 200 sieve, based on the minus three-quarter-inch fraction). Subgrade Preparation Foundation and slab subgrade surfaces should consist of competent, undisturbed native soil or structural fill placed and compacted atop competent native soil. ESNW should observe subgrade areas prior to placing formwork. Supplementary recommendations for subgrade improvement may be provided at the time of construction; such recommendations would likely include further mechanical compaction effort or overexcavation and replacement with suitable structural fill. Wet Season Grading Earthwork activities that occur during wet weather conditions may require additional measures to protect structural subgrades and soils intended for use as structural fill. Site-specific recommendations can be provided at the time of construction and may include leaving cut areas several inches above design elevations, covering working surfaces with crushed rock, protecting structural fill soils from adverse moisture conditions, and additional TESC recommendations. ESNW can assist in obtaining a wet season grading permit or extension, where appropriate, if required by the governing jurisdiction. Structural Fill Structural fill is defined as compacted soil placed in foundation, slab-on-grade, roadway, permanent slope, retaining wall, and utility trench backfill areas. The following recommendations are provided for soils intended for use as structural fill:  Moisture content At or slightly above optimum Relative compaction (minimum)95 percent (per ASTM D1557) Loose lift thickness (maximum)12 inches Existing site soil may only be considered suitable for use as structural fill if it can achieve a suitable moisture content at the time of placement and compaction. If the on-site soil cannot meet the above specifications, use of an imported structural fill material will likely be necessary. With respect to underground utility installations and backfill, local jurisdictions will likely dictate soil type(s) and compaction requirements. DRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Zarnoor Associates, LLC ES-7282 c/o Mr. Karim Karmali Page 7 March 31, 2021 Earth Solutions NW, LLC Foundations In our opinion, the proposed mixed-use structure may be constructed on a conventional continuous and spread footing foundations bearing upon competent native soil, recompacted native soil, or new structural fill placed directly on competent native soil. Competent native soil suitable for support of the proposed building will likely be encountered beginning at depths of about two-and-one-half to five feet bgs across most of the site. Soils encountered at B-3 (northwest corner) were characterized as loose to medium dense to a depth of about 10 feet bgs. Loose native soil will likely need to be either mechanically recompacted or overexcavated and replaced with suitable structural fill to establish competent and uniform soil bearing conditions. ESNW should be on site during foundation preparation activities to further delineate areas requiring remediation and provide additional recommendations. In general, where loose or unsuitable soil conditions are exposed at foundation subgrade elevations, compaction of the soil to the specifications of structural fill or overexcavation and replacement with suitable structural fill will be necessary. Provided the foundations will be supported as suggested, the following parameters may be used for design: Allowable soil bearing capacity 3,000 psf Passive earth pressure 300 pcf (equivalent fluid)  Coefficient of friction 0.40 The above passive pressure and friction values include a factor-of-safety (FOS) of 1.5. A one- third increase in the allowable soil bearing capacity may be assumed for short-term wind and seismic loading conditions. With structural loading as expected, total settlement in the range of one inch and differential settlement of about one-half inch is anticipated. Most settlement should occur during construction when dead loads are applied. Seismic Design We presume the project will be vested under the 2015 International Building Code (2015 IBC), which recognizes the American Society of Civil Engineers (ASCE) for seismic site class definitions. Based on our exploration and evaluation, Site Class C should be used for design. If the project will be designed under the 2018 IBC, ESNW can provide further evaluation and coordination with the project structural engineer to determine appropriate seismic design parameters, which may include additional geotechnical and geophysical investigation on site. In our opinion, site susceptibility to liquefaction may be considered low. The in-situ density and gradation of the native soil and the absence of a uniformly established, shallow groundwater table were the primary bases for this opinion. DRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Zarnoor Associates, LLC ES-7282 c/o Mr. Karim Karmali Page 8 March 31, 2021 Earth Solutions NW, LLC Slab-on-Grade Floors Slab-on-grade floors for the proposed mixed-use structure should be supported on competent, firm, and unyielding subgrades. Unstable or yielding subgrade areas should be recompacted or overexcavated and replaced with suitable structural fill prior to slab construction. A capillary break consisting of at least four inches of free-draining crushed rock or gravel should be placed below each slab. The free-draining material should have a fines content of 5 percent or less (where the fines content is defined as the percent passing the Number 200 sieve, based on the minus three-quarter-inch fraction). In areas where slab moisture is undesirable, installation of a vapor barrier below the slab should be considered. Vapor barriers should be made from material specifically designed for use as a vapor barrier and should be installed in accordance with the manufacturer’s recommendations. Retaining Walls Retaining walls must be designed to resist earth pressures and applicable surcharge loads. The following parameters may be used for design: Active earth pressure (unrestrained condition) 35 pcf (equivalent fluid) At-rest earth pressure (restrained condition) 55 pcf Traffic surcharge* (passenger vehicles)70 psf (rectangular distribution) Passive earth pressure 300 pcf (equivalent fluid)  Coefficient of friction 0.40  Seismic loading condition 8H psf** * Where applicable ** Where H equals the retained height (in feet) The above passive pressure and friction values include a FOS of 1.5 and are based on a level backfill condition and level grade at the wall toe. Revised design values will be necessary if sloping grades are to be used above or below retaining walls. Additional surcharge loading from adjacent foundations, sloped backfill, or other relevant loads should be included in the retaining wall design. Retaining walls should be backfilled with free-draining material that extends along the height of the wall and a distance of at least 18 inches behind the wall. The upper 12 inches of the wall backfill may consist of a less permeable soil, if desired. A sheet drain may be considered in lieu of free-draining backfill. A perforated drainpipe should be placed along the base of the wall and connected to an approved discharge location. A typical retaining wall drainage detail is provided on Plate 3. If drainage is not provided, hydrostatic pressures should be included in the wall design. DRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Zarnoor Associates, LLC ES-7282 c/o Mr. Karim Karmali Page 9 March 31, 2021 Earth Solutions NW, LLC Drainage Discrete zones of perched groundwater seepage should be anticipated in site excavations depending on the time of year grading operations take place, particularly within deeper excavations for utilities. Temporary measures to control surface water runoff and groundwater during construction would likely involve interceptor trenches, interceptor swales, and sumps. ESNW should be consulted during preliminary grading to both identify areas of seepage and provide recommendations to reduce the potential for seepage-related instability. Finish grades must be designed to direct surface drain water away from structures and slopes. Water must not be allowed to pond adjacent to structures or slopes. In our opinion, foundation drains should be installed along building perimeter footings. A typical foundation drain detail is provided on Plate 4. Preliminary Infiltration Feasibility Full infiltration is not recommended from a geotechnical standpoint given the predominance of dense silty sand encountered across most of the site. Sandier soils encountered near the northwest site corner may prove feasible for limited, targeted infiltration. However, any design would need to incorporate provisions for overflow. For feasibility and sizing considerations only, a preliminary infiltration rate of 0.5 inches per hour may be considered for infiltration facilities proposed near the northwest site corner. If infiltration is pursued, ESNW should be contacted to provide supplementary consulting and testing services. Additional services concerning infiltration feasibility would likely include in-situ testing and soil suitability verification. Utility Support and Trench Backfill In our opinion, the native soil will generally be suitable for support of utilities. Remedial measures may be necessary in some areas to provide support for utilities, such as overexcavation and replacement with structural fill and/or placement of geotextile fabric. Groundwater seepage may be encountered within utility excavations, and caving of trench walls may occur where groundwater is encountered. Depending on the time of year and conditions encountered, dewatering or temporary trench shoring may be necessary during utility excavation and installation. The on-site soil may only be suitable for use as structural backfill throughout the utility trench excavations if the soil is at (or slightly above) the optimum moisture content at the time of placement and compaction. Moisture conditioning of the soil may be necessary at some locations prior to use as structural fill. Each section of the utility lines must be adequately supported in the bedding material. Utility trench backfill should be placed and compacted to the structural fill specifications previously detailed in this report or to the applicable specifications of the presiding jurisdiction. DRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Zarnoor Associates, LLC ES-7282 c/o Mr. Karim Karmali Page 10 March 31, 2021 Earth Solutions NW, LLC LIMITATIONS This study has been prepared for the exclusive use of Zarnoor Associates, LLC, and its representatives. The recommendations and conclusions provided in this study are professional opinions consistent with the level of care and skill that is typical of other members in the profession currently practicing under similar conditions in this area. No warranty, express or implied, is made. Variations in the soil and groundwater conditions observed at the boring locations may exist and may not become evident until construction. ESNW should reevaluate the conclusions provided in this study if variations are encountered. Additional Services ESNW should have an opportunity to review final project plans with respect to the geotechnical recommendations provided in this report. ESNW should also be retained to provide testing and consultation services during construction. DRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Drwn. MRS Checked CGH Date Mar. 2021 Date 03/29/2021 Proj. No. 7282 Plate 1 Earth Solutions NWLLC Geotechnical Engineering,Construction EarthSolutionsNWLLC EarthSolutions NW LLC Observation/Testing and Environmental Services Vicinity Map Harrington Redevelopment Renton, Washington NORTHReference: King County, Washington OpenStreetMap.org NOTE: This plate may contain areas of color. ESNW cannot be responsible for any subsequent misinterpretation of the information resulting from black & white reproductions of this plate. SITE Renton DRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Plate Proj. No. Date Checked By Drwn. ByEarth Solutions NWLLCGeotechnical Engineering,ConstructionObservation/Testing and Environmental ServicesEarthSolutionsNWLLCEarthSolutionsNWLLCMRS CGH 03/29/2021 7282 2Boring Location PlanHarrington RedevelopmentRenton, Washington LEGEND Approximate Location of ESNW Test Pit, Proj. No. ES-7282, Feb. 2021 Subject Site Existing Building NORTH 0 20 40 80 Scale in Feet 1"=40' NOTE: This plate may contain areas of color. ESNW cannot be responsible for any subsequent misinterpretation of the information resulting from black & white reproductions of this plate. NOTE: The graphics shown on this plate are not intended for design purposes or precise scale measurements, but only to illustrate the approximate test locations relative to the approximate locations of existing and / or proposed site features. The information illustrated is largely based on data provided by the client at the time of our study. ESNW cannot be responsible for subsequent design changes or interpretation of the data by others. B-1 B-1 B-2 B-3 N.E. SU N SET BOULEVARDHARRI NGTON AVENUE S.E. 340 334 340 334 DRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Drwn. MRS Checked CGH Date Mar. 2021 Date 03/29/2021 Proj. No. 7282 Plate 3 Earth Solutions NWLLCEarthSolutionsNWLLC EarthSolutions NW LLC Geotechnical Engineering,Construction Observation/Testing and Environmental Services Retaining Wall Drainage Detail Harrington Redevelopment Renton, Washington NOTES: Free-draining Backfill should consist of soil having less than 5 percent fines. Percent passing No. 4 sieve should be 25 to 75 percent. Sheet Drain may be feasible in lieu of Free-draining Backfill, per ESNW recommendations. Drain Pipe should consist of perforated, rigid PVC Pipe surrounded with 1-inch Drain Rock. LEGEND: Free-draining Structural Backfill 1-inch Drain Rock 18" Min. Structural Fill Perforated Rigid Drain Pipe (Surround in Drain Rock) SCHEMATIC ONLY - NOT TO SCALE NOT A CONSTRUCTION DRAWINGDRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Drwn. MRS Checked CGH Date Mar. 2021 Date 03/29/2021 Proj. No. 7282 Plate 4 Earth Solutions NWLLC Geotechnical Engineering,Construction Observation/Testing and Environmental Services EarthSolutionsNWLLC EarthSolutions NW LLC Footing Drain Detail Harrington Redevelopment Renton, Washington Slope Perforated Rigid Drain Pipe (Surround in Drain Rock) 18" Min. NOTES: Do NOT tie roof downspouts to Footing Drain. Surface Seal to consist of 12" of less permeable, suitable soil. Slope away from building. LEGEND: Surface Seal: native soil or other low-permeability material. 1-inch Drain Rock SCHEMATIC ONLY - NOT TO SCALE NOT A CONSTRUCTION DRAWINGDRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Earth Solutions NW, LLC Appendix A Subsurface Exploration Boring Logs ES-7282 Subsurface conditions at the subject site were explored on February 12, 2021, by advancing three borings using a drill rig and operators retained by our firm. The approximate locations of the borings are illustrated on Plate 2 of this study. The boring logs are provided in this Appendix. The borings were advanced to a maximum depth of approximately 26.5 feet bgs. The final logs represent the interpretations of the field logs and the results of laboratory analyses. The stratification lines on the logs represent the approximate boundaries between soil types. In actuality, the transitions may be more gradual. DRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB DRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB 316.0 SS SS SS SS SS 67 67 67 100 0 22-24-31 (55) 17-28-28 (56) 14-15-20 (35) 19-26-28 (54) 50/5" MC = 9.3% Fines = 23.9% MC = 6.5% MC = 13.2% MC = 5.3% MC = 8.4% SM 20.0 Brown silty SAND, medium dense, moist -becomes gray, very dense [USDA Classification: slightly gravelly SAND] -becomes dense -minor perched groundwater seepage -increased sand content -becomes very dense NOTES Surface Conditions: asphalt ~1.5" to 2" GROUND ELEVATION 336 ft LOGGED BY CGH DRILLING METHOD HSA HOLE SIZE DRILLING CONTRACTOR Geologic Drill Partners GROUND WATER LEVELS: CHECKED BY KDH DATE STARTED 2/12/21 COMPLETED 2/12/21 AT TIME OF DRILLING --- AT END OF DRILLING --- AFTER DRILLING --- (Continued Next Page)SAMPLE TYPENUMBERDEPTH(ft)0 5 10 15 20 PAGE 1 OF 2 BORING NUMBER B-1 PROJECT NUMBER ES-7282 PROJECT NAME Harrington Redevelopment GENERAL BH / TP / WELL - 7282.GPJ - GINT STD US.GDT - 3/31/21Earth Solutions NW, LLC 15365 N.E. 90th Street, Suite 100 Redmond, Washington 98052 Telephone: 425-449-4704 Fax: 425-449-4711 RECOVERY %BLOWCOUNTS(N VALUE)TESTS U.S.C.S.MATERIAL DESCRIPTION GRAPHICLOGDRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB SS 100 50/6"MC = 9.0% Boring terminated at 20.5 feet below existing grade. Groundwater seepage encountered at 10.0 feet during drilling. Boring backfilled with bentonite.SAMPLE TYPENUMBERDEPTH(ft)20 PAGE 2 OF 2 BORING NUMBER B-1 PROJECT NUMBER ES-7282 PROJECT NAME Harrington Redevelopment GENERAL BH / TP / WELL - 7282.GPJ - GINT STD US.GDT - 3/31/21Earth Solutions NW, LLC 15365 N.E. 90th Street, Suite 100 Redmond, Washington 98052 Telephone: 425-449-4704 Fax: 425-449-4711 RECOVERY %BLOWCOUNTS(N VALUE)TESTS U.S.C.S.MATERIAL DESCRIPTION GRAPHICLOGDRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB 331.5 316.0 SS SS SS SS SS 100 100 100 100 50 1-1-1 (2) 4-14-19 (33) 50/5" 11-14-18 (32) 50/4" MC = 14.2% MC = 13.9% Fines = 26.6% MC = 8.7% MC = 11.0% MC = 10.7% SM SM 4.5 20.0 Brown silty SAND, very loose, moist (Fill) -trace organic material Brown silty SAND, loose, moist [USDA Classification: slightly gravelly sandy LOAM] -becomes gray, dense -minor iron oxide staining -becomes very dense -becomes dense -possible obstruction -no recovery due to obstruction. Sample taken from spoils. NOTES Surface Conditions: asphalt ~1" GROUND ELEVATION 336 ft LOGGED BY CGH DRILLING METHOD HSA HOLE SIZE DRILLING CONTRACTOR Geologic Drill Partners GROUND WATER LEVELS: CHECKED BY KDH DATE STARTED 2/12/21 COMPLETED 2/12/21 AT TIME OF DRILLING --- AT END OF DRILLING --- AFTER DRILLING ---SAMPLE TYPENUMBERDEPTH(ft)0 5 10 15 20 PAGE 1 OF 1 BORING NUMBER B-2 PROJECT NUMBER ES-7282 PROJECT NAME Harrington Redevelopment GENERAL BH / TP / WELL - 7282.GPJ - GINT STD US.GDT - 3/31/21Earth Solutions NW, LLC 15365 N.E. 90th Street, Suite 100 Redmond, Washington 98052 Telephone: 425-449-4704 Fax: 425-449-4711 RECOVERY %BLOWCOUNTS(N VALUE)TESTS U.S.C.S.MATERIAL DESCRIPTION GRAPHICLOGBoring terminated at 20.0 feet below existing grade. No groundwater encountered during drilling. Boring backfilled with bentonite. SS 50/5"DRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB SS SS SS SS SS 67 67 67 100 55 5-5-6 (11) 4-4-6 (10) 5-3-2 (5) 2-3-13 (16) 13-50/5" MC = 8.4% MC = 6.8% Fines = 9.5% MC = 9.6% MC = 11.0% Fines = 29.9% MC = 7.5% SP- SM SM 7.5 20.0 Brown poorly graded SAND with silt and gravel, medium dense, moist [USDA Classification: very gravelly loamy coarse SAND] Brown silty SAND, loose, moist [USDA Classification: gravelly fine sandy LOAM] -becomes gray, medium dense -becomes very dense NOTES Surface Conditions: asphalt ~1" GROUND ELEVATION LOGGED BY CGH DRILLING METHOD HSA HOLE SIZE DRILLING CONTRACTOR Geologic Drill Partners GROUND WATER LEVELS: CHECKED BY KDH DATE STARTED 2/12/21 COMPLETED 2/12/21 AT TIME OF DRILLING --- AT END OF DRILLING --- AFTER DRILLING --- (Continued Next Page)SAMPLE TYPENUMBERDEPTH(ft)0 5 10 15 20 PAGE 1 OF 2 BORING NUMBER B-3 PROJECT NUMBER ES-7282 PROJECT NAME Harrington Redevelopment GENERAL BH / TP / WELL - 7282.GPJ - GINT STD US.GDT - 3/31/21Earth Solutions NW, LLC 15365 N.E. 90th Street, Suite 100 Redmond, Washington 98052 Telephone: 425-449-4704 Fax: 425-449-4711 RECOVERY %BLOWCOUNTS(N VALUE)TESTS U.S.C.S.MATERIAL DESCRIPTION GRAPHICLOGDRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB SS SS 100 100 25-30-38 (68) 26-26-42 (68) MC = 7.4% Fines = 10.3% MC = 5.0% SM SW- SM 21.0 26.5 Gray silty SAND, very dense, moist [USDA Classification: slightly gravelly coarse SAND] Gray well-graded SAND with silt, very dense, moist -4" silty sand lens Boring terminated at 26.5 feet below existing grade. No groundwater encountered during drilling. Boring backfilled with bentonite.SAMPLE TYPENUMBERDEPTH(ft)20 25 PAGE 2 OF 2 BORING NUMBER B-3 PROJECT NUMBER ES-7282 PROJECT NAME Harrington Redevelopment GENERAL BH / TP / WELL - 7282.GPJ - GINT STD US.GDT - 3/31/21Earth Solutions NW, LLC 15365 N.E. 90th Street, Suite 100 Redmond, Washington 98052 Telephone: 425-449-4704 Fax: 425-449-4711 RECOVERY %BLOWCOUNTS(N VALUE)TESTS U.S.C.S.MATERIAL DESCRIPTION GRAPHICLOGDRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Earth Solutions NW, LLC Appendix B Laboratory Test Results ES-7282 DRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 0.0010.010.1110100 3 D100 140 Specimen Identification 1 fine 6 HYDROMETER 304 23.9 26.6 9.5 29.9 10.3 101/2 COBBLES Specimen Identification 4 coarse 20 401.5 8 14 USDA: Gray Slightly Gravelly Loamy Sand. USCS: SM. USDA: Gray Slightly Gravelly Sandy Loam. USCS: SM. USDA: Brown Very Gravelly Loamy Coarse Sand. USCS: SP-SM with Gravel. USDA: Gray Gravelly Fine Sandy Loam. USCS: SM. USDA: Gray Slightly Gravelly Coarse Sand. USCS: SW-SM. 6 60 PERCENT FINER BY WEIGHTD10 0.115 0.096 0.345 0.075 0.232 0.376 0.371 2.788 0.214 0.599 GRAIN SIZE DISTRIBUTION 100 35.00 8.22 LL B-01 B-02 B-03 B-03 B-03 0.08 3/4 U.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS GRAVEL SAND 19 19 37.5 37.5 9.5 %Silt 0.54 1.24 B-01 B-02 B-03 B-03 B-03 2 2003 Cc CuClassification %Clay 16 PID60 D30 coarse SILT OR CLAYfinemedium GRAIN SIZE IN MILLIMETERS 3/8 50 2.5ft. 5.0ft. 5.0ft. 10.0ft. 20.0ft. 2.50ft. 5.00ft. 5.00ft. 10.00ft. 20.00ft. PL PROJECT NUMBER ES-7282 PROJECT NAME Harrington Redevelopment GRAIN SIZE USDA ES-7282 HARRINGTON REDEVELOPMENT.GPJ GINT US LAB.GDT 2/24/21Earth Solutions NW, LLC 15365 N.E. 90th Street, Suite 100 Redmond, Washington 98052 Telephone: 425-449-4704 Fax: 425-449-4711 DRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Earth Solutions NW, LLC Report Distribution ES-7282 EMAIL ONLY Zarnoor Associates, LLC c/o Mr. Karim Karmali 19515 North Creek Parkway, Suite 314 Bothell, Washington 98011 Attention: Mr. Nazim Karmali EMAIL ONLY Grouparchitect 1735 Westlake Avenue North, Suite 200 Seattle, Washington 98109 Attention: Mr. Kyle Stevens DRAFTDocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB United States Department of Agriculture A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for King County Area, Washington Natural Resources Conservation Service May 17, 2021 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/ portal/nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid=nrcs142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require 2 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Contents Preface....................................................................................................................2 How Soil Surveys Are Made..................................................................................5 Soil Map..................................................................................................................8 Soil Map................................................................................................................9 Legend................................................................................................................10 Map Unit Legend................................................................................................11 Map Unit Descriptions.........................................................................................11 King County Area, Washington.......................................................................13 RdC—Ragnar-Indianola association, sloping..............................................13 Ur—Urban land...........................................................................................14 References............................................................................................................15 4 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB How Soil Surveys Are Made Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil 5 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB scientists classified and named the soils in the survey area, they compared the individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil-landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil-landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field-observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and Custom Soil Resource Report 6 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. Custom Soil Resource Report 7 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 8 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB 9 Custom Soil Resource Report Soil Map 5260860526087052608805260890526090052609105260920526093052609405260950526096052608605260870526088052608905260900526091052609205260930526094052609505260960561620 561630 561640 561650 561660 561670 561680 561690 561620 561630 561640 561650 561660 561670 561680 561690 561700 47° 29' 57'' N 122° 10' 54'' W47° 29' 57'' N122° 10' 50'' W47° 29' 53'' N 122° 10' 54'' W47° 29' 53'' N 122° 10' 50'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 10N WGS84 0 25 50 100 150 Feet 0 5 10 20 30 Meters Map Scale: 1:559 if printed on A portrait (8.5" x 11") sheet. Soil Map may not be valid at this scale. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB 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 16, Jun 4, 2020 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jul 25, 2020—Jul 27, 2020 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. Custom Soil Resource Report 10 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI RdC Ragnar-Indianola association, sloping 0.3 40.7% Ur Urban land 0.4 59.3% Totals for Area of Interest 0.7 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, Custom Soil Resource Report 11 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB onsite investigation is needed to define and locate the soils and miscellaneous areas. An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha-Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. Custom Soil Resource Report 12 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB King County Area, Washington RdC—Ragnar-Indianola association, sloping Map Unit Setting National map unit symbol: 1hmty Elevation: 0 to 1,000 feet Mean annual precipitation: 30 to 65 inches Mean annual air temperature: 48 to 54 degrees F Frost-free period: 150 to 210 days Farmland classification: Farmland of statewide importance Map Unit Composition Ragnar and similar soils:45 percent Indianola and similar soils:40 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Ragnar Setting Landform:Kames, terraces, eskers Parent material:Glacial outwash Typical profile H1 - 0 to 4 inches: ashy fine sandy loam H2 - 4 to 27 inches: ashy fine sandy loam H3 - 27 to 60 inches: loamy sand Properties and qualities Slope:2 to 15 percent Depth to restrictive feature:20 to 40 inches to strongly contrasting textural stratification Drainage class:Well drained Capacity of the most limiting layer to transmit water (Ksat):High (1.98 to 5.95 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Available water capacity:Low (about 3.7 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3e Hydrologic Soil Group: A Forage suitability group: Droughty Soils (G002XN402WA) Other vegetative classification: Droughty Soils (G002XN402WA) Hydric soil rating: No Description of Indianola Setting Landform:Terraces Parent material:Glacial drift Typical profile H1 - 0 to 6 inches: loamy fine sand Custom Soil Resource Report 13 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB H2 - 6 to 30 inches: loamy fine sand H3 - 30 to 60 inches: sand Properties and qualities Slope:2 to 15 percent Depth to restrictive feature:More than 80 inches Drainage class:Somewhat excessively drained Capacity of the most limiting layer to transmit water (Ksat):High (1.98 to 5.95 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Available water capacity:Low (about 5.0 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3e Hydrologic Soil Group: A Forage suitability group: Droughty Soils (G002XN402WA) Other vegetative classification: Droughty Soils (G002XN402WA) Hydric soil rating: No Ur—Urban land Map Unit Composition Urban land:100 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Urban Land Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 8 Hydric soil rating: No Custom Soil Resource Report 14 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB References American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs142p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ home/?cid=nrcs142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 15 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/soils/scientists/?cid=nrcs142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/? cid=nrcs142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf Custom Soil Resource Report 16 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Site Planning Civil Engineering Landscape Architecture Project Management Land Use Consulting APPENDIX B ARBORIST REPORT DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB LAYTON TREE CONSULTING, LLC It’s all about trees…… PO BOX 572, SNOHOMISH, WA 98291-0572 * 425-220-5711 * bob@laytontreeconsulting.com ARBORIST REPORT/TREE PLAN 960 Harrington Avenue NE Renton, WA Report Prepared by: Bob Layton Registered Consulting Arborist #670 Certified Arborist #PN-2714A April 19, 2021 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Arborist Report – 960 Harrington AVE NE Page 2 Layton Tree Consulting LLC April 19, 2021 Table of Contents Assignment.................................................................................................................................................... 3 Description .................................................................................................................................................... 3 Methodology ................................................................................................................................................. 3 Judging Condition...................................................................................................................................... 3 Observations ................................................................................................................................................. 4 Discussion/Recommendations ...................................................................................................................... 4 Tree Density-Tree Replacement ................................................................................................................... 5 Arborist Disclosure Statement ...................................................................................................................... 6 Attachments Photos, pages 7 - 13 Tree Summary Table Tree Plan Map City of Renton – Approved Tree List DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Arborist Report – 960 Harrington AVE NE Page 3 Layton Tree Consulting LLC April 19, 2021 Assignment Layton Tree Consulting, LLC was asked to compile an Arborist Report for one parcel in Renton. The subject property is located at 960 Harrington AVE NE. The purpose of the report is to satisfy City requirements regarding tree retention regulations associated with the proposed redevelopment of the property. My assignment is to prepare a written report on present tree conditions, and to provide appropriate recommendations for the protection of retained or protected trees during development. This report covers all of the criteria set forth under the City of Renton’s tree regulations, Municipal Code Section 4-4-130 - Tree Retention and Land Clearing Regulations. Date of Field Examination: April 13, 2021 Description Three significant trees were identified on the property. A significant tree is any tree with a caliper of at least 6-inches or alder or cottonwood tree at least 8-inches. A numbered aluminum tag was attached to the lower trunk of the subject trees. These tag numbers correspond with the numbers on the attached Tree Summary Table and attached Tree Plan Map. An additional three off-site trees were also assessed. These exist within the right-of-way of NE Sunset Blvd. These are all mature London plane trees. Methodology Each tree in this report was visited. Tree diameters were measured by tape. The tree heights were measured using a Spiegel Relaskop. Each tree was visually examined for defects and vigor. The tree assessment procedure involves the examination of many factors: • The crown or canopy of the tree is examined for current vigor/health by examining the foliage for appropriate color and density, the vegetative buds for color and size, and the branches for structural form and annual shoot growth; and the overall presence of limb dieback and/or any disease issues. • The trunk or main stem of the tree is inspected for decay, which includes cavities, wounds, fruiting bodies of decay (conks or mushrooms), seams, insect pests, bleeding or exudation of sap, callus development, broken or dead tops, structural defects and unnatural leans. Structural defects can include but are not limited to excessive or unnatural leans, crooks, forks with V-shaped crotches, multiple attachments. • The root collar and exposed surface roots are inspected for the presence of decay, insect damage, as well as if they have been injured or wounded, undermined or exposed, or the original grade has been altered. Judging Condition The three condition categories are described as follows: DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Arborist Report – 960 Harrington AVE NE Page 4 Layton Tree Consulting LLC April 19, 2021 Good – free of significant structural defects, no disease concerns, minor pest issues, no significant root issues, good structure/form with uniform crown or canopy, foliage of normal color and density, average or normal vigor, will be wind firm if isolated or left as part of a grouping or grove of trees, suitable for its location Fair – minor to moderate structural defects not expected to contribute to a failure in near future, no disease concerns, moderate pest issues, no significant root issues, asymmetric or unbalanced crown or canopy, average or normal vigor, foliage of normal color, moderate foliage density, will be wind firm if left as part of a grouping or grove of trees, cannot be isolated, suitable for its location Poor – major structural defects expected to cause fail in near future, disease or significant pest concerns, decline due to old age, significant root issues, asymmetric or unbalanced crown or canopy, sparse or abnormally small foliage, poor vigor, not suitable for its location The attached Tree Summary Table provides specific information on tree sizes and dripline measurements. Observations The subject trees are described as follows: Tree #1 is a semi-mature to mature Austrian pine. It has developed an asymmetric crown and lean to the south away from Tree #2. The root crown and ground around the tree are covered with a dense matt of English ivy. Vigor is good. Foliage is of normal color and density. The lower trunk appears sound. Root growth has cracked surrounding pavement and lifted curb sections. Condition is ‘fair’. Tree #2 is a mature London plane. It is surrounded by pavement and a sidewalk. There is obvious root growth beneath the pavement that extends up to 20-feet from the trunk to the east. The tree has developed good structural form. Vigor appears good. No concerning conditions were observed. Condition is rated as ‘good’. Tree #3 is a young to semi-mature Austrian pine, comprised of two stems or trunks. It also has an asymmetric crown and lean to the south away from the larger plane trees. Condition is ‘fair’. Right-of-way Trees Trees #4, #5 and #6 are mature London plane trees within the right-of-way of Sunset Blvd. NE. Trees #4 and #5 have developed good structural form with no concerning issues. Lower trunks are sound with no outward indicators of any internal decay issues. Vigor appears good. Condition is rated as ‘good’. The lower trunk of Tree #6 forks into two main stems or trunks, which are codominant (equal diameter). There is a moderate buildup of included or embedded bark between the forked stems. Vigor appears good. Condition is rated as ‘fair’. Discussion/Recommendations It is my understanding the City would like to see Trees #4, #5 and #6 preserved. Tree #6 is well away from the subject property and not likely to be impacted. London plane is actually quite hardy and DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Arborist Report – 960 Harrington AVE NE Page 5 Layton Tree Consulting LLC April 19, 2021 tolerable of construction impacts, so long as those impacts are kept to acceptable levels. It is also my understanding that Trees #1, #2 and #3 are being proposed for removal. Whether or not Trees #4 and #5 can be retained will depend on the required street frontage improvements. Relocating the sidewalk to the opposite sides of Trees #4 and #5 will create major disturbances and have consequential impacts on long-term health. The existing grades are not conducive to relocating the sidewalk as it slopes down from the elevation of the existing sidewalk. If the existing sidewalk can be left as-is, the odds of successful retention are much higher. Tree locations are shown on the attached Tree Plan Map. The driplines of trees have been delineated on the map, as well as the recommended location of the critical root zone boundary. The critical root zone boundary is based on species, age, condition, dripline, prior improvements, proposed impacts and the anticipated cumulative impacts to the entire root zone. Encroachment beyond this limit is likely to compromise long-term health or longevity. Pavement or sidewalk sections within the critical root zone boundary shall be removed using primarily hand-labor. Pavement/concrete can be broken up with a manual jack-hammer and removed by hand from the tree protection zone. Keep equipment off of the critical root zone boundary to protect soils and surface roots. A tree protection barrier shall be placed around any retained or protected trees to the largest extent possible and fully protect the critical root zone. Cover tree protection areas with a protective +/- 6-inch layer of coarse arborist wood chip mulch or hog fuel. Thoroughly irrigate any newly exposed areas from pavement/concrete removal prior to covering with wood chips. Any roots encountered during work outside of the tree protection areas shall be pruned clean at sound tissue prior to backfilling or finishing areas. Sound tissue is where the root is undamaged and the bark is completely intact with the root. Any authorized work within dripline of retained and/or protected trees shall be supervised by the project arborist in an effort to ensure impacts are kept as minimal as possible or to acceptable levels. Some pruning may be needed to provide adequate construction clearance. The amount of anticipated pruning or removal of branches is not significant and not expected to have any adverse impacts on tree health or stability. All clearance pruning will conform to ANSI A-300 Pruning Standards. Simply finish the landscape within the driplines of any retained/protected trees by cutting/hand-pulling any unwanted vegetation, raking off half of the protective wood chips and applying a more attractive 2 to 4-inch covering of organic mulch/beauty bark. Keep large plantings, irrigation/dispersion trenches and construction of hardscapes outside of the dripline where possible. Tree Density-Tree Replacement Consult with your City planner on tree replacement/landscape requirements. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Arborist Report – 960 Harrington AVE NE Page 6 Layton Tree Consulting LLC April 19, 2021 Replacement trees shall be at least 2-inch caliper for deciduous species and 6-feet in height for evergreen species. The City’s approved tree list is attached. Replacement tree species shall be chosen from this list. Plant new trees in areas where they can fully mature without conflicting with new improvements. Arborist Disclosure Statement Arborists are tree specialists who use their education, knowledge, training and experience to examine and assess trees, recommend measures to enhance the beauty and health of trees, and attempt to reduce the risks associated with living near trees. Clients may choose to accept or disregard the recommendations of the arborist, or to seek additional advice. Arborists cannot detect every condition that could possibly lead to the structural failure of a tree. Trees are living organisms that grow, respond to their environment, mature, decline and sometimes fail in ways we do not fully understand. Conditions are often hidden within trees and below ground. Arborists cannot guarantee that a tree will be healthy and/or safe under all circumstances, or for a specified period of time. Likewise, remedial treatments, like any medicine, cannot be guaranteed. Treatment, pruning and removal of trees may involve considerations beyond the scope of the arborist’s services such as property boundaries, property ownership, site lines, disputes between neighbors, and other issues. Arborists cannot take such considerations into account unless complete and accurate information is disclosed to the arborist. An arborist should then be expected to reasonably rely upon the completeness and accuracy of the information provided. Trees can be managed, but they cannot be controlled. To live near trees is to accept some degree of risk. The only way to eliminate all risk associated with trees is to eliminate all trees. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Arborist Report – 960 Harrington AVE NE Page 7 Layton Tree Consulting LLC April 19, 2021 Photo Documentation Tree #1 – lower trunk Tree #1 – lower trunk, obvious root growth beneath pavement DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Arborist Report – 960 Harrington AVE NE Page 8 Layton Tree Consulting LLC April 19, 2021 Trees #1 and #2, looking north up Harrington Ave NE Tree #2 – lower trunk DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Arborist Report – 960 Harrington AVE NE Page 9 Layton Tree Consulting LLC April 19, 2021 Tree #2 – mid crown Tree #2 – lower trunk, sidewalk has lifted and been repaired in the past DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Arborist Report – 960 Harrington AVE NE Page 10 Layton Tree Consulting LLC April 19, 2021 Tree #3 on right, #4 on left, #5 in background Tree #4 – lower trunk, large surface roots extending several feet to the south DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Arborist Report – 960 Harrington AVE NE Page 11 Layton Tree Consulting LLC April 19, 2021 Trees #4 and #5 within proximity to sidewalk Tree #5 in foreground, #4 in background DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Arborist Report – 960 Harrington AVE NE Page 12 Layton Tree Consulting LLC April 19, 2021 Tree #5 in foreground, #4 in background Tree #6 – lower trunk DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Arborist Report – 960 Harrington AVE NE Page 13 Layton Tree Consulting LLC April 19, 2021 Tree #6 – lower trunk Tree #6 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Layton Tree Consulting LLC For:Zarnoor Associates Site:960 Harrington AVE NE - Renton Tree Summary Table Date: Tree/DBH Height Tag #Species (inches)(feet)Condition Comments Proposal N S E W 1 Austrian pine 23 45 6 15 12 8 Fair asymmetric crown/lean south, root crown covered with ivy Remove 2 London plane 42 83 30 32 36 24 Good trunk sound ,sound stem attachments Remove 3 Austrian pine 9,5 (10)24 6 14 10 4 Fair leans south, natural lean Remove OFF-SITE TREES 4 London plane 34 67 22 26 20 36 Good sound trunk, large exposed surface roots to south TBD 5 London plane 29 70 18 28 22 21 Good sound trunk, large exposed surface roots to south TBD 6 London plane 46 85 28 30 NA 30 Fair trunk forks at 5 feet, noteworthy included bark Protect Drip-Line measurements from face of trunk TBD - to be determined Drip-Line / Limits of Disturbance (feet) 4/13/2021 Calculated DBH: the DBH is parenthesis is the square root of the sum of the dbh for each individual stem squared (example with 3 stems: dbh = square root [(stem1)2 +(stem2)2 +(stem3)2 ]). DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB APPROVED TREE LIST – Small, Medium, and Large H:\CED\Data\Forms-Templates\Self-Help Handouts\Planning\treeslist_march2010.doc P. 1 In the City of Renton there is an overabundance of maple and cherry species. According to the most recent street tree inventory, maples currently comprise 35% and cherry 24% of all species. To reduce a catastrophic loss of species, experts agree that 10% o r less of any species or cultivar exist within a street tree population. Because of this, planting maple or cherry trees within the right -of-way is discouraged. SMALL TREES: 30 feet in height or less Botanical name / Common Name Mature Height in Feet Mature Spread in Feet Fall Color Comments Acer buergeranum / Trident Maple 20 20 yellow orange and red Adaptable to urban environments. Decidiuous: prefers moist, well-drained soils: tolerates infertile sites. Drought tolerant. Acer campestre / Hedge Maple 30 30 yellow Deciduous; prefers moist, rich soils; slow growing tree tolerant of air pollution and soil compaction; yellow fall color; cultivars available including Queen Elizabeth maple (‘Evelyn’) with dark green, glossy foliage. Acer circinatum / Vine Maple 20-25 10 orange and red Deciduous; prefers moist, well-drained soils; tolerates seasonal saturation and varying soil types; drought tolerant once established; bushy shrub or small tree; most often multi-trunked and does well in small groups; white flowers April- June. Acer ginnala 'Flame' / Amur Maple 20 20 red Deciduous; prefers moist, well-drained soils, but is tolerant of drought; is often multi-trunked, but can be pruned to a single stem; rounded form; fragrant, yellowish-white flowers in spring; cultivars are available such as ‘Flame’ and ‘Embers’ with differing fall colors. Select or prune for single stem; can be multi- trunked. Acer grandidentatum 'Schmidt' / Rocky Mt. Glow Maple 25+ 15 intense Acer griseum / Paperback Maple 25 20 scarlet Deciduous; prefers moist, well-drained soils, but is moderately drought tolerant; bronze peeling bark provides year-round visual interest; often multitrunked, but can be trained to a single stem; slow growing; disease and pest resistant. Smooth, peeling, cinnamon colored bark. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB APPROVED TREE LIST – Small, Medium, and Large H:\CED\Data\Forms-Templates\Self-Help Handouts\Planning\treeslist_march2010.doc P. 2 Botanical name / Common Name Mature Height in Feet Mature Spread in Feet Fall Color Comments Acer palmatum / Japanese Maple 20 24 yellow, orange, red Prefers moist, well-drained soils; deciduous; slow to moderate growth rate; multi-trunked with spreading branches; intolerant of inundation but moderately drought resistant; vibrant fall colors; many cultivars available including ‘Emperor I’, ‘Katsura’, and ‘Osakazuki’. Hundreds of varied cultivars. Can be slow growing. Acer saccharum 'Apollo' 25 10 yellow, orange Prefers well drained soils, but grows in varying soils; hearty. Acer platanoides 'Globosum' / Globe Norway Maple 20 18 yellow Moist soils preferred, but tolerates drought and seasonal inundation; tolerant of urban pollution; dense, compact, round form; slow-growing deciduous tree with brilliant fall color; shallow root system may make mowing under the tree slightly difficult; good selection for locations under power lines; another cultivar well suited for such a location is A. platanoides ‘Almira,’ reaching only 20-25 ft. Rounded top, and compact growth. Acer truncatum / Purpleblow maple 20-25 20-25 Prefers moist, well-drained soil, but drought tolerant; very cold hardy deciduous tree; moderate growth rate; yellow flowers in spring; an additional maple cultivar of interest is 'Pacific sunset'. Acer truncatum x A. platanoides 'Warren's Red' / Pacific Sunset 30 25 yellow- orange/ red Acer Triflorum - Roughbark maple 25-30 20-25 apricot, gold Deciduous; prefers moist soils, but somewhat drought tolerant once established; rough, knobby trunk provides interest in winter; disease and pest resistant; non- aggressive roots do not damage sidewalks or driveways. Amelanchier grandiflora 'Princess Diana' 20 15 bright red Good for limited space. Amelanchier x grandiflora 'Autumn Brilliance' Serviceberry 20 15 red or yellow Moist to dry, well-drained soils; small tree; drought tolerant; white clustered flowers in spring; also try 'Princess Diana' for bright red fall color and the slightly taller 'Robin Hill' (20-30 feet). Reliable bloom. Amelanchier laevis ' lustre' / Luster Serviceberry 25 25 red or yellow Moist to dry, well-drained soils; small tree; drought tolerant; white clustered flowers in spring. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB APPROVED TREE LIST – Small, Medium, and Large H:\CED\Data\Forms-Templates\Self-Help Handouts\Planning\treeslist_march2010.doc P. 3 Botanical name / Common Name Mature Height in Feet Mature Spread in Feet Fall Color Comments Arbutus 'Marina' 25 15 evergreen Good substitute for Pacific Madrone. May exceed 25' height under some site conditions. Carpinus caroliniana / American hornbeam 20-30 20-20 Deciduous; prefers moist, rich soils; grows near saturated areas but is only weakly tolerant of saturation; blooms March-May; slow growing; deep coarse laterally spreading roots; medium life span; also consider Carpinus japonica (Japanese hornbeam). Cercis canadensis / Eastern Redbud 25 30 yellow Deciduous; prefers moist, rich soils; tolerant of shade; somewhat drought resistant, but not in full sun; purple-lavender flowers; medium longevity; often multi-trunked; shallow, fibrous roots become deeper on drier sites; fairly short- lived; blooms March-May. Blooms before leaves are out. Cornus kousa 'Chinensis' / Chinese Kousa Dogwood 20 20 reddish to scarlet Prefers moist soils; tolerant of varying soil types; moderate growth rate; deciduous; white flowers in June and large red fruits that resemble a raspberry in September; red to maroon fall color; more disease resistant than other dogwoods; many additional cultivars available. Most resistant to disease of the dogwoods. Crataegus crus-galli 'Inermis' / Thornless Cockspur Hawthorn 25 30 orange to scarlet Red persistent fruit. Crataegus x lavalii / Lavalle Hawthorne 28 20 bronze, coppery red Deciduous; prefers moist, well-drained soil, but tolerant of varying soil types; white flowers in spring; fruit can be a bit messy. Thorns on younger trees. Crataegus phaenopyrum / Washington Hawthorn 25 20 scarlet Thorny. Fraxinus pennsylvanica 'Johnson' / Leprechaun Ash 18 16 yellow Prefers moist, well-drained soils; deciduous: slow to moderate growth rate; tolerant of inundation but moderately drought resistant. A miniature in every way. Magnolia x loebneri 20 20 yellow Several cultivars. Magnolia grandiflora 'Little Gem' 15 10 evergreen Useful where larger varieties are inappropriate. Magnolia grandiflora 'Victoria' 25 20 evergreen DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB APPROVED TREE LIST – Small, Medium, and Large H:\CED\Data\Forms-Templates\Self-Help Handouts\Planning\treeslist_march2010.doc P. 4 Botanical name / Common Name Mature Height in Feet Mature Spread in Feet Fall Color Comments Malus spp. / Flowering crabapple 15-25 6-15 Selection should be based on disease resistance to apple scab and fireblight. Tolerant of prolonged soil saturation; short lived; tolerant of drought and seasonally saturated soils; deciduous; white or faintly pink flowers in spring; numerous Malus species and cultivars provide a variety of foliage and flower colors, forms and fruit. Malus 'Adirondack' 18 8 yellow Red fruit. Excellent scab resistance. Malus 'Red Barron' 18 8 yellow Good for narrow spaces. Red berries. Malus 'Golden Raindrops' 18 13 yellow Abundant yellow fruit. Malus 'Tschonoskii' 28 14 scarlet Sparse green fruit, pyramidal. Parrotia persica / Persian Parrotia 30 20 yellow- orange red Moist to dry soils; drought tolerant when established, deciduous tree with moderate growth rate; brilliant fall color; often multi-trunked, but can be trained to have just one; tolerates urban pollution and soil compaction; surface roots do not generally cause problems; virtually disease and pest-free. Pranus 'Frankthrees' / Mt. St. Helens Plum 20 20 Purple foliage. Prunus 'Newport' / Newport Plum 20 20 reddish to scarlet Purple red foliage. Prunus cerasifera 'Krauter Vesuvius' / Flowering Plum 30 15 Upright growth, darkest foliage of the plums. Prunus cerasifera 'Thundercloud' / Plum 20 20 Dark purple foliage. Prunus x hillieri 'Spire' 30 10 orange red Prunus 'Snowgoose' / Snow Goose Cherry 20 20 Upright when young, spreading when older. Prunus serrulata 'Amanogawa' / Flowering Cherry 20 6 bronze Particularly useful for very narrow planting strips. Prunus serrulata 'Shirofugen' / Japanese flowering cherry 25 25 Deciduous flowering tree; moist, well-drained soils; double pink to white blooms in spring; vigorous grower; additional desirable choices include P. serrulata ‘Snowgoose’, ‘Kwanzan’, and ‘Shirotae’. Prunus x yedoensis 'Akebono' / Flowering Cherry 25 25 yellow DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB APPROVED TREE LIST – Small, Medium, and Large H:\CED\Data\Forms-Templates\Self-Help Handouts\Planning\treeslist_march2010.doc P. 5 Botanical name / Common Name Mature Height in Feet Mature Spread in Feet Fall Color Comments Quercus Ilex / Holly Oak 20 20 Prefers moist soils, but grows in varying soils; hearty, slow-growing evergreen tree; light pink flowers May-June; pruning will keep tree small for a hedge, without pruning may grow considerably larger – not appropriate under utility lines; tolerates salt water spray. Prune to keep small, leave it alone to grow large. Styrax japonica / Japanese Snowbell 25 25 yellow Plentiful, green 1/2 inch seeds. Styrax obassia / Fragrant Snowbell 30 25 Prefers moist, well-drained soil but tolerates wide variations; fragrant with flowers; twisting bark. Try other Styrax species. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB APPROVED TREE LIST – Small, Medium, and Large H:\CED\Data\Forms-Templates\Self-Help Handouts\Planning\treeslist_march2010.doc P. 6 MEDIUM TREES: 30 to 50 feet in height Botanical name / Common Name Mature Height in Feet Mature Spread in Feet Fall Color Comments Acer campestre 'Evelyn' / Queen Elizabeth Maple 35 30 yellow More upright branching than the species. Acer platanoides 'Columnar' / Columnar Norway maple 40 15 yellow Deciduous; adapts to varying soils; upright or columnar in form making this cultivar a better choice for narrow locations; tolerant of drought and seasonal inundation; tolerates urban pollution and displays brilliant fall color; shallow rooting necessitates locating at least 4-6 feet from sidewalks and driveways to prevent heaving of pavement. Good close to buildings. Acer truncatum x A. platanoides 'Klethsform' / Norwegian Sunset 35 25 yellow- orange/ red Acer rubrum 'Bowhall' / Bowhall Maple 40 15 yellow orange Acer rubrum 'Karpick' / Karpick Maple 35-40 20 yellow to orange May work under very high powerlines with arborist's approval. Acer rubrum 'Scarsen' / Scarlet Sentinel Maple 40 20 yellow orange Acer rubrum / Red Maple 35-50 15-40 Deciduous tree known for fall color; prefer wet or moist soils; fast growing with roots that may heave sidewalks or interfere with mowing; many cultivars of varying heights available including: A. rubrum, 'Armstrong', 'Bowhall', 'Karpick', 'Scarsen', and 'Red Sunset'. Betula jacquemontii / Jacquemontii Birch 40 30 yellow White bark makes for good winter interest. Carpinus betulus 'Fastigiati' / Pyramidal European Hornbeam 35 25 yellow Fagus sylvatica 'Dawyck Purple' / Dawyck Purple Beech 40 12 Purple foliage. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB APPROVED TREE LIST – Small, Medium, and Large H:\CED\Data\Forms-Templates\Self-Help Handouts\Planning\treeslist_march2010.doc P. 7 Botanical name / Common Name Mature Height in Feet Mature Spread in Feet Fall Color Comments Fraxinus americana 'Autumn Applause' / Ash 40 25 purple Deciduous; prefers moist, well-drained soils; dense, wide spreading canopy; long-lived; purple fall color; moderate growth rate; also try F. Americana 'Junginger'. Fraxinus oxycarpa 'Raywood' / Raywood Ash 35 25 reddish purple Pyrus calleryana 'Aristocrat' / Pear 40 45 red Pyrus calleryana 'Chanticleer' / Flowring Pear 40 15 Deciduous tree that grows well in a variety of soil types; orange to reddish fall color; white flowers in spring; additional cultivars of interest include P. calleryana 'Redspire' and 'Aristocrat'. Pyrus calleryana 'Redspire' / Pear 40 45 red Pyrus calleryana 'Autumn Blaze' / Pear 30 25 scarlet Vigorous. Ginko biloba 'Autumn Gold' / Maidenhair tree 45 35 yellow Moist soils; deciduous ornamental tree; fast growing and long-lived; tolerant of urban pollution, summer drought and winter inundation; showy fall color; grows in soils of varying quality; provides dense canopy; additional cultivars available. Ginko biloba 'Princeton Sentry' 40 15 yellow Very narrow growth. Gleditsia triacanthos inermis 'Shademaster' / Shademaster Thornless Honeylocust 45 35 yellow Deciduous; prefers moist, rich soils, but will grow in varying soil types; a thornless cultivar tolerant of drought and seasonal inundation; adapts to urban pollution and displays vigorous growth; deciduous tree with showy yellow fall color; additional cultivars available such as ‘Imperial,’ which grows 30-35 feet, ‘Moraine,’ and ‘Rubylace’. Do not confuse with 'Sunburst'. Koelreuteria paniculata / Goldenrain Tree 20-35 10-30 yellow Deciduous; prefers moist well-drained soils, but is tolerant of poor soils; medium rate of growth and longevity; tolerant of periods of drought and seasonal inundation; tolerates urban pollution; provides a dense, wide-spreading canopy. Midsummer blooming. Oxydendron arboreum / Sourwood 35 12 reddish purple Consistent and brilliant fall color. Prunus sargentii 'Columnarus' 35 15 orange to orange red The cherry with the best fall color. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB APPROVED TREE LIST – Small, Medium, and Large H:\CED\Data\Forms-Templates\Self-Help Handouts\Planning\treeslist_march2010.doc P. 8 Botanical name / Common Name Mature Height in Feet Mature Spread in Feet Fall Color Comments Quercus 'Crimschmidt' / Crimson Spire Oak 45 15 Hard to find. Robinia x ambigua 'Idahoensis' / Pink Idaho Locust 35 25 yellow Fragrant flowers. Tilia americana 'Redmond' 35 20 yellow Pyramidal, needs water. Tilia cordata 'Chancole' / Chancelor Linden 35 20 yellow Pyramidal. Tilia cordata 'De Groot' / Linden 30-50 20 yellow Compact, suckers less than other Lindens. Tilia cordata 'Greenspire' / Greenspire Linden 40 30 yellowish Symmetrical pyramidal form. Tilia cordata 'Littleleaf' / Littleleaf Linden 30-50 30 Deciduous; prefers moist, well-drained soils, but tolerant of a variety of soil types; tolerant of wind and urban pollution; fast growing and long-lived; tolerates summer drought and seasonal inundation; provides a dense canopy; C. cordata is the hardiest Linden; many forms available including, T. cordata ‘Chancellor’, ‘Corzam’, and ’Greenspire’. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB APPROVED TREE LIST – Small, Medium, and Large H:\CED\Data\Forms-Templates\Self-Help Handouts\Planning\treeslist_march2010.doc P. 9 LARGE TREES: 50 feet in height or taller Botanical name / Common Name Mature Height in Feet Mature Spread in Feet Fall Color Comments Acer freemanli / Autumn Blaze Maple 50 40 orange Abies grandis / Grand Fir 100 40 Evergreen; tolerant of fluctuating water tables and floods; medium rate of growth; root structure depends on site conditions – shallow in moist areas, deep taproot in drier conditions. Acer nigrum 'Green Colunm' / Green Column Maple 50 20 yellow to orange Good close to buildings. Acer platanoides 'Emerald Queen' 50 40 yellow Deciduous; fast growing with an erect, spreading form; prefers moist soils, but is tolerant of summer drought and seasonal inundation; tolerates urban pollution; avoid locating near structures due to shallow, vigorous rooting; additional cultivars available including A. platanoids ‘Parkway’. Acer pseudoplatanus / Sycamore maple 40-60 25-40 Deciduous; prefers moist, well-drained soils but is adaptable to may soil types; tolerates summer drought and seasonal inundation; tolerant of urban pollution with a moderate growth rate; sturdy, resistant to wind and salt spray; a number of cultivars are available including: A. pseudoplatanus ‘Atropurpureum,’ ‘ Brilliantissimum,’ ‘Cox’ (Lustre), and ‘Puget Pink’. Acer saccharum 'Bonfire' 50 40 bright orange red Fastest growing sugar maple. Acer saccharum 'Commemoration' 50 35 orange to orange- red Resistant to leaf tatter. Acer saccharum 'Green Mountain' 45 35 red to orange Acer saccharum / Sugar maple 60-75 35 yellow, orange Deciduous; prefers moderately moist, well-drained soils; long-lived and tolerant of urban pollutants; slow to medium growth rate; needs large planting area; a variety of cultivars available including Acer saccharum ‘Legacy’. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB APPROVED TREE LIST – Small, Medium, and Large H:\CED\Data\Forms-Templates\Self-Help Handouts\Planning\treeslist_march2010.doc P. 10 Botanical name / Common Name Mature Height in Feet Mature Spread in Feet Fall Color Comments Calocedrus decurrens / Incense cedar 75-90 10-20 Evergreen; tolerant of poor soils; drought tolerant after established; tolerant of wind and urban conditions; narrow growth habit makes this a good choice for smaller spaces and ideal for screening, fragrant tree; slow growing and long- lived. Carpinus betulus / European Hornbeam 40-60 30-40 Deciduous tree: tolerant of urban pollution and poor soils; cultivars available and suggested include 'Fasigiata' (30-40 ft height) and 'Franz Fontaine' (30-35 ft height). Cedrus deodara / Deodar cedar 40-60 20-40 Evergreen; prefers moist, well-drained soils, but drought tolerant when established; fairly fast growing and long lived; dense, wide spreading canopy; attractive cultivars available. Cercidiphyllum japonicum / Katsura Tree 40-60 20-40 apricot, orange Deciduous; requires moist soil and does not do well on hot dry sites. Leaves are heart-shaped. Cercidiphyllum japonicum / Katsura Tree 40 40 yellow to orange Fagus sylvatica / Green Beech 50 40 bronze Silvery-grey bark. Fraxinus american 'Autumn Purple' / Autumn Purple White Ash 60-80 50-70 to a dark purple Deciduous; prefers moist well-drained soils but tolerates a range of soil types; Also try 'Rosehill'. Fraxinus latifolia / Oregon Ash 40-80 30 Deciduous; saturated, ponded or moist soils; flood tolerant; small green-white flowers; tolerant of poor soils. Fraxinus pennsylvanica / Green Ash 50 40 Deciduous; prefers moist soils; fast growth rate; salt, seasonal drought and urban pollution; numerous cultivars including'Patmore' (50-60 ft. height), 'Summit' (to 45 ft. height), and 'Urbanite' (to 50 ft. height). Fraxinus pennsylvanica 'Patmore' / Patmore Ash 45 35 yellow Extremely hardy, may be seedless. Fraxinus pennsylvanica 'Urbanite' / Ash 50 40 deep bronze Gleditsia triacanthos inermis 'Skyline' / Skyline Thornless Honeylocust 60-70 40 yellow Deciduous; prefers moist soils, but will grow in poor soils; tolerant of drought, seasonal inundation, and urban pollution; occasionally fruit pods can create litter during winter months; thornless. Do not confuse with 'Sunburst'. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB APPROVED TREE LIST – Small, Medium, and Large H:\CED\Data\Forms-Templates\Self-Help Handouts\Planning\treeslist_march2010.doc P. 11 Botanical name / Common Name Mature Height in Feet Mature Spread in Feet Fall Color Comments Gymnocladus dioicus espresso / Espresso Kentucky Coffeetree 50 35 yellow Deciduous; drought and variable soil tolerant; seedless. Liquidamber styraci fleia / American sweetgum 60-75 40 Deciduous; prefers moist well-drained soils but tolerant of poor soils; drought tolerant after established; avoid major roadways and restricted sites. Many cultivars available. Liriodendron tulipifera / Tulip Tree 60-80 30-60 yellow Deciduous; prefers moist, deep, well-drained soils, but tolerates poor soils; fast growing; needs large growing area, lower growing cultivars available such as 'Columnar'. Fast-growing tree. Metasequoia glyptostoboides / Dawn redwood 70-100 25 Deciduous; prefers moist, deep, well-drained soils, but tolerates compacted and poor soils; long-lived, fast growing conifer; tolerant of seasonal inundation and drought; can grow in standing water; needles turn russet in the fall; needs large growing area; lower growing cultivars available such as M. glyptostroboides ‘Gold Rush’ and ‘Sheridan Spire’. Nothofagus antartica / Southern Beech 50 35 none Rugged twisted branching and petite foliage. Nyssa sylvatica / Tupelo 70+ 20 apricot to bright red Handsomely chunky bark. Picca omorika / Serbian spruce 50-60 20-25 Slow growing; tolerant of varying soils and urban pollution; moderately drought tolerant once established; elegant evergreen spruce, good for narrow locations; lower growing cultivars available. Pseudotsuga menziesii / Douglas fir 75-120 40 Evergreen conifer; moist to dry soils; long-lived with a medium to fast rate of growth; tolerant of summer drought, winter inundation, and poor soils; withstands wind and urban pollution; provides a nice canopy, but potential height will restrict placement. Quercus coccinea / Scarlet oak 50-60 45 brilliant scarlet to red Deciduous; grows in a variety of soil types; long-lived with a moderate growth rate; tolerant of summer drought and urban pollution; does not tolerate saturated soils or shade. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB APPROVED TREE LIST – Small, Medium, and Large H:\CED\Data\Forms-Templates\Self-Help Handouts\Planning\treeslist_march2010.doc P. 12 Botanical name / Common Name Mature Height in Feet Mature Spread in Feet Fall Color Comments Quercus macrocarpa / Burr oak 70-80 30-40 Prefers moist soils, but is adaptable to varying soils; slow growing and long-lived; rugged looking deciduous tree; tolerant of seasonal drought and inundation; tolerates urban pollution and city conditions; provides a wide-spreading, dense canopy. Quercus phellos / Willow oak 60-70 50 Deciduous; prefers moist, well-drained soils, but grows in a wide range of soils types; long-lived tree with moderate growth rate and fibrous root system; tolerant of seasonal drought and inundation, as well as urban pollution; provides a wide-spreading, dense canopy; small delicate leaves. Quercus palustris 'Crownright' 80 40 More upright form of Pin Oak. Quercus robar / English oak 40-60+ 40 Prefers well-drained soil; slow to moderate growth rate; long-lived deciduous tree; tolerant of seasonal drought and inundation; tolerates urban pollution, poor soils and constrained root space; susceptible to powdery mildew; many varieties and cultivars available including: ‘Concordia,’ ‘Fastigiata,’ ‘Foliis Variegatis, and ’Westminster Globe.’ Quercus rubra / Northern red oak 60-75 50 Prefers moist, well-drained soils, but drought tolerant when established; tolerates seasonal inundation, urban pollution and salt spray; moderate rate of growth and longevity; provides a dense, wide-spreading canopy; susceptible to oak wilt fungus. Quercus shumardii / Shumard's oak to 70 50 Prefers moist, well-drained soils; deciduous, long-lived tree; tolerant of seasonal drought and inundation, urban pollution and poor soils. Taxodium distichum / Bald cypress to 75 40 Deciduous conifer; wet, mucky soils; tolerant of summer drought and seasonal flooding; will grow in poor soils; slow growing; long-lived with a wide-spreading canopy; roots do not appear to lift sidewalks as readily as other species; prune lower branches for sight-lines; cultivars include T. distichum ‘Shawnee Brave’. Thuja plicata / Western red cedar 200+ 60 Moist to swampy soils; evergreen tree tolerant of seasonal flooding and saturated soils; a good tree for screening; long-lived; cultivars ‘Pumilio’ and ‘Cuprea’ are shorter versions, ‘Aurea’ and ‘Atrovirens’ have distinctive foliage. Tilia americana x euchlora 'Redmond' / Redmond Linden 50 35 yellow Prefers moist, rich soils, but tolerant of a variety of soils; tolerant of seasonal drought and inundation, urban pollution and poor soils; deciduous tree resistant; also try 'Sentry' and 'Boulevard'. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB APPROVED TREE LIST – Small, Medium, and Large H:\CED\Data\Forms-Templates\Self-Help Handouts\Planning\treeslist_march2010.doc P. 13 Botanical name / Common Name Mature Height in Feet Mature Spread in Feet Fall Color Comments Tilia plalyphyllos / Bigleaf linden 60-80 60 Prefers moist, well-drained soils, but grows in a variety of soil types; deciduous tree with medium growth rate; long-lived; tolerant of seasonal drought and inundation; tolerates urban pollutants; provides a wide-spreading, dense canopy; yellowish-white flowers attract bees. Tilia tomentosa / Silver Linden 40-75 25-45 Deciduous; prefers moist, well-drained soils, but drought tolerant when established; urban tolerant. Cultivars include 'sterlay' and 'Green Mountain'. Ulmus ssp. / Elm hybrids 50-60 35-50 yellow Deciduous; prefers moist, well-drained soils, but drought tolerant; rapid grower; a hybrid elm resistant to Dutch elm disease; suggested hybrids include ‘Accolade’, ‘Homestead’ and ‘Pioneer’. Ulmus 'Homestead' / Homestead Elm 60 35 yellow Ulmus parvifolia / Lace Bark Elm 50 40 Deciduous; prefers moist, well drained soils but tolerant of soil types and hot dry conditions. Flaking bark of orange, gray, green and brown color. Several cultivars including 'Allee' and 'Bosque'. Ulmus 'Pioneer' / Pioneer Elm 60 50 yellow Resistant to Dutch elm disease. Umbellularia californica / Oregon myrtle 40-75+ to 50 Prefers moist, well-drained soils; slow growing evergreen tree with aromatic leaves; tolerates seasonal drought and inundation; tolerant of urban pollution; provides a wide spreading, dense canopy; resistant to pests and disease; good for tall hedges or, when trunks are thinned, as a street tree; requires summer watering until established. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Site Planning Civil Engineering Landscape Architecture Project Management Land Use Consulting APPENDIX C WWHM REPORTS DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB WWHM2012 PROJECT REPORT DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:32:21 AM Page 2 General Model Information Project Name:Total Basin peak flows Site Name:Harrington Redevelopment Site Address:960 Harrington Ave NE City:Renton Report Date:6/10/2021 Gage:Seatac Data Start:1948/10/01 Data End:2009/09/30 Timestep:15 Minute Precip Scale:1.000 Version Date:2019/09/13 Version:4.2.17 POC Thresholds Low Flow Threshold for POC1:50 Percent of the 2 Year High Flow Threshold for POC1:50 Year DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:32:21 AM Page 3 Landuse Basin Data Predeveloped Land Use North Basin Bypass:No GroundWater:No Pervious Land Use acre A B, Lawn, Mod 0.05 Pervious Total 0.05 Impervious Land Use acre ROADS FLAT 0.22 Impervious Total 0.22 Basin Total 0.27 Element Flows To: Surface Interflow Groundwater DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:32:21 AM Page 4 Upstream Flow-Through Bypass:No GroundWater:No Pervious Land Use acre Pervious Total 0 Impervious Land Use acre DRIVEWAYS MOD 0.087 Impervious Total 0.087 Basin Total 0.087 Element Flows To: Surface Interflow Groundwater DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:32:21 AM Page 5 South Basin Bypass:No GroundWater:No Pervious Land Use acre A B, Lawn, Mod 0.02 Pervious Total 0.02 Impervious Land Use acre ROADS FLAT 0.38 Impervious Total 0.38 Basin Total 0.4 Element Flows To: Surface Interflow Groundwater DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:32:21 AM Page 6 North Frontage Bypass:No GroundWater:No Pervious Land Use acre A B, Lawn, Mod 0.03 Pervious Total 0.03 Impervious Land Use acre ROADS FLAT 0.03 Impervious Total 0.03 Basin Total 0.06 Element Flows To: Surface Interflow Groundwater DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:32:21 AM Page 7 South Frontage Bypass:No GroundWater:No Pervious Land Use acre A B, Lawn, Mod 0.01 Pervious Total 0.01 Impervious Land Use acre ROADS FLAT 0.11 Impervious Total 0.11 Basin Total 0.12 Element Flows To: Surface Interflow Groundwater DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:32:21 AM Page 8 Mitigated Land Use North Basin Bypass:No GroundWater:No Pervious Land Use acre A B, Lawn, Flat 0.05 Pervious Total 0.05 Impervious Land Use acre ROADS FLAT 0.23 Impervious Total 0.23 Basin Total 0.28 Element Flows To: Surface Interflow Groundwater DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:32:21 AM Page 9 Upstream Flow-Through Bypass:No GroundWater:No Pervious Land Use acre Pervious Total 0 Impervious Land Use acre DRIVEWAYS MOD 0.087 Impervious Total 0.087 Basin Total 0.087 Element Flows To: Surface Interflow Groundwater DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:32:21 AM Page 10 South Basin Bypass:No GroundWater:No Pervious Land Use acre A B, Lawn, Flat 0.05 Pervious Total 0.05 Impervious Land Use acre ROADS FLAT 0.35 Impervious Total 0.35 Basin Total 0.4 Element Flows To: Surface Interflow Groundwater DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:32:21 AM Page 11 North Frontage Bypass:No GroundWater:No Pervious Land Use acre A B, Lawn, Flat 0.03 Pervious Total 0.03 Impervious Land Use acre ROADS FLAT 0.04 Impervious Total 0.04 Basin Total 0.07 Element Flows To: Surface Interflow Groundwater DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:32:21 AM Page 12 South Frontage Bypass:No GroundWater:No Pervious Land Use acre A B, Lawn, Flat 0.06 Pervious Total 0.06 Impervious Land Use acre ROADS FLAT 0.06 Impervious Total 0.06 Basin Total 0.12 Element Flows To: Surface Interflow Groundwater DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:32:21 AM Page 13 Routing Elements Predeveloped Routing DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:32:21 AM Page 14 Mitigated Routing DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:32:21 AM Page 15 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area:0.11 Total Impervious Area:0.827 Mitigated Landuse Totals for POC #1 Total Pervious Area:0.19 Total Impervious Area:0.767 Flow Frequency Method:Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.320762 5 year 0.405842 10 year 0.463723 25 year 0.538879 50 year 0.596453 100 year 0.655467 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.298238 5 year 0.377691 10 year 0.431783 25 year 0.502057 50 year 0.555918 100 year 0.611147 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.415 0.386 1950 0.446 0.414 1951 0.262 0.244 1952 0.227 0.211 1953 0.249 0.232 1954 0.262 0.243 1955 0.297 0.276 1956 0.287 0.267 1957 0.327 0.303 1958 0.266 0.247 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:33:06 AM Page 16 1959 0.274 0.254 1960 0.268 0.249 1961 0.277 0.257 1962 0.244 0.226 1963 0.274 0.255 1964 0.269 0.250 1965 0.337 0.313 1966 0.224 0.208 1967 0.389 0.361 1968 0.451 0.419 1969 0.306 0.284 1970 0.298 0.277 1971 0.356 0.331 1972 0.371 0.348 1973 0.224 0.208 1974 0.326 0.303 1975 0.372 0.345 1976 0.254 0.236 1977 0.272 0.253 1978 0.341 0.317 1979 0.459 0.426 1980 0.405 0.377 1981 0.332 0.308 1982 0.469 0.435 1983 0.382 0.355 1984 0.239 0.222 1985 0.329 0.305 1986 0.287 0.266 1987 0.443 0.411 1988 0.269 0.250 1989 0.351 0.326 1990 0.589 0.561 1991 0.464 0.433 1992 0.238 0.221 1993 0.211 0.197 1994 0.229 0.212 1995 0.295 0.274 1996 0.329 0.308 1997 0.308 0.287 1998 0.310 0.288 1999 0.637 0.592 2000 0.315 0.292 2001 0.351 0.326 2002 0.400 0.371 2003 0.324 0.302 2004 0.599 0.557 2005 0.268 0.249 2006 0.242 0.226 2007 0.561 0.521 2008 0.449 0.418 2009 0.412 0.383 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.6375 0.5920 2 0.5992 0.5615 3 0.5895 0.5568 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:33:06 AM Page 17 4 0.5606 0.5209 5 0.4687 0.4350 6 0.4637 0.4333 7 0.4588 0.4263 8 0.4512 0.4195 9 0.4486 0.4177 10 0.4459 0.4138 11 0.4432 0.4113 12 0.4150 0.3855 13 0.4119 0.3830 14 0.4049 0.3770 15 0.4000 0.3711 16 0.3891 0.3612 17 0.3823 0.3549 18 0.3720 0.3485 19 0.3711 0.3452 20 0.3563 0.3309 21 0.3510 0.3265 22 0.3507 0.3262 23 0.3409 0.3171 24 0.3370 0.3131 25 0.3318 0.3084 26 0.3293 0.3079 27 0.3288 0.3055 28 0.3266 0.3031 29 0.3259 0.3027 30 0.3245 0.3022 31 0.3147 0.2921 32 0.3099 0.2877 33 0.3077 0.2866 34 0.3063 0.2842 35 0.2980 0.2767 36 0.2971 0.2760 37 0.2950 0.2738 38 0.2874 0.2667 39 0.2867 0.2661 40 0.2772 0.2570 41 0.2743 0.2550 42 0.2738 0.2544 43 0.2720 0.2525 44 0.2695 0.2502 45 0.2689 0.2498 46 0.2684 0.2490 47 0.2679 0.2490 48 0.2658 0.2468 49 0.2617 0.2444 50 0.2616 0.2433 51 0.2540 0.2361 52 0.2495 0.2317 53 0.2439 0.2264 54 0.2420 0.2260 55 0.2393 0.2220 56 0.2377 0.2206 57 0.2285 0.2124 58 0.2270 0.2106 59 0.2243 0.2081 60 0.2240 0.2081 61 0.2108 0.1966 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:33:06 AM Page 18 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:33:06 AM Page 19 Duration Flows The Facility PASSED Flow(cfs)Predev Mit Percentage Pass/Fail 0.1604 1756 1341 76 Pass 0.1648 1609 1213 75 Pass 0.1692 1428 1078 75 Pass 0.1736 1319 983 74 Pass 0.1780 1173 882 75 Pass 0.1824 1077 825 76 Pass 0.1868 991 752 75 Pass 0.1912 895 679 75 Pass 0.1956 836 629 75 Pass 0.2000 755 572 75 Pass 0.2044 705 530 75 Pass 0.2088 647 487 75 Pass 0.2132 600 440 73 Pass 0.2176 556 411 73 Pass 0.2220 510 384 75 Pass 0.2265 471 361 76 Pass 0.2309 433 336 77 Pass 0.2353 407 303 74 Pass 0.2397 383 289 75 Pass 0.2441 354 259 73 Pass 0.2485 333 245 73 Pass 0.2529 306 228 74 Pass 0.2573 288 210 72 Pass 0.2617 264 200 75 Pass 0.2661 246 181 73 Pass 0.2705 233 172 73 Pass 0.2749 218 164 75 Pass 0.2793 202 148 73 Pass 0.2837 187 142 75 Pass 0.2881 177 128 72 Pass 0.2925 166 121 72 Pass 0.2969 159 113 71 Pass 0.3013 146 109 74 Pass 0.3057 138 101 73 Pass 0.3101 128 92 71 Pass 0.3145 120 90 75 Pass 0.3190 112 87 77 Pass 0.3234 110 78 70 Pass 0.3278 102 74 72 Pass 0.3322 92 68 73 Pass 0.3366 91 63 69 Pass 0.3410 88 61 69 Pass 0.3454 81 57 70 Pass 0.3498 78 53 67 Pass 0.3542 71 52 73 Pass 0.3586 66 48 72 Pass 0.3630 61 46 75 Pass 0.3674 59 44 74 Pass 0.3718 57 41 71 Pass 0.3762 53 38 71 Pass 0.3806 52 33 63 Pass 0.3850 49 31 63 Pass 0.3894 48 29 60 Pass DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:33:06 AM Page 20 0.3938 46 27 58 Pass 0.3982 42 23 54 Pass 0.4026 39 22 56 Pass 0.4070 36 20 55 Pass 0.4115 31 20 64 Pass 0.4159 30 17 56 Pass 0.4203 27 14 51 Pass 0.4247 25 14 56 Pass 0.4291 23 13 56 Pass 0.4335 22 13 59 Pass 0.4379 20 10 50 Pass 0.4423 20 8 40 Pass 0.4467 17 8 47 Pass 0.4511 15 8 53 Pass 0.4555 14 8 57 Pass 0.4599 13 8 61 Pass 0.4643 11 8 72 Pass 0.4687 9 8 88 Pass 0.4731 8 8 100 Pass 0.4775 8 8 100 Pass 0.4819 8 8 100 Pass 0.4863 8 8 100 Pass 0.4907 8 7 87 Pass 0.4951 8 7 87 Pass 0.4995 8 7 87 Pass 0.5040 8 7 87 Pass 0.5084 8 7 87 Pass 0.5128 8 6 75 Pass 0.5172 8 5 62 Pass 0.5216 8 4 50 Pass 0.5260 8 4 50 Pass 0.5304 7 3 42 Pass 0.5348 6 3 50 Pass 0.5392 6 3 50 Pass 0.5436 6 3 50 Pass 0.5480 6 3 50 Pass 0.5524 6 3 50 Pass 0.5568 5 3 60 Pass 0.5612 4 2 50 Pass 0.5656 4 1 25 Pass 0.5700 3 1 33 Pass 0.5744 3 1 33 Pass 0.5788 3 1 33 Pass 0.5832 3 1 33 Pass 0.5876 3 1 33 Pass 0.5920 2 1 50 Pass 0.5965 2 0 0 Pass DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:33:06 AM Page 21 Water Quality Water Quality BMP Flow and Volume for POC #1 On-line facility volume:0 acre-feet On-line facility target flow:0 cfs. Adjusted for 15 min:0 cfs. Off-line facility target flow:0 cfs. Adjusted for 15 min:0 cfs. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:33:06 AM Page 22 LID Report DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:33:52 AM Page 23 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. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:33:52 AM Page 24 Appendix Predeveloped Schematic DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:33:57 AM Page 25 Mitigated Schematic DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:34:01 AM Page 26 Predeveloped UCI File RUN GLOBAL WWHM4 model simulation START 1948 10 01 END 2009 09 30 RUN INTERP OUTPUT LEVEL 3 0 RESUME 0 RUN 1 UNIT SYSTEM 1 END GLOBAL FILES <File> <Un#> <-----------File Name------------------------------>*** <-ID-> *** WDM 26 Total Basin peak flows.wdm MESSU 25 PreTotal Basin peak flows.MES 27 PreTotal Basin peak flows.L61 28 PreTotal Basin peak flows.L62 30 POCTotal Basin peak flows1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 8 IMPLND 1 IMPLND 6 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 North Basin MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 8 A/B, Lawn, Mod 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 8 0 0 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 8 0 0 4 0 0 0 0 0 0 0 0 0 1 9 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:34:01 AM Page 27 END PRINT-INFO PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 8 0 0 0 0 0 0 0 0 0 0 0 END PWAT-PARM1 PWAT-PARM2 <PLS > PWATER input info: Part 2 *** # - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC 8 0 5 0.8 400 0.1 0.3 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 8 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 8 0.1 0.5 0.25 0 0.7 0.25 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 8 0 0 0 0 3 1 0 END PWAT-STATE1 END PERLND IMPLND GEN-INFO <PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 1 ROADS/FLAT 1 1 1 27 0 6 DRIVEWAYS/MOD 1 1 1 27 0 END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** 1 0 0 1 0 0 0 6 0 0 1 0 0 0 END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* 1 0 0 4 0 0 0 1 9 6 0 0 4 0 0 0 1 9 END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** 1 0 0 0 0 0 6 0 0 0 0 0 END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC 1 400 0.01 0.1 0.1 6 400 0.05 0.1 0.08 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:34:01 AM Page 28 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN 1 0 0 6 0 0 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 1 0 0 6 0 0 END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** North Basin*** PERLND 8 0.05 COPY 501 12 PERLND 8 0.05 COPY 501 13 IMPLND 1 0.22 COPY 501 15 Upstream Flow-Through*** IMPLND 6 0.087 COPY 501 15 South Basin*** PERLND 8 0.02 COPY 501 12 PERLND 8 0.02 COPY 501 13 IMPLND 1 0.38 COPY 501 15 North Frontage*** PERLND 8 0.03 COPY 501 12 PERLND 8 0.03 COPY 501 13 IMPLND 1 0.03 COPY 501 15 South Frontage*** PERLND 8 0.01 COPY 501 12 PERLND 8 0.01 COPY 501 13 IMPLND 1 0.11 COPY 501 15 ******Routing****** END SCHEMATIC NETWORK <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** END NETWORK RCHRES GEN-INFO RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out *** END GEN-INFO *** Section RCHRES*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:34:01 AM Page 29 END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** END HYDR-PARM1 HYDR-PARM2 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES END FTABLES EXT SOURCES <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP END EXT SOURCES EXT TARGETS <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** COPY 501 OUTPUT MEAN 1 1 48.4 WDM 501 FLOW ENGL REPL END EXT TARGETS MASS-LINK <Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 12 PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12 MASS-LINK 13 PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13 MASS-LINK 15 IMPLND IWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 15 END MASS-LINK END RUN DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:34:01 AM Page 30 Mitigated UCI File RUN GLOBAL WWHM4 model simulation START 1948 10 01 END 2009 09 30 RUN INTERP OUTPUT LEVEL 3 0 RESUME 0 RUN 1 UNIT SYSTEM 1 END GLOBAL FILES <File> <Un#> <-----------File Name------------------------------>*** <-ID-> *** WDM 26 Total Basin peak flows.wdm MESSU 25 MitTotal Basin peak flows.MES 27 MitTotal Basin peak flows.L61 28 MitTotal Basin peak flows.L62 30 POCTotal Basin peak flows1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 7 IMPLND 1 IMPLND 6 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 North Basin MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 7 A/B, Lawn, Flat 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 7 0 0 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 7 0 0 4 0 0 0 0 0 0 0 0 0 1 9 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:34:01 AM Page 31 END PRINT-INFO PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 7 0 0 0 0 0 0 0 0 0 0 0 END PWAT-PARM1 PWAT-PARM2 <PLS > PWATER input info: Part 2 *** # - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC 7 0 5 0.8 400 0.05 0.3 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 7 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 7 0.1 0.5 0.25 0 0.7 0.25 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 7 0 0 0 0 3 1 0 END PWAT-STATE1 END PERLND IMPLND GEN-INFO <PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 1 ROADS/FLAT 1 1 1 27 0 6 DRIVEWAYS/MOD 1 1 1 27 0 END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** 1 0 0 1 0 0 0 6 0 0 1 0 0 0 END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* 1 0 0 4 0 0 0 1 9 6 0 0 4 0 0 0 1 9 END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** 1 0 0 0 0 0 6 0 0 0 0 0 END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC 1 400 0.01 0.1 0.1 6 400 0.05 0.1 0.08 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:34:01 AM Page 32 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN 1 0 0 6 0 0 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 1 0 0 6 0 0 END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** North Basin*** PERLND 7 0.05 COPY 501 12 PERLND 7 0.05 COPY 501 13 IMPLND 1 0.23 COPY 501 15 Upstream Flow-Through*** IMPLND 6 0.087 COPY 501 15 South Basin*** PERLND 7 0.05 COPY 501 12 PERLND 7 0.05 COPY 501 13 IMPLND 1 0.35 COPY 501 15 North Frontage*** PERLND 7 0.03 COPY 501 12 PERLND 7 0.03 COPY 501 13 IMPLND 1 0.04 COPY 501 15 South Frontage*** PERLND 7 0.06 COPY 501 12 PERLND 7 0.06 COPY 501 13 IMPLND 1 0.06 COPY 501 15 ******Routing****** END SCHEMATIC NETWORK <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** END NETWORK RCHRES GEN-INFO RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out *** END GEN-INFO *** Section RCHRES*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:34:01 AM Page 33 END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** END HYDR-PARM1 HYDR-PARM2 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES END FTABLES EXT SOURCES <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP END EXT SOURCES EXT TARGETS <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** COPY 1 OUTPUT MEAN 1 1 48.4 WDM 701 FLOW ENGL REPL COPY 501 OUTPUT MEAN 1 1 48.4 WDM 801 FLOW ENGL REPL END EXT TARGETS MASS-LINK <Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 12 PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12 MASS-LINK 13 PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13 MASS-LINK 15 IMPLND IWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 15 END MASS-LINK END RUN DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:34:01 AM Page 34 Predeveloped HSPF Message File DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:34:01 AM Page 35 Mitigated HSPF Message File DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Total Basin peak flows 6/10/2021 8:34:01 AM Page 36 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. 2005-2021; 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 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Site Planning Civil Engineering Landscape Architecture Project Management Land Use Consulting APPENDIX D DOWNSTREAM ANALYSIS & OFF-SITE PHOTOS DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Site Planning Civil Engineering Landscape Architecture Project Management Land Use Consulting Offsite Drainage Map DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE SURFACE WATER DESIGN MANUAL, CORE REQUIREMENT #2 Basin: East Lake Washington - Renton Subbasin Name: North Renton Basin Subbasin Number: Symbol Drainage Component Type, Name, and Size Drainage Component Description Slope Distance from site discharge Existing Problems Potential Problems Observations of field inspector, resource reviewer, or resident see map Type: sheet flow, swale, stream, channel, pipe, pond; Size: diameter, surface area drainage 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 erosion tributary area, likelihood of problem, overflow pathways, potential impacts A 24” Conc. Pipe Existing SD System 2.18% 0’-59’ None Observed None Observed - B 12” Conc. Pipe Existing SD System 2.90% 59’-249’ None Observed None Observed - C 12” Conc. Pipe Existing SD System 3.74% 249’-344’ None Observed None Observed - D 12” Conc. Pipe Existing SD System 6.63% 344’-482’ None Observed None Observed - E 20” Conc. Pipe Existing SD System - 482’-879’ None Observed None Observed No more pipe data available. F 24” Conc. Pipe Existing SD System 0.67% 879’-1093’ None Observed None Observed - G 24” Conc. Pipe Existing SD System 0.26% 1093’-1112’ None Observed None Observed - H 24” Conc. Pipe Existing SD System 0.79% 1112’-1324’ None Observed None Observed - I 20” Conc. Pipe Existing SD System 0.71% 1324’-1440’ None Observed None Observed - J 20” Conc. Pipe Existing SD System 1.41% 1440’- None Observed None Observed - DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE SURFACE WATER DESIGN MANUAL, CORE REQUIREMENT #2 Basin: East Lake Washington - Renton Subbasin Name: North Renton Basin Subbasin Number: Symbol Drainage Component Type, Name, and Size Drainage Component Description Slope Distance from site discharge Existing Problems Potential Problems Observations of field inspector, resource reviewer, or resident see map Type: sheet flow, swale, stream, channel, pipe, pond; Size: diameter, surface area drainage 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 erosion tributary area, likelihood of problem, overflow pathways, potential impacts L 12” Pipe Existing SD System 3.97% 0’-92’ None Observed None Observed - M 12” Pipe Existing SD System 1.53% 92’-210’ None Observed None Observed - N 12” Pipe Existing SD System 2.59% 210’-341’ None Observed None Observed - O 12” Pipe Existing SD System 2.29% 341’-455’ None Observed None Observed - P 12” PE Pipe Existing SD System 0.59% 455’-470’ None Observed None Observed - Q 12” Conc. Pipe Existing SD System 2.56% 470’-580’ None Observed None Observed - R 12” Conc. Pipe Existing SD System 11.44% 580’-677’ None Observed None Observed - S 12” Conc. Pipe Existing SD System 11.84% 677’-741’ None Observed None Observed - T 12” Conc. Pipe Existing SD System 9.55% 741’-954’ None Observed None Observed - U 15” Conc. Pipe Existing SD System 0.92% 954’-1124’ None Observed None Observed - V 18” Conc. Pipe Existing SD System 1.07% 1124’-1257’ None Observed None Observed - W 20” Conc. Pipe Existing SD System 5.53% 1257’-1550’ None Observed None Observed - DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Site Planning Civil Engineering Landscape Architecture Project Management Land Use Consulting PHOTO #1: LOOKING NORTHEAST FROM HARRINGTON AVE NE WHERE THE SITE CONVEYANCE SYSTEM CONNECTS TO THE EXISTING PUBLIC STORM DRAINAGE SYSTEM. PHOTO #2: LOOKING SOUTH WHERE THE UNDERGROUND STORM MAIN RUNS ALONG THE EAST SIDE OF HARRINGTON AVE NE. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Site Planning Civil Engineering Landscape Architecture Project Management Land Use Consulting PHOTO #3: LOOKING EAST DOWN NE 9TH ST WHERE IT INTERSECTS HARRINGTON AVE NE. THE STORM MAIN REDIRECTS TOWARDS THE WEST AT THIS INTERSECTION. PHOTO #4 & 5: LOOKING WEST WHERE THE STORM MAIN FROM FERNDALE CIRCLE NE CROSSES UNDER TWO PROPERTIES TO EDMONDS AVE NE. AT THIS CATCH BASIN, THE DISCHARGE FROM THE NORTH PORTION OF THE SITE UNITE WITH THE DISCHARGE OF THE SOUTH PORTION OF THE SITE. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Site Planning Civil Engineering Landscape Architecture Project Management Land Use Consulting PHOTO #6 & 7: THE STORM MAIN COMING FROM FERNDALE CIR NE ENDS AT THE CATCH BASIN IN PHOTO #6. IT CONNECTS TO THE CATCH BASIN IN PHOTO # 5. FROM HERE IT RUNS UNDER TWO PROPERTIES TO DAYTON AVE NE AND CONTINUES GENERALLY TOWARDS THE WEST. PHOTO #8 & 9: LOOKING EAST DOWN NE SUNSET BLVD WHERE THE STORM MAIN RUNS UNTIL IT REDIRECTS SOUTH THROUGH THE PROPERTY SHOWN IN PHOTO #9 AND ENDS IN THE CATCH BASIN SHOWN IN PHOTO #4. DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB Site Planning Civil Engineering Landscape Architecture Project Management Land Use Consulting APPENDIX E PRELIMINARY WATER QUALITY DATA WATER QUALITY FLOWS: DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB 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 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB 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 DocuSign Envelope ID: 9A2B0C09-72D8-490B-A60E-EAD24B2FAACB