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BLD2022-0694_Storm_Drainage_Report_12-28-2023_APPROVED_STM_BLD2022-0694+Storm_Drainage_Report+11.13.2023_9.54.58_AM+3895796September 2021 November 2022 April 2023 August 2023 November 2023 Owner: BKInvestment Group, LLC c% Johnathan Kurth 577 Roy St, Suite 125 Seattle, WA 98109 For Submittal to: City of Edmonds RESUB Nov 13 2023 CITY OF EDMONDS DEVELOPMENT SERVICES DEPARTMENT BLD2022-0694 COMPLIES WITH APPLICABLE CITY STORM CODE Y-.7 P �. 11 /27/2023 DAVIDO CONSULTING GROUP, INC. CIVIL ■ STRUCTURAL ■ LAND USE Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds CERTIFICATE OF ENGINEER November 2023 The technical material and data contained within this report has been prepared by or under the direction of the following registered professional engineer(s), licensed in accordance with the laws of the State of Washington to practice in the State of Washington. IN . v S �� Si o� n di s ate: x 3 .10 ►L . IST �FG54 1 o_ Davido Consulting Group, Inc. Page i 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds QUICK REFERENCE PROJECT INFORMATION General Proi ect Information November 2023 Project Description Demolition of two (2) existing buildings and the construction of three (3) buildings containing six (6) live/work units and eight (8) residential units with associated driveway, walkways, and alley improvements. Improvements also include drainage, grading, paving, utilities, and landscaping. Project Address 614 5th Ave S Edmonds, WA 98020 Project Size (onsite only) Site = 17,162 SF (0.39 acres) Owner/Developer BK Investment Group, LLC c/o Johnathan Kurth 577 Roy St, Suite 125 Seattle, WA 98109 Consulting Engineer Ben Iddins, PE Davido Consulting Group, Inc. 9706 4th Ave NE, Suite 300 Seattle, WA 98115 Phone: 206 523-0024 ext. 115 Drainage Drainage 2012 DOE Stormwater Management Manual for Western Requirements Washington (as amended in December 2014) and City of Edmonds amendments in the 2017 Stormwater Code Supplement (the combination of which is hereafter known as "The Stormwater Manual"). • Minimum Requirements # 1-9 Tributary Drainage Predeveloped Conditions: Developed Conditions: Area & Land Cover Impervious Surface = 9,565 SF Total Impervious = 16,407 SF Summary (onsite only) Pervious Surface = 7,595 SF Pervious Surface = 755 SF Total = 17,162 SF 0.39 Acres Total = 17,162 SF 0.39 Acres Soils Geotechnical analysis was performed by PanGEO, Inc and summarized in a geotechnical report dated September 2021. The geotechnical report states that the site is underlain by pre -Frasier deposits (geologic map unit Qpf). See APPENDIX A for the full geotechnical report. Drainage • Two infiltration facilities Improvements • Two Biopods (Water Quality Treatment Facilities) • 10" stormwater drain extension within the private alley south of Project Site ESC Measures TESC plan required per the Stormwater Manual. TESC measures include storm drain inlet protection, perimeter protection, construction entrance, construction fencing, interceptor swales, sediment trap, and street cleaning. Davido Consulting Group, Inc. Page ll 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 Stormwater Site Plans - Rev 4 614 5th Ave S Edmonds November 2023 TABLE OF CONTENTS 1. Project Overview.......................................................................................................... I 1.1 General Description of Project......................................................................................2 1.2 Predeveloped Site Conditions.......................................................................................2 1.3 Developed Site Conditions............................................................................................2 1.4 Site Area and Size of Improvements.............................................................................3 1.5 Predeveloped Stormwater Runoff Conditions...............................................................3 1.6 Post -developed Stormwater Runoff Conditions.............................................................4 1.7 Site Map.......................................................................................................................4 2. Minimum Requirements...............................................................................................4 2.1 Minimum Requirement #1: Preparation of Stormwater Site Plans.................................4 2.2 Minimum Requirement #2: Construction Stormwater Pollution Prevention Plan (SWPPP)......................................................................................................................4 2.3 Minimum Requirement #3: Source Control of Pollution...............................................4 2.4 Minimum Requirement #4: Preservation of Natural Drainage Systems and Outfalls .....5 2.5 Minimum Requirement #5: On -Site Stormwater Management......................................5 2.6 Minimum Requirement #6: Runoff Treatment..............................................................6 2.7 Minimum Requirement #7: Flow Control.....................................................................8 2.8 Minimum Requirement #8: Wetlands Protection...........................................................9 2.9 Minimum Requirement #9: Operation and Maintenance...............................................9 3. Site and Basin Assessment............................................................................................9 3.1 Offsite Analysis..........................................................................................................10 3.2 Subbasin Description..................................................................................................11 3.3 Soils/Infiltration Rates................................................................................................11 3.4 Critical Areas and Flood Plain....................................................................................11 3.5 Assessment Summary.................................................................................................11 3.6 Stormwater BMP Sizing.............................................................................................11 4. Construction Stormwater Pollution Prevention Plan (SWPPP)....................................13 5. Permanent Stormwater Control Plan...........................................................................17 5.1 Flow Control..............................................................................................................17 5.2 Water Quality.............................................................................................................17 5.3 Source Control & Operation and Maintenance............................................................17 5.4 Conveyance System Analysis and Design...................................................................17 6. Special Reports and Studies........................................................................................18 6.1 Geotechnical Report...................................................................................................18 7. Other Permits..............................................................................................................18 8. Bonds.........................................................................................................................18 9. Additional Figures......................................................................................................18 Davido Consulting Group, Inc. Page iii 20231110_614 5th Ave S Edmonds -Drainage Report Rev 4 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds APPENDICES APPENDIX A Geotechnical Report APPENDIX B WWHM Summary APPENDIX C Operation and Maintenance Manual APPENDIX D Declaration of Covenant APPENDIX E Conveyance Calculations APPENDIX F King County Site Improvement Bond Quantity Worksheet November 2023 LIST OF TABLES TABLE 1 Project Site Area and Size of Improvements.........................................................3 TABLE 2 Infiltration Trench Sizing Table..........................................................................13 TABLE 3 Proposed ESC Measures.....................................................................................16 LIST OF FIGURES FIGURE1 Site Location.......................................................................................................I FIGURE 2 Site Assessment and Summary...............................................................................19 FIGURE3 Drainage Plan.....................................................................................................20 FIGURE4 TESC Plan..........................................................................................................21 FIGURE 5 Offsite Analysis Photos......................................................................................22 FIGURE 6 Offsite Drainage System Analysis.......................................................................23 FIGURE 7 Developed Conditions Sub -Basin Exhibit...........................................................24 Davido Consulting Group, Inc. Page iv 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds November 2023 1. PROJECT OVERVIEW The project involves the demolition of two (2) existing buildings and the construction of three (3) buildings containing six (6) live/work units and eight (8) residential units with associated driveway, walkways, parking, and alley improvements. Improvements also include drainage, grading, paving, utilities, and landscaping. Vehicular access to the site will be via the alley adjacent to the south property line of the site. The project site is bounded to the north by commercial buildings/lots, to the west by residential buildings/lots, to the east by 5th Ave S, and to the south by a privately owned, unnamed alley. The project location is shown in FIGURE 1. The City of Edmonds has adopted the 2012 Washington State Department of Ecology Stormwater Management Manual for the Puget Sound Basin (as Amended in December 2014), City of Edmonds Stormwater Management Code, and the 2017 City of Edmonds Stormwater Addendum; the combination of which is herein referred to as the "Stormwater Manual". This report follows the Stormwater Site Plan requirements as stipulated in the Stormwater Manual. FIGURE 1 Site Location Davido Consulting Group, Inc. Page 1 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds November 2023 1.1 General Description of Project The project involves the demolition of two (2) existing buildings and the construction of three (3) buildings containing six (6) live/work units and eight (8) residential units with associated driveway, walkways, and alley improvements. Improvements also include drainage, grading, paving, utilities, and landscaping. Frontage improvements along 5th Ave S include new curb, gutter, and sidewalk where an existing curb cut is being replaced and where utility connections are needed. Street trees are also being placed along the 5th Ave S frontage. Additionally, the alley pavement adjacent to the south property line is being widened to encompass the entire alley width. 1.2 Predeveloped Site Conditions Existing impervious surfaces on the site include two (2) commercial buildings, concrete walkways, asphalt parking, a concrete wall along the north property line, and a concrete driveway off 5th Ave S. The remainder of the site is vegetation which includes five (5) trees. 1.3 Developed Site Conditions The developed site conditions, shown in the project plans submitted under separate cover, will include three (3) new townhome and live/work buildings, walkways, and a driveway/parking area on the west side of each respective building, landscaping along the west property line, and associated frontage improvements. Drainage for the developed site will include two (2) infiltration trenches along the west side of Building B and C, respectively, that will mitigate the entirety of the new roof and driveway runoff onsite. New stormwater collection includes two (2) Type 1 CB's along the northern portion of the site, two (2) Type 1 CB's near the southern property line, and two (2) trench drains spanning along the vehicular access along the southern property line. Stormwater will be routed through an Enhanced Water Quality Treatment facility prior to entering the infiltration facilities. Stormwater overflow from the infiltration trenches on - site will be routed to a 10" storm line in the alley south of the site. TABLE 1 summarizes the predeveloped and developed site conditions and land cover. Davido Consulting Group, Inc. Page 2 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds November 2023 1.4 Site Area and Size of Improvements The project site is a 0.39-acre parcel located on 5th Ave S. The drainage basin for the project site is the site itself in addition to the adjacent alley to the south and the frontage improvements along 5th Ave S. The site area and size of improvements are shown in the project plans and summarized in TABLE 1. See FIGURE 2 of this report for a layout of the proposed improvements. See FIGURE 6 for an exhibit showing the sub -basin areas within the site. TABLE 1 Project Site Area and Size of Improvements Project Site Areas Existing Developed SF Acres SF Acres Impervious Areas: Building (Onsite) 3,020 0.07 9,556 0.21938 Walkways (Onsite) 954 0.02 292 0.00670 Driveways (Onsite) 5,591 0.13 6,559 0.15057 Alley & Utility Cuts (ROW) - - 2,583 0.05930 Sidewalk, Curb (ROW) - - 1,690 0.03880 Ineffective (Onsite) Impervious Surface 9,565 0.22 16,407 0.37665 Effective (ROW) Impervious Surface (Full -Depth) - - 4,273 0.09809 Total Impervious Surface (Onsite + ROW): - - 20,680 0.47475 Pollution Generating Impervious Surface (Onsite + ROW) 6,545 0.07 9,142 0.20987 Pervious Areas: Onsite Landscaping 7,595 0.17 755 0.01733 ROW Landscaping - - 66 0.00152 Total Pervious Surface 7,595 0.17 821 0.01885 Total Project Area Onsite Area 17,162 0.39 17,162 0.39399 ROW Area (Alley + 5th Ave S) - - 4,339 0.09961 Project Site Area (Onsite + Alley + 5th Ave S) - - 21,501 0.49360 The existing areas in TABLE 1 were determined by area measurements in AutoCAD from a topographic survey dated January 5, 2021. As shown in TABLE 1, the developed site impervious surfaces total 20,680 SF consisting of the new building, driveways, alley pavement, walkways, and associated frontage improvements. The areas in TABLE 1 represent the site coverage in the basin draining to the proposed infiltration trenches, and/or the 10" storm system within the alley. 1.5 Predeveloped Stormwater Runoff Conditions Stormwater runoff from the two (2) existing buildings is collected in a gutter and downspout system and is likely conveyed to the City's storm system in 4th Ave S. Similarly, stormwater runoff from the asphalt parking is collected via a catch basin along the west of the parking appears to be conveyed west to the City's storm system in 4th Ave S through private property to the west. All existing storm infrastructure on the site will be removed. Davido Consulting Group, Inc. Page 3 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds November 2023 1.6 Post -developed Stormwater Runoff Conditions Stormwater runoff from the entirety of the building roof areas and on -site at -grade hard surfacing will be fully infiltrated via two (2) infiltration trenches. Infiltration Trench #2 is located west of Building B and will mitigate the entirety of the roof areas for Building A and B as well as the driveway area between Building C and Buildings A&B. Infiltration Trench #1, located west of Building C, will mitigate the entirety of the roof area for Building C and the cdriveway surfacing between the west property line and Building C. Overflow for the infiltration trenches will discharge directly into the 10" storm line within the alley. See Sections 2.5 and 5 for additional information on the proposed stormwater system and BMPs. See FIGURE 6 for an exhibit showing the sub -basin areas within the site. 1.7 Site Map Plans showing the proposed improvements have been attached in FIGURE 2 of this report and contain all requirements set forth in the Stormwater Manual. 2. MINIMUM REQUIREMENTS Since the project proposes greater than 5,000 SF of new plus replaced hard surfaces it is considered a Category 2 project site and is therefore subject to all Minimum Requirements listed in the Stormwater Manual (MR 1-9). The project meets the Stormwater Manual Minimum Requirements as summarized in the following sections. 2.1 Minimum Requirement #1: Preparation of Stormwater Site Plans The Stormwater Site Plan was prepared in accordance with Volume 1 Chapter 3 of the SWMMWW and Section 5.1 of the City of Edmonds's Addendum to the SWMMWW and includes the minimum requirements applicable to the subject site based on thresholds of new and replaced site impervious coverage. 2.2 Minimum Requirement #2: Construction Stormwater Pollution Prevention Plan (SWPPP) The SWPPP was prepared in accordance with Volume 1 Chapter 2 Section 2.5.2 of the Stormwater Manual and is described in Section 4. The Temporary Erosion and Sediment Control Plan (TESC Plan) can be seen in FIGURE 3 of this report and serves as a guide for the contractor to implement a final TESC Plan. As the site disturbance is less than one acre, a General Permit through the DOE is not required. 2.3 Minimum Requirement #3: Source Control of Pollution The proposed infiltration trenches, Enhanced Water Quality treatment facilities, Type 1 catch basins and spill control elbows serve as source control of pollution on the project site. In order to control pollutants, proper maintenance and cleaning of debris, sediments, and oil from stormwater collection and conveyance systems is required per the operation and maintenance recommendations found in Volume 5 Section 4.6 of the Stormwater Manual in addition to the BMPs in Volume IV Section 2.2. See APPENDIX C for operation and maintenance requirements pertaining to the project. Note that the covered areas are cantilevered for Buildings C and Building A, and the areas that are covered have open sides, and therefore rainfall will land Davido Consulting Group, Inc. Page 4 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds November 2023 on those surfaces due to sideways rain and slope towards the drainage collection areas within the driveway. Trash and recycling will be handled on -site within each unit, and there will be no common enclosures anywhere on the site. Trash staging will be placed along the alley ROW south of Building C and Building B. 2.4 Minimum Requirement #4: Preservation of Natural Drainage Systems and Outfalls The proposed drainage system consisting of two infiltration trenches will emulate the natural pre -developed conditions of the site (i.e., forested conditions) as much as possible as stormwater will be infiltrated onsite or will enter the City's storm system in the alley and eventually drain to Shellabarger Creek, thus maintaining the natural drainage course from the site. 2.5 Minimum Requirement #5: On -Site Stormwater Management According to the City's Stormwater Code (Ch 18.30), Category 2 projects that discharge directly or indirectly to the City's MS4 and are required to comply with Minimum Requirements No. I through No. 9 shall either: a. Use On -site Stormwater Management BMPs from List No.2 for all new plus replaced hard surfaces and land disturbed (See ECDC 18.30.060.D.5.e); or b. Demonstrate compliance with the LID Performance Standard (See ECDC 18.30.060.D.5.c). Additionally, Section I-2.5.5 Minimum Requirement #5: Onsite Stormwater Management (Page 55) of the Stormwater Manual states "Projects qualifying as flow control exempt in accordance with I-2.5.7 Minimum Requirement #7: Flow Control (p.64) do not have to achieve the LID performance standard, nor consider bioretention, rain gardens, permeable pavement, and full dispersion if using List #1 or List #2. However, those projects must implement BMP T5.13: Post -Construction Soil Quality and Depth (p.911); BMP T5.10A: Downspout Full Infiltration (p.905) or BMP T5.1013: Downspout Dispersion Systems (p.905) or BMP T5.10C: Perforated Stub -out Connections (p.905); and BMP T5.11: Concentrated Flow Dispersion (p.905) or BMP T5.12: Sheet Flow Dispersion (p.908), if feasible." Since the project does qualify as flow control exempt, the code above clearly states the performance standard is not required. Therefore, the List Approach using List #2 is being utilized to meet Core Requirement #5 and the following BMPs were evaluated and/or chosen in the following order: Law and Landscaped Areas: • Lawn and landscaped areas will meet the Post -Construction Soil Quality and Depth in accordance with BMP T5.13 in Chapter 5 of Volume V of the SWMMWW. Roofs and Other Hard Surfaces: • Downspout Full Infiltration in accordance with BMP T5.10A in Chapter 5 of Volume V of the SWMMWW: Downspout Full Infiltration per BMP T5.10A is not feasible due to lack of space onsite for additional infiltration facilities beyond the infiltration trenches being utilized to meet flow control. However, the infiltration trenches proposed provide 100% infiltration to all hard surfaces onsite, including all roof areas, according to a full Davido Consulting Group, Inc. Page 5 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds November 2023 period of record data within WWHM2012. See Section 3.3 and Section 3.6 for additional information on the site soils and infiltration trench sizing. • Downspout Dispersion in accordance with BMP T5.IOB: This BMP is not feasible as the minimum required vegetated flowpath length is not available onsite. • Perforated Stub -out Connections in accordance with BMP T5.1 OC: This BMP is not feasible as all runoff is being fully infiltrated within the proposed infiltrations. • Concentrated Flow Dispersion in accordance with BMP T5.11: This BMP is not feasible as the minimum required vegetated flowpath length is not available onsite. • Sheet Flow Dispersion in accordance with BMP T5.12: This BMP is not feasible as the minimum required vegetated flowpath length is not available onsite. 2.6 Minimum Requirement #6: Runoff Treatment Since this project is proposing more than 5,000 SF of new plus replaced pollution generating hard surface (PGHS), runoff treatment is required. Each of the two Infiltration Trenches are preceded by a BioPod Biofilter System that will treat all proposed runoff to the Enhanced Water Quality Standard. The 4'x4' Biopod Biofilter System will meet Enhanced Water Quality up to an offline treatment flow rate of 0.029 cfs. According to WWHM 2012 modeling software the off- line treatment flowrate for the area tributary to Biopod #1 is 0.0125 and the off-line flowrate for the area tributary to Biopod #2 is 0.0163. Each of these Biopod system flowrates are below the maximum treatment flowrate for the proposed system, thus meeting Enhanced Water Quality and satisfying MR #6. Davido Consulting Group, Inc. Page 6 20231110_614 5th Ave S Edmonds —Drainage Report Rev 4 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds Analysis Analysis BIOPOD # 1 Water Quafity On -Line BMP 24 hour Volume (ac•ft) 10.0149 Standard Flow Rate (cfs) 0.0222 Standard Flow Rate (cfs) 0.0125 November 2023 Stream Protection Duration I LID Duration I Flow Frequency_ Water Quality L Hydrograph Wetland Input Volumes I LID Report I Recharge Duration I Recharge Predeveloped I Recharge Mitigated Analyze datasets Compact WDM Delete Selected r Mont* Duration Chart 1 Puget East 36 Evap A 2 Puget East 36 Precip 501 POC 1 Predeveloped flow 701 Inflow to POC 1 Mitigated 801 POC 1 Miti ated flow 802 POC 2 Mitigated 803 POC 3 Mitigated flow 901 COPY Mitigated All Datasets Flow Evap POC 1 Stage Precip Flood Frequency Method POC 2 POC 3 r: Log Pearson Type III 17B t Weibull r Cunnane r" Gringorten Davido Consulting Group, Inc. Page 7 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds November 2023 N BIOPOD #2 61 Run Analysis Water Quality On -Line BMP 24 hour Volume (ac-ft) 0 Standard Flow Rate (cfs) 0.02f39 Off -Line BMP Standard Flow Rate (cfs) 0.0163 Stream Protection Duration LID Duration Flow Frequency Water Quality Hydrograph Wetland Input Volumes I UD Report I Recharge Duration Recharge PredeveIoped Recharge Mitigated Analyze datasets Compact WDM ( Delete Selected ( r Monthly FF Duration Chart 1 Puget East 36 Evap A 2 Puget East 36 Precip 501 POC 1 Predeveloped flow 701 Inflow to POC 1 Mitigated 601 POC 1 Mitigated flow 1 901 COPY Mitigated v All Datasets Flow Flood Frequency Method Evap POC 1 �StCage��JPrecip OC 3 JLog Pearson Type III 17B Weibull Cunnane G ringorten 2.7 Minimum Requirement #7: Flow Control This project is not required to implement Minimum Requirement #7 since the total effective impervious surface is less than 10,000 SF, the project will not convert 3/4 acres or more of vegetation to lawn or landscape, or convert 2.5 acres or more of native vegetation to pasture in a threshold discharge area, and will not create a 0.15-cfs increase (using 15-minute timesteps) in the 100-year flow frequency from a threshold discharge area. Since all roof and driveway/walkway area on the site will be fully infiltrated (according to a full period of record data within WWHM) within the two proposed infiltration trenches, the only effective impervious surfaces are within the ROW and the alley and those areas total 4,191 SF. By definition per Chapter 18.30 of the stormwater management, ""Effective impervious surface" Davido Consulting Group, Inc. Page 8 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds November 2023 means those impervious surfaces that are connected via sheet flow or discrete conveyance to a drainage system. Impervious surfaces on residential development sites are considered ineffective if (1) the runoff is dispersed through at least 100 feet of native vegetation in accordance with BMP T5.30 — "Full Dispersion, " as described in Chapter S of Volume V of the SWMMWW, (2) residential roof runoff is infiltrated in accordance with downspout full infiltration systems in MP T5.10A in Volume III of the SWMMWW, or (3) approved continuous runoff modeling methods indicate the entire runoff file is infiltrated" All impervious surfaces on the site will be fully infiltrated according to a full period of record data within WWHM and therefore are ineffective. The effective and ineffective areas are noted in TABLE 1 in Section 1.4 of this report. Additionally, the WWHM2012 modeling report, which is included in APPENDIX B, shows that the increase in the 100-year flow frequency using 15-minute timesteps is less than 0.15 cfs. 2.8 Minimum Requirement #8: Wetlands Protection The site is not tributary to a wetland, therefore MR #8 is not triggered, making the wetlands protections standard not applicable. 2.9 Minimum Requirement #9: Operation and Maintenance An operation and maintenance manual consistent with Volume V of the Stormwater Manual has been provided in APPENDIX C. 3. SITE AND BASIN ASSESSMENT The proposed project aims to preserve natural resources and maintain or restore natural hydrologic conditions on the site. The existing site conditions are summarized in the following sections. Existing Site Conditions: A. Topography The site generally slopes down from east to west with an approximate grade change of 10 feet to a vacant vegetated area at the western portion of the site with a maximum slope of approximately 15-40% along the vegetated, undisturbed area and a maximum slope of 3.3% in the developed portion along the east side of the site. B. Existing ground cover The existing site contains 9,565 SF of impervious surface, 7,595 SF of pervious surface, and 6,545 SF of pollution generating impervious surface (PGIS). C. Natural features of the parcel The pervious areas on the existing site consist of trees, grass, and shrubs. D. Offsite drainage to the property Very little, if any, offsite stormwater enters the site from the neighboring parcels, 5th Ave S, or the paved alley, which surround the site. E. Environmentally sensitive areas on or down gradient of the property N/A. No environmentally sensitive areas exist on or immediately adjacent to the property. F. Drains, channels, and swales, within the project site and immediately adjacent Davido Consulting Group, Inc. Page 9 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds November 2023 An existing roof downspout system associated with the buildings and a catch basin collecting the parking area onsite exists. Stormwater appears to be routed to the City's storm system in 0 Ave S through the neighboring parcel to the west. G. Points of exit for existing drainage from the property Existing stormwater runoff from the site appears to be routed west to the existing storm system in 4th Ave S. H. Known historical drainage problems There are no known historical drainage problems associated with the site. I. Existing Structures/Improvements Existing impervious surfaces on the site include a 3,020 SF of buildings (commercial) 954 SF of concrete walkway, and 5,591 SF of asphalt drive aisles. J. New Structures Improvements Three townhouses totaling 9,556 SF are proposed. K. Future Structures/Improvements Planned No future structures or improvements are planned for the site at this time. L. Remaining Undisturbed Land: The entire site will be cleared for the proposed development, thus leaving no undisturbed land on the site. 3.1 Offsite Analysis An offsite analysis is required for this project since the project proposes to discharge stormwater offsite to the City's storm system in the alley, although only the alley upgrades and some minor road/sidewalk replacement in 5th Ave S will drain to the public storm system since all new and replaced impervious surfaces on the site will be fully infiltrated onsite. An offsite analysis was conducted on June 18, 2021 by DCG, Inc staff. Prior to inspecting the upstream and downstream drainage system, research on the drainage system was conducted using available online GIS mapping. It is clear from the online GIS mapping as well as the visual inspection of the drainage system that runoff from the site will eventually discharge to Shellabarger Creek. The downstream drainage system was followed from the site discharge point in the alley south of the project site to the discharge location to Shellabarger creek, which is approximately 0.20 miles downstream. The project is proposing to discharge to the existing public storm system (MS4) in the alley. The inspection for the analysis was as follows (note that all lineal feet are approximate): From CB 11-107 (locked); 131 LF west via 8" concrete pipe to CB 11-108 (unlocked), 62 LF north via 8" concrete pipe to CB 11-55 (unlocked), 34 LF via 12" concrete pipe west to MH 11-56 (unlocked), 157.92 LF via 12" concrete pipe west (through private property, measured from GIS) to MH 11-62 (locked), 181 LF north via 12" concrete pipe to CB 11-216 (unlocked), 46 LF north via 12" concrete pipe to MH 11-61 (unsafe to open), 144 LF west via 12" PVC to CB 11-180 (unsafe to open), 41 LF west via 12" PVC to MH 11-60 (unsafe to open), 157 LF north to MH 11-59 (unsafe to open) where it then discharges directly into Shellabarger creek. Downstream of the creek the stormwater crosses Edmonds Way and discharges into Edmonds Marsh, where it then ultimately discharges to The Sound via Admiral Way. Davido Consulting Group, Inc. Page 10 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds November 2023 There was no visual indication of conveyance system capacity problems, localized flooding, erosion impacts, or violations of surface water quality standards. See FIGURE 4 and FIGURE 5 for offsite analysis photos and table. 3.2 Subbasin Description Offsite flow from the alley south of the site will be captured via a Type 1 catch basin and conveyed into the city's MS4 storm system. All on -site drainage will be collected and routed to two (2) infiltration trenches where it will fully infiltrate the stormwater (according to a full period of record data within WWHM). Overflow from the Infiltration Trenches will gravity flow to an extended 10" storm main in the alley south of the site, although overflows should rarely, if ever, occur. Runoff from new sidewalks and replaced roadway surfaces along 5th Ave S will be collected within existing drainage structure within 5th Ave S. 3.3 Soils/Infiltration Rates A geotechnical analysis was performed by PanGEO, Inc and summarized in an Infiltration Assessment dated August 23, 2021. PanGEO Inc. excavated three (3) small Pilot Infiltration Tests (PIT) at depths of 5.5, 6, and 12 feet with infiltration rates of approximately 1.2, 0.8, and 1.8 in/hour, respectively. In general, it was determined that the site is underlain by pre -Fraser deposits (geologic map unit Qpf) which consists of interbedded sand, gravel, and silt that has been glacially overridden and typically dense to very dense. Per the Infiltration Report, "Pre - Fraser deposits generally have moderate infiltration capability." Groundwater or seepage was not observed in the test pits. Note that two (2) existing monitoring wells were observed on -site, but the details regarding these wells could not be found via the Department of Ecology Well Report Viewer. See APPENDIX A for the full geotechnical report. Groundwater was measured to be 25' and 16.50' below ground surface in the parking lot for both wells. 3.4 Critical Areas and Flood Plain There are no known critical areas on or in the immediate vicinity of the site. 3.5 Assessment Summary The area of study for this project was the project site itself, 51h Ave S, and the paved alley south of the site. While the proposed project adds more impervious surface to the site than the existing conditions, runoff from all impervious surfaces on the site (not including the alley or 5th Ave S ROW) will be fully infiltrated onsite according to a full period of record data within WWHM (see Section 2.5). 3.6 Stormwater BMP Sizing Two infiltration trenches were selected to manage stormwater runoff from the entirety of the roof areas and all other hard surfaces onsite. Infiltration Trench # 1 (IT# 1), located west of Building C, receives stormwater from the entirety of Building C roof area as well as the western drive aisle. Infiltration Trench #2 (IT#2), located east of Building C and west of Building B, receives stormwater from the entirety of Building A & B roof areas as well as the eastern drive aisle and walkway/stairs leading to 5th Ave S. WWHM2012 was used to size the infiltration trenches in accordance to Volume V — Chapter 4 of the DOE Stormwater Manual, ECDC 18.30, and Checklist 6 in the COE Stormwater Addendum. The two infiltration tests conducted in the location of IT# 1 yielded design infiltration rates of 0.8 in/hr and 1.2 in/hr. Therefore, the lower Davido Consulting Group, Inc. Page It 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds November 2023 of the two rates (0.8 in/hr) was used to size IT#1. An infiltration rate of 1.2 in/hr, in accordance with the geotechnical report in APPENDIX A, was used to size IT#2. The bottom of the infiltration trenches was placed at an elevation near where the infiltration tests were conducted. A 2' depth was determined to be the appropriate gravel depth given size constraints and the footprint of the trenches were increased until 100% infiltration was achieved. The table below shows each infiltration size and the amount of roof area draining to each trench. Davido Consulting Group, Inc. Page 12 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds TABLE 2 Infiltration Trench Sizing Table November 2023 Mini Rqr'd Area Infiltration Infiltration Trench Provided Trench Trench Number Area Tributary (SF) Area SF (SF) Dimensions Building C Roof 5,283 12'W x 1 West Parking 1847 1,044 1,044 87'L x 2'D Total 7,130 Buildings A & B 4,273 Roof 20' W x 2 East Parking & 1,000 1,000 50'L x 2'D Pedestrian Path 5,004 Total 9,277 - Total Impervious 2,044 2,044 Area 16,407 See APPENDIX B for the full WWHM report. 4. CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN (SWPPP) The SWPPP was prepared in accordance with the Stormwater Manual. A Temporary Erosion and Sediment Control Plan is required per the Stormwater Manual. Erosion and sediment control (ESC) measures were designed for the project and shown on the TESC plan in Section 0 of this report. Both the SWPPP and TESC Plan serve as guides as the contractor is required to design a working TESC plan for the site. Refer to the TESC plan and TABLE 3 in this report for TESC measures. Element 1: Preserve Vegetation/Mark Clearing Limits BMPs used: • BMP C103: High Visibility Fence • BMP C233: Silt Fence High visibility fence shall be placed around the site to mark the clearing limits and silt fence will be placed around the low points of the perimeter of the site (as shown on the TESC Plan in FIGURE 3). Element 2: Establish Construction Access BMPs used: • BMP C 105: Stabilize Construction Entrance/Exit The project site will have one construction access connecting to the alley south of the site. The contractor shall install a temporary construction entrance made from quarry spalls. All streets surrounding the site, including the alley, will be swept daily, or as needed, to remove sediment tracked from the project site. Element 3: Control Flow Rates BMPs used: • BMP C235: Wattles Davido Consulting Group, Inc. Page 13 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds November 2023 • BMP C240: Sediment Trap A sediment trap will be placed at the low spot (SW corner) of the site. If necessary, the contractor will implement compost socks and/or straw wattles to supplement the sediment trap to control flow rates. Element 4: Install Sediment Controls BMPs used: • BMP C233: Silt Fence • BMP C235: Wattles • BMP C240: Sediment Trap A sediment trap will be placed at the low spot (SW corner) of the site to allow for sedimentation prior to stormwater discharge offsite. Additionally, silt fencing or straw wattles will be placed along the low points of the perimeter of the construction site to prevent sediment from escaping downstream of the site. Element 5: Stabilize Soils BMPs used: • BMP C 121: Mulching • BMP C 140: Dust Control Mulch will be used by the contractor whenever soils will be left exposed for a significant amount of time or whenever a rainfall event is anticipated. During summer months water will be sprinkled on the site as needed to minimize the amount of dust coming from the site. Element 6: Protect Slopes BMPs used: • BMP C 121 Mulching Mulch will be added to soils on significant slopes to provide temporary protection from erosion. Element 7: Protect Drain Inlets BMPs used: • BMP C220: Storm Drain Inlet Protection Temporary catch basin inlet protection on all existing catch basins on and adjacent to the site as well as proposed catch basins will be implemented to prevent sediment from entering the drainage system. Element 8: Stabilize Channels and Outlets BMPs used: • BMP C207: Check Dams While there are no existing channels on the site, check dams will be used as necessary to control flowrates, trap sediment, and protect against erosion during construction. Element 9: Control Pollutants BMPs used: • BMP C153: Material Delivery, Storage and Containment • BMP C154: Concrete Washout Area A material delivery, storage and containment area shall be designated by the contractor and located away from traffic and near the construction entrance. An onsite concrete washout area for any concrete mixing shall be designated by the contractor as well. Element 10: Control De -Watering BMPs used: • Water Bars Davido Consulting Group, Inc. Page 14 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds November 2023 De -watering should not be an issue on this site as the groundwater table is not known to be near the surface. However, the contractor shall apply water bars during construction as needed. Element 11: Maintain BMPs BMPs used: • BMP C 150: Materials On Hand • BMP C160: Certified Erosion and Sediment Control Lead The contractor shall keep erosion prevention and sediment control materials onsite for regular maintenance and emergency situations. The contractor will be the person in charge of erosion and sediment control for this project. Element 12: Manage the Project BMPs used: • BMP C 150: Materials On Hand • BMP C 160: Certified Erosion and Sediment Control Lead • BMP C162: Scheduling The contractor will be in control of erosion and sediment control and will keep erosion prevention and sediment control materials onsite for regular maintenance and emergency situations. The construction project shall be sequenced in an orderly manner to minimize the duration of exposed soil to erosion. Element 13: Protect Low -Impact Development BMPs BMPs used: • BMP C 102: Buffer Zone • BMP C103: High Visibility Fence • BMP C233: Silt Fence A high visibility fence and silt fence shall be placed around the site where sedimentation is most likely to escape and potentially harm any Low -Impact Development BMPs. Davido Consulting Group, Inc. Page 15 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds TABLE 3 Proposed ESC Measures November 2023 (All ESC Measures Shall Comply with the Stormwater Manual) ESC Measure Comment 1 Identify Project Limits Mark by fencing or other means to contain the grubbing and grading activities. 2 Catch Basin Inlet Protection Install catch basin inlet protection in any drainage structures that may collect any stormwater flowing from the construction site. 3 Phase Grubbing and Grading Phase clearing so that only those areas that are actively being worked are uncovered. From October I through April 30, no soils shall remain exposed for more than 2 days. From May 1 through September 30, no soils shall remain exposed for more than 7 days. 4 Install Straw Wattles Install straw wattles around disturbed areas where sediment could be transported off - site. Adjust straw wattles as required by site conditions and construction sequencing. 5 Sod/Seed Exposed Areas Cleared areas will be sod/seeded as soon as possible after grading completed (few weeks). 6 Soil Removal Remove excess soil from the site as soon as possible after backfillin . 7 Protect Adjacent Properties Adjacent properties shall be protected from sediment deposition by appropriate use of vegetative buffer strips, sediment barriers or filters, dikes or mulching, or by a combination of these measures and other appropriate BMPs. 8 Street Cleaning Provide for periodic street cleaning to remove any sediment that may have been tracked out. Sediment should be removed by shoveling or sweeping and carefully removed to a suitable disposal area where it will not be re -eroded. 9 Inspect ESC BMPs Inspect all erosion and sediment control BMPs installed regularly, especially after any large storm. Maintenance, including removal and proper disposal of sediment should be done as necessary. Davido Consulting Group, Inc. Page 16 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds November 2023 5. PERMANENT STORMWATER CONTROL PLAN Total areas for new plus replaced impervious surfaces are shown in TABLE 1. The stormwater facility requirement thresholds are as follows: ➢ On -site stormwater management BMPs are required to handle site stormwater runoff. See Section 2.5. ➢ Flow Control is not triggered (< 10,000 SF of effective impervious surface). ➢ Water quality treatment is required for the site (> 5,000 SF new PGIS). The following sections address and summarize site specifics and requirements: 5.1 Flow Control N/A. See Section 2.7. 5.2 Water Quality Runoff treatment is required for this project since the total new plus replaced pollution - generating impervious surface in the threshold discharge area for the project is greater than 5,000 SF. Each of the two Infiltration Trenches are preceded by a BioPod Biofilter System that will treat all proposed runoff to the Enhanced Water Quality Standard. The 4'x4' Biopod Biofilter System will meet Enhanced Water Quality up to an offline treatment flow rate of 0.029 cfs. According to WWHM 2012 modeling software the off-line treatment flowrate for the area tributary to Biopod #1 is 0.0125 and the off-line flowrate for the area tributary to Biopod #2 is 0.0163. Each of these Biopod system flowrates are below the maximum treatment flowrate for the proposed system, thus meeting Enhanced Water Quality. 5.3 Source Control & Operation and Maintenance The infiltration trenches, Type 1 catch basins, and spill control elbows serve as source control of pollution on the project site. To control pollutants, proper maintenance and cleaning of debris, sediments, and oil from stormwater collection and conveyance systems is required per the operation and maintenance recommendations found in Volume 5 Section 4.6 of the Stormwater Manual in addition to the BMPs in Volume IV Section 2.2. See APPENDIX C for operation and maintenance requirements pertaining to the project. 5.4 Conveyance System Analysis and Design The proposed onsite conveyance system is comprised of four (4) new Type 1 catch basins, two (2) trench drains, and four to 6-inch storm drain pipe. Four -inch roof downspouts will route the entirety of roof stormwater runoff to the onsite Infiltration Trenches. Stormwater in the driveways will be collected via two catch basins and two trench drains and routed to their respective infiltration trenches. Any overflow for the infiltration trenches will be routed to the 10" storm main in the alley. All proposed storm drains onsite have been sized to handle an anticipated site runoff from a 100-year storm event. See conveyance calculations located in APPENDIX E. Davido Consulting Group, Inc. Page 17 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds 6. SPECIAL REPORTS AND STUDIES November 2023 6.1 Geotechnical Report A geotechnical analysis was performed by PanGEO, Inc and summarized in a geotechnical report dated September 2021. PanGEO Inc. See APPENDIX A for the full geotechnical report. 7. OTHER PERMITS A copy of the Ecology UIC registration will be required prior to construction permit issuance. 8. BONDS The bond amount for the project has been calculated using the King County Site Improvement Bond Quantity Worksheet. A completed King County Site Improvement Bond Quantity Worksheet is included in APPENDIX F. 9. ADDITIONAL FIGURES Please see following pages. Davido Consulting Group, Inc. Page 18 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds FIGURE 2 Site Assessment and Summary November 2023 Davido Consulting Group, Inc. Page 19 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 A B C D E F G H I J K I I I KEY NOTES 39 20'-WIDE TYPE 1 ALLEY APPROACH PER COE STD DTL TR-541 CONCRETE SIDEWALK PER COE STD DTL TR-531 I/cog H/C09 GENERAL NOTES: FRONTAGE NOTES: LEGEND: r w macaw w KEY DESCRIPDETAIL/40 DETAIL/ SHEET 41 CONCRETE CURB AND GUTTER PER COE STD DTL TR-520 G/C09 N 1. STORM SYSTEM IN PRIVATE ALLEY IS A PRIVATE STORM SYSTEM. 10 5 0 10 za 1. STREET TREE SPECIES TO BE DETERMINED BY THE EDMONDS PRIOR TO PLANTING. REFER TO LANDSCAPE CITY OF PLANS. ° CONCRETE # m r m r w oQ w m K U r r r z > w PRIVATE CB #1 - TYPE 1 OKIC09 W/ HERRINGBONE GRATE RIM 81.90 FULL -DEPTH PAVEMENT RESTORATION FOR 5TH AVE S SHALL 2. INFRASTRUCTURE LOCATED IN THE PUBLIC ROW IS 2. STAIRS AND RAILINGS SHALL NOT BE LOCATED WITHIN THE CITY Z w z w z w w m w w wow r w 6" IE 79.00 (E) W/ SPILL CONTROL ELBOW 42 BE 6" HMA (OR MATCH EX IF GREATER) OVER 6" CSBC 5/8" SIEVE (OR MATCH EX OF GREATER) OVER COMPACTED SUBGRADE PER COE STD DTL GU�10 P/C10 & F-F/C11 PUBLIC INFRASTRUCTURE. SCALE IN FEET 3. ALL PRIVATE ON -SITE SD PIPES W/ >2' COVER SHALL RIGHT-OF-WAY. 3. A FINAL RESTORATION INSPECTION IS REQUIRED, PRIOR TO ASPHALT (FULL DEPTH) 2 z O o Q 2 O # 00 ' m o U I O ' U z w z a o S � - O 20 LF 6" PVC SD @ 2.00% MIN - ONSITE ASPHALT PAVEMENT SECTION: 43 4" COMPACTED DEPTH HMA (PER STD SPEC 5-04) CC -cc & BE PVC. 4. ALL PRIVATE ON -SITE SD PIPES W/ ¢2' UNDER A PAVING, TO DETERMINE THE LIMITS OF RESTORATION. APPROXIMATE EXTENTS OF 2" HMA GRIND & m W U m w U-- - U z D_ D z OD_ - o! g U y¢mwr ¢ 98 LF 6" PVC SD 2.00 % MIN O @ _ SPEC 9- OVER 6" CSCB (PER WSDOT STD SPEC 9-03.9 (3) ALLEY PAVING SECTION: a" MIN HMA CL 1/2" (PG 58H22), OR MATCH EX IF GREATER 44 OVER 6" CSBC (PER WSDOT STD SPEC 9-03.9 (3), OR MATCH EX O IF GREATER OR1"HMA GRIND& OVERLAY IN AREAS NOT SHOWN FOR FULL -DEPTH RESTORATION 45 8' WALL. SEE STRUCTURAL PLANS FOR MORE DETAILS O Do-oD/coa EE-EE/C05 - DRIVABLE SURFACE COVER SHALL BE DIP OR C900. 1- - - l - - - - - ,SIN _ CONCRETE 98 FT ---, IE = 72.18 FT \ 4' ''PVC N IE = 72.18 FT BUILDING 610 5TH AVE S / / / / I/ OVERLAY (PER CITY INSPECTOR DISCRETION) INFILTRATION TRENCH LANDSCAPE m K w z Q N�N� m I K !r z a Or z Q Q o w O z m w w LL O a z O U O Q = w ' z caw.=a w U r> O O w o m m r m O�ww O 4" ROOF DOWNSPOUT (TYP) - O4" FOOTING DRAIN TIGHTLINE @ 2.00 % MIN & 2' MIN COVER a" IE 76.13 (DRN) O4"PVC ROOF DOWNSPOUT TIGHTLINE @ 2.00% MIN &2'MIN COVER - BIOPOD #2 OR APPROVED EQUAL PROVIDING 0.0163 CFS MIN OFF-LINE FLOWRATE 46 MAX CONCRETE WALL S3.1 \ \\ \ PEDESTRIAN PATH (SEE '5 m m m m m w . z o ¢ o ¢ RIM 77.30 3' \ 43 45 _ \ \\ / / 18 i / t ESCAPE PLANS FOR 3 ¢ w o o o O6" 7 IE (SW) 75.42 (OVERFLOW) 6" IE (E) 75.42 (INLET) T/C12 2"HMA GRIND 8 OVERLAY MAYBE BE REQUIRED FOR PARKING - LANE AREAS THAT DO NOT OTHERWISE REQUIRE FULL -DEPTH N BBo5 .. VV / j/ � DETAILS) ¢ N 6" IE (SE) 74.38 (INLET) 47 RESTORATION (KEYNOTE 42) PER DISCRETION OF CITY ASPH4 T / 0 o 6" IE N 72.75 OUTLET TO IT () ( ) "OVERFLOW IE BASED ON 2.67' HYDRAULIC DROP WITHIN INSPECTOR (TYP) ROADWAY PAVEMENT STRIPING FOR PARKING PER COE STD `. 16 �• t 4 48 « BUILDING ENTRYWAY rn\ p W BIOPOD 8 0.5' FREEBOARD @LOWEST POINT OF TRENCH DTL TR-561. NEW PARKING PAINT TO BEGIN AT SOUTHERN Ja a DRAIN 48 EXTENT OF EXISTING PARKING STRIPING NEAR NORTH EXTENT O OF PROJECT, AS SHOWN HEREON UC09 .I .' �: ' 3 a f INFILTRATION TRENCH #2 (50.0'L x 20.0'W x 2.0'D) TOP OF FACILITY 73.70 6" PERF PIPE 72.70 STAMPED CONCRETE PEDESTRIAN PATH DISTINGUISHED . .....{j ; .; 4 ' . I N F I LT RATION 16 a 0_ O8 BOTTOM OF FACILITY 71.70 V/C11 FROM VEHICULAR PAVEMENT USING STRIPING, ALTERNATIVE 49 MATERIALS, OR SIMILAR. SEE LANDSCAPE ARCHITECTURAL ........+ TRENCH PERIMETER TO BE LINED WITH PLASTIC MEMBRANE PLANS FOR DETAILS 60 .,. TRENCH # 1 4 ' ' ' ry LINER PER PROJECT GEOTECHNICAL ENGINEER'S SPECIFICATIONS 50 LONG SWEEP ELBOW (TYP) 51 REPL EX PARKING SPACE STRIPING IN -KINDS 52 20' WIDE UTILITY EASEMENT - _ W ✓+ y - { I 1 ; : W15 I IN 6 : 25 BUILDINGA C FF 83.00 «'� �... T: '- I- : T ;; w o ry 8. ¢ ¢ 3 � iO " Og 154 LF fi" SLOTTED PVC PIPE LAID FLAT @ 72.70 - 10 6" SDCO #1 RIM TO FG R/C11 6"JE72.70 O 4" RETAINING WALL FOOTING DRAIN TIGHTLINE (SOLID-WALL61i 53 - { ��N{{j{ m - W • ✓ TRENCH DRAIN #1 11 RIM VARIES 75.92-77.97 PVC) @ 2.00% MIN - N.-. ■ sow--�- s sn 41 P 6. IE 74.64 (N) PRIVATE CB#7-TYPE 1 W/SOLID LOCKING LID M ■ sn 22 " ' ' •; ' • ' - - \ ; \ : J7 (n 0_ 17 LF 6" PVC SD 2.00%MIN 12 @ - 54 RIM 79.00 4" IE 75.89 (E) K/C09 W ..:.-' ..'..� .. ... * y to INFILTRATION F"' PRIVATE CB #3 - TYPE 1 W/ VANED GRATE M 78.3.. W/ZMINSUM W/2' MIN SUMP '. 4 ..I. �... \ 13 4I E (N)75.40 K/CO9 55 FG 78.49 O _.. - . •::: .... :: :: ':. �,.. j .. g TRENCH #2.':,.'.: : /t:: : \\ 6"IE74.16 (N) 4"IE 75.20 .'.:.: 6"IE73.76 (W) PRIVATE CB W/SOLID LOCKING LID 3 3 - \ a \ 68 LF 6"PVC SD@2.00%MIN 14 - 56 RIM 7202 4" IE 69.49 (E) 4" IE 69.39 (W) �C09 - qg I ( V \ \ \ - PRIVATE CB #4 - TYPE 1 15 W/ HERRINGBONE GRATES KIC09 W/ 2' MIN SUMP 3�` :•' RIM 73.00 6" IE 71.00 (E) W/ SPILL CONTROL ELBOW FG 71.15 57 q• IE 69.77 5 LF6 PVC SD 1.00%MIN 58 @ _ - 3 ''� BUILDING C •: o �' }� I \ .{ ., j{` FF 74.00. '1:'� -_ a \ N o b W \ .N .. \ WV / (n W i6 PERIMETER FOOTING DRAIN - a" PERFORATED PVC PIPE IN 6" MIN WASHED GRAVEL, WRAPPED IN NON -WOVEN FILTER SEE ARCH PLANS FABRIC OBSERVATION WELL. RELOCATE TO CENTER DISTRIBUTION ° - ' DEOTAIL 59 PIPE SOUTH OF CROSS IF 6" SCH 40 PVC 6-WAY ELBOW CANNOT BE ACQUIRED V-V/C11 .:.. \ , ' ' " ' Q'� d 17 O­ YELLOW NO -PARKING CURB PAINT _ 6' SoCO #8 RIM 73.80t 606" \ W .�g _ {F 18 SEE STRUCTURAL PLANS FOR FOOTING DRAIN PENETRATIONS THROUGH FOUNDATION (TYP) _ IE 70.75D#1 61 14 LF 6" PVC SO @ 2.00% MIN O 62 100 LF 6" SD@150%MIN _ m:BIOPO .. N.. W - - ...: " .� •,y .:. .. .. 4 �' �, a ...... ROW PA VING TO RE REVIEWED UNDE THE ROW a .a .1 �c '4ecrs G� SStONAL OR APPROVED EQUAL PROVIDING 0.0125 CPS MIN OFF-LINE FLOWRATE RIM 71.90t 19 6" IE (SW) 70.05 (OVERFLOW) 6" IE(E) 69.05(INLET) S/C12 63 4"SD TIGHTLINE @ AREAS _ _ _ _ _ .y: \.: ::::.I PERMIT PERMIT NUMBER PENDING) I 6" IE (SE) 68.70 (INLET) 6" SDCO {{{{{{ If \' 4 6" IE (N) 67.38 (OUTLET TO IT) `OVERFLOW 64 RIM 73.15t - W a I IE BASED ON 2.67' HYDRAULIC DROP WITHIN INFILTRATION TRENCH BIOPOD & 0.5' FREEBOARD @ LOWEST POINT OF TRENCH DRAIN 65 11 LF 6"SD .0%MIN �" h . '.g' INFILTRATION TRENCH #1(87.0'L x 12.0'W x 2.0'D) 20 TOP OF FACILITY 68.33 6"PERF PIPE 67.33 U/C11 AREA DESCRIPTION: SF ACRES W '� - ..h .. - BUILDING B / ' 2 31 cn BOTTOM OF FACILITY 66.33 TOTAL SITE AREA (ON -SITE) 17162 0.39399 I I �,. 'IIj \ U - U.� C 1 " _ _ _ _ FF 84.40 3 51 � P 21 173 LF 6" SLOTTED PVC PIPE LAID FLAT @ 67.33 - TOTAL SITE AREA (ROW) 4339 0.09961 TOTAL SITE AREA (ON-SITE+ROW) 21501 0.49360E- \ J. : ' ' ' - a 22 6" SDCO #5 6" I 6.33 EXISTING AREA - IMPERVIOUS AREAS (TBR) 9565 0.21958 F _ F C 1 1 J to Q E PVC SD 2.00%MIN 23 @ EXISTING AREA - PERVIOUS AREAS (TBR) 7595 0.17436 :: INFILTRATION TRENCH #2 4 . N. ,, V {II 1 yU... .,01111 \ / C 1 1 ° : v I 4� '" '' '• NO� C• W Q N d a � W NEW 10" SD CONNECTION TO EX PUBLIC CB EX RIM 69.29 NEW 8"SD IE(E)66.35 �: q0 '.' H - \ F cp C O) Z Z 24 6" IE 67.04 (N) - PROPOSED AREA DESCRIPTION - �. �. ..� \ - - - - - - Iay�`-,,�I d 27 { \ a W"IE 66.29 (W) 6" IE 66.69 (S) IMPERVIOUS AREAS(ON-SITE): BUILDING A ROOF AREA 2441 0.05604 \ 30� ': �. ' 59 \ 58 .. .. °'. .. ;_ - z6 W } a \ a >a F Z F W a (� d 6" SDCO #3 25 RIM 82.70 R/C11 BUILDING B ROOF AREA 1832 0.04206 .3 ..:.:.:.:......'� :'ci. .... " ' '_" ' ..... :.':. ::.'..; ....... ..... 1� ........... { J r F ; Z W 6" IE 78.72 BUILDING C ROOF AREA 5283 0.12128 36 3a :. 32 ::.'::: 58 :.':.::: .. :.' 27 2gW ::.::. .::.:...: 65 '::::. ;a �t':�...... ::.: :. :.'.' ). ... .. V) I F Q F Q Q 0 (� = Q 6" SDCO #2 26 RIM 78.38 _ ASPHALT &CONCRETE SURFACE 6851 0.15728 .'. .. .... �'. .. ""s' v`�..':.:'.: 2g w:: T' :::: f:::::::::: ' (n LU W '_ F Z 6" IE 75.65 TOTAL IMPERVIOUS AREA 16407 0.37665 'r "'' ■:.:: so::':' 33 50"' " b .::::::..................... .... ry- '...........W..---':' .W:-.W::: ■:::sa: 5 ;;;%• :::'/.:' .. I w _ l!') 0 Q � 27 6" SDCO #6 W/ SEALED LOCKING LID RIM 739.18 6" IE 69.18 _ PROPOSED AREA DESCRIPTION - PERVIOUS AREAS (ON -SITE) LANDSCAPING 755 0.01733 TOTAL PERVIOUS AREA: 755 0.01733 35 : .... .TT..� 57 �:': �'�y:' ����/��� .•••..................... ...... .1'J ..................................................... ::: '.N.. .......................:.... ..... ....... 55 :::: ::'. .......... _ ::'► ::: p:::::::::: '.:::.. 11 � ::::::::::::.:::: .. .... ..................... .. .............. ..0: ,,.... T ................... ': .: .... :::.::: �::: :..::'5:::::: �:y........ '::::::::::::::::::: ' ..:..::::::.:::: ::::::: � : �... /........... w :. ....: ... ::...........:'.:_'_::i.:'.: ::'.: .. ::: :: :'.:.. :::' .: 7 .. 54 .... .. ................_. _ ::1...:rlr:::::::::_:::?.'+:::::::�::;.?'._-"::::: '::...::::..::::: .i 4s ::................ o.................... .. ....::::: i......::::.:::::::::::::::::::::::::::. a " :::'::.1::::::::..I'::::::::::::::::::::.:::::::::::. 53 :-Emm :::::'........ :.'::.).::::: ................... \ 0 28 O 6"PVC SD (TRENCH DRAIN OUTLET)@1.00%MIN - 29 O 9 LF 6" SD PVC 2.00% MIN @ - PROPOSED AREA DESCRIPTION -/ ........=...'.-.:::.:::.... I.................................................................................. ... _.. ............... ............. ..... .............::. ................ ....... ..::: '_r_'_'-]'::::::: t'.'.:.:..,.�._._._._.. ................ ..................... ip ....... ................/ ................................................................'......... .. ............I �..................... ......................... ..::.:::......::::::'. ......:::::::::::::' 52 :::::::::::::::::.::.y.......:::' ................................ .... ............................ \ '.. ........................ \ a .... ...... ..p. S.. ) ..........�..... 5..... OBSERVATION WELL. RELOCATE TO CENTER DISTRIBUTION „ 30 O PIPE SOUTH OF CROSS IF 6 SC 40 PVC 6-WAY ELBOW CANNOT BE ACQUIRED U-U/C11 IMPERVIOUS AREAS (OFF -SITE): ALLEY FULL DEPTH TRENCHING :. '.�:::::::::.gip:::: so so,,,--.,. D,,,.....,_,g�,.:.1�.,;,,,....gD ......._ ...::.':.;:.:: ......--_.._....::.'. .:::::::::::::::::::::::.. '::::::::::::::: :::::::::::::::::: )::: :•:::::... 7... .�.:...._. .:::V.'. ° �.. ..................................... .............+................ ••. ................... 31 O CONNECT FOOTING DRAINS BETWEEN BUILDINGS W/ SOLID WALLED 'PVC PIPE ALLEY GRIND AND OVERLAY 618 0.01419� ................................. .................... ....... .. ........................ ......... ....�.......... -'::::':., 3...............:.,.,,^::::::.''I'::::::'::-.""'-""'': .'. � �. ° .E................. .................. .. v 32 26 LF 6" PVC SO @ 1.00% MIN - 5TH AVE SFULL-DEPTH TRENCHING 497 0.01141 5TH AVE 5 GRIND AND OVERLAY 2558 0.05872 CONCRETE CURB, GUTTER, AND SIDEWALK 1690 0.03880 24 38 I / \ �� - is / ` DIS ARGE LOCATION DISCHARGE LOCATION P o X 33 2LF6"PVC SO@1.00%MIN _ v1, rn \ a 6"SDCO #4 W/SEALED LOCKING LID PROD. MANAGER: BI DESIGNED BY : las 34 RIM 76.25 R/C11 TOTAL FULL -DEPTH IMPERVIOUS AREA: 4273 0.17101 ALES O PUBLIC STORM �� �� 6" IE 74.62 COMBINED ON-SITE+ROW IMPERVIOUS 20680 0.47475 SURFACE AREAS TO PUBLIC STORM � _ � 0_ DRAWN BY: Gs TRENCH DRAIN #2 CHECKED BY: Ms 35 RIM VARIES 70.55-73.32 - COMBINED PGIS ON-SITE+ROW 9142 0.20987 BUI' SYSTEM (OVERFLOWS \ / ( 6" IE 69.25(N) SYSTEM (OVERFLOWS 6 22 5TH FROM INFILTRATION O �\ I H SCALE: ASSHOWN 3s 4" FOOTING DRAIN TIGHTLINE @2.00%MIN &2'MIN COVER REV. SHEET 4" E 70.95 (DRN) - PROPOSED AREA DESCRIPTION - PERVIOUS AREAS (OFF -SITE) FROM INFILTRATION TRENCH #2 ONLY) \\ 11/10/2023 4 OF 13 PRIVATE CB#6-TYPE 1 W/ SOLID LOCKING LID APPROVAL FOR CONSTRUCTION SHEET NUMBER 37 7E K/C0g LANDSCAPING 66 0.00152 TRENCH #1 ONLY) 61: 6" IE 68.00 (N,E) IN 6 .0 8' IE 66.64 (W) OUT TOTAL PERVIOUS AREA: 66 0.00152 COMBINED PERVIOUS SURFACE (ON-SITE+ROW) 821 0.01885 _ CITY OF EDMONDS DATE: /1 0 {�'� `J 38 15 LF 8"PVC SO@2.00%MIN - BY: CITY ENGINEERING DIVISION A A 6 C A D A E F A G A H A I J K Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds FIGURE 3 Drainage Plan November 2023 Davido Consulting Group, Inc. Page 20 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 oX aw o� �o 0 0 o 0 aN ma o� �o rA'¢ a /2mo Zwp m.o y ss 5 KEY NOTES 39 20'-WIDE TYPE 1 ALLEY APPROACH PER COE STD DTL TR-541 I/cog GENERAL NOTES: FRONTAGE NOTES: r w DETAIL/ LEGEND: macaw KEY DESCRIPDETAIL/40 CONCRETE SIDEWALK PER COE STD DTL TR-531 H/C09 w SHEET N 1. STORM SYSTEM IN PRIVATE ALLEY IS A PRIVATE 1. STREET TREE SPECIES TO BE DETERMINED BY THE CITY OF # w o w PRIVATE CB #1 - TYPE 1 41 CONCRETE CURB AND GUTTER PER COE STD DTL TR-520 G/C09 STORM SYSTEM. CONCRETE m m m qa r W/ HERRINGBONE GRATE 10 5 0 10 20 EDMONDS PRIOR TO PLANTING. REFER TO LANDSCAPE PLANS. r r r r z ui 1 OKIC09 FULL -DEPTH PAVEMENT RESTORATION FOR 5TH AVE S SHALL 2. INFRASTRUCTURE LOCATED IN THE PUBLIC ROW IS Z z z w w m RIM 81.90 2. STAIRS AND RAILINGS SHALL NOT BE LOCATED WITHIN THE CITY ° w w w w wow r 6" IE 79.00 (E) W/ SPILL CONTROL ELBOW 42 BE 6" HMA (OR MATCH EX IF GREATER) OVER 6" CSBC 5/8" P/C10 & PUBLIC INFRASTRUCTURE. RIGHT-OF-WAY. ASPHALT (FULL DEPTH) 2 2 ' m o U w y SIEVE (OR MATCH EX OF GREATER) OVER COMPACTED F-F/C11 SCALE IN FEET z O O O ' U z w z 3. ALL PRIVATE ON -SITE SD PIPES W/ >2' COVER SHALL O 20 LF 6" PVC SD @ 2.00% MIN - SUBGRADE PER COE STD DTL GU�10 3. A FINAL RESTORATION INSPECTION IS REQUIRED, PRIOR TO o Q # 00 a o S � - ONSITE ASPHALT PAVEMENT SECTION: BE PVC. APPROXIMATE EXTENTS rn m z � � J z CC -CC & PAVING, TO DETERMINE THE LIMITS OF RESTORATION. w o a - g U-- y¢mwr O 98 LF 6" PVC SD @ 2.00 % MIN - 43 4" COMPACTED DEPTH HMA (PER SPEC 9- STD SPEC 5-04) 4. ALL PRIVATE ON -SITE SD PIPES W/ ¢2' UNDER A OF 2" HMA GRIND & x Q - U U w p p ¢ OVER 6" CSCB (PER WSDOT STD SPEC 9-03.9 (3) DD-DD/coa DRIVABLE SURFACE COVER SHALL BE DIP OR C900. OVERLAY (PER CITY m m m w w LL ALLEY PAVING SECTION: z m O O4 4" ROOF DOWNSPOUT (TYP) - a^ MIN HMA CL 1/2" (PG 58H22), OR MATCH EX IF GREATER 1- - - / INSPECTOR DISCRETION) w z a a a j w O4" FOOTING DRAIN TIGHTLINE @ 2.00% MIN & 2' MIN COVER 44 OVER 6" CSBC (PER WSDOT STD SPEC 9-03.9 (3), OR MATCH EX EE-EE/C05 l - - - - - / z Or z z w, O a" IE 76.13 (DRN) O IF GREATER ,SIN _ CONCRETE INFILTRATION TRENCH Q Q Q Q = w ' z O4"PVC ROOF DOWNSPOUT TIGHTLINE @ 2.00% MIN &2'MIN OR1"HMA GRIND& OVERLAY IN AREAS NOT SHOWN FOR 98 FT ---, BUILDING / N�N� caw.=a - FULL -DEPTH RESTORATION / w U r> O O COVER IE = 72.18 FT I/ LANDSCAPE o w o m m r m BIOPOD #2 45 8' WALL. SEE STRUCTURAL PLANS FOR MORE DETAILS - 4• 610 5TH AVE S O ''PVC N IE = 72.18 FT O�ww OR APPROVED EQUAL PROVIDING 0.0163 CFS MIN OFF-LINE \ � m � m w � z p FLOWRATE 46 3' MAX CONCRETE WALL S3.1 \ \\ \ 43 \ q5 / / J PEDESTRIAN PATH (SEE m m m ¢ o ¢ RIM 77.30 _ \ 18 i LSCAPE PLANS FOR 3 2 OV IE (SW) 75.42 (OVERFLOW) 2"HMA GRIND 8 OVERLAY MAYBE BE REQUIRED FOR PARKING - \\ N BBo5 .. VV / Z DETAILS) w 7 6" IE (E) 75.42 (INLET) T/C12 LANE AREAS THAT DO NOT OTHERWISE REQUIRE FULL -DEPTH o o N 6" IE (SE) 74.38 (INLET) 47 RESTORATION (KEYNOTE 42) PER DISCRETION OF CITY ASPH4 T / / 6" IE (N) 72.75 (OUTLET TO IT) INSPECTOR (TYP) - 4 48 « BUILDING ENTRYWAY p "OVERFLOW IE BASED ON 2.67' HYDRAULIC DROP WITHIN ROADWAY PAVEMENT STRIPING FOR PARKING PER COE STD 16 * + V1\ W BIOPOD 8 0.5' FREEBOARD @LOWEST POINT OF TRENCH O DTL TR-561. NEW PARKING PAINT TO BEGIN AT SOUTHERN �_ Ja 0_ \ \ i J Q DRAIN 48 EXTENT OF EXISTING PARKING STRIPING NEAR NORTH EXTENT Uu09 a INFILTRATION TRENCH #2 (50.0'L x 20.9W x 2.0'D) OF PROJECT, AS SHOWN HEREON .I `-' y 3 f TOP OF FACILITY 73.70 I 6 STAMPED CONCRETE PEDESTRIAN PATH DISTINGUISHED {f 6" PERF PIPE 72.70 �I �: � : �q � � � ' a FROM VEHICULAR PAVEMENT USING STRIPING, ALTERNATIVE _ " ' " O8 BOTTOM OF FACILITY 71.70 Vlull 49 MATERIALS, OR SIMILAR. SEE LANDSCAPE ARCHITECTURAL TRENCH PERIMETER TO BE LINED WITH PLASTIC MEMBRANE PLANS FOR DETAILS 60 q LINER PER PROJECT GEOTECHNICAL ENGINEER'S - - - - - - w ' ' ' ' N w o SPECIFICATIONS 50 LONG SWEEP ELBOW (TYP) - _ W 6 �- ry Og 154 LF fi" SLOTTED PVC PIPE LAID FLAT @ 72.70 - I z - ¢ 51 REPLEXPARKING SPACE STRIPING IN -KIND ® : 25 BUILDING T: : T $ 3 6' SDCO #1 ; ' �� FF 83.00 V t 10 RIM TO FG R/C11 52 20' WIDE UTILITY EASEMENT - {{ 1 «\. .. w N 6 3 6"IE 72.70 TRENCH DRAIN #1 O 4" RETAINING WALL FOOTING DRAIN TIGHTLINE (SOLID -WALL 61 III : Y, : - qN _ ; .✓ . 11 RIM VARIES 75.92-77.97 53 PVC) @ 2.00% MIN 6"IE 74.64(N) PRIVATE CB#7-TYPE 1 M sn _ _ 12 17 LF 6" PVC SD 2.00% MIN W/SOLID LOCKING LID 22 - - 3 \ 7 . � m a �.-.::.. @ 54 RIM 79.00 K/C09 .. 0_ 0_ PRIVATE CB#3-TYPE1 4"IE 75.99(E) f.. \ W/ VAN GRATE a" IE 75.69 (W) F, \ W/ 2' MIN SUMP 1 13 RIM (N 7 K/CO9 y 4 4"IE (N)75.40 55 FG 78.49 S.. 4 . jg ../.. .. \ 6"IE 74) 6(N) 4"IE 75.20 q :/, \ 6" IE 73.76 (W) PRIVATE CB#7-TYPE 1 $} : f AV \ W/SOLID LOCKING LID 0.1 14 68 LF 6"PVC SD@2.00%MIN - 56 RIM 72.02 KIC09� PRIVATE CB #4 - TYPE 1 4" IE 69.49 (E) \ - 4"IE BIN (W) W/HERRINGBONE GRATE �\ � ( :•' \ � 15 KIC09 W/ 2' MIN SUMP I RIM 73.00 FG 71.15 \ 4 6" IE 71.00(E)W/ SPILL CONTROL ELBOW 57 q"IE 69.77 - BUILDING C I _ \ - ✓ 'N WV T PERIMETER FOOTING DRAIN - a" PERFORATED PVC PIPE IN 6" SEE ARCH \ .{ .. FF 74.00 . U) W ... o b .. / O - W °\ w i6 MIN WASHED GRAVEL, WRAPPED IN NON -WOVEN FILTER PLANS 58 5 LF 6" PVC SD @ 1.00%MIN � FABRIC DFOOR OBSERVATION WELL. RELOCATE TO CENTER DISTRIBUTION 59 PIPE SOUTH OF CROSS IF 6" SCH 40 PVC 6-WAY ELBOW V-V/C11 O17 YELLOW NO -PARKING CURB PAINT _ CANNOT BE ACQUIRED 6"soco#8 l a _. nsP OSEE STRUCTURAL PLANS FOR FOOTING DRAIN PENETRATIONS 60 RIM 73.BOt - tl11 10 31 _. _ - . �; I @: a O F'''''{{j, yP 11 9Q THROUGH FOUNDATION (TYP) 6" IE 70 75 . I.. BIOPOD #1 61 14 LF 6" PVC SO@2.00%MIN _ W - :: �' C "e :207'"�� OR APPROVED EQUAL PROVIDING 0.0125 CPS MIN OFF-LINE •g j,;; q a ROW PAVING TO BE ccS'4ecrs O` FLOW RATE sz 10o LF 6 SD @ 1 so%MIN _ 4 i REVIEWED UNDER THE ROW a StoNAL RIM 71.90t PERMIT PERMIT NUMBER 6'IE(SW) 7005(OVERFLOW)!j8 4r 19 6'IE (E)69.05(INLET) S/C12 63 4"SD TIGHTLINE@2.00%MIN W car _ _ _ :: .PENDING) I 6" IE (SE) 68.70 (INLET) \ 4/ • 6"SDCO 6" IE (N) 67.38 (OUTLET TO IT) 64 RIM 73.15t - {{{{{{ I a I ' ' 5 `OVERFLOW IE BASED ON 2.67' HYDRAULIC DROP WITHIN O 6" IE 69.23 INFILTRATION TRENCH #1 _ BIOPOD & 0.5' FREEBOARD @ LOWEST POINT OF TRENCH W L.. . DRAIN 65 11LF6"SD@1.50%MIN C INFILTRATION TRENCH #1 (87.01Lx 12.0'W x2.0'D) C �' 9'O1" .� d I TOP OF FACILITY 68.33 W • • " ' 20 6" PERF PIPE 67.33 U/ul l BOTTOM OF FACILITY 66.33 21 173 LF 6" SLOTTED PVC PIPE LAID FLAT @ 67.33 - 22 6" SDCO #5 RIM TO FG R/C11 6" IE 67.33 23 17 LF 6" PVC SD @ 2.00% MIN - NEW 10" SO CONNECTION TO EX PUBLIC CB EX RIM 69.29 NEW 8"SD IE(E)66.35 24 6' IE 67.04 (N) 10" IE 66.29 (W) 6' IE 66.69 (S) 0RIM 6' SDCO #3 82.70 R/C11 6" IE 78.72 0RIM 6" SDCO #2 78.38 - 6" "IE 75.65 O6" 27 SDCO #6 W/ SEALED LOCKING LID RIM 70.65t - 6" IE 69.18 28 6" PVC SO (TRENCH DRAIN OUTLET) @ 1.00% MIN - 29 O 9 LF 6" SO PVC @ 2.00% MIN - O30 OBSERVATION WELL. RELOCATE TO CENTER DISTRIBUTION PIPE SOUTH OF CROSS IF 6" SCH 40 PVC 6-WAY ELBOW U-U/C11 CANNOT BE ACQUIRED OCONNECT FOOTING DRAINS BETWEEN BUILDINGS W/ SOLID 31 WALLED 4" PVC PIPE 32 26 LF 6" PVC SO @ 1.00% MIN - 33 2LF 6" PVC SO@1.00%MIN - G34 V SDCO #4 W/ SEALED LOCKING LID RIM 76.25 RIC11 6" IE 74.62 TRENCH DRAIN #2 35 RIM VARIES 70.55-73.32 - 6" IE 69.25 (N) 4" FOOTING DRAIN TIGHTLINE @ 2.00% MIN & 2' MIN COVER 36 I 4" IE 70.95 (DRN) PRIVATE CB #6 - TYPE 1 W/ SOLID LOCKING LID 37 RIM 71.00 K/CO9 6"IE 68.00(N,E)IN 8" IE 66.64 (W) OUT 38 15 LF 8" PVC SO @ 2.00% MIN - AREA DESCRIPTION: SF ACRES TOTAL SITE AREA (ON -SITE) 17162 0.39399 TOTAL SITE AREA (ROW) 4339 0.09961 TOTAL SITE AREA (ON-SITE+ROW) 21501 0.49360 EXISTING AREA- IMPERVIOUS AREAS(TBR) 9565 0.21958 EXISTING AREA PERVIOUS AREAS (TBR) 7595 0.17436 PROPOSED AREA DESCRIPTION - IMPERVIOUS AREAS (ON -SITE): BUILDING A ROOF AREA 2441 0.05604 BUILDING B ROOF AREA 1832 0.04206 BUILDING C ROOF AREA 5283 0.12128 ASPHALT& CONCRETE SURFACE 6851 0.15728 TOTAL IMPERVIOUS AREA 16407 0.37665 PROPOSED AREA DESCRIPTION - PERVIOUS AREAS ON -SITE LANDSCAPING 755 0.01733 TOTAL PERVIOUS AREA: 755 0.01733 PROPOSED AREA DESCRIPTION - IMPERVIOUS AREAS OFF -SITE: ALLEY FULL -DEPTH TRENCHING 2086 0.04789 ALLEY GRIND AND OVERLAY 618 0.01419 5TH AVE S FULL -DEPTH TRENCHING 497 0.01141 5TH AVE 5 GRIND AND OVERLAY 2558 0.05872 CONCRETE CURB, GUTTER, AND SIDEWALK 1690 0.03880 TOTAL FULL -DEPTH IMPERVIOUS AREA: 4273 0.17101 COMBINED ON-SITE+ROW IMPERVIOUS SURFACE AREAS 20680 0.47475 COMBINED PGIS ON-SITE+ROW 9142 0.20987 PROPOSED AREA DESCRIPTION - PERVIOUS AREAS (OFF -SITE) LANDSCAPING 66 0.00152 TOTAL PERVIOUS AREA: 66 0.00152 COMBINED PERVIOUS SURFACE (ON-SITE+ROW) 821 0.01885 w .. BUILDING B FF 84.40 2 P u .v... ::::::: Q o Q a rN. INFILTRATION TRENCH #2 V 111 1 y V ° d N rn 0 0 o CL -c :. C11 I. 0 F LU 00 (7 � } 4 U= a a Q> 6 d \ Z F W In d LU gj oa z6 64 36 34 32 58 9�......:. a° F .. .. I O W Of Q Q O C� = Q .: ...'S0. 5 T ........:.:.::.:. :.: ............... �LU i Cn l!'J w Z I 35 .... ..... ...... ...........W.......:.'N::-.W::: -w .... ....... ::ZO .... 1 � ......50 IQ ... ........... .. ....... .. ... 7 .. 54 .... ................_. _v............._ ::.y.......:::' !... a- .:... ...S..D............................... S..D.............. .......................s....o......-...................-.......S.....P...:.-.......-....�...-.....•.-....�...s.U....:.�.:..:..........._...s.. ............... o':�.:.:::�60...... .. sp,� .. �. ..................� .. a .... ... ........... 7 ........... .�..-..� _- - ................... ................................................................... T c�1 a ................... 24 38 I WOOD-/ .� - __ P \\ ~ z 3 o a i crF.irr 1 _. d \ PROD. MANAGER: SI ' WALLS DESIGNED BY: As BUILDING!! ' \ \ ( I 0 DRAWN BY: GS CHECKED BY: As �` 622 5TH AVE S 3 !! I \ H SCALE: ASSHOWN REV. SHEET \\ (0 3 !!! I J 11,10/2023 4 OF I I APPROVAL FOR CONSTRUCTION SHEET NUMBER CITY OF EDMONDS DATE: BV: Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds FIGURE 4 TESC Plan November 2023 Davido Consulting Group, Inc. Page 21 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 KEY NOTES KEY DESCRIPTION DETAIL/ SHEET 0 PROTECT EX POWER VAULT (TYP) - OINSTALL TEMPORARY STORM DRAIN B/C08 INLET PROTECTION CONTRACTOR TO SWEEP STREETS O3 DAILY OR AT MORE FREQUENT - INTERVALS AS NEEDED OAPPROX LOCATION OF TEST PIT PER GEOTECHNICAL REPORT EX FLOWER POLE TO BE REMOVED. ONCE POLE IS REMOVED, O CONTRACTOR SHALL CALL PARKS - DEPARTMENT FOR PICKUP. POLE WILL NOT BE REPLACED OLIMITS OF STRIPING REMOVAL. SEE SHEET C06 FOR NEW STRIPING (TYP) EX WATER SERVICE TO BE RETIRED (D AT THE MAIN AND METER TO BE SALVAGED TO CITY AT DEVELOPER'S EXPENSE EX 1" WATER SERVICE TO BE CUT & OCAPPED NEAR PL FOR REUSE. MODIFY SERVICE TO INCLUDE HOSE SPIGOT & AVB ON METER OUTLET EX BENCH TO BE REMOVED AND ORELOCATED. RETURN TO PARKS DEPARTMENT FOR HOLDING DURING CONSTRUCTION CONSTRUCTION STORMWATER TO DISCHARGE TO NEW SO CONNECTION AFTER COMPLETION OF PRIVATE DRAINAGE SYSTEM IN PRIVATE ALLEY. 10 REFER TO DEMOLITION PERMIT PLANS (BLD2022-1612 & BLD2022-1614)FOR CONSTRUCTION STORMWATER DISCHARGE LOCATION PRIOR TO COMPLETION OF PRIVATE DRAINAGE SYSTEM IN PRIVATE ALLEY INSTALL TEMPORARY STORM DRAIN 11 INLET PROTECTION TO ALL STORM B/C08 DRAIN INLETS 50' DOWNSTREAM OF PROPERTY LINE 12 PHASE SEDIMENT TRAP AS -NEEDED E/C08 POST -DEMOLITION a INTERCEPTOR SWALE D/C08 14 SILT FENCE AND/OR STRAW WATTLES A & F/C08 UTILIZE ORANGE PROTECTION FENCING AS -NEEDED TO PROTECT SUBGRADE OF PROPOSED INFILTRATION FACILITIES FROM 15 COMPACTION DURING CONSTRUCTION WHEN POSSIBLE. IF COMPACTION OCCURS, SCARIFY SUBGRADE TO ITS ORIGINAL STATE AND OBTAIN GEOTECHNICAL APPROVAL PRIOR TO PLACING DRAIN ROCK (TYP) *INSTALL PERIMETER PROTECTION SUCH AS SILT FENCING, COMPOST SOCKS, OR STRAW WATTLES (PER F/CO8) IN ACCORDANCE WITH VOL. II OF THE DOE (2014 AMENDED) STORMWATER MANAGEMENT MANUAL FOR WESTERN WASHINGTON GENERALNOTES 1. A SEPARATE RIGHT-OF-WAY CONSTRUCTION PERMIT IS REQUIRED FOR ALL WORK WITHIN THE CITY RIGHT-OF-WAY. 2. EXISTING SIDEWALK FRONTAGE IMPROVEMENTS SHALL BE MAINTAINED AS LONG AS POSSIBLE DURING THE COURSE OF CONSTRUCTION. 3. INSTALL AND MAINTAIN ALL TESC MEASURES ACCORDING TO APPROVED PLANS, CITY OF EDMONDS STANDARD DETAILS, AND ALL OTHER MEASURES THAT MAY BE REQUIRED DURING CONSTRUCTION. 4. SIDEWALK ALONG 5TH AVE S PROPERTY FRONTAGE SHALL REMAIN OPEN EXCEPT AS NEEDED TO PERFORM SPECIFIC ACTIVITIES SUCH AS SIDEWALK REPLACEMENT AND UTILITY CONNECTIONS. SOIL AMENDMENT NOTE: 1. ALL DISTURBED PERVIOUS SURFACE AREAS SHALL BE AMENDED TO MEET THE SOIL QUALITY AND DEPTH REQUIREMENT PER BMP T5.13 OF THE 2014 DOE STORMWATER MANAGEMENT MANUAL FOR WESTERN WASHINGTON (SEE DETAIL SA/C10). - N 88'5 — 2�•, W � ASPH T ET e i \\� , I 1 / , ELECTRIC METER BUILDING 6" ET e ❑ �;;;; WOOD FENCE III j I 1 I TEL RISER 614 5TH AVE S (TYPICAL) I, `�, / d I I 1 POWER I III 1 11 1 1 1 VAULT I -A FFE = 84.05 FT f T==--sfi-- '---CN 4 I I ( I I I I I I \ \ ❑I I I I I III ■ to AA�� 10 5 0 10 20 SCALE IN FEET n i I ■ �k_i ICI n ■ 2— (EDGE OF I VEGETATION IIII I I � JJ 2 \\N TA \NO. \ / 27032600102900 i\ 111 IIjllljl I \\\ UNKNOWN I I \\\ IIII I CATCH BASIN I CONNECTION \/ \\ \ I d I I I I I I I I (IIII RIM = 82.22 FT 10" CON W IF = 80. I 2 FTI POINT MONITOR II 4" CONIC E IE = 80. 2 F WELL \\ / SD \\ 13000, / PARC ASPHALT PARKING CURB /A (IIIIIII 4 I GETAA [ON 11 1 1 1 1 1 W d l 1 1 - \"WALL I r-I- j/ \\\\ / OSURE I I\ / P -CO 1s ETE (TYP ICAL)\ \ \ e II II \I \I\PT 12 I I ---- 1I I I L HAUL ROUTE PLAN V MiniaturesiMoreQ �\ 614 5th Avenue Southp \ -' Ed s C y P- rk Nartnsople Natural ric ne u ey Homes NW v -�1 Nemiock Way- nrtcoSer,,ces9 \ W\ walow creel er-nr � \\ I I )/\ 6" SIDE SEWER', 1 Imon 4 watersheA_. \ (RECORD) vkes 111 vlmn vm • \ II l T`� � \ Rich pano Loan Officer NMIS 120146, Home_ Pe� Pl�eld \ \ p E ■ I \ \ \ Geri on Construction, 9 v \\ romm u" aplenne Commumry I \ ANITARY �ANHOL —,! — / -"fix Shamrock PlazaContl Ek3t R'PI n 1 \ IM 70 69.68 FT yC HAND = 63.0� FT \ PSS / Elm v,, H q SS > iser Forman— SD ■ SO SD—rSD�SD—SD �SO /SD�SD�50- uthorized Agent k''now Crep4 I I \1 \,� / / / as"e a Eun nag �` FENCE I 4 a — es D aI� " U) I © 11 / \ VI r� STABILIZED CONSTRUCTION ENTRANCE, C/C09 —X— PERIMETER PROTECTION —�HV'FF— HIGH VISIBILITY FENCING ( X REMOVE EXISTING TREE t� INTERCEPTOR SWALE � — 1 STOCKPILE LOCATION SOIL AMENDMENT,SA/C10 INFILTRATION TRENCH ASPHALT APPROX LOCATION OF SOIL ❑ TEST PIT - PAVEMENT PAINT STRIPING REMOVAL 1 / a I \ a / D n 3 N —T I T / \ P _P j I aN a 3 / \ I Wes/ \ \ / N \ WV BEN. \ 5 DT I POST XV VA LT / I L'. ..., METER DING W TH AVE S I e II 26 FT MAIN I jIlI / .59 FT ALLEY II I III Ij 1 T I I T ■ I I 14 I I I II I I I I II l l 1 I I I II PSS ! / 1 PTS / 0 ■ / / I / I a � II / 2 I I VAuuT II M / BUILDING I STREET SIGN (TYPICAL) POWER VAUL POWER POLE W/LUMINAIR INIM = 8" PVC 6" PVC CROSSW Y W co cofQ is 8 w��F ttv F 1 z zz ww:om�o w ww ZKOwF M M2 .<OmF M M 2 m O O W m O O# 0 0 < O B V z i>n F W F F 0 oc to 0 W MI yOwZwp2 ¢ 0na ww22U mZmm Oww�u_ w mmF 0MM a>c2=¢m a0aa wa cw vi . i ZUZZ H.>>Z owoo Luw c, W OWW fLOh'K Q"�oof° p ww > �m�m wZp Z ' 3 z a j- WQz J w o Z m riaw aVi: I d 2 1 CATCH B N RIM = 8. 8" PVC 1 /I \ J Lo Z Y Q d ROW DEMOLITION TO BE REVIEWED UNDER THE ROW f1 NN 0) Q o -7� PERMIT (PERMIT NUMBER Z) - o IL o O PENDING) CATCH BASK` RIM = 84.39 Q LU aQ W - rn w 00 g Z W e ' \ 8" PVC W IE 0 < EL 0 I Z F LU to J Ll p 7 O ~ Q O 3 w w F Q I \ a N In o_ 100 w ~ 7 / \\ SANITARY I I RIM = 85.E F Q TR CHANN Z o 03 a PSS 0 PROJ. MANAGER: BI DESIGNED BY: MS CN (/ d \ DRAWN BY: GS \ \ CHECKED BY: MS \ \\=EREV. H I SCALE: ASSHOWN P d \ 11/10/2023 4 SHEET B OF O_ APPROVAL FOR CONSTRUCTION SHEET NUMBER / \ I CITY OF EDMONDS DATE: BYCITY ENGINEERING GIVISION 0 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds FIGURE 5 Offsite Analysis Photos November 2023 Davido Consulting Group, Inc. Page 22 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 Downstream Analysis Photo Exhibit Project: 614 5th Ave S, Edmonds, Parcel A: 270326-001-009-00 & Parcel B: 270326-001-029-00 {., - Photo 1 (Looking West): CB 11-107 (locked) 8" concrete outlet flows west Photo 2 (Looking North): CB 11-108 (unlocked) 8" Concrete inlet east flows north via 8" concrete outlet 11111" Photo 3 (Looking down/south): CB 11-108 F� �t loll/fill 0� IM, 1 s Photo 4 (Looking North): CB 11-55 (unlocked) 8" concrete inlet south flows west via 12" concrete outlet Photo 5 (Looking down/south): CB 11-55 Photo 7 (Looking West): MH 11-56 (unlocked) 12" concrete inlet east flows west via 12" concrete pipe through private property Downstream Analysis Photo Exhibit Project: 614 5th Ave S, Edmonds, Parcel A: 270326-001-009-00 & Parcel B: 270326-001-029-00 Photo 8 (Looking down/West) MH 11-56 Photo 9 (Looking North) MH 11-62 (locked) 12" concrete inlet east flows north via 12" concrete pipe along alley fir[•<<T Photo 10 (Looking South) CB 11-216 (unlocked) 12" concrete inlet flows north via 12" concrete pipe Photo 11 (Looking down/east) CB 11-216 Photo 12 (Looking west) MH 11-61 (locked) 12" inlet south flows west via 12" PVC pipe Photo 13 (Looking north) CB 11-180 (locked) 12" PVC inlet flows west via 12" PVC pipe Downstream Analysis Photo Exhibit Project: 614 5ch Ave S, Edmonds, Parcel A: 270326-001-009-00 & Parcel B: 270326-001-029-00 ti!Zl y `� \\1!`\, Photo 14 (Looking East) MH 11-60 (locked) 12" PVC inlet east flows north via 12" concrete pipe Photo 15 (Looking west) MH 11-59 (locked) 12" concrete inlet south flows west via 24" concrete pipe which then outfalls into Shellabarger Creek Looking West along Edmonds Way at the discharge point from Shellabarger Creek to the Edmonds Marsh Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds FIGURE 6 Offsite Drainage System Analysis November 2023 Davido Consulting Group, Inc. Page 23 20231110_614 5th Ave S Edmonds —Drainage Report Rev 4 DOWNSTREAM DRAINAGE SYSTEM ANALYSIS Project: 614 5th Ave S Owner: Johnathan Kurth Parcel A: 270326-001-009-00 & Parcel B: 270326-001-029- Parcels: 00 Drainage Component Type, Drainage Component Name, and Size Description 1111 Type: sheet flow, swale, drainage basin, vegetatio tream, channel, pipe, pond; cover, depth, type of Size: diameter, surface area sensitive area, volume CB 11-107 to CB From CB 11-107 to CB 11-108 Pavement 11-108 through 8" concrete pipe CB 11-108 to CB From CB 11-108 to CB 11-55 Pavement 11-55 through 8" concrete pipe CB 11-55 to MH From CB 11-55 to MH 11-56 11-56 through 12" concrete pipe Pavement MH 11-56 to MH From MH 11-56 to MH 11-62 Grass 11-62 through 12" concrete pipe MH 11-62 to CB From MH 11-62 to CB 11-216 Grass 11-216 through 12" concrete pipe CB 11-216 to From CB 11-216 to MH 11-61 MH 11-61 through 12" concrete pipe Pavement MH 11-61 to CB From CB 11-61 to CB 11-180 11-180 through 12" PVC pipe Pavement CB 11-180 to From MH 11-180 to MH 11-60 Pavement MH 11-60 through 12" PVC pipe MH 11-60 to MH From MH 11-60 to MH 11-59 11-59 through 12" concrete pipe Pavement MH 11-59 to From MH 11-59 to Shellabarger Shellabarger creek through 24" Pavement Creek concrete pipe Basin: Shellabarger Creek Subbasin: N/A Subbasin #: N/A Distance from site i" discharge 1A ml = 1,320 ft.,, 2.0% 131 0 to 131 2.0% 63 131 to 194 2.0% 34 194 to 228 2.0% 158 228 to 386 2.0% 178 386 to 564 Date: 9/24/2021 Date of Inspection: 6/18/2021 Weather: Sunny Observations of field O inspector, resource reviewer, Existing Problems Potential Problems or resident onstrictions, under capacity, ponding, overtopping, floodin )" Yributary area, likelihood of habitat or organism destruction, scouring, bank sloughing, problem, overflow pathways, sedimentation, incision, other erosion i) I) potential impacts No Problems No Problems None No Problems No Problems None No Problems No Problems None No Problems No Problems None No Problems No Problems None 2.0% 47 564 to 611 No Problems No Problems None 2.0% 144 611 to 755 No Problems No Problems None 2.0% 144 755 to 899 No Problems No Problems None 2.0% 144 899 to 1043 No Problems No Problems None 2.0% 6 611 to 617 No Problems No Problems None Page 1 of 1 Stormwater Site Plans — Rev 614 5th Ave S Edmonds FIGURE 7 Developed Conditions Sub -Basin Exhibit November 2023 Davido Consulting Group, Inc. Page 24 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 KEY NOTES KEY DESCRIPTION PRIVATE CB #1 - TYPE 1 OW/ HERRINGBONE GRATE RIM 81.90 6" IE 79.00 (E) W/ SPILL CONTROL ELBOW O20 LF 6" PVC SO@2.00%MIN O98 LF 6- PVC ED@2.00%MIN O4 4" ROOF DOWNSPOUT(TYP) O4" FOOTING DRAIN TIGHTLINE @ 2.00% MIN & 2' MIN COVER 4" IE 76.13 (DRN) O4" PVC ROOF DOWNSPOUT TIGHTLINE @ 2.00% MIN & 2' MIN COVER BIOPOD #2 OR APPROVED EQUAL PROVIDING 0.0163 CFS MIN OFF-LINE FLOWRATE RIM 77.30 6'• IE (SW) 75.42 (OVERFLOW) O7 6" IE (E) 75.42 (INLET) 6" 6'• O8 BC TR LIN SP Og 15` 6" ,0 RIP 6'• TR RIP 6" 2 17 PR W/ 3 RIP 6" 6" 4 68 PR 5 W/ RIP 6" PE ,6 MII FA 7 YE 39 20'-WIDE TYPE 1 ALLEY APPROACH PER COE STD DTL TR-541 I/CO9 DETAIL/ SHEET q0 CONCRETE SIDEWALK PER COE STD DTL TR-531 H/CO9 41 CONCRETE CURB AND GUTTER PER COE STD DTL TR-520 G/C09 K/CO9 FULL -DEPTH PAVEMENT RESTORATION FOR 5TH AVE S SHALL 42 BE 6" HMA (OR MATCH EX IF GREATER) OVER 6" CSBC 5/8" SIEVE (OR MATCH EX OF GREATER) OVER COMPACTED SUBGRADE PER COE STD DTL GU-410 P/C10 & F-F/C11 - ONSITE ASPHALT PAVEMENT SECTION: 43 4" COMPACTED DEPTH HMA (PER WSDOT STD SPEC 5-04) CC -CC & & - OVER 6" CSCB (PER WSDOT STD SPEC 9-03.9 (3) DD-DD/ 04 _ 44 ALLEY PAVING SECTION: 4" MIN HMA CL 1/2" (PG OVER BC(PERWS TO IT #1 - FGREATER IDRVIEWAY OR 1" HMA GRIND & OV - FULL -DEPTH RESTORA 1 847 SF 45 8' WALL. SEE STRUCTU 46 3' MAX CONCRETE WALL S3.1 2" HMA GRIND & OVERLAY MAY BE REQUIRED FOR PARKING 7/C12 LANE AREAS THAT DO NOT OTHERWISE REQUIRE FULL -DEPTH 47 ER DISCRETION OF CITY G FOR PARKING PER COE STD AT AREA TRIBUTARY TO STRIPINGT TOINEARSOUTHERN ORTH EXTENT UC09 IT#1 (1,847 SF) ON RIAN PATH DISTINGUISHED USING STRIPING, ALTERNATIVE AREA TRIBUTARY TO IT#1 (5,283 SF) AREA TRIBUTARY TO IT#2 (5,004 SF) AREA TRIBUTARY TO IT#2 (4,273 SF) AREA BYPASSING BMPS (4,273 SF) LANDSCAPE AREA OR (821 SF) FL RI 6" 19 6" IE (E) 69.05 (INLET) 6" IE (SE) 68.70 (INLET) 6" IE (N) 67.38 (OUTLET TO IT) `OVERFLOW IE BASED ON 2.13T HYDRAULIC DROP WITHIN BIOPOD & 0.5' FREEBOARD @ LOWEST POINT OF TRENCH DRAIN INFILTRATION TRENCH #1 (87.01 x 12.0'W x 2.0'D) 20 TOP OF FACILITY 68.33 6" PERF PIPE 67.33 BOTTOM OF FACILITY 66.33 21 173 LF 6" SLOTTED PVC PIPE LAID FLAT @ 67.33 61• SDCO #5 22 RIM TO FG 6" IE 67.33 23 17 LF 6" PVC SO @ 2.00% MIN NEW 10" SD CONNECTION TO EX PUBLIC CB EX RIM 69.29 24 NEW 8" SO IE (E) 66.35 6" IE 67.04 (N) 10" IF 66,29 (W) 6" IE 66.69 (S) 6'• SDCO #3 25 RIM 82.70 6" IE 78.72 6" SDCO #2 26 RIM 78.38 6" IE 75.65 6'• SDCO #6 W/ SEALED LOCKING LID 27 RIM 70.65t 6'• IE 69.18 28 6" PVC SO (TRENCH DRAIN OUTLET) @ 1.00% MIN 29 9LF 6" SO PVC @2.00%MIN OBSERVATION WELL, RELOCATE TO CENTER DISTRIBUTION 30 PIPE SOUTH OF CROSS IF 6" SCH 40 PVC 6-WAY ELBOW CANNOT BE ACQUIRED 31 CONNECT FOOTING DRAINS BETWEEN BUILDINGS W/ SOLID WALLED 4" PVC PIPE 32 26 LF 6" PVC SD@1.00%MIN 33 2LF 6" PVC BID @1.00%MIN 6" SDCO #4 W/ SEALED LOCKING LID G34 RIM 76.25 6" IE 74.62 TRENCH DRAIN #2 35 RIM VARIES 70.55-73.32 VIE 69.25 (N) 36 4" FOOTING DRAIN TIGHTLINE @ 2.00% MIN & 2' MIN COVER 4" IE 70.95 (DRN) PRIVATE CB #6 - TYPE 1 W/ SOLID LOCKING LID 37 RIM 71.00 6"IE 68.00(N,E)IN 8" IE 66.64 (W) OUT @ 15 LF 8" PVC SO @ 2.00% MIN U/C11 R/C11 R/C11 U-U/C11 I RIC11 K/CO9 IN -KIND GENERAL NOTES: FRONTAGE NOTES: LEGEND: N 1. STORM SYSTEM IN PRIVATE ALLEY IS A PRIVATE 1. STORM SYSTEM. STREET TREE SPECIES TO BE DETERMINED BY THE CITY OF EDMONDS PRIOR TO PLANTING. REFER TO LANDSCAPE PLANS. CONCRETE y 0 5 0 o zo 2. INFRASTRUCTURE LOCATED IN THE PUBLIC ROW IS 2, STAIRS AND RAILINGS SHALL NOT BE LOCATED WITHIN THE CITY w PUBLIC INFRASTRUCTURE. ON -SITE SD PIPES W/ >2'COVER SHALL B' RIGHT- BLDG A TO IT #2 ASPHALT (FULL DEPTH) 2 °# BLDG C TO IT #1 A�NG, APPROXIMATE EXTENTS rn w ON -SITE SD PIPES W/ <2' UNDER A RFACE COVER SHALL BE DIP OR C900. 2,441 S F _ OF 2" HMA GRIND & OVERLAY (PER CITY u F m i 5 283 S F INSPECTOR DISCRETION) ' WALKWAYS AND / y O ,SIN -- 3 / )ING INFILTRATION TRENCH 0 55 98 FT DRIVEWAY TO IT #2 IE = 72. FT I/ LANDSCAPE 5o I O 4" 'PVC AVE S N IE = 72.18 T 5,004 SF � PEDESTRIAN PATH (SEE L / 7' \ \ \ N 88'52' i / / _ - LSCAPE PLANS FOR DETAILS) F N N i 48 « BUILDING ENTRYWAY N\ f\ a F :..:.]6::::::: .1-1 :. �.�. ......:::...... N BUILDING ::T::::::::::: T $3 .. ................./ n \ ..... .................. m .... .. mrnw ali Wes_ -W W------ W n 31 41 ::: :: >?a :' P . mmmmmmm :.%: �rrrrrrrrrrrrr \ co LANDSCAPE IN 5TH AVE S p sigrf�� } :: '.� eld 66 SF 1 • ., ROW PAVING TO BE PO'O`cSRec"5" .?o7G • 11 i REVIEWED UNDER THE ROW a S/oNAL %J PERMIT (PERMIT NUMBER 0: 0 ®�TRENCH #1.� AREA DESCRIPTION: SF ACRES TOTAL SITE AREA (ON -SITE) 17112 0.39399 TOTAL SITE AREA (ROW) 4339 0.09961 TOTAL SITE AREA (ON-SITE+ROW) 21501 0.49360 LANDSCAPE 755 SF EXISTING AREA -IMPERVIOUS ARE EXISTING AREA - PERVIOUS AREAS PROPOSED AREA DESCRIPTION - IMPERVIOUS AREAS (ON -SITE): BUILDING A ROOF AREA 2441 0.05604 BUILDING B ROOF AREA 1832 0.04206 BUILDING C ROOF AREA 5283 0.12128 ASPHALT& CONCRETE SURFACE 6851 0.15728 TOTAL IMPERVIOUS AREA 16407 0.37665 PROPOSED AREA DESCRIPTION - PERVIOUS AREAS (ON -SITE) LANDSCAPING 755 0.01733 TOTAL PERVIOUS AREA: 755 0.01733 PROPOSED AREA DESCRIPTION - IMPERVIOUS AREAS (OFF -SITE): ALLEY FULL -DEPTH TRENCHING 2086 0.64789 ALLEY GRIND AND OVERLAY 618 0.01419 5TH AVE S FULL -DEPTH TRENCHING 497 0.01141 5TH AVE 5 GRIND AND OVERLAY 2558 0.05872 CONCRETE CURB, GUTTER, AND SIDEWALK 1690 0.03880 TOTAL FULL -DEPTH IMPERVIOUS AREA: 4273 0.17101 COMBINED ON-SITE+ROW IMPERVIOUS SURFACE AREAS 20680 0.47475 COMBINED PGIS ON-SITE+ROW 9142 0.20987 PROPOSED AREA DESCRIPTION - PERVIOUS AREAS (OFF -SITE) LANDSCAPING 66 0.00152 TOTAL PERVIOUS AREA: 66 0.00152 COMBINED PERVIOUS SURFACE (ON-SITE+ROW) 821 0.01885 CO \ F-1 \ F c11 J J a j o d o d \ O F 00 W 11 U Z 6 \ �I ZF� (n� O_ a W (q W W p LOU Q O Q Q FRONTAGE = UJ a W F Z � � W < ..:.: IMPROVEMENTS o I I,VJL VI � M I I � \� I 622 5TH AVE FIGURE 7 - BASIN AND SUBBASINS J APPROVAL FOR CONSTRUCT" CITY OF EDMONDS DATE: BY: CITY ENGINEERING DIVISION K U w w z 0 0 a PROJ. MANAGER: 61 DESIGNED BY: MS DRAWN BY: GS CHECKED BY: MS SCALE: ASSHOWN REV. I SHEET -- 8 11/10/2023 4 OF 1� SHEET NUMBER C06 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds APPENDIX A Geotechnical Report November 2023 20231110_614 5th Ave S Edmonds_Drainage Report Rev 4 Prepared for: Seattle Luxury Homes, LLC PmGE@ 1 N C O R P O R A T E D GEOTECHNICAL REPORT PROPOSED TOWNHOMES 614 & 616 - 5T" AVENUE SOUTH EDMONDS, WASHINGTON Project No. 21-372 September 2021 Geotechnical & Earthquake Engineering Consultants 3213 Eastlake Avenue East, Ste B Seattle, Washington 98102-3513 Tel: 206.262.0370 Fax: 206.262.0374 Iran ■ c o a r o e w r e o Geotechnical & Earthquake Engineering Consultants September 21, 2021 Project No. 21-372.200 Mr. Jonathan Kurth 557 Roy St, Suite 125 Seattle, WA 98109 Subject: Geotechnical Report Proposed Townhomes 614 & 616 — 5" Avenue South, Edmonds, Washington Dear Mr. Kurth: Attached please find our geotechnical report for the proposed development at the above site in Edmonds, Washington. This report documents the subsurface conditions at the site and presents our geotechnical engineering design recommendations for the proposed townhome development. In summary, based on test pits excavated at the site, the east portion of the site is generally underlain by between 8 to 10 feet of fill overlying native, medium dense to dense poorly graded sand. At the west portion of the site, fill soils were encountered up to about 4 feet below existing grade overlying native medium dense to dense sand. In our opinion, the proposed buildings may be supported on conventional shallow footings, bearing on the dense native soils or compacted structural fill placed on the native dense soils. Alternatively, a deep foundations system consisting of small diameter steel pipe piles (pin piles) may be used to support the east buildings, to avoid deep over -excavations below the building foundations. Temporary unsupported excavations may be sloped as steep as 1 H:1 V (Horizontal: Vertical). We appreciate the opportunity to work on this project. Please call if there are any questions. Sincerely, Michael H. Xue, P.E. Principal Geotechnical Engineer 3213 Eastlake Avenue East, Suite B Seattle, WA 98102 Tel (206) 262-0370 TABLE OF CONTENTS 1.0 INTRODUCTION...................................................................................................................1 2.0 PROJECT AND SITE DESCRIPTION............................................................................... 1 3.0 SUBSURFACE EXPLORATIONS....................................................................................... 2 3.1 CURRENT SUBSURFACE EXPLORATION.................................................................................. 2 3.2 PREVIOUS SUBSURFACE EXPLORATION.................................................................................. 3 4.0 SITE GEOLOGY AND SUBSURFACE CONDITIONS.................................................... 3 4.1 SITE GEOLOGY....................................................................................................................... 3 4.2 SOIL CONDITIONS.................................................................................................................. 3 4.3 GROUNDWATER..................................................................................................................... 4 5.0 CRITICAL AREAS AMF SITE STABILITY..................................................................... 5 5.1 EROSION HAZARD AREA........................................................................................................ 5 5.2 SITE STABILITY...................................................................................................................... 5 6.0 GEOTECHNICAL RECOMMENDATIONS...................................................................... 6 6.1 SEISMIC DESIGN PARAMETERS.............................................................................................. 6 6.2 BUILDING FOUNDATIONS....................................................................................................... 6 6.2.1 General........................................................................................................................... 6 6.2.2 Conventional Footings................................................................................................... 6 6.2.3 Allowable Bearing Pressure........................................................................................... 7 6.2.4 Foundation Performance................................................................................................ 7 6.2.5 Lateral Resistance.......................................................................................................... 7 6.2.6 Perimeter Footing Drains............................................................................................... 8 6.2.7 Footing Subgrade Preparation and Protection............................................................... 8 6.2.8 Pin Piles......................................................................................................................... 8 6.3 CONCRETE RETAINING WALL DESIGN PARAMETERS........................................................... 11 6.3.1 Lateral Earth Pressures................................................................................................. 11 6.3.2 Wall Surcharge............................................................................................................. 12 6.3.3 Lateral Resistance........................................................................................................ 12 6.3.4 Wall Drainage.............................................................................................................. 12 6.3.5 Wall Backfill................................................................................................................ 13 6.4 CONCRETE SLAB-ON-GRADE............................................................................................... 13 7.0 CONSTRUCTION CONSIDERATIONS..........................................................................13 7.1 DEMOLITION & SITE PREPARATION..................................................................................... 13 7.2 MATERIAL REUSE................................................................................................................ 14 7.3 TEMPORARY EXCAVATIONS................................................................................................. 14 7.4 STRUCTURAL FILL PLACEMENT AND COMPACTION............................................................. 15 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page i PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 7.5 PERMANENT CUT AND FILL SLOPES ............. 7.6 EROSION AND DRAINAGE CONSIDERATIONS 7.7 WET EARTHWORK RECOMMENDATIONS ...... ...................................................................... 15 ...................................................................... 15 ...................................................................... 16 8.0 ADDITIONAL SERVICES..................................................................................................17 9.0 LIMITATIONS.....................................................................................................................17 10.0 REFERENCES.................................................................................................................... 19 LIST OF ATTACHMENTS Figure 1 Figure 2 Appendix A Figure A-1 Figure A-2 Figure A-3 Figure A-4 Figure A-5 Figure A-6 Figure A-7 Appendix B Vicinity Map Site and Exploration Plan Summary Test Pit Logs Terms and Symbols for Boring and Test Pit Logs Log of Test Pit PIT-1 Log of Test Pit PIT-2 Log of Test Pit PIT-3 Log of Test Pit TP-1 Log of Test Pit TP-2 Log of Test Pit TP-3 Previous Test Boring Logs and Laboratory Results 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page ii PanGEO, Inc. GEOTECHNICAL REPORT PROPOSED TOWNHOMES 614 & 616 - 5TH AVENUE SOUTH EDMONDS, WASHINGTON 1.0 INTRODUCTION This report presents the results of a geotechnical study that was undertaken to support the design and construction of the proposed development in Edmonds, Washington. Our study was performed in general accordance with our mutually agreed -upon scope of work as outlined in our proposal dated August 2, 2021. Our service scope included reviewing readily available geologic and geotechnical data at the subject site and in the site vicinity, conducting a site reconnaissance, excavating six (6) test pits, and developing the geotechnical design recommendations presented in this report. 2.0 PROJECT AND SITE DESCRIPTION The project site consists of two adjacent parcels located at 614 and 616 — 5th Avenue South in Edmonds, Washington (see Figure 1, Vicinity Map). The combined site is an approximate 0.39 acre lot. It is bordered by 5th Avenue South to the east, multi -family residences to the west, retail establishments to the north, and an improved private alley to the south. The site is currently occupied by a single -story retail building at the north portion of the site and a single -story retail building with full basement at the southern portion of the site, with a surface parking lot between the two buildings. The site generally slopes down from east to west with an approximate grade change of 10 feet to a vacant vegetated area at the western portion of the site. According to the City, an erosion hazard (slope gradient between 15% and 40%) is present at the approximate central portion of the lot, associated with previous grading at the site. No other geologic hazards are mapped on the property by the City or County. We understand that you plan to remove the existing buildings, and construct three buildings at the site, consisting of two live -work townhome buildings (Buildings A and B) along the east property line and a townhome building (Building C) in the western portion of the site (see Figure 2). Based on review of the preliminary plans, the proposed buildings will be 3-story, wood -frame structures with concrete slabs on grade. We envisage that site grading for the proposed project will include cuts and fill up to about 8 to 10 feet for the foundation construction. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 1 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 BUILDING A BUILDING C u Plate 1. Typical East-West Building Section, looking North. The conclusions and recommendations outlined and provided in this report are based on our understanding of the proposed development, which is in turn based on the project information provided. If the above project description is incorrect, or the project information changes, we should be consulted to review the recommendations contained in this study and make modifications, if needed. 3.0 SUBSURFACE EXPLORATIONS 3.1 CURRENT SUBSURFACE EXPLORATION Our current subsurface exploration consisted of excavating six (6) test pits (PIT-1, PIT-2, PIT-3 and TP-1, TP-2, TP-3) at the project site on August 4 and August 6, 2021. PIT-1 was initially excavated to 5.5 feet for infiltration testing and was then excavated to about 9 feet deep after the test. PIT-2 was initially excavated to 6 feet for infiltration testing and was then excavated to at about 9 feet deep after the test. PIT-3 was initially excavated to 12 feet for infiltration testing and was then excavated to practical digging refusal at about 15 feet deep after the test. TP-1 was excavated to practical digging refusal at 13 feet below grade and TP-2, and TP-3 were each excavated to about 11 feet below the existing grade. The approximate test pit locations are shown on the attached Figure 2. The relative in -situ density of cohesionless soils, or the relative consistency of fine-grained soils, was estimated from the excavating action of the excavator, probing the sidewalls with a 1/2-inch diameter steel rod, and the stability of the test pit sidewalls. Where soil contacts were gradual or undulating, the average depth of the contact was recorded in the log. After the test pits were 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 2 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 completed, the excavations were backfilled with the excavated soils and the surface was tamped and re -graded smooth. A geologist from our firm was present throughout the explorations to assist in sampling, and to document the soil samples obtained from the explorations. The summary test pit logs are included in Appendix A. 3.2 PREVIOUS SUBSURFACE EXPLORATION In addition to the current explorations at the site, we also reviewed readily available subsurface data in the site vicinity. Specifically, we reviewed five boring logs (B-1 through B-5) at the subject site by Zipper Geo Associates, LLC (ZGA) in October 2015. The previous test boring logs and laboratory results are included in Appendix B for reference. We also observed two existing monitoring wells (Department of Ecology Well Tags BKH-527 and BKH-528) installed by others at the site. Details of these monitoring wells are not known, and they could not be found on the Department of Ecology Well Report Viewer. These groundwater monitoring wells will need to be decommissioned per the Washington State Department of Ecology's standards prior to, or during construction. 4.0 SITE GEOLOGY AND SUBSURFACE CONDITIONS 4.1 SITE GEOLOGY Based on our review of the Composite Geologic Map of the Sno-King Area, Central Puget Lowland (Booth, 2004), the site is underlain by Pre -Fraser Deposits (geologic map unit Qpf). Pre -Fraser Deposits generally consist of interbedded sand, gravel, and silt that has been glacially overridden and typically dense to very dense. This unit is similar to the younger Vashon Advance Outwash but is characterized by its stratigraphic position and generally heterogenous grain size. 4.2 SOIL CONDITIONS For a detailed description of the subsurface conditions encountered at each exploration location, please refer to our summary test pit logs provided in Appendix A and previous test boring logs in Appendix B. The stratigraphic contacts indicated on the logs represent the approximate depth to boundaries between soil units. Actual transitions between soil units may be more gradual or 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 3 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 occur at different elevations. The descriptions of groundwater conditions and depths are likewise approximate. The following is a generalized description of the soils encountered in the test pits. UNIT 1: Fill — Test pits PIT-1, PIT-2, and TP-1, excavated in the western portion of the site, test pits, generally encountered approximately 4 to 4.5 feet of fill below surface vegetation. The fill encountered in these test pits generally consisted of loose to medium dense silty to poorly graded sand with some plastic, asphalt, and brick debris. Test pits PIT- 3, TP-2, and TP-3, excavated in the central and eastern portion of the site, encountered approximately 8 to 10 feet of fill below the surface asphalt. The fill generally consisted of loose to medium dense silty sand with gravel with varying amounts of wood, concrete, and construction debris. UNIT 2: Pre -Fraser Deposits — Directly below the fill in each test pit, medium dense to dense poorly graded sand was observed in the test pits extending to the bottom of test pits. We interpreted this unit as the mapped pre -Fraser Deposits within the project vicinity. Our subsurface descriptions are based on the conditions encountered at the time of our exploration. Soil conditions between our exploration locations may vary from those encountered. The nature and extent of variations between our exploratory locations may not become evident until construction. If variations do appear, PanGEO should be requested to reevaluate the recommendations in this report and to modify or verify them in writing prior to proceeding with earthwork and construction. Previous Test Borings: The previous test borings by ZGA generally encountered fill up to 13 feet overlying medium dense to dense native sand that extended to a maximum depth of about 24 feet below the surface. 4.3 GROUNDWATER Groundwater or seepage was not observed in our test pits or previous test borings by ZGA at the time of exploration. Groundwater was measured in the previously installed groundwater monitoring wells on August 5, 2021 at a level of approximately 25 feet below ground surface in the parking lot area (approximate EL 59 feet) and 16.5 feet below ground surface in the lower vegetated area (approximate EL 57.5 feet). No groundwater was encountered within the drilling depths in the borings by ZGA. It should be noted that groundwater elevations may fluctuate depending on the seasonal rainfall, local subsurface and groundwater conditions, and other factors. In general, the water level is the 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 4 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 highest and the seepage rate in the greatest during the winter and early spring (typically October through May). 5.0 CRITICAL AREAS AMF SITE STABILITY 5.1 EROSION HAZARD AREA The site is mapped as an erosion hazard area in accordance with the City of Edmonds Critical Areas Map and City of Edmonds Development Code Section 23.80.020, due to presence of slopes with gradient between 15 and 40 percent. Based on the USDA Soil Survey data and the test pits/borings, the site soils (Alderwood/Everett series) are anticipated to exhibit low to moderate erosion potential when disturbed and left unprotected. However, in our opinion, the potential erosion hazards at the site can be effectively mitigated with the best management practice during construction and with properly designed and implemented landscaping for permanent erosion control. During construction, the temporary erosion hazard can be effectively managed with an appropriate erosion and sediment control plan, including but not limited to installing silt fence at the construction perimeter, limiting removal of vegetation near the construction area, placing rocks or hay bales at the disturbed/traffic areas and on the downhill side of the project, covering stockpile soil or cut slopes with plastic sheets, constructing a temporary drainage pond to control surface runoff and sediment trap if needed, placing rocks at the construction entrance, etc. Permanent erosion control measures should include establishing vegetation, landscape plants, and hardscape established at the end of project. 5.2 SITE STABILITY As part of our study, we conducted a site reconnaissance on August 4, 2021 to observe the conditions of the slope. Based on our observations, the slope follows the east -west grade break located at the approximate center of the two parcels. The earthen slope at the center of the two parcels has a gradient of approximately 35 to 40 percent with a vertical height of about 7 feet. The slope area is currently heavily vegetated. No evidence of groundwater seepage was observed on or near the slope. Based on the results of our field exploration and our field observations, it is our opinion that the site is currently stable. It is also our opinion that the proposed development as currently planned will not adversely impact the subject site and surrounding properties, provided that the proposed project is properly designed and constructed. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 5 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 6.0 GEOTECHNICAL RECOMMENDATIONS 6.1 SEISMIC DESIGN PARAMETERS We understand that the project will be designed in conformance with the 2018 edition of the International Building Code (IBC). The 2018 International Building Code (IBC) is based on a design level earthquake event having a 2% probability of occurrence in 50 years (return interval of 2,475 years), and the 2008 USGS seismic hazard maps. Based on site soils conditions, it is our opinion that Site Class D (Stiff Soil) may be assumed for the seismic design of the proposed structures. 6.2 BUILDING FOUNDATIONS 6.2.1 General Based on the subsurface conditions and current design plans, it is our opinion that the proposed buildings may be supported by conventional shallow footings, bearing on dense native soils or structural fill/controlled density fill (CDF) placed on the competent native soils. However, use of this foundation system will require over -excavation of fill/loose soils and backfill of structural fill/CDF. Over -excavations of existing fill below foundations will be up to about 4 feet for the west building and will be up to about 10 to 12 feet for the two east buildings. Alternatively, to avoid deep over-excavations/structural backfill and the need for temporary shoring, it is our opinion that a deep foundation system consisting of small diameter steel pipe piles (pin piles) may be considered to support the east buildings. It should be noted that large concrete pieces were encountered in the test pits in the existing fill. As such, obstructions may be encountered during pin pile installation and pile locations may need to be moved to avoid obstructions. Alternatively, the obstructions may be removed by the excavator, where encountered, to facilitate pile installation. The following sections present our design recommendations for shallow conventional footings and pin piles. 6.2.2 Conventional Footings In our opinion, the proposed west building may be supported on conventional footings bearing on the medium dense to dense, undisturbed native soils (Soil Unit 2: Pre -Fraser Deposits). Footings may also be founded on properly compacted structural fill placed on undisturbed native soil. The structural backfill should extend horizontally with an approximately I H: IV line beyond the footing edges. It is our opinion that it will be more appropriate to support the two east buildings with pin piles. Please note that the competent bearing soil depths in the vicinity of our test pits are approximate. The actual amount of over -excavation required will need to be 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 6 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 determined during construction based on actual soil conditions found at the proposed footing locations and elevations. In designing the footings, the shape of footings will need to be considered regarding the available space for temporary excavations. Where space may be limited for an unsupported open cut, it may be necessary to use L-shaped perimeter footings to conserve space and to allow the temporary excavations to be made within the property limits. 6.2.3 Allowable Bearing Pressure We recommend that an allowable soil bearing pressure of 2,500 pounds per square feet (psf) be used to size the footings, bearing on medium dense to dense native soil, or structural fill/lean- mix concrete placed on the competent native soils. Continuous and individual spread footings should have minimum widths of 18 and 24 inches, respectively. Footings should be placed at least 18 inches below final exterior grade. Interior footings should be placed at least 12 inches below the top of slab. 6.2.4 Foundation Performance Total and differential settlements are anticipated to be within tolerable limits for foundation designed and constructed as discussed above. For the proposed buildings supported by conventional footings bearing on competent native soils and structural fill/lean-mix concrete, the building settlement under static loading conditions is estimated to be approximately one inch, and differential settlement should be on the order of about 1/2 inch. Most settlement should occur during construction as loads are applied. 6.2. S Lateral Resistance Lateral forces from wind or seismic loading may be resisted by a combination of passive earth pressures acting against the embedded portions of the foundations and walls, and by friction acting on the base of the foundations. Passive resistance values may be determined using an equivalent fluid weight of 300 pounds per cubic foot (pcf). This value includes a factor safety of at least 1.5 assuming that densely compacted structural fill will be placed adjacent to the sides of the foundation. A friction coefficient of 0.35 may be used to determine the frictional resistance at the base of the foundation. This coefficient includes a factor of safety of approximately 1.5. Unless covered by pavements or slabs, the passive resistance in the upper 12 inches of soil should be neglected. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 7 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 6.2.6 Perimeter Footing Drains Footing drains should be installed around the perimeter of the building, at or just below the invert of the footings. The footing drains should consist of 4-inch diameter, schedule 40 PVC or SDR 35, perforated pipe embedded in washed drain rock/pea gravel and wrapped in filter fabric. Under no circumstances should roof downspout drain lines be connected to the footing drain systems. Roof downspouts must be separately tightlined to appropriate discharge locations. Cleanouts should be installed at strategic locations to allow for periodic maintenance of the footing drain and downspout tightline systems. 6.2.7 Footing Subgrade Preparation and Protection All footing subgrades should be carefully prepared. The adequacy of footing subgrade should be verified by a representative of PanGEO, prior to placing forms or rebar. The footing subgrade at should be in a firm/dense condition prior to concrete pour. Any over -excavations in the footing areas should be backfilled with compacted structural fill. Footing excavations should be observed by PanGEO to confirm that the exposed footing subgrade is consistent with the expected conditions and adequate to support the design bearing pressure. It should be noted that site soils are highly moisture sensitive and can be easily disturbed when exposed to moisture. As such, the exposed footing subgrade should be adequately protected. This may be accomplished with placing quarry spalls or crushed surfacing base course (CSBQ on the footing subgrade immediately after excavations if excavations are planned during inclement weather. 6.2.8 Pin Piles In the eastern portion of the site where upwards of 13 feet of fill was observed in our test pits and previous borings, it is our opinion that 3- and 4-inch diameter driven pin piles may be considered in -lieu of deep over -excavation and structural backfill. Three- and four -inch diameter pin piles are typically driven with a hammer mounted to a small excavator. Pin Pile Capacity — The number of piles required depends on the magnitude of the design load and the pile size. Table 1, below, provides the allowable axial capacities in compression for pin piles with an approximate factor of safety of at least 2.0. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 8 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 Table 1— Pin Pile Capacities Pile Diameter (in) Allowable Axial Capacity in Compression (tons) 3 6 4 10 Penetration resistance required to achieve the capacities will be determined based on the hammer used to install the pile. The tensile and lateral capacities of pin piles should be ignored in design calculations. It is our experience that the driven pipe pile foundations should provide adequate support with total settlements on the order of 1/2-inch or less. Pin Pile Specifications — We recommend that the following specifications be included on the foundation plan: 1. 3-inch and 4-inch diameter piles should consist of Schedule-40, ASTM A-53 Grade "A" pipe. 2. 3-inch piles shall be driven to refusal with a minimum 600-lb hydraulic hammer. We recommend the following refusal criteria based on the size of hammer utilized: Table 2 — Three-inch Pile Refusal Criteria Hammer Approx. Refusal Criteria Blows per Size Minute (3-inch pile) 600 lbs 1000 12 seconds per inch 850 lbs 900 10 seconds per inch 1100 lbs 900 6 seconds per inch The driving criteria recommended in the table above will be verified by a static load test program (see discussion in Item 5). 3. 4-inch piles shall be driven to refusal with a minimum 850-lb hydraulic hammer. We recommend the following refusal criteria based on the size of hammer utilized: 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 9 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 Table 3 — Four -inch Pile Refusal Criteria Hammer Approx. Refusal Criteria Blows per Size Minute (4-inch pile) ) 850 lbs 900 16 seconds per inch 1100 lbs 900 10 seconds per inch 2000 lbs 600 4 seconds per inch The driving criteria recommended in the table above will be verified by a static load test program (see discussion in Item 5). 4. Piles shall be driven in nominal sections and connected with compression fitted sleeve couplers (see detail below — Courtesy of McDowell Pile King, Kent, WA). We discourage welding of pipe joints, particularly when galvanized pipe is used, as we have frequently observed welds broken during driving. Pipe 10 2" to 6" New Steel Pipe Section to 1�� S 1 1/4" to 2" wide X-Strong Steel Ring 1/4" filet welded to pipe sleeve Driven Steel Pipe Section Beveled End to aid insertion 5. At least 3 percent (but no more than 5) of the 3-inch and 4-inch pin piles should be load tested. All load tests shall be performed in accordance with the procedure outlined in ASTM D1143. The maximum test load shall be 2 times the design load. The objective of the testing program is to verify the adequacy of the driving criteria, and the efficiency of the hammer used for the project. 6. The geotechnical engineer of record or their representative shall provide full time observation of pile installation and testing. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 10 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 The quality of a pin pile foundation is dependent, in part, on the experience and professionalism of the installation company. We recommend that a company with experienced personnel be selected to install the piles. Lateral Resistance — Lateral capacity of vertical pin piles should be ignored in design calculations. Some resistance to lateral loads may be accomplished by battering the piles to a slope of l (H):4(V), or steeper. Passive soil resistance values for embedded pile caps and grade beams may be determined using an equivalent fluid weight of 250 pounds per cubic foot (pcf). This value includes a factor of safety of at least 1.5 assuming that a properly compacted structural fill will be placed adjacent to the sides of the pile caps and grade beams. Friction at the base of pile cap should be ignored in the design calculations. For the seismic condition, the recommended passive pressure may be increased by one third. Estimated Pile Length — The subsurface conditions at the site may vary across the site. Based on the soil conditions at the site and our experience in the project area, for planning and cost estimating purposes, we estimate that pile length may range from about 20 to 25 feet. A minimum pile length of 10 feet should also be specified in the project plans. Obstructions — Construction and concrete debris was encountered in test pits PIT-3, TP-2, and TP-3 beneath the existing parking area. In so, obstructions may be encountered during pile driving. Where possible, the obstructions should be removed to facilitate the pile driving. If obstructions cannot be removed, the structural engineer of record should be notified to revise the pile layout to accommodate the adjustment. 6.3 CONCRETE RETAINING WALL DESIGN PARAMETERS Retaining walls should be properly designed to resist the lateral earth pressures exerted by the soils behind the wall. Proper drainage provisions should also be provided behind the walls to intercept and remove groundwater that may be present behind the wall. Our geotechnical recommendations for the design and construction of the retaining and below -grade walls are presented in the sections below. 6.3.1 Lateral Earth Pressures We recommend that concrete cantilever walls that are free to rotate be designed for an equivalent fluid pressure of 35 pcf for level backfills behind the walls; and 50 pcf with a backslope no steeper than 2H:IV. Restrained walls such as basement walls should be designed for 50 and 60 pcf for level and 2H:1 V backslope, respectively. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 11 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 For the seismic condition, we recommend a uniform lateral earth pressure of 8H psf (where H is the wall height) be added to the static pressure for sizing the retaining and basement walls. The recommended lateral pressure assumes that adequate wall drainage will be incorporated into the design and construction of the walls to prevent the development of hydrostatic pressure. 6.3.2 Wall Surcharge The retaining and basement walls should be designed to accommodate traffic surcharge pressures if the traffic load is located within the height dimension of the wall. As a minimum, the traffic surcharge should be considered equivalent to 2 feet of soils surcharge (i.e., 80 psf of horizontal uniform pressure). Similarly, surcharge loads from construction equipment or soil/material stockpiles should be considered in the retaining and basement wall design. We recommend that a lateral load coefficient of 0.4 be used to compute the lateral pressure on the wall face resulting from surcharge loads located within a horizontal distance of one-half wall height. 6.3.3 Lateral Resistance Lateral forces from wind or seismic loading and unbalanced lateral earth pressures may be resisted by a combination of passive earth pressures acting against the embedded portions of the foundations and by friction acting on the base of the foundations. Passive resistance values may be determined using an equivalent fluid weight of 300 pounds per cubic foot (pcf). This value includes a factor of safety of 1.5, assuming the footing is poured against recompacted native soil or properly compacted structural fill adjacent to the sides of footing. A friction coefficient of 0.35 may be used to determine the frictional resistance at the base of the footings. This coefficient also includes a safety factor of at least 1.5. 6.3.4 Wall Drainage Provisions for wall drainage should consist of a 4-inch diameter perforated drainpipe behind and at the base of the wall footings, embedded in 12 to 18 inches of clean crushed rock and pea gravel wrapped with a layer of filter fabric. Where applicable, in -lieu of conventional footing drains, weep holes (2" diameter of 10 feet on center) may be used for site retaining walls. A minimum 18-inch-wide zone of free draining granular soils (i.e., pea gravel or washed rock) is recommended to be placed adjacent to the wall for the full height of the wall. Alternatively, a composite drainage material, such as Miradrain 6000, may be used in lieu of the clean crushed rock or pea gravel. The drainpipe at the base of the wall should be graded to direct water to a suitable outlet. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 12 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 6.3. S Wall Backfill Wall backfill should consist of free draining granular soils. In our opinion, the on -site fill soils have a high fines content, and are not suitable to be re -used as wall backfill. Imported wall backfill such as Gravel Borrow (Section 9.03.14 (1) of the 2020 WSDOT Standard Specifications) should be assumed for this project. The fill should be moisture conditioned to near its optimum moisture content, placed in loose, horizontal lifts less than about a foot in thickness, and systematically compacted to a dense and relatively unyielding condition. The adequacy of the compaction should be verified by PanGEO. If density tests will be performed, the test results should indicate at least 95 percent of the maximum dry density, as determined using test method ASTM D 1557. Within 5 feet of the wall, the backfill should be compacted to 90 percent of the maximum dry density. 6.4 CONCRETE SLAB -ON -GRADE The floor slabs for the proposed buildings may be constructed using conventional concrete slab - on -grade floor construction. The floor slabs should be supported on competent native soil or compacted structural fill. Any loose soils at the slab subgrade should be either recompacted to a dense condition or over -excavated to expose dense undisturbed native soils. Over -excavation should be replaced with compacted structural fill. Interior concrete slab -on -grade floors should be underlain by a capillary break consisting of at least of 4 inches of pea gravel or compacted 3/4-inch, clean crushed rock (less than 3 percent fines). The capillary break material should also have no more than 10 percent passing the No. 4 sieve and less than 5 percent by weight of the material passing the U.S. Standard No. 100 sieve. The capillary break should be placed on the subgrade that has been compacted to a dense and unyielding condition. A 10-mil polyethylene vapor barrier should also be placed directly below the slab. We also recommend that construction joints be incorporated into the floor slab to control cracking. 7.0 CONSTRUCTION CONSIDERATIONS 7.1 DEMOLITION & SITE PREPARATION We envisage site preparation for the proposed project includes demolishing the existing structures, stripping and clearing of surface vegetation, and excavations to the design subgrade. All footings and floor slabs of the existing buildings, as well as building debris and concrete rubble should be removed from the site prior to the start of excavations or grading. All stripped 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 13 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 surface materials should be properly disposed off -site or be "wasted" on site in non-structural landscaping areas. Following site clearing and excavations, the adequacy of the subgrade where foundations, slabs, or pavements are to be placed should be verified by a representative of PanGEO. The subgrade soil in the improvement areas, if recompacted and still yielding, should be over -excavated and replaced with compacted structural fill or CDF/lean-mix concrete. The test pits for this study were backfilled with the excavated soils. The backfill was tamped with the excavator bucket and the ground surface leveled. The backfill was not compacted to the requirements of structural fill. During construction of the project, the earthwork contractor should locate the test pits, remove the loose backfill and replace it with properly compacted structural fill. 7.2 MATERIAL REUSE In the context of this report, structural fill is defined as compacted fill placed under footings, concrete stairs and landings, and slabs, or other load -bearing areas. The contractor should be aware that the site soils are poorly graded and may be difficult to compact to the requirements of structural fill. As a result, the excavated site materials may not be suitable for use as structural backfill, particularly during periods of wet weather. If import structural fill is needed, it should consist of a well -graded granular material, such as WSDOT CSBC, Gravel Borrow or approved equivalent. Well -graded recycled concrete may also be considered as a source of structural fill. Use of recycled concrete as structural fill should be approved by the geotechnical engineer. The on -site soil can be used as general fill in the non-structural and landscaping areas. If use of the on -site soil is planned, the excavated soil should be stockpiled and protected with plastic sheeting to prevent softening from rainfall in the wet season. 7.3 TEMPORARY EXCAVATIONS As currently planned, excavations on the order of 10 feet are needed for the foundation construction. As such, we anticipate that unsupported slope cuts may be incorporated into the excavation design. All temporary excavations should be performed in accordance with Part N of WAC (Washington Administrative Code) 296-155. The contractor is responsible for maintaining safe excavation slopes and/or shoring. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 14 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 In general, vertical cuts should be limited to 4 feet in areas not close to the property lines. The vertical cuts should be limited to 2 feet along the property lines. Temporary excavations deeper than a total of 4 feet should be sloped, benched, or shored. Excavations more than 2 feet along property lines, will also need to be sloped or supported if sufficient space is not available to lay back the excavations without encroaching into neighboring properties. If temporary shoring is needed to support the excavations, PanGEO can provide shoring design recommendations if requested. For planning purposes, the temporary unsupported excavation may be sloped as steep as 1 H:1 V (Horizontal: Vertical). The cut slopes may also need to be flattened in the wet seasons and should be covered with plastic sheets. We also recommend that heavy construction equipment, building materials, excavated soil, and vehicular traffic should not be allowed within a distance equal to 1/3 the slope height from the top of any excavation. 7.4 STRUCTURAL FILL PLACEMENT AND COMPACTION Structural fill should be moisture conditioned to within about 3 percent of optimum moisture content, placed in loose, horizontal lifts less than 8 inches in thickness, and systematically compacted to a dense and relatively unyielding condition and to at least 95 percent of the maximum dry density, as determined using test method ASTM D 1557. Depending on the type of compaction equipment used and depending on the type of fill material, it may be necessary to decrease the thickness of each lift to achieve adequate compaction. PanGEO can provide additional recommendations regarding structural fill and compaction during construction. 7.5 PERMANENT CUT AND FILL SLOPES Based on the anticipated soil that will be exposed in the planned excavation, we recommend permanent cut and fill slopes be constructed no steeper than 2H:1V (Horizontal:Vertical). 7.6 EROSION AND DRAINAGE CONSIDERATIONS Surface runoff can be controlled during construction by careful grading practices. Typically, this includes the construction of shallow, up -grade perimeter ditches or low earthen berms to collect runoff and prevent water from entering the excavation. All collected water should be directed to a positive and permanent discharge system such as an approved City storm sewer. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 15 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 It should be noted that the site soils are prone to surficial erosion. Special care should be taken to avoid surface water on open cut excavations. As previously mentioned in Section 7.3, we recommend that the exposed temporary slopes be covered with plastic sheeting. Permanent control of surface water and roof runoff should be incorporated in the final grading design. In addition to these sources, irrigation and rainwater infiltrating into landscape and planter areas adjacent to paved areas or building walls should also be controlled. All collected runoff should be directed into conduits that carry the water away from the pavement or structure and into City storm drain systems or other appropriate outlets. Adequate surface gradients should be incorporated into the grading design such that surface runoff is directed away from structures. 7.7 WET EARTHWORK RECOMMENDATIONS General recommendations relative to earthwork performed in inclement weather or in wet conditions are presented below: • All surface of the foundation subgrade should be protected against inclement weather. It is the contractor's responsibility to protect the footing subgrade from disturbance. One option is to place a 2- to 3-inch-thick layer of lean -mix concrete on the footing subgrade as soon as the subgrade is exposed. • Earthwork should be performed in small areas to minimize subgrade exposure to wet weather. Excavation or the removal of unsuitable soil should be followed promptly by the placement and compaction of clean structural fill. The size and type of construction equipment used may have to be limited to prevent soil disturbance. • During wet weather, the allowable fines content of the structural fill should be reduced to no more than 5 percent by weight based on the portion passing 3/4-inch sieve. The fines should be non -plastic. • The ground surface within the construction area should be graded to promote run-off of surface water and to prevent the ponding of water. • Geotextile silt fences should be strategically located to control erosion and the movement of soil. Erosion control measures should be installed along all the property boundaries. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 16 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 • Excavation slopes and soils stockpiled on site should also be covered with plastic sheets. 8.0 ADDITIONAL SERVICES To confirm that our recommendations are properly incorporated into the design and construction of the proposed development, PanGEO should be retained to conduct a review of the final project plans and specifications, and to monitor the construction of geotechnical elements. Modifications to our recommendations presented in this report may be necessary, based on the actual conditions encountered during construction. 9.0 LIMITATIONS We have prepared this report for use by Jonathan Kurth and the project design team. Recommendations contained in this report are based on a site reconnaissance, review of pertinent subsurface information, and our understanding of the project. The study was performed using a mutually agreed -upon scope of work. Variations in soil conditions may exist between the explorations and the actual conditions underlying the site. The nature and extent of soil variations may not be evident until construction occurs. If any soil conditions are encountered at the site that are different from those described in this report, we should be notified immediately to review the applicability of our recommendations. Additionally, we should also be notified to review the applicability of our recommendations if there are any changes in the project scope. The scope of our work does not include services related to construction safety precautions. Our recommendations are not intended to direct the contractors' methods, techniques, sequences or procedures, except as specifically described in our report for consideration in design. Additionally, the scope of our work specifically excludes the assessment of environmental characteristics, particularly those involving hazardous substances. We are not mold consultants nor are our recommendations to be interpreted as being preventative of mold development. A mold specialist should be consulted for all mold -related issues. This report has been prepared for planning and design purposes for specific application to the proposed project in accordance with the generally accepted standards of local practice at the time this report was written. No warranty, express or implied, is made. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 17 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 This report may be used only by the client and for the purposes stated, within a reasonable time from its issuance. Land use, site conditions (both off and on -site), or other factors including advances in our understanding of applied science, may change over time and could materially affect our findings. Therefore, this report should not be relied upon after 24 months from its issuance. PanGEO should be notified if the project is delayed by more than 24 months from the date of this report so that we may review the applicability of our conclusions considering the time lapse. It is the client's responsibility to see that all parties to this project, including the designer, contractor, subcontractors, etc., are made aware of this report in its entirety. The use of information contained in this report for bidding purposes should be done at the contractor's option and risk. Any party other than the client who wishes to use this report shall notify PanGEO of such intended use and for permission to copy this report. Based on the intended use of the report, PanGEO may require that additional work be performed and that an updated report be reissued. Noncompliance with any of these requirements will release PanGEO from any liability resulting from the use this report. We appreciate the opportunity to be of service. Sincerely, Spenser P. Scott, L.G. Staff Geologist Michael H. Xue, P.E. Principal Geotechnical Engineer 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 18 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 10.0 REFERENCES ASTM D2488-17, Standard Practice for Description and Identification of Soils (Visual -Manual Procedures), ASTM International, West Conshohocken, PA, 2017, www.astm.org. International Code Council, 2018, International Building Code (IBC). Booth, D. B., Cox, B. F., Troost, K. G., Shimel, S. A., 2004, Composite Geologic Map of the Sno-King Area, Central Puget Lowland, Washington: Seattle -Area Geologic Mapping Project, University of Washington, and the United States Geological Survey, scale 1:24000. Washington Administrative Code (WAC), 2016, Chapter 296-155 - Safety Standards for Construction Work, Part N - Excavation, Trenching, and Shoring, Olympia, Washington. Washington State Department of Transportation, 2020, Standard Specifications for Road, Bridge and Municipal Construction, M 41-10, Washington State Department of Transportation. Zipper Geo Associates, LLC., February 2016, Geotechnical Engineering Report, Proposed Home Street Bank, 614 & 616 5' Avenue South, Edmonds, Consultant report prepared for Home Street Bank. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 19 PanGEO, Inc. :: z zoom sl SW z a � Y R R L E 7" PUGET O cl i SOUND C Daley St rvrc CoNor 1 A� 3' Rid" Pbyt"a s/r Park Craq* (Edmonds W r n St o rn Dayton St Q f > W Pk St Yo N Park Alder St M n dnwrd> > r, LO Shel/, walnut St Nbt sh y v �s� i wooin dmonds Q ?� Wa r rn t3rk C, L 216th St SW to, Project Site 21eth s1 sw a2201h St SW40 Q > Q L m L G G m a o ' a� L = ; 0 2261h St SW - o 0 22eth St SW t\SW Geer Creek �s9 0"r Park %se ve Edmonds' Esperance z3zro s1 Wact,,ir .'r? rr Hrkman Park Woodway %$Ila*" � 1 Marysville n,, Pon Hael,ck l—dn le n Whidbey '_. N., r 1 sland Everett wmorr Gole F'. 0--d r�r . Xf �y„ 1. NORTH r� Redm1 nd ?- A Not to Scale z st Sw R Base Map: ESRI Topographic Proposed Townhomes VICINITY MAP RnGEO614 & 616 5thA�/ve S r N C o R P o R A.rE D Edmonds, V ,1A Project No. 21-372 Figure No. 1 t-j()TE: LE,;-J,AL DESCF-IF71--�Dh ;-j-'--/EFL."`-'P'-. ll,jTc-i FIC"HT CIF 1,1VA i' 171F 47H '.-TREE-T Legend: N A CONDO 4CIF-1 P HA L T P4PK'--'1E'11'11' T'%,',IN. A CONDOMINIt p-.4 517 47H AVE S 131.37 ONE B,ALLARD LLC/ 610 5TH AVE S WAL� ............... P ONE S70BUILDING:.S... 614 5TAVE:::•: FF ..84-.05: ........... -1 z z z z� �I Building A z z .......... . I M .7z82.22-' TP �-ON*--)N IE=80,42. " 4 CONC zE---jE=B0.62' ... .......... ': BKH-5281 ....... .. .......... ASPHALT PA-RKi ........... ........... 50 FT P - 31; 11 z z B-2 . z ....... ....... ...... �W z z M PIT-3 z ................. Building B 9 tp 2 STi--)PY CONC, BI- 16 5TH A� FFE=85,26' FFE=76.59' --z<;'44H RIM = 69,68 CHAPARCa B: Ifj 6;5, 08 Approximate Test Pit Location Approximate Parcel Boundary PanGEO, Inc., August 2021 F-1 - ----- Previous Test boring Location Zipper Geo Associates, October 2015 F-1 Approximate Proposed Building Approximate Observed Monitoring Well Approx. Scale: 1 inch = 20 fee - ACft 11 P Base map modified from ALTA/ACSM Land Title Survey by PACE Engineering, dated July 17, 2015 APPENDIX A SUMMARY TEST PIT LOGS RELATIVE DENSITY / CONSISTENCY SAND / GRAVEL SILT / CLAY SPT Approx. Relative SPT Approx. Undrained Shear DensityN-values Density (%) Consistency N-values Strength (psf) Very Loose <4 <15 Very Soft <2 <250 Loose 4 to 10 15 - 35 Soft 2 to 4 250 - 500 Med. Dense 10 to 30 35 - 65 Med. Stiff 4 to 8 500.1000 Dense 30 to 50 65 - 85 Stiff 8 to 15 1000 - 2000 Very Dense >50 85.100 Very Stiff 15 to 30 2000 - 4000 Hard >30 >4000 UNIFIED SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONS GROUP DESCRIPTIONS •�' GW: Well -graded GRAVEL Gravel GRAVEL (<5% fines) .. .....: ...................................................... 50% or more of the coarse o ° GP : : Poorly -graded GRAVEL fraction retained on the #4 sieve. Use dual symbols leg. o ° GM ...................................................... Silty GRAVEL GP -GM) for 5% to 12% fines. GRAVEL (>12% fines) •••••••••••••••••••••••••••••• GC : ........................••• Clayey GRAVEL ...................................................................... .......................................................... SW: Well -graded SAND Sand SAND (<5 /° fines) '' 50% or more of the coarse ....................................:....> % SP Poorly -graded raded SAND y-g fraction passing the #4 sieve. Use duals leg. SP-SM ) ; ":r" ............................................................ SM: Silt SAND y %fin for s%to12%fines.g SAND (>1 2% fines) , ••••••••••••••••••••••••••••••••••••••••••••••••••••••••• SC : Clayey SAND ...................................................................... ............................................................. ML : SILT Liquid Limit < 50 ............................................................ CL : Lean CLAY Silt and Clay ............................................................ OL : Organic SILT or CLAY == — 50%or more passing #200 sieve :.................................. :...................................................... MH : Elastic SILT Liquid Limit > 50 CH Fat CLAY OH Organic SILT or CLAY — , ........................... ...................................... Highly Organic Soils ............................................................ PT : PEAT Notes: 1. Soil exploration to s contain material descriptions based on visual observation and field tests using a system modified from the Uniform Soil Classification System (USCS). Where necessary laboratory tests have been conducted (as noted in the "Other Tests" column), unit descriptions may include a classification. Please refer to the discussions in the report text for a more complete description of the subsurface conditions. 2. The graphic symbols given above are not inclusive of all symbols that may appear on the borehole to s. Other symbols may be used where field observations indicated mixed soil constituents or dual constituent materials. DESCRIPTIONS OF SOIL STRUCTURES Layered: Units of material distinguished by color and/or Fissured: Breaks along defined planes composition from material units above and below Slickensided: Fracture planes that are polished or glossy Laminated: Layers of soil typically 0.05 to 1 mm thick, max.1 cm Blocky: Angular soil lumps that resist breakdown Lens: Layer of soil that pinches out laterally Disrupted: Soil that is broken and mixed Interlayered: Alternating layers of differing soil material Scattered: Less than one per foot Pocket: Erratic, discontinuous deposit of limited extent Numerous: More than one per foot Homogeneous: Soil with uniform color and composition throughout BCN: Angle between bedding plane and a plane normal to core axis COMPONENT DEFINITIONS COMPONENT SIZE / SIEVE RANGE COMPONENT SIZE / SIEVE RANGE Boulder: > 12 inches Sand Cobbles: 3 to 12 inches Coarse Sand: #4 to #10 sieve (4.5 to 2.0 mm) Gravel Medium Sand: #10 to #40 sieve (2.0 to 0.42 mm) Coarse Gravel: 3 to 3/4 inches Fine Sand: #40 to #200 sieve (0.42 to 0.074 mm) Fine Gravel: 3/4 inches to #4 sieve Silt 0.074 to 0.002 mm Clay <0.002 mm TEST SYMBOLS for In Situ and Laboratory Tests listed in "Other Tests" column. ATT AtterbergLimit Test Comp Compaction Tests Con Consolidation DD Dry Density DS Direct Shear %F Fines Content GS Grain Size Perm Permeability PP Pocket Penetrometer R R-value SG Specific Gravity TV Torvane TXC Triaxial Compression UCC Unconfined Compression SYMBOLS Sample/In Situ test types and intervals 2-inch OD Split Spoon, SPT (140-lb. hammer, 30" drop) H3.25-inch OD Spilt Spoon (300-lb hammer, 30" drop) Non-standard penetration test (see boring log for details) Thin wall (Shelby) tube Grab Rock core ® Vane Shear MONITORING WELL SZ Groundwater Level at time of drilling (ATD) 1 Static Groundwater Level Cement / Concrete Seal Bentonite grout / seal Silica sand backfll Slotted tip Slough Bottom of Boring MOISTURE CONTENT Dry Dusty, dry to the touch Moist Damp but no visible water Wet Visible free water GPmE® Terms and Symbols for I IN C 0 R P 0 R A T E D Boring and Test Pit Logs Figure A-1 Phone: 206.262.0370 Test Pit No. PIT-1 Approximate ground surface elevation (NAVD88): 74 feet Coordinates (Washington State Plane - North): 297653, 1260821 Death ft Material Description Light vegetation above loose to medium dense, gray -brown, silty fine SAND 0-2 with gravel; trace plastic, asphalt, and brick debris, some angular rock, trace ----------------------- rootlets; disrupted texture, non -plastic, dry to moist ---------------------------------------------------------------------------------------------------------------------------- Medium dense, light brown, poorly graded fine SAND; trace silt, trace angular 2 — 4.5 rock, trace roots, burnt wood fragments; iron -oxide staining; disrupted texture non -plastic, moist [Fill] Dense, gray -brown, poorly graded fine SAND; trace gravel, trace silt; non- 4.5 — 9 plastic, moist [Qpf — Pre -Fraser Deposits] - Becomes dense, gray, poorly graded fine SAND from 7 to 9 feet o• JI -Av_ _ - � � l _ yy 1 ti_ s eve Photo PIT-1 (left): Shows PIT-1 at approximately 5.5 feet in depth before testing Photo PIT-1 (right): Shows spoils from PIT-1 at approximately 9 feet in depth after testing PIT-1 was terminated approximately 5.5 feet below grade for infiltration testing. After the test, PIT-1 was over -excavated to 9 feet in depth to check for shallow groundwater or groundwater mounding. No groundwater seepage was encountered during explorations. 21-372 Test Pit Logs Figure A-2 PanGEO, Inc. Test Pit No. PIT-2 Approximate ground surface elevation (NAVD88): 73.5 feet Coordinates (Washington State Plane - North): 297574, 1260814 Death ftj Material Description Light vegetation above loose to medium dense, gray -brown, silty fine SAND 0 — 2.5 with gravel; trace asphalt debris, some angular rock, trace rootlets; disrupted ----------------------- texture, non -plastic, dry to moist ---------------------------------------------------------------------------------------------------------------------------- Medium dense, light brown, poorly graded fine SAND; trace silt, trace angular 2.5-4 rock, some roots, burnt wood fragments; trace iron -oxide staining; disrupted texture non -plastic, moist [Fill] Dense, gray -brown, poorly graded fine SAND; trace gravel, trace silt; non- 4-9 plastic, moist [Qpf — Pre -Fraser Deposits] - Becomes dense, gray, poorly graded fine SAND from 7 to 9 feet ..!t r a. V.. W Photo PIT-2 (left): Shows PIT-2 at approximately 6 feet in depth before testing Photo PIT-2 (right): Shows spoils from PIT-2 at approximately 9 feet in depth after testing PIT-2 was terminated approximately 6 feet below grade for infiltration testing. After the test, PIT-2 was over -excavated to 9 feet in depth to check for shallow groundwater or groundwater mounding. No groundwater seepage was encountered during explorations. 21-372 Test Pit Logs Figure A-3 PanGEO, Inc. Test Pit No. PIT-3 Approximate ground surface elevation (NAVD88): 83.5 feet Coordinates (Washington State Plane - North): 297594, 1260886 De th ft Material Description Approximate 2-inch asphalt overlay above loose to medium dense, gray -brown, 0-7 ----------------------- slightly silty SAND with gravel and cobble; trace wood debris; non -plastic, moist ---------------------------------------------------------------------------------------------------------------------------- Loose, dark brown to black, slightly organic silty SAND; trace brick debris, wood 7 — 8.5 debris, some concrete and construction debris; disrupted texture; non -plastic, moist ----------------------- ---------------------------------------------------------------------------------------------------------------------------- Medium dense, light brown to red -brown, poorly graded fine SAND; trace silt, 8.5 — 10 burnt wood fragments; trace iron -oxide staining; disrupted texture non -plastic, moist [Fill] Dense, gray -brown, poorly graded fine to medium SAND; trace gravel, trace silt, 10-15 trace iron -oxide staining; non -plastic, moist [Qpf— Pre -Fraser Deposits] tip " 1 ` � _ '7 • . Ate. �,� t}K' : � �' ; AL Photo PIT-3 (left): Shows PIT-3 at approximately 12 feet in depth before testing Photo PIT-3 (right): Shows spoils from PIT-3 at approximately 10 feet in depth after testing PIT-3 was terminated approximately 6 feet below grade for infiltration testing. After the test, PIT-3 was over -excavated to 15 feet in depth to check for shallow groundwater or groundwater mounding. No groundwater seepage was encountered during explorations. 21-372 Test Pit Logs Figure A-4 PanGEO, Inc. Test Pit No. TP-1 Approximate ground surface elevation (NAVD88): 74 feet Coordinates (Washington State Plane - North): 297615, 1260818 Death ftj Material Description Light vegetation and gravel above loose to medium dense, gray -brown, silty 0-2 fine SAND with gravel; trace concrete debris, some angular rock, trace rootlets; ----------------------- disrupted texture, non -plastic, dry to moist ---------------------------------------------------------------------------------------------------------------------------- Medium dense, light brown, poorly graded fine SAND; trace silt, trace angular 2-4 rock, trace roots, burnt wood fragments; iron -oxide staining; disrupted texture non -plastic, moist [Fill] Dense, gray -brown to gray, poorly graded fine to medium SAND; trace gravel, trace silt; non -plastic, moist 4 —13 • Top approximate 2 feet weathered to red -brown w/ iron -oxide staining • Cobble layer from approximately 11 to 12 feet below ground surface [Qpf — Pre -Fraser Deposits] i ! ,t 1.4 1 � l v Photo TP-1 (left): Shows TP-1 at approximately 13 feet in depth Photo TP-1 (right): Shows spoils from TP-1 at approximately 10 feet in depth TP-1 was terminated approximately 13 feet below grade. No groundwater seepage was encountered during explorations. 21-372 Test Pit Logs Figure A-5 PanGEO, Inc. Test Pit No. TP-2 Approximate ground surface elevation (NAVD88): 84 feet Coordinates (Washington State Plane - North): 297617, 1260919 Death ftj Material Description Approximate 2-inch asphalt overlay above loose to medium dense, gray -brown, 0-8 ----------------------- slightly silty SAND with gravel and cobble; trace wood debris; non -plastic, moist ---------------------------------------------------------------------------------------------------------------------------- Loose, dark brown to black, slightly organic silty SAND; trace brick debris, wood 8-9 debris, some concrete and construction debris; disrupted texture; non -plastic, moist [Fill] Medium dense, light brown to red -brown, poorly graded fine SAND; trace silt, 9-11 burnt wood fragments; trace iron -oxide staining; disrupted texture non -plastic, moist [Qpf — Pre -Fraser Deposits] • r '• i Photo TP-2 (left): Shows TP-2 at approximately 11 feet in depth Photo TP-2 (right): Shows spoils from TP-2 at approximately 10 feet in depth TP-2 was terminated approximately 11 feet below grade. No groundwater seepage was encountered during explorations. 21-372 Test Pit Logs Figure A-6 PanGEO, Inc. Test Pit No. TP-3 Approximate ground surface elevation (NAVD88): 83 feet Coordinates (Washington State Plane - North): 297651, 1260854 PeiqthftjMaterial Description Approximate 2-inch asphalt overlay above loose to medium dense, gray -brown, 0-7 slightly silty SAND with gravel and cobble, layers of gray, sandy SILT; metal ---------------------------- debris, wood debris, large fragments of concrete slab; non -plastic, moist ------------------------------------------------------------------------------------------------------------------------------------------------------ Loose, dark brown to black, slightly organic silty SAND; metal debris, wood 7-8 debris, some concrete and construction debris; disrupted texture; non -plastic, moist [Fill] Medium dense, light brown to red -brown, poorly graded fine SAND; trace silt, 8 —11 burnt wood fragments; trace iron -oxide staining; disrupted texture non -plastic, moist [Qpf — Pre -Fraser Deposits] f 4 Photo TP-3 (left): Shows TP-3 at approximately 10 feet in depth Photo TP-3 (right): Shows spoils from TP-3 at approximately 10 feet in depth TP-3 was terminated approximately 10 feet below grade. No groundwater seepage was encountered during explorations. Date of Test Pit Excavations: August 4 and August 6, 2021 Excavations Logged by: S. Scott and J. Manke 21-372 Test Pit Logs Figure A-7 PanGEO, Inc. APPENDIX B PREVIOUS TEST BORING LOGS AND LABORATORY RESULTS 10 El SB-1 a (10 °°TSB-2� B-3 `n 1 1 _ O oaf °°" po cl IB-rJ u° low=.11�:>!11 ao 0 od o pO LEGEND B-1 BORING NUMBER AND APPROXIMATE LOCATION 30 0 15 30 APPROXIMTATE SCALE IN FEET w 0q Fi.. ' 'd o BASE DRAWING PROVIDED BY HOMESTREET BANK, UNDATED. Boring Location: See Figure 1, Site and Exploration Plan Drilling Companv: Environmental Bore Hole Dia.: 8" Top Elevation: - Drilling Method: Hollow Stem Auger Hammer Type: Auto B-1 Date Drilled: 10/19/2015 Drill Rig: Truck Logged by.. TAJ aThe ° SOIL DESCRIPTION /^ 9 vJ E J Q n (6 0 C PENETRATION RESISTANCE (blows/foot) o U ° m 0) W stratification lines represent the approximate boundaries between soil types. The transition may be gradual. Refer to report text and appendices for additional information. Standard Penetration Test Hammer Weight and Drop: 0 20 40 60 -0 2 inches asphalt over about 2 inches Crushed Surfacing Base Course over gravelly SAND with trace to some silt —i +✓-+tip+I-++ IIIIIIIII I I -I I l l-I-I IIIIIIIII I I��+�� I... IIIIIIII- Loose, wet, gray -brown, gravelly SAND with some silt Fill ( ) S-1 18 I IIIIIIIII +t��th1�� 1.J 1 1Ii rr IIIIIIIII ��I I I I -I -I IIIIII --, rrl-i-I IIIIIIII -1-4-4-4�Probable 1 1 1 1 1 II1111� 10 -5 - IIIIII IIIIIIII, I 1I- __ 4 _ __ .._. _I I __ ... Loose, wet, gray, SAND with silt and gravel (Probable Fill) T S-2 11 181, 10 GSA Loose, moist, gray, gravelly SAND with trace to some silt Probable Filo__________________________________ 1.o9Se,maiSi.dlsbravyn.�aodkSll_T�E�Ii�I�s9il�-------- S3 18" � I� I I -rrrrrrr IIIIIII I I I I I I I I I rrr�rl��� 111ii1 I I I I I ��� 11 7 Loose, moist, orange -brown, SAND with gravel, some silt 111 c L L L1_I I IIII 111111I11 I_L_I hill IIIIIIII- T S-4 1151, 9 GSA LL I IIIIIIIII I I I I I I I I I I I S-5 18 I + IIII I I I I I IIIIIIIII I I I I I I IIIIIIII 8 III IIIII IIIIIIIII IIIIIIIII IIIIIIIII IIIIIIII IIIII '..- •15 IIIIIIIII IIIIIIIII IIIIII -------------------------------------------- Dense, moist, light brown, SAND with some silt, some gravel S-6 I 15" IIIIII 1 1 1 1 I I I 1 j 1 34 IIIIII �♦-�FFI IIIIIIIII III II '....� I I I 1-1 - IIIIII IIIII -111� .... IIIIIIII- Dense, wet, brown, gravelly SAND with silt Boring completed at approximately 24 feet. • 25 No groundwater observed ATD. SAMPLE LEGEND GROUNDWATER LEGEND I2-inch O.D. split spoon sample ❑ Clean Sand 3-inch I.D. Shelby tube sample ® Bentonite Grout/Concrete ® Screened Casing TESTING KEY ❑ Blank Casing GSA = Grain Size Analysis VGroundwater level at time of drilling (ATD) or 20OW = 200 Wash Analysis ti on date of Consol. = Consolidation Test N measurement. Att. = Atterberq Limits T- T-F L_L L.LLI I ._.I_. I I _J__ IIIIIII IIIIII IIIIIIII' -1 I I IIIIII IIIIIIII- S-7 18" II q6 I IIIII I IIIII 0 % Fines (<0.075 mm) O % Water (Moisture) Content Plastic Limit Liquid Limit Natural Water Content Homestreet Bank 614 & 616 5th Ave S. Edmonds, WA Date: - Project No.: 1527.01 Zipper Geo Associates BORING 19023 36th Ave. W, Suite D LOG; B_ 1 Lynnwood, WA Page 1 of 1 See Figure 1, Site and Exploration Plan 10/19/2015 SOIL DESCRIPTION Z The stratification lines represent the approximate boundaries a) between soil types. The transition may be gradual. Refer to report text and appendices for additional information. -0 2 - 2.5 inches asphalt over about 2.5 inches CSBC over dark brown, moist, silty SAND Drilling Company: Environmental Bore Hole Dia.: 8" Drilling Method: Hollow Stem Auger Hammer Type: Auto B-2 Drill Rig: Truck Logged by.. TAJ PENETRATION RESISTANCE (blows/foot) U) Standard Penetration Test J o c Hammer Weight and Drop: U F= <0 o o H U 0 20 40 60 Medium dense, moist, brown -gray, SAND with silt and gravel S-1 151• I (Possible Fill) - 5 Medium dense, moist, brown, SAND with silt and gravel T (Possible Fillj._Blowcounts ov_erstated_due to gravel- _ _ _ _ _ _ _ _ S-2 I 181, Very dense, moist, brown, sandy GRAVEL with some silt and cobbles (Possible Fill) T Loose, moist, brown, SAND with some silt to with silt, trace to S-3 I 3" some gravel T Loose, moist, brown, SAND with some silt to with silt, trace to S-4 I 19 some gravel (2 inches wood at 11 feet; root?) (Wood in cuttings) Dense, moist, gray, SAND with silt and gravel to silty SAND s-5 18^ with gravel (Glacial Till -like) •15 Dense, moist, gray, interbedded fine SAND with trace silt and S-6 I 18" silty SAND with some gravel Boring completed at approximately 19 feet. No groundwater observed ATD. • 25 ' SAMPLE LEGEND GROUNDWATER LEGEND I2-inch O.D. split spoon sample ❑ Clean Sand 3-inch I.D. Shelby tube sample ® Bentonite Grout/Concrete ® Screened Casing TESTING KEY ❑ Blank Casing GSA = Grain Size Analysis VGroundwater level at time of drilling (ATD) or 20OW = 200 Wash Analysis ti on date of Consol. = Consolidation Test N measurement. Att. = Atterberq Limits 12 1 GSA 14 _ 9 JJJJ� I I I I I I I I I I 1-4 -4 -4 -4 33 Illli II i 41 (IIIII (IIIII III illlillll Iilill IIIIIIII IIIIIIII 1 l i lllll!' iIIlI11 till II11 i r FF jlll --i LLL1 ------------ Illlili 111 Illll' 0 % Fines (<0.075 mm) O % Water (Moisture) Content Plastic Limit Liquid Limit Natural Water Content Homestreet Bank 614 & 616 5th Ave S. Edmonds, WA Date: - Project No.: 1527.01 Zipper Geo Associates BORING 19023 36th Ave. W, Suite D LOG; B_ 2 Lynnwood, WA Page 1 of 1 See Figure 1, Site and Exploration Plan 10/19/2015 SOIL DESCRIPTION Z The stratification lines represent the approximate boundaries a) between soil types. The transition may be gradual. Refer to report text and appendices for additional information. -0 2.5 inches asphalt over about 2.5 inches CSBC over brown, moist, SAND with silt some gravel Drilling Company: Environmental Bore Hole Dia.: 8" Drilling Method: Hollow Stem Auger Hammer Type: Auto B-3 Drill Rig: Truck Logged by.. TAJ PENETRATION RESISTANCE (blows/foot) U) Standard Penetration Test J o c Hammer Weight and Drop: U F= <0 o o H U 0 20 40 60 Loose, moist, gray, SAND with silt, trace gravel (Probable Fill) s 1 I 18" -5 1 Medium dense, moist, gray, silty SAND with trace gravel s 2 16" (Probable Fill) Loose, damp to moist, gray, SAND with trace to some silt and T gravel (Probable Fill) _ _ _ _ _ _ _ _ _ _ s-s 18" I Loose, damp to moist, dark brown, silty SAND (Relic Topsoil?) --------------------------------------------- Medium dense, damp to moist, orange -brown grading to yellow -gray, SAND with trace to some silt trace gravel S-4 T 181, Medium dense, damp to moist, gray, fine SAND with silt S-5 181, •15 -------------------------------------------- Very dense, moist, gray, sandy GRAVEL with some silt S-6 15" Boring completed at approximately 19 feet. No groundwater observed ATD. • 25 ' SAMPLE LEGEND GROUNDWATER LEGEND I2-inch O.D. split spoon sample ❑ Clean Sand 3-inch I.D. Shelby tube sample ® Bentonite Grout/Concrete ® Screened Casing TESTING KEY ❑ Blank Casing GSA = Grain Size Analysis VGroundwater level at time of drilling (ATD) or 20OW = 200 Wash Analysis ti on date of Consol. = Consolidation Test N measurement. Att. = Atterberq Limits 50/5" IIIIII IIIIII IIIII -..... illllll - IIIIII (IIIIIII- (IIIIIII I II I llll'�- IIIIIII till (III I r F_F (LILII - -L i IIIIIII IIIIII Illll' 0 % Fines (<0.075 mm) O % Water (Moisture) Content Plastic Limit Liquid Limit Natural Water Content Homestreet Bank 614 & 616 5th Ave S. Edmonds, WA Date: - Project No.: 1527.01 Zipper Geo Associates BORING 19023 36th Ave. W, Suite D LOG; B-3 Lynnwood, WA Page 1 of 1 Boring Location: See Figure 1, Site and Exploration Plan Drilling Companv: Environmental Bore Hole Dia.: 8" Top Elevation: - Drilling Method: Hollow Stem Auger Hammer Type: Auto B-4 Date Drilled: 10/19/2015 Drill Rig: Truck Logged by.. TAJ SOIL DESCRIPTION PENETRATION RESISTANCE (blows/foot) /^ 9 vJ E J (6 0) Standard Penetration Test aThe stratification lines represent the approximate boundaries Hammer Weight and Drop: o U ° between soil types. The transition may be gradual. Refer to Q o W report text and appendices for additional information. n ° m C0 0 20 40 60 -0 _Vyeed�LaysidarkJ)rQvyrl dBDV_tomaiat. siUy-S8UD�IQpwJ Encountered 1/2-inch diameter PVC pipe at 14 inches 1 IIIIIIIII IIIIIIIII IIIIIIII- Medium dense, damp to moist, brown grading to orange- S-1 18 I IIIIIIIII IIIIIIIII IIIIIIII 12 GSA brown, SAND with some silt and 9ravel ! 11 IIIIIIIII _ IIIIIIII -5 Loose, damp to moist, yellow -brown, SAND with silt to SAND S-2 18 with some silt Medium dense, moist, light brown, silty fine SAND S-3 Dense, moist, brown -gray, SAND with some silt S-4 18" Boring completed at approximately 11.5 feet No groundwater observed ATD. •15 • 25 ' SAMPLE LEGEND GROUNDWATER LEGEND I2-inch O.D. split spoon sample ❑ Clean Sand 3-inch I.D. Shelby tube sample ® Bentonite Grout/Concrete ® Screened Casing TESTING KEY ❑ Blank Casing GSA = Grain Size Analysis V Groundwater level at time of drilling (ATD) or 20OW = 200 Wash Analysis ti on date of Consol. = Consolidation Test N measurement. Att. = Atterberq Limits 38 T IIIIII T TI I I i l IIIIIIIII 11 IIIIIIII- LLL11 JL LIII LLLJLI-I-I J JJJJ� I I I 1 1 1 I I I I I I I I I I I I I I IIIIIIIII I I I I I I IIIIIIIII I I I I I I IIIIIIII- IIIIIIIII tt�ti-�FF� IIIIIIIII FFI I I -I -I -I I IIIIIIII- 1�11���-I - - - - 7 7 F . I i_I_I 11T_ Illllll -I IIIIII IIIIII '..- IIIIIIIII - IIIIII IIIIIIII- �Illll I it I FI FJ L _ L..L L I I . _.!..._. IIIIII IIIIII IIIIIIII' 0 % Fines (<0.075 mm) O % Water (Moisture) Content Plastic Limit Liquid Limit Natural Water Content Homestreet Bank 614 & 616 5th Ave S. Edmonds, WA Date: - Project No.: 1527.01 Zipper Geo Associates BORING 19023 36th Ave. W, Suite D LOG; B_ 4 Lynnwood, WA Page 1 of 1 See Figure 1, Site and Exploration Plan 10/19/2015 SOIL DESCRIPTION Z The stratification lines represent the approximate boundaries a) between soil types. The transition may be gradual. Refer to report text and appendices for additional information. -0 JYeeds_aysi Ioospa, soaisL dk.brawrr silty SAND 4Zap3oi - - - - Medium dense, damp, orange -brown, fine SAND with silt to silty fine SAND with trace gravel 5 Medium dense, damp to moist, orange -brown and gray, fine SAND with silt to silty fine SAND •15 Drilling Company: Environmental Bore Hole Dia.: 8" Drilling Method: Hollow Stem Auger Hammer Type: Auto B-5 Drill Rig: Truck Logged by.. TAJ PENETRATION RESISTANCE (blows/foot) U) Standard Penetration Test J o c Hammer Weight and Drop: U F= <0 o o H U 0 20 40 60 Medium dense, moist, gray, SAND with silt --------------------------------------- Very dense, moist, gray, sandy GRAVEL, with some silt s-s 1e Boring completed at approximately 11.5 feet No groundwater observed ATD. • 25 ' SAMPLE LEGEND GROUNDWATER LEGEND I2-inch O.D. split spoon sample ❑ Clean Sand 3-inch I.D. Shelby tube sample ® Bentonite Grout/Concrete ® Screened Casing TESTING KEY ❑ Blank Casing GSA = Grain Size Analysis V Groundwater level at time of drilling (ATD) or 20OW = 200 Wash Analysis ti on date of Consol. = Consolidation Test N measurement. Att. = Atterberq Limits 12 21 51 illll�llI lilt hill llilll l ililllll �Illll I l i illjll till 111 i r FF 111 --i LLLI I ._.i_. Illlili 111 Illll' 0 % Fines (<0.075 mm) O % Water (Moisture) Content Plastic Limit Liquid Limit Natural Water Content Homestreet Bank 614 & 616 5th Ave S. Edmonds, WA Date: - Project No.: 1527.01 Zipper Geo Associates BORING 19023 36th Ave. W, Suite D LOG; B'.ri Lynnwood, WA Page 1 of 1 GRAIN SIZE ANALYSIS Test Results Summary ASTM D 422 100 90 = 80 W ?� 70 In W 60 W Z 50 Z W U W 40 W a 30 20 10 0 1000.000 100.000 10.000 1.000 0.100 0.010 0.001 PARTICLE SIZE IN MILLIMETERS BOULDERS COBBLES Coarse Fine Coarse Medium Fine Silt Clay GRAVEL SAND FINE GRAINED Comments: Exploration Sample Depth (feet) Moisture (%) Fines (%) Description B-1 S-2 5 - 6.5 ft. 9.9 26.0 SAND with silt and gravel Project No.: 1527.01 Project Name: Zipper Geo Associates, LLC Geotechnical and Environmental Consultants Date of Testing: 10/21/2015 Edmonds HomeStreet Bank GRAIN SIZE ANALYSIS Test Results Summary ASTM D 422 100 90 = 80 W ?� 70 In W 60 W Z 50 Z W U W 40 W a 30 20 10 0 1000.000 100.000 10.000 1.000 0.100 0.010 0.001 PARTICLE SIZE IN MILLIMETERS BOULDERS COBBLES Coarse Fine Coarse Medium Fine Silt Clay GRAVEL SAND FINE GRAINED Comments: Exploration Sample Depth (feet) Moisture (%) Fines (%) Description B-1 S-4 10 - 11.5 ft. 6.1 7.4 SAND with gravel, some silt Project No.: 1527.01 Project Name: Zipper Geo Associates, LLC Geotechnical and Environmental Consultants Date of Testing: 10/21/2015 Edmonds HomeStreet Bank GRAIN SIZE ANALYSIS Test Results Summary ASTM D 422 100 90 = 80 W ?� 70 In W 60 W Z 50 Z W U W 40 W a 30 20 10 0 1000.000 100.000 10.000 1.000 0.100 0.010 0.001 PARTICLE SIZE IN MILLIMETERS BOULDERS COBBLES Coarse Fine Coarse Medium Fine Silt Clay GRAVEL SAND FINE GRAINED Comments: Exploration Sample Depth (feet) Moisture (%) Fines (%) Description B-2 S-1 2.5 - 4 ft. 8.2 21.7 SAND with silt and gravel Project No.: 1527.01 Project Name: Zipper Geo Associates, LLC Geotechnical and Environmental Consultants Date of Testing: 10/21/2015 Edmonds HomeStreet Bank GRAIN SIZE ANALYSIS Test Results Summary ASTM D 422 100 90 = 80 W ?� 70 In W 60 W Z 50 Z W U W 40 W a 30 20 10 0 1000.000 100.000 10.000 1.000 0.100 0.010 0.001 PARTICLE SIZE IN MILLIMETERS BOULDERS COBBLES Coarse Fine Coarse Medium Fine Silt Clay GRAVEL SAND FINE GRAINED Comments: Exploration Sample Depth (feet) Moisture (%) Fines (%) Description B-4 S-1 2.5 - 4 ft. 6.6 12.0 SAND with some silt and gravel Project No.: 1527.01 Project Name: Zipper Geo Associates, LLC Geotechnical and Environmental Consultants Date of Testing: 10/21/2015 Edmonds HomeStreet Bank PanGEO C O R P O R A T E D Geotechnical & Earthquake Engineering Consultants August 23, 2021 Project No. 21-372.100 Mr. Jonathan Kurth 557 Roy St, Suite 125 Seattle, WA 98109 Subject: Infiltration Assessment Proposed Townhomes 614 & 616 — 511 Avenue South, Edmonds, Washington Dear Mr. Kurth: As requested, PanGEO, Inc. completed an infiltration assessment of the site soils to assist the project team with the drainage design at the above referenced property. Our service consisted of excavating six test pits, performing three Small Pilot Infiltration Tests (PIT), and preparing this summary report. In summary, three small pilot infiltration tests completed at the site of the site at a depth of about 5.5 feet, 6 feet, and 12 feet yielded long-term infiltration rates of approximately 1.2, 0.8, and 1.8 inches per hour, respectively. We appreciate the opportunity to be of service. Please call if you have any questions. Sincerely, Michael H. Xue, P.E. Principal Geotechnical Engineer 3213 Eastlake Avenue E, Ste B Seattle, WA 98102 Tel (206) 262-0370 Fax (206) 262-0374 TABLE OF CONTENTS 1.0 INTRODUCTION................................................................................................................... 1 2.0 SITE AND PROJECT DESCRIPTION............................................................................... 1 3.0 SUBSURFACE EXPLORATIONS.......................................................................................1 4.0 SUBSURFACE CONDITIONS............................................................................................. 2 4.1 SITE GEOLOGY....................................................................................................................... 2 4.2 SOIL CONDITIONS................................................................................................................... 2 4.3 GROUNDWATER..................................................................................................................... 3 5.0 INFILTRATION TESTING AND RECOMMENDATIONS ............................................ 4 5.1 TEST METHOD........................................................................................................................ 4 5.2 CORRECTION FACTORS.......................................................................................................... 4 5.3 LONG TERM INFILTRATION RATE FOR DESIGN....................................................................... 5 5.4 CONSTRUCTION CONSIDERATIONS......................................................................................... 5 6.0 LIMITATIONS....................................................................................................................... 6 7.0 LIST OF REFERENCES....................................................................................................... 9 LIST OF ATTACHMENTS Figure 1 Vicinity Map Figure 2 Site and Exploration Plan Appendix A Summary Test Pit Logs Figure A-1 Terms and Symbols for Boring and Test Pit Logs Figure A-2 Log of Test Pit PIT-1 Figure A-3 Log of Test Pit PIT-2 Figure A-4 Log of Test Pit PIT-3 Figure A-5 Log of Test Pit TP-1 Figure A-6 Log of Test Pit TP-2 Figure A-7 Log of Test Pit TP-3 21-372 - 614 & 616 5th Ave S - Infiltration Rpt.doc i PanGEO, Inc. INFILTRATION ASSESSMENT 614 & 616 — 5TH AVENUE SOUTH EDMONDS, WASHINGTON 1.0 INTRODUCTION As requested, PanGEO, Inc. completed an infiltration assessment of the site soils to assist the project team with the drainage design at the above referenced property. Our service consisted of excavating six test pits, performing three Small Pilot Infiltration Tests (PIT), and preparing this summary report. The intent of our work is to evaluate the infiltration feasibility of the site soils and to provide a design infiltration rate, if feasible, for the design of the proposed infiltration system to be constructed at the site. 2.0 SITE AND PROJECT DESCRIPTION The project site consists of two adjacent parcels located at 614 and 616 — 5th Avenue South in Edmonds, Washington (see Figure 1, Vicinity Map). The subject property is an approximate 0.39 acre lot. It is bordered by 5th Avenue South to the east, multi -family residences to the west, retail establishments to the north, and an improved private alley to the south. The site is currently occupied by a single -story retail building at the north portion of the site and a single - story retail building with full basement at the southern portion of the site, with a surface parking lot between the two buildings. The site generally slopes down from east to west with an approximate grade change of 10 feet to a vacant vegetated area at the western portion of the site. We understand that you plan to construct three buildings on the site, consisting of a combination of multi -use townhomes and residential townhomes. Based on review of the preliminary plans, the proposed buildings will be 3-story, wood -frame structures. We envisage that site grading for the proposed project will include cuts and fill up to about 8 to 10 feet for the foundation construction. We understand it is planned to infiltrate surface water from the proposed improvements into the site soils, if feasible. The approximate layout of the site is shown on the attached Figure 2, Site and Exploration Plan. 3.0 SUBSURFACE EXPLORATIONS Six test pits (PIT-1, PIT-2, PIT-3, TP-1, TP-2, and TP-3) were excavated at the project site on August 4 and 6, 2021. PIT-1 was initially excavated to 5.5 feet for infiltration testing and was 21-372 - 614 & 616 5th Ave S - Infiltration Rpt.doc I PanGEO, Inc. Infiltration Assessment Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington August 23, 2021 then excavated to about 9 feet deep after the test. PIT-2 was initially excavated to 6 feet for infiltration testing and was then excavated to at about 9 feet deep after the test. PIT-3 was initially excavated to 12 feet for infiltration testing and was then excavated to practical digging refusal at about 15 feet deep after the test. TP-1 was excavated to practical digging refusal at 13 feet below grade and TP-2, and TP-3 were each excavated to about 11 feet below the existing grade. The approximate test pit locations are shown on the attached Figure 2. The relative in -situ density of cohesionless soils, or the relative consistency of fine-grained soils, was estimated from the excavating action of the excavator, probing the sidewalls with a 1/2-inch diameter steel rod, and the stability of the test pit sidewalls. Where soil contacts were gradual or undulating, the average depth of the contact was recorded in the log. After the infiltration test was completed, the excavations were backfilled with the excavated soils and the surface was tamped and re -graded smooth. A geologist from our firm was present throughout the boring and infiltration test program to observe the explorations, assist in sampling, and to document the soil samples obtained from the explorations and perform the tests. The summary boring and test pit logs are included in Appendix A. 4.0 SITE GEOLOGY AND SUBSURFACE CONDITIONS 4.1 SITE GEOLOGY Based on our review of the Composite Geologic Map of the Sno-King Area, Central Puget Lowland (Booth, 2004), the site is underlain by Pre -Fraser Deposits (geologic map unit Qpf). Pre -Fraser Deposits generally consist of interbedded sand, gravel, and silt that has been glacially overridden and typically dense to very dense. This unit is similar to the younger Vashon Advance Outwash but is characterized by its stratigraphic position and generally heterogenous grain size. Pre -Fraser Deposits generally have moderate infiltration capability. 4.2 SOIL CONDITIONS For a detailed description of the subsurface conditions encountered at each exploration location, please refer to our summary exploration logs provided in Appendix A. The stratigraphic contacts indicated on the logs represent the approximate depth to boundaries between soil units. Actual transitions between soil units may be more gradual or occur at different elevations. The 21-372 - 614 & 616 5th Ave S - Infiltration Rpt.doc Page 2 PanGEO, Inc. Infiltration Assessment Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington August 23, 2021 descriptions of groundwater conditions and depths are likewise approximate. The following is a generalized description of the soils encountered in the test pits. UNIT 1: Fill — Test pits PIT-1, PIT-2, and TP-1, excavated in the western portion of the site, test pits, generally encountered approximately 4 to 4.5 feet of fill below surface vegetation. The fill encountered in these test pits generally consisted of loose to medium dense silty to poorly graded sand with some plastic, asphalt, and brick debris. Test pits PIT- 3, TP-2, and TP-3, excavated in the central and eastern portion of the site, encountered approximately 8 to 10 feet of fill below the surface asphalt. The fill generally consisted of loose to medium dense silty sand with gravel with varying amounts of wood, concrete, and construction debris. UNIT 2: Pre -Fraser Deposits — Directly below the fill in each test pit, medium dense to dense poorly graded sand was observed in the test pits extending to the bottom of test pits. We interpreted this unit as the mapped pre -Fraser Deposits within the project vicinity. Our subsurface descriptions are based on the conditions encountered at the time of our exploration. Soil conditions between our exploration locations may vary from those encountered. The nature and extent of variations between our exploratory locations may not become evident until construction. If variations do appear, PanGEO should be requested to reevaluate the recommendations in this report and to modify or verify them in writing prior to proceeding with earthwork and construction. 4.3 GROUNDWATER Groundwater or seepage was not observed in our test pits at the time of our exploration. We observed two existing monitoring wells (Department of Ecology Well Tags BKH-527 and BKH- 528) installed by others at the site. Their approximate locations are on Figure 2, Site and Exploration Plan. Details of these monitoring wells are not known, and they could not be found on the Department of Ecology Well Report Viewer. Groundwater was measured in these wells on August 5, 2021 at a level of approximately 25 feet below ground surface in the parking lot area (approximate EL 59 feet) and 16.5 feet below ground surface in the lower vegetated area (approximate EL 57.5 feet). 21-372 - 614 & 616 5th Ave S - Infiltration Rpt.doc Page 3 PanGEO, Inc. Infiltration Assessment Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington August 23, 2021 It should be noted that groundwater levels will fluctuate depending on the season, amount of rainfall, surface water runoff, tides, and other factors. Generally, the water level is higher and seepage rates are greater in the wetter, winter months (typically October through May). 5.0 INFILTRATION TESTING AND RECOMMENDATIONS Three field infiltration tests, PIT-1, PIT-2 and PIT-3 were performed at the project site on August 5, 2021. The test location is indicated on the attached Figure 2. The test method and the results are discussed below. 5.1 TEST METHOD The field infiltration tests were conducted in general accordance with the procedure for Small - Scale Pilot Infiltration Test (PIT) as outlined in section B.3.2 of the June 2017 — Edmonds Stormwater Addendum. In general, the test consisted of the following procedure: • A test pit was excavated to the approximate design bottom of the proposed infiltration facilities with a minimum bottom area of 12 square feet. • The test pit was pre-soaked by maintaining a water level of at least 12 inches above the bottom of the pit. • At the end of pre-soak period, a flow meter was used to monitor the amount of water needed to maintain a constant head of 12 inches for at least one hour and until at least a point at which a constant volume of water per time unit was achieved. • At the end of the constant head test, we measured the falling head infiltration rate by shutting off the water flow and recording the drop in water level over regular time intervals for one hour or until all of the water was infiltrated. The field infiltration rate was then calculated based on the final measured volume per time unit, and the surface area of the hole. The results of our test are summarized in Table 1, below. 5.2 CORRECTION FACTORS The infiltration rates calculated based on field measurements are considered short-term rates and should be reduced through correction factors for design. The corrections factors account for site variability, test method, and number of locations tested, degree of long-term maintenance, and degree of influent control to prevent siltation and bio-buildup. The correction factors are outlined in Appendix B.2 of the June 2017 — Edmonds Stormwater Addendum, and are summarized and discussed below: 21-372 - 614 & 616 5th Ave S - Infiltration Rpt.doc Page 4 PanGEO, Inc. Infiltration Assessment Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington August 23, 2021 • Site Variability (CFv) — A range of 0.33 to 1.0 is provided in the Edmonds Stormwater Addendum. Based on the test pits excavated across the project site, the soil conditions at the site are generally consistent at the proposed infiltration depth. In our opinion, a CFv of 1.0 is appropriate for this site. • Test Method (CFt) — For small scale infiltration tests, we assume CFt = 0.5. • Degree of influent control to prevent siltation and bio-buildup (CFm) — Assuming a good degree of control, we assume CFm of 0.9. The Total Correction Factor (CFT) is then calculated as: CFT = CFv x CFt x CFm = 0.45. 5.3 LONG TERM INFILTRATION RATE FOR DESIGN With the Total Correction Factor (CFT) of 0.45, the long-term design rate can be calculated from the field measured rates. Table 1, below, details the infiltration data collected and the long-term design rates calculated for each location. TABLE l: Small Pilot Infiltration Test Data Corrected for Long Term Design Rate Field Pre -Soak Long Term Test Test Test Measured Correction Duration Design Rate Location Stage Duration Rate Factor (hrs) (in/hr) (in/hr) PIT-1 at 5.5 6 Constant 1 hour 2.6 0.45 1.2 feet Head PIT-2 at 6 6 Constant 1 hour 1.7 0.45 0.8 feet Head PIT-3 at 12 6 Constant 1 hour 4.1 0.45 1.8 feet Head 5.4 CONSTRUCTION CONSIDERATIONS Infiltration facilities are post -construction facilities which are designed to improve the quality and manage the volume of stormwater runoff by encouraging natural infiltration on -site. In order to protect the infiltration receptor soils from becoming clogged with sediment and/or 21-372 - 614 & 616 5th Ave S - Infiltration Rpt.doc Page 5 PanGEO, Inc. Infiltration Assessment Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington August 23, 2021 becoming compacted during construction, we recommend the following measures be implemented during construction: • The infiltration facilities should be constructed as late in the schedule as feasible and should not be constructed until after the upstream areas are stabilized. • Heavy equipment traffic on prepared subgrades should be limited, especially during wet weather. • If fine grained sediment is deposited or tracked onto the infiltration system subgrade, it should be removed using an excavator with a grade plate, a small dozer or a vacuum truck. • The subgrade should be scarified prior to placing fill to prevent sealing of the receptor soils. • Structural fill and aggregate base materials should be end -dumped at the edge of the fill area and the material pushed out over the subgrade. • Grading of the infiltration galleries should be accomplished using low -impact earth - moving equipment to prevent compaction of the underlying soils. Wide tracked vehicles such as excavator, small dozers and bobcats are suggested. • The infiltration system subgrade soils should be reviewed after excavation to verify the soils encountered are as anticipated. Test Pit Backfill: It should be noted that the backfill in the test pit locations was not compacted to a dense condition or the requirements of structural fill. As such, during construction of the project, the earthwork contractor should locate the test pits, remove the loose backfill and replace it with properly compacted structural fill, if they are located with the structural loading areas. 6.0 LIMITATIONS We have prepared this report for Jonathan Kurth and the project design team. Recommendations contained in this report are based on a site reconnaissance, a subsurface exploration program, 21-372 - 614 & 616 5th Ave S - Infiltration Rpt.doc Page 6 PanGEO, Inc. Infiltration Assessment Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington August 23, 2021 review of pertinent subsurface information, and our understanding of the project. The study was performed using a mutually agreed -upon scope of work. Variations in soil conditions may exist between the locations of the explorations and the actual conditions underlying the site. The nature and extent of soil variations may not be evident until construction occurs. If any soil conditions are encountered at the site that are different from those described in this report, we should be notified immediately to review the applicability of our recommendations. Additionally, we should also be notified to review the applicability of our recommendations if there are any changes in the project scope. The scope of our work does not include services related to construction safety precautions. Our recommendations are not intended to direct the contractors' methods, techniques, sequences or procedures, except as specifically described in our report for consideration in design. Additionally, the scope of our work specifically excludes the assessment of environmental characteristics, particularly those involving hazardous substances. This report has been prepared for planning and design purposes for specific application to the proposed project in accordance with the generally accepted standards of local practice at the time this report was written. No warranty, express or implied, is made. This report may be used only by the client and for the purposes stated, within a reasonable time from its issuance. Land use, site conditions (both off and on -site), or other factors including advances in our understanding of applied science, may change over time and could materially affect our findings. Therefore, this report should not be relied upon after 24 months from its issuance. PanGEO should be notified if the project is delayed by more than 24 months from the date of this report so that we may review the applicability of our conclusions considering the time lapse. It is the client's responsibility to see that all parties to this project, including the designer, contractor, subcontractors, etc., are made aware of this report in its entirety. The use of information contained in this report for bidding purposes should be done at the contractor's option and risk. Any party other than the client who wishes to use this report shall notify PanGEO of such intended use and for permission to copy this report. Based on the intended use of the report, PanGEO may require that additional work be performed and that an updated report be reissued. Noncompliance with any of these requirements will release PanGEO from any liability resulting from the use this report. 21-372 - 614 & 616 5th Ave S - Infiltration Rpt.doc Page 7 PanGEO, Inc. Infiltration Assessment Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington August 23, 2021 We appreciate the opportunity to be of service. Sincerely, Spenser P. Scott, L.G. Michael H. Xue, P.E. Staff Geologist Principal Geotechnical Engineer 21-372 - 614 & 616 5th Ave S - Infiltration Rpt.doc Page 8 PanGEO, Inc. Infiltration Assessment Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington August 23, 2021 7.0 LIST OF REFERENCES Booth, D. B., Cox, B. F., Troost, K. G., Shimel, S. A., 2004, Composite Geologic Map of the Sno-King Area, Central Puget Lowland, Washington: Seattle -Area Geologic Mapping Project, University of Washington, and the United States Geological Survey, scale 1:24000. City of Edmonds, 2017, Appendix B, Edmonds Stormwater Addendum. 21-372 - 614 & 616 5th Ave S - Infiltration Rpt.doc Page 9 PanGEO, Inc. :: z zoom sl SW z a � Y R R L E 7" PUGET O cl i SOUND C Daley St rvrc CoNor 1 A� 3' Rid" Pbyt"a s/r Park Craq* (Edmonds W r n St o rn Dayton St Q f > W Pk St Yo N Park Alder St M n dnwrd> > r, LO Shel/, walnut St Nbt sh y v �s� i wooin dmonds Q ?� Wa r rn t3rk C, L 216th St SW to, Project Site 21eth s1 sw a2201h St SW40 Q > Q L m L G G m a o ' a� L = ; 0 2261h St SW - o 0 22eth St SW t\SW Geer Creek �s9 0"r Park %se ve Edmonds' Esperance z3zro s1 Wact,,ir .'r? rr Hrkman Park Woodway %$Ila*" � 1 Marysville n,, Pon Hael,ck l—dn le n Whidbey '_. N., r 1 sland Everett wmorr Gole F'. 0--d r�r . Xf �y„ 1. NORTH r� Redm1 nd ?- A Not to Scale z st Sw R Base Map: ESRI Topographic Proposed Townhomes VICINITY MAP RnGEO614 & 616 5thA�/ve S r N C o R P o R A.rE D Edmonds, V ,1A Project No. 21-372 Figure No. 1 C" A CONDO ONE B,ALLARD LL L 4011 H(10q'I,,ELL L 610 5TH AVE S r ",- CONCRFTF 'OV ----------------- Al-� [-J()TE: LE,;-J,AL DESCF-IFTI.-�Dh ;-j-'--/EFL."`-'P'-. ll,jTc-i FIC"HT CIF 1,1'1iA i' 171F 47H '.-TREE-T P4PK'--'1E'11'11' T'%,',IN. A CON DOMIN10,4 /517 47H AVE S 70 N89'54'04" ONE S70 B� 6 17LISINQ: ................ 614 ST :AVE:.:: .... ..... FF ..84 :05* PIT-1 . . . . . . . . . . . . z z CB RIM**.-.---!82.22-1 'CON ...... 10", ' -.,)N IE=80,42'%/,: 4" CON C -E- -JE=0.62 .... . .. ...... BKH-528 .......... .. .... .... .. ......... IBKH-5271 .. .... ASPHALT ......... ............. SD GRASS ........ RQ-L;'A . . ..... . ..... . . ......... ll P-3 z z z h) 0 M PHALT-.. PIT-3 C4 ........... t9> ...... ..... . . . . . . . 7. J'PIT-2 ...................... 2 S T FlY C N C. BLkK-- :I*L*bl*N*d: ..... 77 S ........... 60 .16 5TH AV I � 11:: 7 C RIM = 6- 9. 5 4 .. .... "i * I .......... ... FFE= 85.2( 1 -4::: FFE= 76.59' . 1L E*:*Y*': ... .6" CON 5 lE=F7,-7,j 131.37' N89'54'04" PHALT: ALLEY--.'. C8 RIM =62.60 ... ..... ..... ..... 11 C 171-31.6 a 0" Q-64C E 117=607 EASEMENT 7603100239;' 5D - LKI SEE EXCEPTION 4 26 1. 37' Legend: Approximate Test Pit Location PanGEO, Inc., August 2021 Approximate Observed Monitoring Well ................ . . . . . . . . . . . .. MYN/w, AME/z .. ................ �SSVIH RIM 69,68 PARCa B. CTIR CHA 63, 08 6 SS ElApproximate Parcel Boundary F-1 Approximate Proposed Building Approx. Scale: 1 inch = 20 feet z z z r. SD - HIP Base map modified from ALTA/ACSM Land Title Survey by PACE Engineering, dated July 17, 2015 r. SD - HIP Base map modified from ALTA/ACSM Land Title Survey by PACE Engineering, dated July 17, 2015 APPENDIX A SUMMARY TEST PIT LOGS RELATIVE DENSITY / CONSISTENCY SAND / GRAVEL SILT / CLAY SPT Approx. Relative SPT Approx. Undrained Shear DensityN-values Density (%) Consistency N-values Strength (psf) Very Loose <4 <15 Very Soft <2 <250 Loose 4 to 10 15 - 35 Soft 2 to 4 250 - 500 Med. Dense 10 to 30 35 - 65 Med. Stiff 4 to 8 500.1000 Dense 30 to 50 65 - 85 Stiff 8 to 15 1000 - 2000 Very Dense >50 85.100 Very Stiff 15 to 30 2000 - 4000 Hard >30 >4000 UNIFIED SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONS GROUP DESCRIPTIONS •�' GW: Well -graded GRAVEL Gravel GRAVEL (<5% fines) .. .....: ...................................................... 50% or more of the coarse o ° GP : : Poorly -graded GRAVEL fraction retained on the #4 sieve. Use dual symbols leg. o ° GM ...................................................... Silty GRAVEL GP -GM) for 5% to 12% fines. GRAVEL (>12% fines) •••••••••••••••••••••••••••••• GC : ........................••• Clayey GRAVEL ...................................................................... .......................................................... SW: Well -graded SAND Sand SAND (<5 /° fines) '' 50% or more of the coarse ....................................:....> % SP Poorly -graded raded SAND y-g fraction passing the #4 sieve. Use duals leg. SP-SM ) ; ":r" ............................................................ SM: Silt SAND y %fin for s%to12%fines.g SAND (>1 2% fines) , ••••••••••••••••••••••••••••••••••••••••••••••••••••••••• SC : Clayey SAND ...................................................................... ............................................................. ML : SILT Liquid Limit < 50 ............................................................ CL : Lean CLAY Silt and Clay ............................................................ OL : Organic SILT or CLAY == — 50%or more passing #200 sieve :.................................. :...................................................... MH : Elastic SILT Liquid Limit > 50 CH Fat CLAY OH Organic SILT or CLAY — , ........................... ...................................... Highly Organic Soils ............................................................ PT : PEAT Notes: 1. Soil exploration to s contain material descriptions based on visual observation and field tests using a system modified from the Uniform Soil Classification System (USCS). Where necessary laboratory tests have been conducted (as noted in the "Other Tests" column), unit descriptions may include a classification. Please refer to the discussions in the report text for a more complete description of the subsurface conditions. 2. The graphic symbols given above are not inclusive of all symbols that may appear on the borehole to s. Other symbols may be used where field observations indicated mixed soil constituents or dual constituent materials. DESCRIPTIONS OF SOIL STRUCTURES Layered: Units of material distinguished by color and/or Fissured: Breaks along defined planes composition from material units above and below Slickensided: Fracture planes that are polished or glossy Laminated: Layers of soil typically 0.05 to 1 mm thick, max.1 cm Blocky: Angular soil lumps that resist breakdown Lens: Layer of soil that pinches out laterally Disrupted: Soil that is broken and mixed Interlayered: Alternating layers of differing soil material Scattered: Less than one per foot Pocket: Erratic, discontinuous deposit of limited extent Numerous: More than one per foot Homogeneous: Soil with uniform color and composition throughout BCN: Angle between bedding plane and a plane normal to core axis COMPONENT DEFINITIONS COMPONENT SIZE / SIEVE RANGE COMPONENT SIZE / SIEVE RANGE Boulder: > 12 inches Sand Cobbles: 3 to 12 inches Coarse Sand: #4 to #10 sieve (4.5 to 2.0 mm) Gravel Medium Sand: #10 to #40 sieve (2.0 to 0.42 mm) Coarse Gravel: 3 to 3/4 inches Fine Sand: #40 to #200 sieve (0.42 to 0.074 mm) Fine Gravel: 3/4 inches to #4 sieve Silt 0.074 to 0.002 mm Clay <0.002 mm TEST SYMBOLS for In Situ and Laboratory Tests listed in "Other Tests" column. ATT AtterbergLimit Test Comp Compaction Tests Con Consolidation DD Dry Density DS Direct Shear %F Fines Content GS Grain Size Perm Permeability PP Pocket Penetrometer R R-value SG Specific Gravity TV Torvane TXC Triaxial Compression UCC Unconfined Compression SYMBOLS Sample/In Situ test types and intervals 2-inch OD Split Spoon, SPT (140-lb. hammer, 30" drop) H3.25-inch OD Spilt Spoon (300-lb hammer, 30" drop) Non-standard penetration test (see boring log for details) Thin wall (Shelby) tube Grab Rock core ® Vane Shear MONITORING WELL SZ Groundwater Level at time of drilling (ATD) 1 Static Groundwater Level Cement / Concrete Seal Bentonite grout / seal Silica sand backfll Slotted tip Slough Bottom of Boring MOISTURE CONTENT Dry Dusty, dry to the touch Moist Damp but no visible water Wet Visible free water GPmE® Terms and Symbols for I IN C 0 R P 0 R A T E D Boring and Test Pit Logs Figure A-1 Phone: 206.262.0370 Test Pit No. PIT-1 Approximate ground surface elevation (NAVD88): 74 feet Coordinates (Washington State Plane - North): 297653, 1260821 Death ft Material Description Light vegetation above loose to medium dense, gray -brown, silty fine SAND 0-2 with gravel; trace plastic, asphalt, and brick debris, some angular rock, trace ----------------------- rootlets; disrupted texture, non -plastic, dry to moist ---------------------------------------------------------------------------------------------------------------------------- Medium dense, light brown, poorly graded fine SAND; trace silt, trace angular 2 — 4.5 rock, trace roots, burnt wood fragments; iron -oxide staining; disrupted texture non -plastic, moist [Fill] Dense, gray -brown, poorly graded fine SAND; trace gravel, trace silt; non- 4.5 — 9 plastic, moist [Qpf — Pre -Fraser Deposits] - Becomes dense, gray, poorly graded fine SAND from 7 to 9 feet o• JI -Av_ _ - � � l _ yy 1 ti_ s eve Photo PIT-1 (left): Shows PIT-1 at approximately 5.5 feet in depth before testing Photo PIT-1 (right): Shows spoils from PIT-1 at approximately 9 feet in depth after testing PIT-1 was terminated approximately 5.5 feet below grade for infiltration testing. After the test, PIT-1 was over -excavated to 9 feet in depth to check for shallow groundwater or groundwater mounding. No groundwater seepage was encountered during explorations. 21-372 Test Pit Logs Figure A-2 PanGEO, Inc. Test Pit No. PIT-2 Approximate ground surface elevation (NAVD88): 73.5 feet Coordinates (Washington State Plane - North): 297574, 1260814 Death ftj Material Description Light vegetation above loose to medium dense, gray -brown, silty fine SAND 0 — 2.5 with gravel; trace asphalt debris, some angular rock, trace rootlets; disrupted ----------------------- texture, non -plastic, dry to moist ---------------------------------------------------------------------------------------------------------------------------- Medium dense, light brown, poorly graded fine SAND; trace silt, trace angular 2.5-4 rock, some roots, burnt wood fragments; trace iron -oxide staining; disrupted texture non -plastic, moist [Fill] Dense, gray -brown, poorly graded fine SAND; trace gravel, trace silt; non- 4-9 plastic, moist [Qpf — Pre -Fraser Deposits] - Becomes dense, gray, poorly graded fine SAND from 7 to 9 feet ..!t r a. V.. W Photo PIT-2 (left): Shows PIT-2 at approximately 6 feet in depth before testing Photo PIT-2 (right): Shows spoils from PIT-2 at approximately 9 feet in depth after testing PIT-2 was terminated approximately 6 feet below grade for infiltration testing. After the test, PIT-2 was over -excavated to 9 feet in depth to check for shallow groundwater or groundwater mounding. No groundwater seepage was encountered during explorations. 21-372 Test Pit Logs Figure A-3 PanGEO, Inc. Test Pit No. PIT-3 Approximate ground surface elevation (NAVD88): 83.5 feet Coordinates (Washington State Plane - North): 297594, 1260886 De th ft Material Description Approximate 2-inch asphalt overlay above loose to medium dense, gray -brown, 0-7 ----------------------- slightly silty SAND with gravel and cobble; trace wood debris; non -plastic, moist ---------------------------------------------------------------------------------------------------------------------------- Loose, dark brown to black, slightly organic silty SAND; trace brick debris, wood 7 — 8.5 debris, some concrete and construction debris; disrupted texture; non -plastic, moist ----------------------- ---------------------------------------------------------------------------------------------------------------------------- Medium dense, light brown to red -brown, poorly graded fine SAND; trace silt, 8.5 — 10 burnt wood fragments; trace iron -oxide staining; disrupted texture non -plastic, moist [Fill] Dense, gray -brown, poorly graded fine to medium SAND; trace gravel, trace silt, 10-15 trace iron -oxide staining; non -plastic, moist [Qpf— Pre -Fraser Deposits] tip " 1 ` � _ '7 • . Ate. �,� t}K' : � �' ; AL Photo PIT-3 (left): Shows PIT-3 at approximately 12 feet in depth before testing Photo PIT-3 (right): Shows spoils from PIT-3 at approximately 10 feet in depth after testing PIT-3 was terminated approximately 6 feet below grade for infiltration testing. After the test, PIT-3 was over -excavated to 15 feet in depth to check for shallow groundwater or groundwater mounding. No groundwater seepage was encountered during explorations. 21-372 Test Pit Logs Figure A-4 PanGEO, Inc. Test Pit No. TP-1 Approximate ground surface elevation (NAVD88): 74 feet Coordinates (Washington State Plane - North): 297615, 1260818 Death ftj Material Description Light vegetation and gravel above loose to medium dense, gray -brown, silty 0-2 fine SAND with gravel; trace concrete debris, some angular rock, trace rootlets; ----------------------- disrupted texture, non -plastic, dry to moist ---------------------------------------------------------------------------------------------------------------------------- Medium dense, light brown, poorly graded fine SAND; trace silt, trace angular 2-4 rock, trace roots, burnt wood fragments; iron -oxide staining; disrupted texture non -plastic, moist [Fill] Dense, gray -brown to gray, poorly graded fine to medium SAND; trace gravel, trace silt; non -plastic, moist 4 —13 • Top approximate 2 feet weathered to red -brown w/ iron -oxide staining • Cobble layer from approximately 11 to 12 feet below ground surface [Qpf — Pre -Fraser Deposits] i ! ,t 1.4 1 � l v Photo TP-1 (left): Shows TP-1 at approximately 13 feet in depth Photo TP-1 (right): Shows spoils from TP-1 at approximately 10 feet in depth TP-1 was terminated approximately 13 feet below grade. No groundwater seepage was encountered during explorations. 21-372 Test Pit Logs Figure A-5 PanGEO, Inc. Test Pit No. TP-2 Approximate ground surface elevation (NAVD88): 84 feet Coordinates (Washington State Plane - North): 297617, 1260919 Death ftj Material Description Approximate 2-inch asphalt overlay above loose to medium dense, gray -brown, 0-8 ----------------------- slightly silty SAND with gravel and cobble; trace wood debris; non -plastic, moist ---------------------------------------------------------------------------------------------------------------------------- Loose, dark brown to black, slightly organic silty SAND; trace brick debris, wood 8-9 debris, some concrete and construction debris; disrupted texture; non -plastic, moist [Fill] Medium dense, light brown to red -brown, poorly graded fine SAND; trace silt, 9-11 burnt wood fragments; trace iron -oxide staining; disrupted texture non -plastic, moist [Qpf — Pre -Fraser Deposits] • r '• i Photo TP-2 (left): Shows TP-2 at approximately 11 feet in depth Photo TP-2 (right): Shows spoils from TP-2 at approximately 10 feet in depth TP-2 was terminated approximately 11 feet below grade. No groundwater seepage was encountered during explorations. 21-372 Test Pit Logs Figure A-6 PanGEO, Inc. Test Pit No. TP-3 Approximate ground surface elevation (NAVD88): 83 feet Coordinates (Washington State Plane - North): 297651, 1260854 PeiqthftjMaterial Description Approximate 2-inch asphalt overlay above loose to medium dense, gray -brown, 0-7 slightly silty SAND with gravel and cobble, layers of gray, sandy SILT; metal ---------------------------- debris, wood debris, large fragments of concrete slab; non -plastic, moist ------------------------------------------------------------------------------------------------------------------------------------------------------ Loose, dark brown to black, slightly organic silty SAND; metal debris, wood 7-8 debris, some concrete and construction debris; disrupted texture; non -plastic, moist [Fill] Medium dense, light brown to red -brown, poorly graded fine SAND; trace silt, 8 —11 burnt wood fragments; trace iron -oxide staining; disrupted texture non -plastic, moist [Qpf — Pre -Fraser Deposits] f 4 Photo TP-3 (left): Shows TP-3 at approximately 10 feet in depth Photo TP-3 (right): Shows spoils from TP-3 at approximately 10 feet in depth TP-3 was terminated approximately 10 feet below grade. No groundwater seepage was encountered during explorations. Date of Test Pit Excavations: August 4 and August 6, 2021 Excavations Logged by: S. Scott and J. Manke 21-372 Test Pit Logs Figure A-7 PanGEO, Inc. PanGEO P O R A T E D Veotechnical & Earthquake Engineering Consultants March 7, 2023 File No. 21-372 Mr. Jonathan Kurth BK Investments LLC 557 Roy St, Suite 125 Seattle, WA 98109 Subject: Response to Stormwater Review Comments Proposed Townhomes 614 & 616 — 5th Avenue South, Edmonds, Washington Application #: PLN2021-0072 Dear Mr. Kurth: This letter responds to Stormwater Compliance (Preliminary) review comments dated January 10, 2023. Specifically, the following review comments are pertinent to our geotechnical study and infiltration testing, and our responses are summarized below. 1. Infiltration Testing in the Dry Season 2017 Edmonds Stormwater Addendum states that infiltration testing should be conducted in the wet season (December 1st and March 31 st). Our interpretation of the addendum is that this is a recommendation, not a requirement. PanGEO has been conducting infiltration testing in other jurisdictions in the dry season. Based on the discussions in the virtual meeting on February 21, 2023, we visited the site and measured the groundwater levels in the two existing monitoring wells on February 24, 2023. The groundwater levels measured in these two wells this time are about the same as the levels we measured in the dry season on August 5, 2021, and is about 14 feet below the upper (east) infiltration trench bottom and about 9 feet below the lower (west) infiltration trench bottom. Figure 1 is a generalized profile (E-W) shows the relationship between infiltration trench location, proposed building location and finish floor elevations, the setback distances from the infiltration trenches to the proposed buildings 3213 Eastlake Ave E, Ste B Seattle, WA 98102 Tel:(206) 262-0370 www.pangeoinc.com Response to Stormwater Review Comments Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington Application #: PLN2021-0072 March 7, 2023 and the adjacent building to the west. The locations of the existing monitoring wells and measures groundwater levels are also shown in Figure 1. The native soils where the infiltration testing conducted are glacially overridden sands with trace of silt. Based on our experience, the moisture content of this soil unit should be similar in the dry season and wet season if they are above the groundwater table. In summary, based on the soil composition, groundwater level measured, and current design, it is our opinion that the infiltration rate obtained in the August 2021 test should be representative of the wet season conditions, and is appropriate to be used for the design. 2. Detailed Method of Analysis In our opinion, the "Detailed Method of Analysis" as referenced in the Edmonds Stormwater Addendum and DOE Stormwater Manual for Western Washington is meant for large sites with more than 1 acre of impervious areas, and are not typically used for relatively small urban in -fill sites. The adjacent building to the west is located approximately 60 feet west of the lower (west) infiltration trench (see Figure 1), and the adjacent building finish floor is estimated to be only about 2.6 feet below the west infiltration trench bottom. Based on the large setback distance, the gentle gradient (less than 5%), and with an emergency overflow, it is our opinion that the currently designed infiltration facilities will not have adverse impacts on the adjacent buildings and properties. The upper (east) infiltration trench is located 10 feet from the proposed west building, and the current design infiltration trench bottom is slightly below the Building C finish floor elevation. In our opinion, the 10-foot setback is considered adequate based on the site conditions and our experience with similar designs. However, to reduce the potential impacts on the Building C, we recommend that bottom of the upper (east) infiltration trench be set at 2 feet below the Building C finish floor elevation. CLOSURE We trust that the information outlined in this letter meets your need at this time. Please call if you have any questions. 21-372 614 & 616 5th Ave S - Comment Response Ltr Mar 2023 2 PanGEO, Inc. Response to Stormwater Review Comments Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington Application #: PLN2021-0072 March 7, 2023 Sincerely, Michael H. Xue, P.E. Principal Geotechnical Engineer Attachment: Figure 1 — Generalized Profile Section A -A' 21-372 614 & 616 5th Ave S - Comment Response Ltr Mar 2023 3 PanGEO, Inc. A City of Edmonds 517 & 519 - 4th Ave S 614 - 5th Avenue South City of Edmonds Ar 4th Avenue South Parcel 00649300100100 Parcel 27032600100900 5th Avenue South m o D W c o 0 m E p co m 140 2 2 � 140 a m a a , 130 @ E 130 E 120 P X a 2 Q 120 Q a Infiltration Trench Infiltration Trench Q 110 TOP 70.0' TOP 75.3' 110 BOT 68.0' BOT 73.3' 100 BLDA/B 100 -56.5 Feet 90 from BLD to PL BLD C 90 517 & 519 - 4th Ave S 80 FF EL 83.0' 8o 0 70 FF EL 74.0' 70 o a 60 FF EL 65.4' / 60 a LU Rockery Observed at w 50 Neighboring Parking 50 Existing Grade Following Alley Grade B 40 Based on 2017 BKH-528 40 North Puget 08/05/2005/2021 - GW EL 59.0' 08/05/2021 - GW EL 57.5' 30 LiDAR Dataset 02/24/2023 - GW EL 58.7' 02/24/2023 - GW EL 57.6' 30 20 20 10 10 0 0 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 360 Horizontal Distance (feet) GRAPHICS LEGEND Boring Designation PG-1 Groundwater Level at time of drilling SPT N-value / (blows per foot) 7 12 Fill i 25 26 Geologic description 50 Contact Contact between 7 geologic units >50 Static Groundwater Level Horizontal & Vertical Scale: 1 inch = 30 feet Notes: 1. Existing ground profile based on 2017 North Puget LiDAR Dataset 3. See Inset at Right for location of Section A -A'. 4. Proposed Buildings in Orange; Proposed Infiltration in Blue; Neighboring Buildings in Yellow 4. See report text for a detailed description of the subsurface conditions across the site. F— HOWELL WAY W Ln h A r A'HOMELAND DR Lj to , W ` > A Q in x I— NOT TO SCALE Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds APPENDIX B WWHM Summary November 2023 20231110_614 5th Ave S Edmonds_Drainage Report Rev 4 WWHM2012 PROJECT REPORT General Model Information WWHM2012 Project Name: 614 5th Ave S WWHM Site Name: Site Address: 614 5th Ave S City: Edmonds Report Date: 11 /3/2023 MGS Region: Puget East Data Start: 1901 /10/1 Data End: 2058/09/30 Timestep: 15 Minute DOT Data Number03 Version Date: 2023/01 /27 Version: 4.2.19 POC Thresholds Low Flow Threshold for POC1: 50 Percent of the 2 Year High Flow Threshold for POC1: 50 Year Low Flow Threshold for POC2: 50 Percent of the 2 Year High Flow Threshold for POC2: 50 Year Low Flow Threshold for POC3: 50 Percent of the 2 Year High Flow Threshold for POC3: 50 Year 614 5th Ave S WWHM 11/3/2023 8:46:35 PM Page 2 Landuse Basin Data Predeveloped Land Use Basin 1 Bypass: No GroundWater: No Pervious Land Use acre C, Forest, Mod 0.493595 Pervious Total 0.493595 Impervious Land Use acre Impervious Total 0 Basin Total 0.493595 614 5th Ave S WWHM 11/3/2023 8:46:35 PM Page 3 Mitigated Land Use BLDG C + Dwy Bypass: No GroundWater: No Pervious Land Use acre Pervious Total 0 Impervious Land Use acre ROOF TOPS FLAT 0.121281 PARKING FLAT 0.042401 Impervious Total 0.163682 Basin Total 0.163682 614 5th Ave S WWHM 11/3/2023 8:46:35 PM Page 4 BLDG A + B + Conc dwy/walkway Bypass: No GroundWater: No Pervious Land Use acre Pervious Total 0 Impervious Land Use acre ROOF TOPS FLAT 0.098095 PARKING FLAT 0.114876 Impervious Total 0.212971 Basin Total 0.212971 614 5th Ave S WWHM 11/3/2023 8:46:35 PM Page 5 Basin 3 Bypass: No GroundWater: No Pervious Land Use acre C, Lawn, Flat 0.017332 Pervious Total 0.017332 Impervious Land Use acre Impervious Total 0 Basin Total 0.017332 614 5th Ave S WWHM 11/3/2023 8:46:35 PM Page 6 Basin 4 Bypass: Yes GroundWater: No Pervious Land Use acre A B, Lawn, Flat 0.00152 Pervious Total 0.00152 Impervious Land Use acre ROADS MOD 0.09809 Impervious Total 0.09809 Basin Total 0.09961 614 5th Ave S WWHM 11/3/2023 8:46:35 PM Page 7 Routing Elements Predeveloped Routing 614 5th Ave S WWHM 11/3/2023 8:46:35 PM Page 8 Mitigated Routing Gravel Trench Bed 1 Bottom Length: Bottom Width: Trench bottom slope 1: Trench Left side slope 0: Trench right side slope 2: Material thickness of first layer: Pour Space of material for first layer: Material thickness of second layer: Pour Space of material for second layer: Material thickness of third layer: Pour Space of material for third layer: Infiltration On Infiltration rate: Infiltration safety factor: Total Volume Infiltrated (ac-ft.): Total Volume Through Riser (ac-ft.): Total Volume Through Facility (ac-ft.): Percent Infiltrated: Total Precip Applied to Facility: Total Evap From Facility: Discharge Structure Riser Height: 2 ft. Riser Diameter: 10 in. Element Flows To: Outlet 1 Outlet 2 87.00 ft. 12.00 ft. 0 To 1 0 To 1 0 To 1 2 0.35 0 0 0 0 0.8 1 64.615 0.003 64.618 100 0 0 Gravel Trench Bed Hydraulic Table Stage(feet) Area(ac.) Volume(ac-%) Discharge(cfs) Infilt(cfs) 0.0000 0.024 0.000 0.000 0.000 0.0233 0.024 0.000 0.000 0.019 0.0467 0.024 0.000 0.000 0.019 0.0700 0.024 0.000 0.000 0.019 0.0933 0.024 0.000 0.000 0.019 0.1167 0.024 0.001 0.000 0.019 0.1400 0.024 0.001 0.000 0.019 0.1633 0.024 0.001 0.000 0.019 0.1867 0.024 0.001 0.000 0.019 0.2100 0.024 0.001 0.000 0.019 0.2333 0.024 0.002 0.000 0.019 0.2567 0.024 0.002 0.000 0.019 0.2800 0.024 0.002 0.000 0.019 0.3033 0.024 0.002 0.000 0.019 0.3267 0.024 0.002 0.000 0.019 0.3500 0.024 0.002 0.000 0.019 0.3733 0.024 0.003 0.000 0.019 0.3967 0.024 0.003 0.000 0.019 0.4200 0.024 0.003 0.000 0.019 0.4433 0.024 0.003 0.000 0.019 0.4667 0.024 0.003 0.000 0.019 0.4900 0.024 0.004 0.000 0.019 0.5133 0.024 0.004 0.000 0.019 0.5367 0.024 0.004 0.000 0.019 614 5th Ave S WWHM 11/3/2023 8:46:35 PM Page 9 0.5600 0.024 0.004 0.000 0.019 0.5833 0.024 0.004 0.000 0.019 0.6067 0.024 0.005 0.000 0.019 0.6300 0.024 0.005 0.000 0.019 0.6533 0.024 0.005 0.000 0.019 0.6767 0.024 0.005 0.000 0.019 0.7000 0.024 0.005 0.000 0.019 0.7233 0.024 0.006 0.000 0.019 0.7467 0.024 0.006 0.000 0.019 0.7700 0.024 0.006 0.000 0.019 0.7933 0.024 0.006 0.000 0.019 0.8167 0.024 0.006 0.000 0.019 0.8400 0.024 0.007 0.000 0.019 0.8633 0.024 0.007 0.000 0.019 0.8867 0.024 0.007 0.000 0.019 0.9100 0.024 0.007 0.000 0.019 0.9333 0.024 0.007 0.000 0.019 0.9567 0.024 0.008 0.000 0.019 0.9800 0.024 0.008 0.000 0.019 1.0033 0.024 0.008 0.000 0.019 1.0267 0.024 0.008 0.000 0.019 1.0500 0.024 0.008 0.000 0.019 1.0733 0.024 0.009 0.000 0.019 1.0967 0.024 0.009 0.000 0.019 1.1200 0.024 0.009 0.000 0.019 1.1433 0.024 0.009 0.000 0.019 1.1667 0.024 0.009 0.000 0.019 1.1900 0.024 0.010 0.000 0.019 1.2133 0.024 0.010 0.000 0.019 1.2367 0.024 0.010 0.000 0.019 1.2600 0.024 0.010 0.000 0.019 1.2833 0.024 0.010 0.000 0.019 1.3067 0.024 0.011 0.000 0.019 1.3300 0.024 0.011 0.000 0.019 1.3533 0.024 0.011 0.000 0.019 1.3767 0.024 0.011 0.000 0.019 1.4000 0.024 0.011 0.000 0.019 1.4233 0.024 0.011 0.000 0.019 1.4467 0.024 0.012 0.000 0.019 1.4700 0.024 0.012 0.000 0.019 1.4933 0.024 0.012 0.000 0.019 1.5167 0.024 0.012 0.000 0.019 1.5400 0.024 0.012 0.000 0.019 1.5633 0.024 0.013 0.000 0.019 1.5867 0.024 0.013 0.000 0.019 1.6100 0.024 0.013 0.000 0.019 1.6333 0.024 0.013 0.000 0.019 1.6567 0.024 0.013 0.000 0.019 1.6800 0.024 0.014 0.000 0.019 1.7033 0.024 0.014 0.000 0.019 614 5th Ave S WWHM 11/3/2023 8:46:35 PM Page 10 1.9133 0.024 0.016 0.000 0.019 1.9367 0.024 0.016 0.000 0.019 1.9600 0.024 0.016 0.000 0.019 1.9833 0.024 0.016 0.000 0.019 2.0067 0.024 0.017 0.004 0.019 2.0300 0.024 0.017 0.045 0.019 2.0533 0.024 0.018 0.108 0.019 2.0767 0.024 0.018 0.186 0.019 614 5th Ave S WWHM 11/3/2023 8:46:35 PM Page 11 Gravel Trench Bed 2 Bottom Length: 50.00 ft. Bottom Width: 20.00 ft. Trench bottom slope 1: 0 To 1 Trench Left side slope 0: 0 To 1 Trench right side slope 2: 0 To 1 Material thickness of first layer: 2 Pour Space of material for first layer: 0.35 Material thickness of second layer: 0 Pour Space of material for second layer: 0 Material thickness of third layer: 0 Pour Space of material for third layer: 0 Infiltration On Infiltration rate: 4.1 Infiltration safety factor: 0.45 Total Volume Infiltrated (ac-ft.): 80.444 Total Volume Through Riser (ac-ft.): 0 Total Volume Through Facility (ac-ft.): 80.444 Percent Infiltrated: 100 Total Precip Applied to Facility: 0 Total Evap From Facility: 0 Discharge Structure Riser Height: 2 ft. Riser Diameter: 10 in. Element Flows To: Outlet 1 Outlet 2 Gravel Trench Bed Hydraulic Table Stage(feet) Area(ac.) Volume(ac-ft.) Discharge(cfs) Infilt(cfs) 0.0000 0.023 0.000 0.000 0.000 0.0233 0.023 0.000 0.000 0.042 0.0467 0.023 0.000 0.000 0.042 0.0700 0.023 0.000 0.000 0.042 0.0933 0.023 0.000 0.000 0.042 0.1167 0.023 0.000 0.000 0.042 0.1400 0.023 0.001 0.000 0.042 0.1633 0.023 0.001 0.000 0.042 0.1867 0.023 0.001 0.000 0.042 0.2100 0.023 0.001 0.000 0.042 0.2333 0.023 0.001 0.000 0.042 0.2567 0.023 0.002 0.000 0.042 0.2800 0.023 0.002 0.000 0.042 0.3033 0.023 0.002 0.000 0.042 0.3267 0.023 0.002 0.000 0.042 0.3500 0.023 0.002 0.000 0.042 0.3733 0.023 0.003 0.000 0.042 0.3967 0.023 0.003 0.000 0.042 0.4200 0.023 0.003 0.000 0.042 0.4433 0.023 0.003 0.000 0.042 0.4667 0.023 0.003 0.000 0.042 0.4900 0.023 0.003 0.000 0.042 0.5133 0.023 0.004 0.000 0.042 0.5367 0.023 0.004 0.000 0.042 0.5600 0.023 0.004 0.000 0.042 0.5833 0.023 0.004 0.000 0.042 614 5th Ave S WWHM 11/3/2023 8:46:35 PM Page 12 0.6067 0.023 0.004 0.000 0.042 0.6300 0.023 0.005 0.000 0.042 0.6533 0.023 0.005 0.000 0.042 0.6767 0.023 0.005 0.000 0.042 0.7000 0.023 0.005 0.000 0.042 0.7233 0.023 0.005 0.000 0.042 0.7467 0.023 0.006 0.000 0.042 0.7700 0.023 0.006 0.000 0.042 0.7933 0.023 0.006 0.000 0.042 0.8167 0.023 0.006 0.000 0.042 0.8400 0.023 0.006 0.000 0.042 0.8633 0.023 0.006 0.000 0.042 0.8867 0.023 0.007 0.000 0.042 0.9100 0.023 0.007 0.000 0.042 0.9333 0.023 0.007 0.000 0.042 0.9567 0.023 0.007 0.000 0.042 0.9800 0.023 0.007 0.000 0.042 1.0033 0.023 0.008 0.000 0.042 1.0267 0.023 0.008 0.000 0.042 1.0500 0.023 0.008 0.000 0.042 1.0733 0.023 0.008 0.000 0.042 1.0967 0.023 0.008 0.000 0.042 1.1200 0.023 0.009 0.000 0.042 1.1433 0.023 0.009 0.000 0.042 1.1667 0.023 0.009 0.000 0.042 1.1900 0.023 0.009 0.000 0.042 1.2133 0.023 0.009 0.000 0.042 1.2367 0.023 0.009 0.000 0.042 1.2600 0.023 0.010 0.000 0.042 1.2833 0.023 0.010 0.000 0.042 1.3067 0.023 0.010 0.000 0.042 1.3300 0.023 0.010 0.000 0.042 1.3533 0.023 0.010 0.000 0.042 1.3767 0.023 0.011 0.000 0.042 1.4000 0.023 0.011 0.000 0.042 1.4233 0.023 0.011 0.000 0.042 1.4467 0.023 0.011 0.000 0.042 1.4700 0.023 0.011 0.000 0.042 1.4933 0.023 0.012 0.000 0.042 1.5167 0.023 0.012 0.000 0.042 1.5400 0.023 0.012 0.000 0.042 1.5633 0.023 0.012 0.000 0.042 1.5867 0.023 0.012 0.000 0.042 1.6100 0.023 0.012 0.000 0.042 1.6333 0.023 0.013 0.000 0.042 1.6567 0.023 0.013 0.000 0.042 1.6800 0.023 0.013 0.000 0.042 1.7033 0.023 0.013 0.000 0.042 1.7267 0.023 0.013 0.000 0.042 1.7500 0.023 0.014 0.000 0.042 614 5th Ave S WWHM 11/3/2023 8:46:35 PM Page 13 1.9600 0.023 0.015 0.000 0.042 1.9833 0.023 0.015 0.000 0.042 2.0067 0.023 0.016 0.004 0.042 2.0300 0.023 0.017 0.045 0.042 2.0533 0.023 0.017 0.108 0.042 2.0767 0.023 0.018 0.186 0.042 614 5th Ave S WWHM 11/3/2023 8:46:35 PM Page 14 Analysis Results POC 1 ni 0.0001 o.oam Percent Time Exceetlir�g . 1 2 5 1. . . . 10 . . . . .. 1 + Predeveloped x Mitigated 01 0.01 001 M. om1 Predeveloped Landuse Totals for POC #1 Total Pervious Area: 0.493595 Total Impervious Area: 0 Mitigated Landuse Totals for POC #1 Total Pervious Area: 0.018852 Total Impervious Area: 0.474743 Flow Frequency Method: Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.008375 5 year 0.012999 10 year 0.015507 25 year 0.018057 50 year 0.019572 100 year 0.020817 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.031448 5 year 0.04246 10 year 0.050666 25 year 0.062124 50 year 0.071487 100 year 0.081591 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1902 0.012 0.036 1903 0.004 0.039 1904 0.007 0.043 1905 0.005 0.023 1906 0.002 0.027 1907 0.013 0.031 1908 0.008 0.025 1909 0.009 0.032 1910 0.014 0.028 1911 0.007 0.034 614 5th Ave S WWHM 11/3/2023 8:46:35 PM Page 15 1912 0.025 0.056 1913 0.013 0.028 1914 0.003 0.090 1915 0.004 0.021 1916 0.007 0.040 1917 0.003 0.019 1918 0.008 0.030 1919 0.006 0.019 1920 0.008 0.028 1921 0.008 0.020 1922 0.009 0.032 1923 0.006 0.026 1924 0.004 0.044 1925 0.004 0.019 1926 0.007 0.038 1927 0.009 0.031 1928 0.006 0.023 1929 0.013 0.041 1930 0.008 0.049 1931 0.008 0.021 1932 0.005 0.025 1933 0.007 0.024 1934 0.018 0.036 1935 0.007 0.021 1936 0.011 0.031 1937 0.009 0.039 1938 0.009 0.021 1939 0.001 0.028 1940 0.007 0.050 1941 0.007 0.052 1942 0.011 0.036 1943 0.004 0.033 1944 0.009 0.046 1945 0.008 0.037 1946 0.007 0.028 1947 0.005 0.022 1948 0.017 0.027 1949 0.014 0.051 1950 0.008 0.026 1951 0.009 0.049 1952 0.025 0.047 1953 0.022 0.043 1954 0.007 0.027 1955 0.006 0.029 1956 0.004 0.021 1957 0.010 0.026 1958 0.023 0.031 1959 0.014 0.029 1960 0.005 0.025 1961 0.014 0.069 1962 0.007 0.030 1963 0.003 0.020 1964 0.007 0.067 1965 0.017 0.041 1966 0.003 0.025 1967 0.007 0.036 1968 0.009 0.028 1969 0.006 0.024 614 5th Ave S WWHM 11/3/2023 8:47:52 PM Page 16 1970 0.010 0.031 1971 0.018 0.028 1972 0.012 0.109 1973 0.013 0.059 1974 0.008 0.040 1975 0.019 0.040 1976 0.009 0.042 1977 0.005 0.020 1978 0.017 0.030 1979 0.004 0.031 1980 0.008 0.035 1981 0.008 0.039 1982 0.006 0.025 1983 0.013 0.034 1984 0.004 0.032 1985 0.008 0.039 1986 0.006 0.020 1987 0.014 0.037 1988 0.010 0.021 1989 0.008 0.030 1990 0.010 0.025 1991 0.008 0.037 1992 0.012 0.036 1993 0.010 0.042 1994 0.017 0.028 1995 0.004 0.019 1996 0.019 0.029 1997 0.009 0.025 1998 0.008 0.029 1999 0.000 0.036 2000 0.006 0.030 2001 0.005 0.039 2002 0.012 0.045 2003 0.009 0.030 2004 0.009 0.038 2005 0.012 0.080 2006 0.006 0.031 2007 0.007 0.037 2008 0.009 0.031 2009 0.005 0.025 2010 0.004 0.031 2011 0.006 0.033 2012 0.008 0.028 2013 0.006 0.032 2014 0.004 0.026 2015 0.017 0.064 2016 0.002 0.026 2017 0.014 0.045 2018 0.023 0.029 2019 0.025 0.065 2020 0.007 0.035 2021 0.011 0.030 2022 0.004 0.041 2023 0.009 0.053 2024 0.020 0.063 2025 0.007 0.044 2026 0.013 0.041 2027 0.006 0.041 614 5th Ave S WWHM 11/3/2023 8:47:52 PM Page 17 2028 0.003 0.018 2029 0.009 0.022 2030 0.018 0.051 2031 0.005 0.017 2032 0.004 0.027 2033 0.005 0.028 2034 0.005 0.022 2035 0.020 0.028 2036 0.011 0.025 2037 0.002 0.035 2038 0.011 0.029 2039 0.001 0.057 2040 0.004 0.026 2041 0.006 0.028 2042 0.021 0.040 2043 0.009 0.043 2044 0.013 0.029 2045 0.008 0.024 2046 0.010 0.022 2047 0.006 0.031 2048 0.008 0.026 2049 0.008 0.040 2050 0.005 0.023 2051 0.008 0.037 2052 0.005 0.031 2053 0.009 0.026 2054 0.011 0.051 2055 0.003 0.033 2056 0.003 0.042 2057 0.006 0.021 2058 0.007 0.039 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.0253 0.1090 2 0.0253 0.0896 3 0.0246 0.0799 4 0.0232 0.0693 5 0.0230 0.0667 6 0.0218 0.0645 7 0.0212 0.0636 8 0.0203 0.0628 9 0.0197 0.0591 10 0.0192 0.0574 11 0.0190 0.0556 12 0.0184 0.0526 13 0.0181 0.0519 14 0.0179 0.0510 15 0.0171 0.0507 16 0.0171 0.0505 17 0.0169 0.0501 18 0.0166 0.0490 19 0.0166 0.0489 20 0.0143 0.0472 21 0.0143 0.0461 22 0.0141 0.0450 23 0.0140 0.0448 614 5th Ave S WWHM 11/3/2023 8:47:52 PM Page 18 24 0.0136 0.0439 25 0.0135 0.0438 26 0.0135 0.0435 27 0.0134 0.0426 28 0.0132 0.0426 29 0.0130 0.0424 30 0.0129 0.0420 31 0.0129 0.0418 32 0.0125 0.0411 33 0.0118 0.0406 34 0.0117 0.0406 35 0.0117 0.0406 36 0.0117 0.0405 37 0.0115 0.0404 38 0.0113 0.0403 39 0.0113 0.0403 40 0.0109 0.0399 41 0.0109 0.0398 42 0.0106 0.0393 43 0.0105 0.0391 44 0.0103 0.0390 45 0.0101 0.0388 46 0.0097 0.0387 47 0.0096 0.0385 48 0.0095 0.0384 49 0.0095 0.0381 50 0.0094 0.0374 51 0.0094 0.0374 52 0.0093 0.0373 53 0.0093 0.0366 54 0.0092 0.0366 55 0.0092 0.0363 56 0.0091 0.0363 57 0.0091 0.0363 58 0.0091 0.0362 59 0.0090 0.0360 60 0.0090 0.0358 61 0.0090 0.0355 62 0.0089 0.0353 63 0.0088 0.0350 64 0.0086 0.0344 65 0.0085 0.0339 66 0.0085 0.0334 67 0.0085 0.0334 68 0.0084 0.0325 69 0.0083 0.0324 70 0.0082 0.0321 71 0.0081 0.0319 72 0.0081 0.0315 73 0.0081 0.0315 74 0.0081 0.0314 75 0.0080 0.0312 76 0.0080 0.0310 77 0.0080 0.0310 78 0.0079 0.0309 79 0.0079 0.0308 80 0.0078 0.0306 81 0.0077 0.0305 614 5th Ave S WWHM 11/3/2023 8:47:52 PM Page 19 82 0.0076 0.0305 83 0.0076 0.0305 84 0.0076 0.0304 85 0.0076 0.0304 86 0.0075 0.0302 87 0.0075 0.0300 88 0.0075 0.0299 89 0.0074 0.0298 90 0.0074 0.0297 91 0.0074 0.0293 92 0.0073 0.0293 93 0.0073 0.0292 94 0.0073 0.0289 95 0.0072 0.0287 96 0.0069 0.0286 97 0.0068 0.0285 98 0.0068 0.0285 99 0.0068 0.0282 100 0.0066 0.0282 101 0.0066 0.0282 102 0.0066 0.0279 103 0.0066 0.0279 104 0.0064 0.0278 105 0.0063 0.0278 106 0.0063 0.0277 107 0.0062 0.0277 108 0.0060 0.0276 109 0.0060 0.0275 110 0.0060 0.0272 111 0.0060 0.0271 112 0.0059 0.0269 113 0.0059 0.0268 114 0.0058 0.0264 115 0.0057 0.0263 116 0.0056 0.0262 117 0.0056 0.0261 118 0.0056 0.0260 119 0.0055 0.0258 120 0.0055 0.0258 121 0.0053 0.0255 122 0.0051 0.0254 123 0.0051 0.0253 124 0.0050 0.0252 125 0.0050 0.0252 126 0.0049 0.0251 127 0.0049 0.0250 128 0.0047 0.0250 129 0.0046 0.0247 130 0.0045 0.0247 131 0.0044 0.0242 132 0.0044 0.0236 133 0.0043 0.0236 134 0.0042 0.0231 135 0.0041 0.0227 136 0.0041 0.0225 137 0.0040 0.0222 138 0.0040 0.0221 139 0.0040 0.0220 614 5th Ave S WWHM 11/3/2023 8:47:52 PM Page 20 140 0.0040 0.0217 141 0.0039 0.0212 142 0.0038 0.0210 143 0.0037 0.0209 144 0.0035 0.0209 145 0.0035 0.0206 146 0.0034 0.0206 147 0.0033 0.0206 148 0.0032 0.0204 149 0.0030 0.0204 150 0.0029 0.0198 151 0.0028 0.0195 152 0.0023 0.0194 153 0.0020 0.0189 154 0.0019 0.0188 155 0.0009 0.0188 156 0.0006 0.0176 157 0.0004 0.0173 614 5th Ave S WWHM 11/3/2023 8:47:52 PM Page 21 Duration Flows The Duration Matching Failed Flow(cfs) Predev Mit Percentage Pass/Fail 0.0042 53300 134378 252 Fail 0.0043 49039 127882 260 Fail 0.0045 45147 121771 269 Fail 0.0047 41778 116101 277 Fail 0.0048 38645 110651 286 Fail 0.0050 35816 105421 294 Fail 0.0051 33239 100467 302 Fail 0.0053 30916 95622 309 Fail 0.0054 28874 91273 316 Fail 0.0056 26936 86759 322 Fail 0.0057 25174 82630 328 Fail 0.0059 23440 78887 336 Fail 0.0061 21866 75309 344 Fail 0.0062 20336 71896 353 Fail 0.0064 18915 68593 362 Fail 0.0065 17666 65455 370 Fail 0.0067 16504 62372 377 Fail 0.0068 15464 59619 385 Fail 0.0070 14456 56922 393 Fail 0.0071 13498 54346 402 Fail 0.0073 12601 52011 412 Fail 0.0075 11792 49754 421 Fail 0.0076 11060 47481 429 Fail 0.0078 10416 45361 435 Fail 0.0079 9837 43539 442 Fail 0.0081 9309 41668 447 Fail 0.0082 8786 39878 453 Fail 0.0084 8291 38155 460 Fail 0.0085 7850 36647 466 Fail 0.0087 7393 35106 474 Fail 0.0088 7035 33625 477 Fail 0.0090 6667 32226 483 Fail 0.0092 6342 30905 487 Fail 0.0093 6039 29667 491 Fail 0.0095 5742 28455 495 Fail 0.0096 5474 27354 499 Fail 0.0098 5220 26264 503 Fail 0.0099 4988 25169 504 Fail 0.0101 4759 24211 508 Fail 0.0102 4548 23264 511 Fail 0.0104 4337 22328 514 Fail 0.0106 4134 21536 520 Fail 0.0107 3943 20688 524 Fail 0.0109 3782 19879 525 Fail 0.0110 3632 19152 527 Fail 0.0112 3491 18436 528 Fail 0.0113 3369 17726 526 Fail 0.0115 3256 17082 524 Fail 0.0116 3147 16488 523 Fail 614 5th Ave S WWHM 11/3/2023 8:47:52 PM Page 22 0.0126 2594 13196 508 Fail 0.0127 2494 12722 510 Fail 0.0129 2393 12282 513 Fail 0.0130 2279 11830 519 Fail 0.0132 2181 11423 523 Fail 0.0134 2081 11054 531 Fail 0.0135 1997 10685 535 Fail 0.0137 1933 10333 534 Fail 0.0138 1866 9964 533 Fail 0.0140 1790 9628 537 Fail 0.0141 1719 9254 538 Fail 0.0143 1666 8935 536 Fail 0.0144 1596 8599 538 Fail 0.0146 1539 8318 540 Fail 0.0148 1482 8037 542 Fail 0.0149 1417 7724 545 Fail 0.0151 1361 7448 547 Fail 0.0152 1298 7195 554 Fail 0.0154 1245 6920 555 Fail 0.0155 1188 6700 563 Fail 0.0157 1147 6468 563 Fail 0.0158 1100 6188 562 Fail 0.0160 1047 5962 569 Fail 0.0162 1000 5747 574 Fail 0.0163 957 5560 580 Fail 0.0165 916 5339 582 Fail 0.0166 877 5144 586 Fail 0.0168 832 4950 594 Fail 0.0169 788 4770 605 Fail 0.0171 755 4615 611 Fail 0.0172 710 4434 624 Fail 0.0174 666 4276 642 Fail 0.0176 627 4122 657 Fail 0.0177 595 3961 665 Fail 0.0179 555 3789 682 Fail 0.0180 517 3620 700 Fail 0.0182 462 3440 744 Fail 0.0183 423 3305 781 Fail 0.0185 392 3161 806 Fail 0.0186 361 3022 837 Fail 0.0188 335 2886 861 Fail 0.0190 306 2732 892 Fail 0.0191 286 2616 914 Fail 0.0193 264 2509 950 Fail 0.0194 248 2419 975 Fail 0.0196 233 2325 997 Fail The development has an increase in flow durations from 1/2 Predeveloped 2 year flow to the 2 year flow or more than a 10% increase from the 2 year to the 50 year flow. The development has an increase in flow durations for more than 50% of the flows for the range of the duration analysis. 614 5th Ave S WWHM 11/3/2023 8:47:52 PM Page 23 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. 614 5th Ave S WWHM 11/3/2023 8:47:52 PM Page 24 LID Report LID Technique Used for Total Volume Volume Infiltration Cumulative Percent Water Quality Percent Comment Treatment? Needs Through Volume Volume Volume Water Quality Treatment Facility (ac-ft) Infiltration Infiltrated Treated (ac-ft) (ac-ft) Credit Gravel Trench Bed 1 POC ❑ 58.80 ❑ 100.00 Gravel Trench Bed 2 POC ❑ 73.20 ❑ 100.00 Total Volume Infiltrated 132.01 0.00 0.00 100.00 n nn 0% No Treat. Credit Duration Compliance with LID Analysis Standard 8% of 2-yr to 50% of Result = 2 yr Failed 614 5th Ave S WWHM 11/3/2023 8:47:52 PM Page 25 POC 2 POC #2 was not reported because POC must exist in both scenarios and both scenarios must have been run. 614 5th Ave S WWHM 11/3/2023 8:48:50 PM Page 26 POC 3 POC #3 was not reported because POC must exist in both scenarios and both scenarios must have been run. 614 5th Ave S WWHM 11/3/2023 8:48:50 PM Page 27 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. 614 5th Ave S WWHM 11/3/2023 8:48:51 PM Page 28 Appendix Predeveloped Schematic EL.�Basin 1 L 0.49ac 614 5th Ave S WWHM 11/3/2023 8:48:51 PM Page 29 Mitigated Schematic atslb 4 .02 �s � .10ac ....a I kway I f I SI Gravel Me&#i Bed 2 614 5th Ave S WWHM 11/3/2023 8:48:51 PM Page 30 Predeveloped UCI File RUN GLOBAL WWHM4 model simulation START 1901 10 01 END RUN INTERP OUTPUT LEVEL 3 0 RESUME 0 RUN 1 END GLOBAL 2058 09 30 FILES <File> <Un#> END FILES OPN SEQUENCE UNIT SYSTEM 1 <----------- File Name----- ------------------------->*** *** INGRP INDELT 00:15 PERLND 11 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<---------- Title ----------- >***TRAN PIVL DIG1 FIL1 1 Basin 1 MAX 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 PYR DIG2 FIL2 YRND 1 2 30 9 <PLS ><------- Name ------- >NBLKS Unit -systems Printer *** # - # User t-series Engl Metr *** in out *** 11 C, Forest, 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 *** 11 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 ********* 11 0 0 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT -INFO 614 5th Ave S WWHM 11/3/2023 8:48:52 PM Page 31 PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 11 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 11 0 4.5 0.08 400 0.1 0.5 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 # - # ***PETMAX PETMIN INFEXP 11 0 0 2 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 # - # CEPSC UZSN NSUR 11 0.2 0.5 0.35 END PWAT-PARM4 AGWRC 0.996 *** INFILD DEEPFR BASETP AGWETP 2 0 0 0 *** INTFW IRC LZETP *** 6 0.5 0.7 PWAT-STATEI <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 11 0 0 0 0 2.5 1 END PWAT-STATEI END PERLND IMPLND GEN-INFO <PLS ><------- Name ------- > END GEN-INFO *** Section IWATER*** Unit -systems Printer *** User t-series Engl Metr *** in out *** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** END ACTIVITY PRINT -INFO <ILS > ******** Print -flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* END PRINT -INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN END IWAT-PARM3 IWAT-STATEI <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS END IWAT-STATEI GWVS 0 614 5th Ave S WWHM 11/3/2023 8:48:52 PM Page 32 END IMPLND SCHEMATIC <-Source-> <Name> # Basin 1*** PERLND 11 PERLND 11 ******Routing****** END SCHEMATIC <--Area--> <-Target-> MBLK <-factor-> <Name> # Tbl# 0.493595 COPY 501 12 0.493595 COPY 501 13 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 ********* END PRINT -INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC Al 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 DIV PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 DIV IMPLND 1 999 EXTNL PREC 614 5th Ave S WWHM 11/3/2023 8:48:52 PM Page 33 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 SURD 0.083333 COPY INPUT MEAN END MASS -LINK 12 MASS -LINK 13 PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS -LINK 13 END MASS -LINK END RUN 614 5th Ave S WWHM 11/3/2023 8:48:52 PM Page 34 Mitigated UC/ File RUN GLOBAL WWHM4 model simulation START 1901 10 01 END 2058 09 30 RUN INTERP OUTPUT LEVEL 3 0 RESUME 0 RUN 1 UNIT SYSTEM 1 END GLOBAL FILES <File> <Un#> <----------- File Name ------------------------------ >*** <-ID-> *** WDM 26 614 5th Ave S WWHM.wdm MESSU 25 Mit614 5th Ave S WWHM.MES 27 Mit614 5th Ave S WWHM.L61 28 Mit614 5th Ave S WWHM.L62 31 POC614 5th Ave S WWHM2.dat 32 POC614 5th Ave S WWHM3.dat 30 POC614 5th Ave S WWHM1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 IMPLND 4 IMPLND 11 PERLND 16 PERLND 7 IMPLND 2 RCHRES 1 RCHRES 2 COPY 502 COPY 503 COPY 1 COPY 501 COPY 601 DISPLY 2 DISPLY 3 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<---------- Title ----------- >***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 2 BLDG C+ Dwy MAX 1 2 31 9 3 BLDG A+ B+ Conc dwy/wal MAX 1 2 32 9 1 Gravel Trench Bed 2 MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 502 1 1 503 1 1 501 1 1 601 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO 614 5th Ave S WWHM 11/3/2023 8:48:52 PM Page 35 <PLS ><------- Name ------- >NBLKS Unit -systems Printer *** # - # User t-series Engl Metr *** in out *** 16 C, Lawn, Flat 1 1 1 1 27 0 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 *** 16 0 0 1 0 0 0 0 0 0 0 0 0 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 ********* 16 0 0 4 0 0 0 0 0 0 0 0 0 1 9 7 0 0 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT -INFO PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 16 0 0 0 0 0 0 0 0 0 0 0 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 16 0 4.5 0.03 400 0.05 0.5 0.996 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 16 0 0 2 2 0 0 0 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 *** 16 0.1 0.25 0.25 6 0.5 0.25 7 0.1 0.5 0.25 0 0.7 0.25 END PWAT-PARM4 PWAT-STATEI <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 16 0 0 0 0 2.5 1 0 7 0 0 0 0 3 1 0 END PWAT-STATEI END PERLND IMPLND GEN-INFO <PLS ><------- Name ------- > 4 ROOF TOPS/FLAT 11 PARKING/FLAT 2 ROADS/MOD END GEN-INFO *** Section IWATER*** Unit -systems Printer *** User t-series Engl Metr *** in out *** 1 1 1 27 0 1 1 1 27 0 1 1 1 27 0 614 5th Ave S WWHM 11/3/2023 8:48:52 PM Page 36 ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** 4 0 0 1 0 0 0 11 0 0 1 0 0 0 2 0 0 1 0 0 0 END ACTIVITY PRINT -INFO <ILS > ******** Print -flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* 4 0 0 4 0 0 4 1 9 11 0 0 4 0 0 0 1 9 2 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 *** 4 0 0 0 0 0 11 0 0 0 0 0 2 0 0 0 0 0 END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC 4 400 0.01 0.1 0.1 11 400 0.01 0.1 0.1 2 400 0.05 0.1 0.08 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN 4 0 0 11 0 0 2 0 0 END IWAT-PARM3 IWAT-STATEI <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 4 0 0 11 0 0 2 0 0 END IWAT-STATEI END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** BLDG C + Dwy *** IMPLND 4 0.1213 RCHRES 2 5 IMPLND 11 0.0424 RCHRES 2 5 BLDG A + B + Conc dwy/walkway*** IMPLND 4 0.0981 RCHRES 1 5 IMPLND 11 0.1149 RCHRES 1 5 Basin 3*** PERLND 16 0.0173 RCHRES 2 2 PERLND 16 0.0173 RCHRES 2 3 BLDG C + Dwy *** IMPLND 4 0.121281 COPY 502 15 IMPLND 11 0.042401 COPY 502 15 BLDG A + B + Conc dwy/walkway*** IMPLND 4 0.098095 COPY 503 15 IMPLND 11 0.114876 COPY 503 15 Basin 4*** PERLND 7 0.00152 COPY 501 12 614 5th Ave S WWHM 11/3/2023 8:48:52 PM Page 37 PERLND 7 0.00152 COPY 601 12 PERLND 7 0.00152 COPY 501 13 PERLND 7 0.00152 COPY 601 13 IMPLND 2 0.09809 COPY 501 15 IMPLND 2 0.09809 COPY 601 15 ******Routing****** IMPLND 4 0.121281 COPY 1 15 IMPLND 11 0.042401 COPY 1 15 IMPLND 4 0.098095 COPY 1 15 IMPLND 11 0.114876 COPY 1 15 PERLND 16 0.017332 COPY 1 12 PERLND 16 0.017332 COPY 1 13 RCHRES 2 1 COPY 501 17 RCHRES 1 1 COPY 501 17 END SCHEMATIC NETWORK <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 502 OUTPUT MEAN 1 1 48.4 DISPLY 2 INPUT TIMSER 1 COPY 503 OUTPUT MEAN 1 1 48.4 DISPLY 3 INPUT TIMSER 1 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 # - #<------------------ >< --- > User T-series in out 1 Gravel Trench Be-008 2 1 1 1 2 Gravel Trench Be-007 2 1 1 1 END GEN-INFO *** Section RCHRES*** Printer *** Engl Metr LKFG *** *** 28 0 1 28 0 1 ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** 1 1 0 0 0 0 0 0 0 0 0 2 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT -INFO <PLS > ***************** Print -flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* 1 4 0 0 0 0 0 0 0 0 0 1 9 2 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT -INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC Al A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** 1 0 1 0 0 4 5 0 0 0 0 0 0 0 0 2 2 2 2 2 2 0 1 0 0 4 5 0 0 0 0 0 0 0 0 2 2 2 2 2 END HYDR-PARM1 HYDR-PARM2 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------ ><--------><-------- ><-------- ><-------- ><-------- ><-------- > *** 1 1 0.01 0.0 0.0 0.5 0.0 2 2 0.02 0.0 0.0 0.5 0.0 END HYDR-PARM2 HYDR-INIT 614 5th Ave S WWHM 11/3/2023 8:48:52 PM Page 38 RCHRES Initial # - # *** VOL *** ac-ft <------><-------- > 1 0 2 0 END HYDR-INIT END RCHRES SPEC -ACTIONS END SPEC -ACTIONS FTABLES FTABLE 2 91 5 conditions for each HYDR section Initial value of COLIND for each possible exit <--- ><--- ><--- ><--- ><---> *** 4.0 5.0 0.0 0.0 0.0 4.0 5.0 0.0 0.0 0.0 Depth Area Volume Outflowl Outflow2 (ft) (acres) (acre-ft) (cfs) (cfs) 0.000000 0.023967 0.000000 0.000000 0.000000 0.023333 0.023967 0.000196 0.000000 0.019333 0.046667 0.023967 0.000391 0.000000 0.019333 0.070000 0.023967 0.000587 0.000000 0.019333 0.093333 0.023967 0.000783 0.000000 0.019333 0.116667 0.023967 0.000979 0.000000 0.019333 0.140000 0.023967 0.001174 0.000000 0.019333 0.163333 0.023967 0.001370 0.000000 0.019333 0.186667 0.023967 0.001566 0.000000 0.019333 0.210000 0.023967 0.001762 0.000000 0.019333 0.233333 0.023967 0.001957 0.000000 0.019333 0.256667 0.023967 0.002153 0.000000 0.019333 0.280000 0.023967 0.002349 0.000000 0.019333 0.303333 0.023967 0.002544 0.000000 0.019333 0.326667 0.023967 0.002740 0.000000 0.019333 0.350000 0.023967 0.002936 0.000000 0.019333 0.373333 0.023967 0.003132 0.000000 0.019333 0.396667 0.023967 0.003327 0.000000 0.019333 0.420000 0.023967 0.003523 0.000000 0.019333 0.443333 0.023967 0.003719 0.000000 0.019333 0.466667 0.023967 0.003915 0.000000 0.019333 0.490000 0.023967 0.004110 0.000000 0.019333 0.513333 0.023967 0.004306 0.000000 0.019333 0.536667 0.023967 0.004502 0.000000 0.019333 0.560000 0.023967 0.004698 0.000000 0.019333 0.583333 0.023967 0.004893 0.000000 0.019333 0.606667 0.023967 0.005089 0.000000 0.019333 0.630000 0.023967 0.005285 0.000000 0.019333 0.653333 0.023967 0.005480 0.000000 0.019333 0.676667 0.023967 0.005676 0.000000 0.019333 0.700000 0.023967 0.005872 0.000000 0.019333 0.723333 0.023967 0.006068 0.000000 0.019333 0.746667 0.023967 0.006263 0.000000 0.019333 0.770000 0.023967 0.006459 0.000000 0.019333 0.793333 0.023967 0.006655 0.000000 0.019333 0.816667 0.023967 0.006851 0.000000 0.019333 0.840000 0.023967 0.007046 0.000000 0.019333 0.863333 0.023967 0.007242 0.000000 0.019333 0.886667 0.023967 0.007438 0.000000 0.019333 0.910000 0.023967 0.007633 0.000000 0.019333 0.933333 0.023967 0.007829 0.000000 0.019333 0.956667 0.023967 0.008025 0.000000 0.019333 0.980000 0.023967 0.008221 0.000000 0.019333 1.003333 0.023967 0.008416 0.000000 0.019333 1.026667 0.023967 0.008612 0.000000 0.019333 1.050000 0.023967 0.008808 0.000000 0.019333 1.073333 0.023967 0.009004 0.000000 0.019333 1.096667 0.023967 0.009199 0.000000 0.019333 1.120000 0.023967 0.009395 0.000000 0.019333 1.143333 0.023967 0.009591 0.000000 0.019333 1.166667 0.023967 0.009787 0.000000 0.019333 1.190000 0.023967 0.009982 0.000000 0.019333 1.213333 0.023967 0.010178 0.000000 0.019333 1.236667 0.023967 0.010374 0.000000 0.019333 *** Initial value of OUTDGT for each possible exit <--- ><--- ><--- ><--- ><---> 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Velocity Travel Time*** (ft/sec) (Minutes)*** 614 5th Ave S WWHM 11/3/2023 8:48:52 PM Page 39 1.260000 0.023967 0.010569 0.000000 0.019333 1.283333 0.023967 0.010765 0.000000 0.019333 1.306667 0.023967 0.010961 0.000000 0.019333 1.330000 0.023967 0.011157 0.000000 0.019333 1.353333 0.023967 0.011352 0.000000 0.019333 1.376667 0.023967 0.011548 0.000000 0.019333 1.400000 0.023967 0.011744 0.000000 0.019333 1.423333 0.023967 0.011940 0.000000 0.019333 1.446667 0.023967 0.012135 0.000000 0.019333 1.470000 0.023967 0.012331 0.000000 0.019333 1.493333 0.023967 0.012527 0.000000 0.019333 1.516667 0.023967 0.012722 0.000000 0.019333 1.540000 0.023967 0.012918 0.000000 0.019333 1.563333 0.023967 0.013114 0.000000 0.019333 1.586667 0.023967 0.013310 0.000000 0.019333 1.610000 0.023967 0.013505 0.000000 0.019333 1.633333 0.023967 0.013701 0.000000 0.019333 1.656667 0.023967 0.013897 0.000000 0.019333 1.680000 0.023967 0.014093 0.000000 0.019333 1.703333 0.023967 0.014288 0.000000 0.019333 1.726667 0.023967 0.014484 0.000000 0.019333 1.750000 0.023967 0.014680 0.000000 0.019333 1.773333 0.023967 0.014875 0.000000 0.019333 1.796667 0.023967 0.015071 0.000000 0.019333 1.820000 0.023967 0.015267 0.000000 0.019333 1.843333 0.023967 0.015463 0.000000 0.019333 1.866667 0.023967 0.015658 0.000000 0.019333 1.890000 0.023967 0.015854 0.000000 0.019333 1.913333 0.023967 0.016050 0.000000 0.019333 1.936667 0.023967 0.016246 0.000000 0.019333 1.960000 0.023967 0.016441 0.000000 0.019333 1.983333 0.023967 0.016637 0.000000 0.019333 2.006667 0.023967 0.017196 0.004816 0.019333 2.030000 0.023967 0.017756 0.045916 0.019333 2.053333 0.023967 0.018315 0.108684 0.019333 2.076667 0.023967 0.018874 0.186796 0.019333 2.100000 0.023967 0.019433 0.276837 0.019333 END FTABLE 2 FTABLE 1 91 5 Depth Area Volume Outflowl Outflow2 Velocity Travel Time*** (ft) (acres) (acre-ft) (cfs) (cfs) (ft/sec) (Minutes)*** 0.000000 0.022957 0.000000 0.000000 0.000000 0.023333 0.022957 0.000187 0.000000 0.042708 0.046667 0.022957 0.000375 0.000000 0.042708 0.070000 0.022957 0.000562 0.000000 0.042708 0.093333 0.022957 0.000750 0.000000 0.042708 0.116667 0.022957 0.000937 0.000000 0.042708 0.140000 0.022957 0.001125 0.000000 0.042708 0.163333 0.022957 0.001312 0.000000 0.042708 0.186667 0.022957 0.001500 0.000000 0.042708 0.210000 0.022957 0.001687 0.000000 0.042708 0.233333 0.022957 0.001875 0.000000 0.042708 0.256667 0.022957 0.002062 0.000000 0.042708 0.280000 0.022957 0.002250 0.000000 0.042708 0.303333 0.022957 0.002437 0.000000 0.042708 0.326667 0.022957 0.002625 0.000000 0.042708 0.350000 0.022957 0.002812 0.000000 0.042708 0.373333 0.022957 0.003000 0.000000 0.042708 0.396667 0.022957 0.003187 0.000000 0.042708 0.420000 0.022957 0.003375 0.000000 0.042708 0.443333 0.022957 0.003562 0.000000 0.042708 0.466667 0.022957 0.003750 0.000000 0.042708 0.490000 0.022957 0.003937 0.000000 0.042708 0.513333 0.022957 0.004125 0.000000 0.042708 0.536667 0.022957 0.004312 0.000000 0.042708 0.560000 0.022957 0.004500 0.000000 0.042708 0.583333 0.022957 0.004687 0.000000 0.042708 0.606667 0.022957 0.004875 0.000000 0.042708 0.630000 0.022957 0.005062 0.000000 0.042708 614 5th Ave S WWHM 11/3/2023 8:48:52 PM Page 40 0.653333 0.022957 0.005249 0.000000 0.042708 0.676667 0.022957 0.005437 0.000000 0.042708 0.700000 0.022957 0.005624 0.000000 0.042708 0.723333 0.022957 0.005812 0.000000 0.042708 0.746667 0.022957 0.005999 0.000000 0.042708 0.770000 0.022957 0.006187 0.000000 0.042708 0.793333 0.022957 0.006374 0.000000 0.042708 0.816667 0.022957 0.006562 0.000000 0.042708 0.840000 0.022957 0.006749 0.000000 0.042708 0.863333 0.022957 0.006937 0.000000 0.042708 0.886667 0.022957 0.007124 0.000000 0.042708 0.910000 0.022957 0.007312 0.000000 0.042708 0.933333 0.022957 0.007499 0.000000 0.042708 0.956667 0.022957 0.007687 0.000000 0.042708 0.980000 0.022957 0.007874 0.000000 0.042708 1.003333 0.022957 0.008062 0.000000 0.042708 1.026667 0.022957 0.008249 0.000000 0.042708 1.050000 0.022957 0.008437 0.000000 0.042708 1.073333 0.022957 0.008624 0.000000 0.042708 1.096667 0.022957 0.008812 0.000000 0.042708 1.120000 0.022957 0.008999 0.000000 0.042708 1.143333 0.022957 0.009187 0.000000 0.042708 1.166667 0.022957 0.009374 0.000000 0.042708 1.190000 0.022957 0.009562 0.000000 0.042708 1.213333 0.022957 0.009749 0.000000 0.042708 1.236667 0.022957 0.009936 0.000000 0.042708 1.260000 0.022957 0.010124 0.000000 0.042708 1.283333 0.022957 0.010311 0.000000 0.042708 1.306667 0.022957 0.010499 0.000000 0.042708 1.330000 0.022957 0.010686 0.000000 0.042708 1.353333 0.022957 0.010874 0.000000 0.042708 1.376667 0.022957 0.011061 0.000000 0.042708 1.400000 0.022957 0.011249 0.000000 0.042708 1.423333 0.022957 0.011436 0.000000 0.042708 1.446667 0.022957 0.011624 0.000000 0.042708 1.470000 0.022957 0.011811 0.000000 0.042708 1.493333 0.022957 0.011999 0.000000 0.042708 1.516667 0.022957 0.012186 0.000000 0.042708 1.540000 0.022957 0.012374 0.000000 0.042708 1.563333 0.022957 0.012561 0.000000 0.042708 1.586667 0.022957 0.012749 0.000000 0.042708 1.610000 0.022957 0.012936 0.000000 0.042708 1.633333 0.022957 0.013124 0.000000 0.042708 1.656667 0.022957 0.013311 0.000000 0.042708 1.680000 0.022957 0.013499 0.000000 0.042708 1.703333 0.022957 0.013686 0.000000 0.042708 1.726667 0.022957 0.013874 0.000000 0.042708 1.750000 0.022957 0.014061 0.000000 0.042708 1.773333 0.022957 0.014249 0.000000 0.042708 1.796667 0.022957 0.014436 0.000000 0.042708 1.820000 0.022957 0.014624 0.000000 0.042708 1.843333 0.022957 0.014811 0.000000 0.042708 1.866667 0.022957 0.014998 0.000000 0.042708 1.890000 0.022957 0.015186 0.000000 0.042708 1.913333 0.022957 0.015373 0.000000 0.042708 1.936667 0.022957 0.015561 0.000000 0.042708 1.960000 0.022957 0.015748 0.000000 0.042708 1.983333 0.022957 0.015936 0.000000 0.042708 2.006667 0.022957 0.016472 0.004816 0.042708 2.030000 0.022957 0.017007 0.045916 0.042708 2.053333 0.022957 0.017543 0.108684 0.042708 2.076667 0.022957 0.018079 0.186796 0.042708 2.100000 0.022957 0.018614 0.276837 0.042708 END FTABLE 1 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 DIV PERLND 1 999 EXTNL PREC 614 5th Ave S WWHM 11/3/2023 8:48:52 PM Page 41 WDM 2 PREC ENGL 1 DIV 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 2 OUTPUT MEAN 1 1 48.4 WDM 702 FLOW ENGL REPL COPY 502 OUTPUT MEAN 1 1 48.4 WDM 802 FLOW ENGL REPL COPY 602 OUTPUT MEAN 1 1 48.4 WDM 902 FLOW ENGL REPL COPY 3 OUTPUT MEAN 1 1 48.4 WDM 703 FLOW ENGL REPL COPY 503 OUTPUT MEAN 1 1 48.4 WDM 803 FLOW ENGL REPL COPY 603 OUTPUT MEAN 1 1 48.4 WDM 903 FLOW ENGL REPL RCHRES 2 HYDR RO 1 1 1 WDM 1000 FLOW ENGL REPL RCHRES 2 HYDR 0 1 1 1 WDM 1001 FLOW ENGL REPL RCHRES 2 HYDR 0 2 1 1 WDM 1002 FLOW ENGL REPL RCHRES 2 HYDR STAGE 1 1 1 WDM 1003 STAG ENGL REPL 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 COPY 601 OUTPUT MEAN 1 1 48.4 WDM 901 FLOW ENGL REPL RCHRES 1 HYDR RO 1 1 1 WDM 1004 FLOW ENGL REPL RCHRES 1 HYDR 0 1 1 1 WDM 1005 FLOW ENGL REPL RCHRES 1 HYDR 0 2 1 1 WDM 1006 FLOW ENGL REPL RCHRES 1 HYDR STAGE 1 1 1 WDM 1007 STAG ENGL REPL END EXT TARGETS MASS -LINK <Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS -LINK 2 PERLND PWATER SURO 0.083333 RCHRES INFLOW IVOL END MASS -LINK 2 MASS -LINK 3 PERLND PWATER IFWO 0.083333 RCHRES INFLOW IVOL END MASS -LINK 3 MASS -LINK 5 IMPLND IWATER SURO 0.083333 RCHRES INFLOW IVOL END MASS -LINK 5 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 MASS -LINK 17 RCHRES OFLOW OVOL 1 COPY INPUT MEAN END MASS -LINK 17 END MASS -LINK END RUN 614 5th Ave S WWHM 11/3/2023 8:48:52 PM Page 42 Predeveloped HSPF Message File 614 5th Ave S WWHM 11/3/2023 8:48:52 PM Page 43 Mitigated HSPF Message File 614 5th Ave S WWHM 11/3/2023 8:48:52 PM Page 44 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. 2005-2023; 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 614 5th Ave S WWHM 11/3/2023 8:48:52 PM Page 45 Stormwater Site Plans 614 5th Ave S Edmonds November 2023 APPENDIX C Operation and Maintenance Manual 20231110_614 5th Ave S Edmonds —Drainage Report Rev 4 614 5" Ave S — Pine Park Operation and Maintenance Manual Person or Organization Responsible for Maintenance of the On -Site Storm System: Johnathan Kurth 614 5th Ave S Edmonds, WA 98020 The Location Where the Operation and Maintenance Manual is to be Kept: 6145thAve S Edmonds, WA 98020 *Note: The manual and maintenance activity log must be made available to the City of Edmonds for inspection purposes. Description of On -Site Storm System The on -site storm system for the 614 5th Ave S townhouses consists of 4-6" storm drain pipe, two BioPod Biofilter Systems, two infiltration trenches, and four Type I catch basins. Stormwater runoff from the proposed townhome buildings will be collected in a gutter and downspout system and routed to their respective BioPod Biofilter Systems and infiltration trenches. Any runoff from the driveway and walkways will be collected in two trench drains along the southern portion of the property line, where it will then be routed into one of the BioPod Biofilter Systems and infiltration trenches. Any overflows from will be conveyed to a new 10" SD extension along the Private Alley to the south which will then flow into the City's storm system in the unnamed alley. The Type I catch basins serve as source control of pollution on the project site. In order to control pollutants, proper maintenance and cleaning of debris, sediments, and oil from stormwater collection and conveyance systems is required per the operation and maintenance recommendations found in Volume 5 Section 4.6 of the Stormwater Manual in addition to the BMPs in Volume IV Section 2.2. See the attached sheets for operation and maintenance requirements pertaining to the project. Contact Information for Stormwater Facility Manufacturers and Installers: Contractor (Installer of On -Site Stormwater Facilities) TBD Civil Engineer (Designer of On -Site Stormwater Facilities) Ben Iddins, P.E. Davido Consulting Group, Inc 9706 4th Ave NE, Suite 300 Seattle, WA 98115 Phone — 206.523.0024 ben(a),dcgwatershed. com Attachmenk • SWMMWW Operation and Maintenance Manual for Catch Basins • SWMMWW Maintenance Standards and Procedures for Infiltration Facilities • Oldcastle Infrastructure BioPod System Inspection & Maintenance Guide Table V-A.1: Maintenance Standards - Detention Ponds (continued) Maintenance Com- Defect Conditions When Maintenance Is Needed Results Expected When Maintenance Is Performed ponent Liner (if Applic- able) Liner is visible and has more than three 1/4-inch holes in it. Liner repaired or replaced. Liner is fully covered. Any part of berm which has settled 4 inches lower than the design elevation If settlement is apparent, measure berm to determine amount of settlement Settlements Settling can be an indication of more severe problems with the berm or outlet works. A Dike is built back to the design elevation. licensed engineer in the state of Washington should be consulted to determine the source of Ponds Berms (Dikes) the settlement. Discernable waterflow through pond berm. Ongoing erosion with potential for erosion to con- tinue. Piping Piping eliminated. Erosion potential resolved. (Recommend a Goethechnical engineer be called in to inspect and evaluate condition and recommend repair of condition. Tree growth on emergency spillways creates blockage problems and may cause failure of the berm due to uncontrolled overtopping. Trees should be removed. If root system is small (base less than 4 inches) the root system may be left in Tree Growth place. Otherwise the roots should be removed and the berm restored. A licensed engineer in the state of Emergency Overflow/ Tree growth on berms over feet in height may lead to piping through the berm which could Washington should be consulted for proper berm/spillway restoration. lead to failure of the berm. Spillway Berms and over feet in height Discernable waterflow through pond berm. Ongoing erosion with potential for erosion to con- tinue. Piping Piping eliminated. Erosion potential resolved. (Recommend a Geotechnical engineer be called in to inspect and evaluate condition and recommend repair of condition. Only one layer of rock exists above native soil in area five square feet or larger, or any expos - Emergency Over- Emergency Over- ure of native soil at the top of out flow path of spillway. Rocks and pad depth are restored to design standards. flow/Spillway flow/Spillway (Rip -rap on inside slopes need not be replaced.) Erosion See "Side Slopes of Pond" Table V-A.2: Maintenance Standards - Infiltration Maintenance Component Defect Conditions When Maintenance Is Needed Results Expected When Maintenance Is Per- formed Trash & Debris See Table V-A.1: Maintenance Standards - Detention Ponds See Table V-A.1: Maintenance Standards - Deten- tion Ponds Poisonous/Noxious Vegetation See Table V-A. Maintenance Standards - Detention Ponds See Table V-A.1: Maintenance Standards - Deten- tion Ponds General Contaminants and Pol- lution See Table V-A. Maintenance Standards - Detention Ponds See Table V-A.1: Maintenance Standards - Deten- tion Ponds Rodent Holes See Table V-A.1: Maintenance Standards - Detention Ponds See Table V-A.1: Maintenance Standards - Deten- tion Ponds Storage Area Sediment Water ponding in infiltration pond after rainfall ceases and appropriate time allowed for infiltration. Treatment basins should infiltrate Water Quality Design Storm Volume within 48 hours, and empty within 24 hours after cessation of most rain events. Sediment is removed and/or facility is cleaned so that infiltration system works according to design. 2019 Stormwater Management Manual for Western Washington Volume V - Appendix - Page 1006 Table V-A.2: Maintenance Standards - Infiltration (continued) Results Expected When Maintenance Is Per- Maintenance Component Defect Conditions When Maintenance Is Needed formed (A percolation test pit ortest of facility indicates facility is only working at 90% of its designed capabilities. Test every 2 to 5 years. If two inches or more sediment is present, remove). Filled with Sediment and Filter Bags if a licable g( applicable) Sediment and debris fill bagmore than 1/2 full. Filter bag is replaced or stem is redesigned. g p y g Debris Rock Filters Sediment and Debris By visual inspection, little or no waterflows through filter during heavy rain storms. Gravel in rock filter is replaced. Side Slopes of Pond Erosion See Table V-A.1: Maintenance Standards - Detention Ponds See Table V-A.1: Maintenance Standards - Deten- tion Ponds See Table V-A.1: Maintenance Standards - Deten- Tree Growth See Table V-A.1: Maintenance Standards - Detention Ponds tion Ponds Emergency Overflow Spillway See Table V-A.1: Maintenance Standards - Deten- and Berms over 4 feet in height. Piping See Table V-A.1: Maintenance Standards -Detention Ponds tion Ponds Rock Missing See Table V-A.1: Maintenance Standards - Detention Ponds See Table V-A.1: Maintenance Standards - Deten- tion Ponds Emergency Overflow Spillway Erosion See Table V-A.1: Maintenance Standards - Detention Ponds See Table V-A.1: Maintenance Standards - Deten- tion Ponds Facility or sump filled Pre -settling Ponds and Vaults with Sediment and/or 6" or designed sediment trap depth of sediment. Sediment is removed. debris Table V-A.3: Maintenance Standards - Closed Detention Systems (Tanks/Vaults) Maintenance Defect Conditions When Maintenance is Needed Results Expected When Maintenance is Per - Component formed Plugged Air Vents One-half of the cross section of a vent is blocked at any point or the vent is damaged. Vents open and functioning. Accumulated sediment depth exceeds 10% of the diameter of the storage area for 1/2 length of storage vault or any point Debris and Sediment depth exceeds 15% of diameter. All sediment and debris removed from storage (Example: 72-inch storage tank would require cleaning when sediment reaches depth of 7 inches for more than 1/2 length of area. Storage Area tank.) Any openings or voids allowing material to be transported into facility. Joints Between Tank/Pipe Section All joint between tank/pipe sections are sealed. (Will require engineering analysis to determine structural stability). Tank Pipe Bent Out of Shape Any part of tank/pipe is bent out of shape more than 10% of its design shape. (Review required by engineer to determine Tank/pipe repaired or replaced to design. structural stability). Cracks wider than 1/2-inch and any evidence of soil particles entering the structure through the cracks, or main- Vault replaced or repaired to design spe- Vault Structure Includes Cracks in Wall, Bottom, tenance/inspection personnel determines that the vault is not structurally sound. cifications and is structurally sound. Damage to Frame and/or Top Slab Cracks wider than 1/2-inch at the joint of any inlet/outlet pipe or any evidence of soil particles entering the vault through the No cracks more than 1/4-inch wide at the joint of walls. the inlet/outlet pipe. 2019 Stormwater Management Manual for Western Washington Volume V - Appendix - Page 1007 Table V-A.S: Maintenance Standards - Catch Basins Maintenance Defect Conditions When Maintenance is Needed Results Expected When Maintenance is per - Component formed Trash or debris which is located immediately in front of the catch basin opening or is blocking inletting capacity of the basin by more than 10%. No Trash or debris located immediately in front of Trash or debris (in the basin) that exceeds 60 percent of the sump depth as measured from the bottom of basin to invert of the lowest pipe into or out of the catch basin or on grate opening. basin, but in no case less than a minimum of six inches clearance from the debris surface to the invert of the lowest pipe. No trash or debris in the catch basin. Trash & Debris Trash or debris in an inlet or outlet pipe blocking more than 1/3 of its height. Y p�p g g Inlet and outlet pipes free of trash or debris. Dead animals or vegetation that could generate odors that could cause complaints or dangerous gases (e.g., methane). No dead animals or vegetation present within the catch basin. Sediment (in the basin) that exceeds 60 percent of the sump depth as measured from the bottom of basin to invert of the lowest pipe into or out of the Sediment basin, but in no case less than a minimum of 6 inches clearance from the sediment surface to the invert of the lowest pipe. No sediment in the catch basin General Structure Damage to To slab has holes larger than 2 square inches or cracks wider than 1/4 inch. Intent is to make sure no material is running into basin p 9 q ( g )� Top slab is free of holes and cracks. Frame and/or Top Slab Frame not sitting flush on top slab, i.e., separation of more than 3/4 inch of the frame from the top slab. Frame not securely attached Frame is sitting flush on the riser rings or top slab and firmly attached. Fractures or Cracks in Maintenance person judges that structure is unsound. Basin replaced or repaired to design standards. Basin Walls/ Bottom Grout fillet has separated or cracked widerthan 1/2 inch and longerthan 1 foot at thejoint of any inlet/outlet pipe or any evidence of soil particles entering Pipe is regrouted and secure at basin wall. catch basin through cracks. Settlement/ Mis- alignment If failure of basin has created a safety, function, or design problem. Basin replaced or repaired to design standards. Vegetation growing across and blocking more than 10% of the basin opening. No vegetation blocking opening to basin. Vegetation Vegetation growing in inlet/outlet pipe joints that is more than six inches tall and less than six inches apart. No vegetation or root growth present. Contamination and Pol- See Table V-A.1: Maintenance Standards - Detention Ponds No pollution present. lution Cover Not in Place Cover is missing or only partially in place. Any open catch basin requires maintenance. Cover/grate is in place, meets design standards, and is secured Catch Basin Locking Mechanism Mechanism cannot be opened by one maintenance person with proper tools. Bolts into frame have less than 1/2 inch of thread. Mechanism opens with proper tools. Cover Not Working Cover Difficult to One maintenance person cannot remove lid after applying normal lifting pressure. Cover can be removed by one maintenance per - Remove (Intent is keep coverfrom sealing off access to maintenance.) son. Ladder Ladder Rungs Unsafe Ladder is unsafe due to missing rungs, not securely attached to basin wall, misalignment, rust, cracks, or sharp edges. Ladder meets design standards and allows main- tenance person safe access. Grate opening Unsafe Grate with opening wider than 7/8 inch. Grate opening meets design standards. Metal Grates Trash and Debris Trash and debris that is blocking more than 20% of grate surface inletting capacity. Grate free of trash and debris. (If Applicable) Grate is in place, meets the design standards, and Damaged or Missing. Grate missing or broken member(s) of the grate. is installed and aligned with the flow path. 2019 Stormwater Management Manual for Western Washington Volume V - Appendix - Page 1009 Table V-A.17: Maintenance Standards - Coalescing Plate Oil/Water Separators Maintenance Component Defect Condition When Maintenance is Needed Results Expected When Maintenance is Performed Monitoring Inspection of discharge water for obvious signs of poor water quality. Effluent discharge from vault should be clearwith no thick visible sheen. Sediment Accumulation Sediment depth in bottom of vault exceeds 6-inches in depth and/or visible signs of sediment on No sediment deposits on vault bottom and plate media, which would impede flow plates. through the vault and reduce separation efficiency. Trash and Debris Accumulation Trash and debris accumulated in vault, or pipe inlet/outlet, floatables and non-floatables. Trash and debris removed from vault, and inlet/outlet piping. Oil Accumulation Oil accumulation that exceeds 1-inch at the water surface. Oil is extracted from vault using vactoring methods. Coalescing plates are cleaned by thoroughly rinsing and flushing. Should be no visible oil depth on water. Damaged Coalescing Plates Plate media broken, deformed, cracked and/or showing signs of failure. A portion of the media pack or the entire plate pack is replaced depending on sever- ity of failure. General Damaged Pipes Inlet or outlet piping damaged or broken and in need of repair. Pipe repaired and or replaced. Baffles Baffles corroding, cracking, warping and/or showing signs of failure as determined by main- Baffles repaired or replaced to specifications. tenance/inspection person. Cracks widerthan 1/2-inch or evidence of soil particles entering the structure through the cracks, Vault replaced or repairs made so that vault meets design specifications and is Vault Structure Damage - Includes Cracks in or maintenance/inspection personnel determine that the vault is not structurally sound. structurally sound. Walls, Bottom, Damage to Frame and/or Top Slab Cracks widerthan 1/2-inch at the joint of any inlet/outlet pipe or evidence of soil particles enter- Vault repaired so that no cracks exist widerthan 1/4-inch at thejoint of the ing through the cracks. inlet/outlet pipe. Access Ladder Damaged Ladder is corroded or deteriorated, not functioning properly, not securely attached to structure Ladder replaced or repaired and meets specifications, and is safe to use as determ- wall, missing rungs, cracks, and misaligned. ined by inspection personnel. Table V-A.18: Maintenance Standards - Catch Basin Inserts Maintenance Component Defect Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Sediment Accumulation When sediment forms a cap over the insert media of the insert and/or unit. No sediment cap on the insert media and its unit. Trash and Debris Accumulation Trash and debris accumulates on insert unit creating a blockage/restriction. Trash and debris removed from insert unit. Runoff freely flows into catch basin. General Media Insert Not Removing Oil Effluent waterfrom media insert has a visible sheen. Effluent waterfrom media insert is free of oils and has no visible sheen. Media Insert Water Saturated Catch basin insert is saturated with water and no longer has the capacity to absorb. Remove and replace media insert Media Insert -Oil Saturated Media oil saturated due to petroleum spill that drains into catch basin. Remove and replace media insert. Media Insert Use Beyond Product Life Media has been used beyond the typical average life of media insert product. Remove and replace media at regular intervals, depending on insert product. Table V-A.19: Maintenance Standards - Media Filter Drain (MFD) Maintenance Component Defect Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Sediment accumulation Remove sediment deposits on grass treatment area of the embankment. When finished, embank - on grass filter Sediment depth exceeds 2 inches or creates uneven grading that interferes with sheet flow. ment should be level from side to side and drain freely toward the toe of the embankment slope. General strip There should be no areas of standing water once inflow has ceased. No -vegetation Flow spreader is uneven or clogged so that flows are not uniformly distributed over entire embankment width. Level the spreader and clean to spread flows evenly over entire embankment width. 2019 Stormwater Management Manual for Western Washington Volume V - Appendix - Page 1017 Pr,i TM ff mm STEM' with StormMix"' Media nspection & Maintenance Guide I� Oldcastle Infrastructure"` A CRH COMPANY BIOPOOTM BIOFILTER WITH STORMMIXTM BIOFILTRATION MEDIA DESCRIPTION The BioPodT' Biofilter System (BioPod) is a storm water biofiltration treatment system used to remove pollutants from storm water runoff. Impervious surfaces and other urban and suburban landscapes generate a variety of contaminants that can enter storm water and pollute downstream receiving waters unless treatment is provided. The BioPod system uses proprietary StormMixT" biofiltration media to capture and retain pollutants including total suspended solids (TSS), metals, nutrients, gross solids, trash and debris as well as petroleum hydrocarbons. FUNCTION The BioPod system uses engineered, high -flow rate filter media to remove storm water pollutants, allowing for a smaller footprint than conventional bioretention systems. Contained within a compact precast concrete vault, the BioPod system consists of a biofiltration chamber and an optional integrated high -flow bypass. The biofiltration chamber is filled with horizontal layers of aggregate, biofiltration media and mulch. Storm water passes vertically down through the mulch and biofiltration media for treatment. The mulch provides pretreatment by retaining most of the solids or sediment. The biofiltration media provides further treatment by retaining finer sediment and dissolved pollutants. The aggregate allows the media bed to drain evenly for discharge through an underdrain pipe or by infiltration. INSPECTION & MAINTENANCE OVERVIEW State and local regulations require all storm water management systems to be inspected on a regular basis and maintained as necessary to ensure performance and protect downstream receiving waters. Without maintenance, excessive pollutant buildup can limit system performance by reducing the operating capacity of the system and increasing the potential for scouring of pollutants during periods of high flow. Some configurations of the BioPod may require periodic irrigation to establish and maintain vegetation. Vegetation will typically become established about two years after planting. Irrigation requirements are ultimately dependent on climate, rainfall and the type of vegetation selected. INSPECTION & MAINTENANCE FREQUENCY Periodic inspection is essential for consistent system performance and is easily completed. Inspection is typically conducted a minimum of twice per year, but since pollutant transport and deposition varies from site to site, a site - specific maintenance frequency should be established during the first two or three years of operation. INSPECTION EQUIPMENT The following equipment is helpful when conducting BioPod inspections: Recording device (pen and paper form, voice recorder, Pad, etc.) Suitable clothing (appropriate footwear, gloves, hardhat, safety glasses, etc.) I PPE as required for entry Traffic control equipment (cones, barricades, signage, flagging, etc.) I Manhole hook or pry bar I Flashlight I Tape measure I Socket INSPECTION PROCEDURES BioPod inspections are visual and are conducted without entering the unit. To complete an inspection, safety measures including traffic control should be deployed before the access covers or tree grates are removed. Once the covers have been removed, the following items should be checked and recorded (see form provided on page 6) to determine whether maintenance is required: If the BioPod unit is equipped with an internal bypass, inspect the inlet rack (or inlet chamber on underground units) and outlet chamber and note whether there are any broken or missing parts. In the unlikely event that internal parts are broken or missing, contact Oldcastle Storm water at (800) 579-8819 to determine appropriate corrective action. Note whether the curb inlet, inlet pipe, or inlet rack is blocked or obstructed. If the unit is equipped with an internal bypass, observe, quantify and record the accumulation of trash and debris in the inlet rack or inlet chamber. The significance of accumulated trash and debris is a matter of judgment. Often, much of the trash and debris may be removed manually at the time of inspection if a separate maintenance visit is not yet warranted. If it has not rained within the past 24 hours, note whether standing water is observed in the biofiltration chamber. I Finally, observe, quantify and record presence of invasive vegetation and the amount of trash and debris and sediment load in the biofiltration chamber. Erosion of the mulch and biofiltration media bed should also be recorded. Often, much of the invasive vegetation and trash and debris may be removed manually at the time of inspection if a separate maintenance visit is not yet warranted. Sediment load may be rated light, medium or heavy depending on the conditions. Loading characteristics may be determined as follows: • Light sediment load — sediment is difficult to distinguish among the mulch fibers at the top of the mulch layer; the mulch appears almost new. • Medium sediment load — sediment accumulation is apparent and may be concentrated in some areas; probing the mulch layer reveals lighter sediment loads under the top 1" of mulch. • Heavy sediment load — sediment is readily apparent across the entire top of the mulch layer; individual mulch fibers are difficult to distinguish; probing the mulch layer reveals heavy sediment load under the top 1" of mulch. www.oldcastleinfrastructure.com 1 (800) 735-5566 MAINTENANCE INDICATORS Maintenance should be scheduled if any of the following conditions are identified during inspection: I The concrete structure is damaged or the tree grate or access cover is damaged or missing I The inlet obstructed I Standing water is observed in the biofiltration chamber more than 24 hours after a rainfall event (use discretion if the BioPod is located downstream of a storage system that attenuates flow) Trash and debris in the inlet rack cannot be easily removed at the time of inspection Trash and debris, invasive vegetation or sediment load in the biofiltration chamber is heavy or excessive erosion has occurred MAINTENANCE EQUIPMENT The following equipment is helpful when conducting BioPod maintenance: Suitable clothing (appropriate footwear, gloves, hardhat, safety glasses, etc.) I Rake, hoe, shovel and broom I PPE as required for entry I Bucket I Traffic control equipment (cones, barricades, signage, flagging, etc.) I Pruners I Manhole hook or pry bar I Vacuum truck (optional) I Flashlight I Socket I Tape measure MAINTENANCE PROCEDURES Maintenance should be conducted during dry weather when no flows are entering the system. In most cases, maintenance may be conducted without entering. Entry may be required to maintain BioPod Underground units, depending on system depth. Once safety measures such as traffic control are deployed, the access covers may be removed and the following activities may be conducted to complete maintenance: Remove all trash and debris from the curb inlet and inlet rack manually or by using a vacuum truck as required. I Remove all trash and debris and invasive vegetation from the biofiltration chamber manually or by using a vacuum truck as required. I If the sediment load is medium or light but erosion of the biofiltration media bed is evident, redistribute the mulch with a rake or replace missing mulch as appropriate. If erosion persists, rocks may be placed in the eroded area to help dissipate energy and prevent recurring erosion. If the sediment load is heavy, remove the mulch layer using a hoe, rake, shovel and bucket, or by using a vacuum truck as required. If the sediment load is particularly heavy, inspect the surface of the biofiltration media once the mulch has been removed. If the media appears clogged with sediment, remove and replace one or two inches of biofiltration media prior to replacing the mulch* layer. Prune vegetation as appropriate and replace damaged or dead plants as required. Replace the tree grate and/or access covers and sweep the area around the BioPod to leave the site clean. All material removed from the BioPod during maintenance must be disposed of in accordance with local environmental regulations. In most cases, the material may be handled in the same manner as disposal of material removed from sumped catch basins or manholes. * Natural, shredded hardwood mulch should be used in the BioPod. Timely replacement of the mulch layer according to the maintenance indicators described above should protect the biofiltration media below the mulch layer from clogging due to sediment accumulation. However, whenever the mulch is replaced, the BioPod should be visited 24 hours after the next major storm event to ensure that there is no standing water in the biofiltration chamber. Standing water indicates that the biofiltration media below the mulch layer is clogged and must be replaced. Please contact Oldcastle Infrastructure at (800) 579-8819 to purchase the proprietary StormMix'" biofiltration media. BIOPOD SURFACE iJ BIOPOO TREE BIOPOO PLANTER BIOPOO UNDERGROUND www.oldcastleinfrastructure.com 1 (800) 735-5566 1 1 INSPECTION & MAINTENANCE L41 BioPod Model Inspection Date Location Condition of Internal Components NOTES: ❑ GOOD ❑ DAMAGED ❑ MISSING Curb Inlet or Inlet Rack Blocked NOTES: ❑ YES ❑ NO Standing Water in Biofiltration Chamber NOTES: ❑ YES ❑ NO Trash and Debris in Inlet Rack NOTES: ❑ YES ❑ NO Trash and Debris in Biofiltration Chamber NOTES: ❑ YES ❑ NO Invasive Vegetation in Biofiltration Chamber NOTES: ❑ YES ❑ NO Sediment in Biofiltration Chamber NOTES: ❑ LIGHT ❑ MEDIUM ❑ HEAVY Erosion in Biofiltration Chamber NOTES: ❑ YES ❑ NO Maintenance Requirements ❑ YES - Schedule Maintenance ❑ NO - Schedule Re -Inspection NOTES www.oldcastleinfrastructure.com 1 (800) 735-5566 0 Oldcastle Infrastructure'` A CRH COMPANY Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds APPENDIX D Declaration of Covenant November 2023 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 After recording return to: City Clerk City of Edmonds 121 Fifth Avenue North Edmonds, WA 98020 Document Title(s) Declaration of Covenant - Private Stormwater Facility Reference Number(s) of Related Documents Grantor(s) (Last, First and Middle Initial) BK Investment Group, LLC Grantee(s) (Last, First and Middle Initial) City of Edmonds Legal Description (abbreviated form; i.e., lot, plat or section, township, range, quarter/quarter) Assessor's Property Tax Parcel/Account Number at the Time of Recording: Parcel A: 270326-001-009-00 & Parcel B: 270326-001-029-00 The Auditor/Recorder will rely on the information provided on this form. The staff will not read the document to verify the accuracy or completeness of the indexing information provided herein. DECLARATION OF COVENANT Private Stormwater Facility WHEREAS, the undersigned Declarant(s) have installed one or more stormwater facilities under Edmonds Community Development Code Chapter 18.30 known as a "low impact development best management practices (LID BMP)" as selected below: ❑ Permeable Pavement ❑ Rain Garden / Bioretention Cell ❑ Drywell ® Infiltration Trench ❑ Gravelless Chamber ❑ Other WHEREAS, the City of Edmonds has allowed installation of the LID BMP, subject to the execution and recording of this Declaration of Covenant; NOW, THEREFORE, THE UNDERSIGNED DECLARANT(S), being the owners of the real property ("the Property") located at the following address: 614 5th Ave S in the City of Edmonds, Washington, and legally described on Exhibit A attached hereto and incorporated herein by this reference as if set forth in full, hereby covenants and agrees, on behalf of himself/herself/themselves/itself and his/her/their/its successors and assigns, as follows: I. Declarant(s) warrant that he/she/they are the owners of the property described on Exhibit A and have the authority to impose this covenant on the property and bind all future owners, successors, and assigns of the Declarant(s). The Declarant(s), future owners, successors, and assigns of the Declarant(s) shall be referred to collectively as "Owners." 2. The Owners of the Property agree that the Property contains one or more stormwater management facilities referred to as an "LID BMP," which was installed to mitigate the stormwater quantity and quality impacts of some or all of the impervious or non-native pervious surfaces on the property. "Low impact development" means development conducted in a way that seeks to minimize or completely prevent alterations to the natural hydrology of the site. Low impact development includes site planning and design to reduce alterations of natural soil and vegetation cover, minimize impervious surfaces, and specific practices that help to replicate natural hydrology such as permeable pavements, green roofs, soil amendments, bioretention systems, and dispersion of runoff. 3. The Owners shall maintain the size, placement, and design of the LID BMP as depicted on the approved site plan, Exhibit B, and design details shall be maintained and may not be changed without written approval either from the Engineering Division of the City of Edmonds or through a future development permit from the City of Edmonds. Chemical fertilizers and pesticides shall not be used where LID BMP is located. All costs of maintenance and repair shall be the sole responsibility of the Owners. 4. The Owners shall inspect LID BMPs annually for physical defects. After major storm events, the system shall also be checked to ensure that the overflow system is working properly. The Owners also shall maintain all LID BMPs so they function as designed on a year-round basis. 5. The City of Edmonds is hereby granted by the Owners the right, but not the obligation, to enter upon the Property described on Exhibit A at all reasonable times for the purpose of inspecting the private stormwater LID BMP facility. If, as the result of any such inspection, the City of Edmonds determines that the LID BMP is in disrepair, requires maintenance or repair, or is otherwise not functioning as provided in the BMP site plan, the City Engineer or his designee shall have the right, but not the obligation, to order the Owners to maintain or repair the same. 6. If the City of Edmonds determines that the LID BMP requires maintenance or repair pursuant to Section 5, the City of Edmonds shall provide notice to the Owners of the deadline within which such maintenance or repair must be completed. Said notice may further advise that, should the violator fail to perform required maintenance or make repairs within the established deadline, the work may be done by the city or a contractor designated by the City Engineer and the expense thereof shall be charged to the Owners. The City's officers, agents, employees, and contractors shall have the right, which is hereby granted by the Owners, to enter upon the Property described on Exhibit A in order to perform such work. The Owners shall bear the cost of all work performed. 7. The Owners shall indemnify, defend and hold harmless the City of Edmonds, its officers, officials, employees and agents from any and all claims, demands, suits, penalties, losses, damages, judgments, attorneys' fees and/or costs of any kind whatsoever, arising out of or in any way resulting from the approval of the LID BMP(s), the installation and presence of the LID BMP(s), and the acts or omissions of the Owners, their officers, employees, contractors, and agents relating to the construction, operation and maintenance of the LID BMP(s) on the Property, except for the City's intentional and willful tortious acts, and waive and release the City of Edmonds from any and all claims for damages and injunctive relief which the Owners may themselves have now or in the future, by reason of the construction, maintenance and operation of said LID BMP(s). 8. This covenant shall run with the land and be binding upon the Owners. Dated: DECLARANT(S): (Signature) (Print Name) (Signature) (Print Name) State of Washington RIM County of Snohomish APPROVED: CITY OF EDMONDS (Signature) (Print Name) (Title) On this day personally appeared before me {Declarant(s)} to me known to be the individual, or individuals described in and who executed the within and foregoing instrument, and acknowledged that he/she/they signed the same as his/her/their free and voluntary act and deed, for the uses and purposes therein mentioned. SUBSCRIBED AND SWORN before me this day of , 201_. (Signature) (Name legibly printed or stamped) Notary Public in and for the State of Washington. Residing at: My commission expires Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds APPENDIX E Conveyance Calculations November 2023 20231110_614 5th Ave S Edmonds_Drainage ReportRev 4 9/24/2021 RATIONAL METHOD for Conveyance Facility Sizing Project: 614 5th Ave S Description: Rational method for SD pipe sizing Design Storm: 100 yr Q=CIA Where: Q = peak flow (cfs) I = peak rainfall intensity (inches/hour) C = estimated composite runoff coefficient A = drainage subbasin area (acres) Composite Runoff Coefficient Cc = (C 1 *A1 +C2*A2 ... )/At Where: Cc = composite runoff coefficient A# = area of land cover (acres) C# = runoff coefficient for Area # At = total area (acres) Area C # Description Area (sf) (acres) C A*C 1 Onsite/New Impervious Surface 6,315 0.14 0.90 0.13 2 Onsite/New Pervious Surface 0 0.00 0.25 0.00 Totals: 0.14 0.13 Cc = 0.90 (total C#*A#)/(total area) Time of Concentration Travel Upper Lower Slope Time Seg. # Description of Flow Path Segment Length (ft) kr Elev Elev (ft/ft) (minutes) 1 Paved Area (sheet flow) and shallow gutter flow 131 20 85.96 70 0.122 0.31 Totals: 131 0.3 Unity Peak Intensity Factor it = ar*Tc^-br where: Tc = time of concentration (minutes) ar and br = coefficients from Table 3.2.1.13 Tc = 6.30 minutes (from table above or 6.3 minimum or 100 max) ar = 2.61 (from Table 3.2.1.13) br = 0.63 (from Table 3.2.1.13) it = 0.82 Peak Rainfall Intensity Ir = Pr*ir where: Ir = peak rainfall intensity (inches/hour) Pr = total 24-hour precipitation for design return period (inches/24 hours) it = unit peak rainfall intensity factor Pr = 4 precipitation (inches) it = 0.82 unit peak intensity factor (from above) Ir = 3.27 inches/hour Peak Runoff Rate Q = C*Ir*A C = 0.90 Cc (unitless) from above Ir = 3.27 Ir (inches/hour) from above A = 0.14 total area (acres) from above Q = 0.427 cfs Pipe Capacity Calculations (Manning's Equation) Full Flow (d/D = 0.90) Description ID (inches) Area (sf) 6" for Entire site 6 0.196349541 Wetted Per. Hyd. Manning's Slope Velocity (ft) Radius (ft) n (ft/ft) (ft/s) 1.57079633 0.125 0.013 0.01 2.87 Pipe Capacity Req'd Flow (cfs) (cfs) 0.563 0.427 Capacity OK Storm Drain Pipe Sizing —Rational Method Calculations occ, Inc. Page 1 of 1 Stormwater Site Plans — Rev 4 614 5th Ave S Edmonds November 2023 APPENDIX F King County Site Improvement Bond Quantity Worksheet 20231110_614 5th Ave S Edmonds —Drainage Report Rev 4 Site Improvement Bond Quantity Worksheet Web date: 04/03/2015 L-9 King County Department of Permitting & Environmental Review 35030 SE Douglas Street, Suite 210 Snoqualmie, Washington 98065-9266 206-296-6600 TTY Relay 711 Project Name: Location: Pine Park 614 614-616 5th Ave S Edmonds Clearing greater than or equal to 5,000 board feet of timber? yes X no If yes, Forest Practice Permit Number: N/A (RCW 76.09) Page 1 of 9 Page 9 of 9 614 5th Ave S_KC BQ_REV 4 For alternate formats, call 206-296-6600. Date: Project No.: Activity No.: 11 /10/2023 BLDG2022-0694 Correction Notice #4 Note: All prices include labor, equipment, materials, overhead and profit. Prices are from RS Means data adjusted for the Seattle area or from local sources if not included in the RS Means database. Unit prices updated: 03/02/2015 Check out the DDES Web site at www.kinpcounty._poy/permits Version: 03/02/2015 Report Date: 11/10/2023 Site Improvement Bond Quantity Worksheet Web date: 04/03/2015 Reference # Unit Price Unit Quantity # of Applications Cost EROSION/SEDIMENT CONTROL Number Backfill & compaction -embankment ESCA $ 6.00 CY Check dams, 4" minus rock ESC-2 SWDM 5.4.6.3 $ 80.00 Each Crushed surfacing 1 1/4" minus ESC-3 WSDOT 9-03.9(3) $ 95.00 CY Ditching ESC-4 $ 9.00 CY Excavation -bulk ESC-5 $ 2.00 CY Fence, silt ESC-6 SWDM 5.4.3.1 $ 1.50 LF 685 1 $ 1,027.50 Fence, Temporary (NGPE) ESC-7 $ 1.50 LF 246 1 $ 369.00 Hydroseeding ESC-8 SWDM 5.4.2.4 $ 0.80 SY Jute Mesh ESC-9 SWDM 5.4.2.2 $ 3.50 SY Mulch, by hand, straw, 3" deep ESC-10 SWDM 5.4.2.1 $ 2.50 SY Mulch, by machine, straw, 2" deep ESCA1 SWDM 5.4.2.1 $ 2.00 SY Piping, temporary, CPP, 6" ESC-12 $ 12.00 LF Piping, temporary, CPP, 8" ESC-13 $ 14.00 LF Piping, temporary, CPP, 12" ESC-14 $ 18.00 LF Plastic covering, 6mm thick, sandbagged ESC-15 SWDM 5.4.2.3 $ 4.00 SY Rip Rap, machine placed; slopes ESC-16 WSDOT 9-13.1(2) $ 45.00 CY Rock Construction Entrance, 50'x15'x1' ESC-17 SWDM 5.4.4.1 $ 1,800.00 Each 1 1 1800 Rock Construction Entrance, 100'x15'x1' ESC-18 SWDM 5.4.4.1 $ 3,200.00 Each Sediment pond riser assembly ESC-19 SWDM 5.4.5.2 $ 2,200.00 Each 1 1 2200 Sediment trap, 5' high berm ESC-20 SWDM 5.4.5.1 $ 19.00 LF Sed. trap, 5' high, riprapped spillway berm section ESC-21 SWDM 5.4.5.1 $ 70.00 LF Seeding, by hand Sodding, 1" deep, level ground ESC-22 SWDM 5.4.2.4 $ 1.00 SY ESC-23 SWDM 5.4.2.5 $ 8.00 SY Sodding, 1" deep, sloped ground ESC-24 SWDM 5.4.2.5 $ 10.00 SY TESC Supervisor ESC-25 $ 110.00 HR 40 1 4400 Water truck, dust control ESC-26 SWDM 5.4.7 $ 140.00 HR WRITE -IN -ITEMS **** (see gape 91 Inlet Protection $ 74.00 Each 10 1 740 ESC SUBTOTAL: 30% CONTINGENCY & MOBILIZATION: ESC TOTAL: COLUMN: Page 2 of 9 Page 9 of 9 Check out the DDES Web site at www.kinpcounty._poy/permits 614 5th Ave S_KC BQ_REV 4 $ 10,536.50 $ 3,160.95 $ 13,697.45 A Unit prices updated: 03/02/2015 Version: 03/02/2015 Report Date: 11/10/2023 Site Improvement Bond Quantitv Worksheet Web date: 04/03/2015 Existing Right -of -Way Future Public Right of Way & Drainage Facilities Private Improvements Unit Price Unit Quant. Cost Quant. Cost Quant. Cost GENERAL ITEMS No. Backfill & Compaction- embankment GI - 1 $ 6.00 CY Backfill & Compaction- trench GI-2 $ 9.00 CY 100 $ 900.00 2493 $ 22,437.00 Clear/Remove Brush, by hand GI - 3 $ 1.00 SY Clearing/Grubbing/Tree Removal GI - 4 $ 10,000.00 Acre Excavation - bulk GI-5 $ 2.00 CY Excavation - Trench GI - 6 $ 5.00 CY 100 $ 500.00 2565 $ 12,825.00 Fencing, cedar, 6' high GI - 7 $ 20.00 LF Fencing, chain link, vinyl coated, 6' high GI - 8 $ 20.00 LF Fencing, chain link, gate, vinyl coated, 20' GI - 9 $ 1,400.00 Each Fencing, split rail, 3' high GI - 10 $ 15.00 LF Fill & compact - common barrow GI - 11 $ 25.00 CY Fill & compact - gravel base GI - 12 $ 27.00 CY Fill & compact - screened topsoil GI - 13 $ 39.00 CY Gabion, 12" deep, stone filled mesh GI - 14 $ 65.00 SY Gabion, 18" deep, stone filled mesh GI - 15 $ 90.00 SY Gabion, 36" deep, stone filled mesh GI - 16 $ 150.00 SY Grading, fine, by hand GI - 17 $ 2.50 SY Grading, fine, with grader GI - 18 $ 2.00 SY 487 $ 974.00 301 $ 602.00 Monuments, 3' long GI - 19 $ 250.00 Each Sensitive Areas Sign GI - 20 $ 7.00 Each Sodding, 1" deep, sloped ground GI - 21 $ 8.00 SY Surveying, line & grade GI - 22 $ 850.00 Day Surveying, lot location/lines GI - 23 $ 1,800.00 Acre Traffic control crew ( 2 flaggers) GI - 24 $ 120.00 HR 40 $ 4,800.00 Trail, 4" chipped wood GI - 25 $ 8.00 SY Trail, 4" crushed cinder GI - 26 $ 9.00 SY Trail, 4" top course GI - 27 $ 12.00 SY Wall, retaining, concrete GI - 28 $ 55.00 SF 1 5 $ 275.00 Wall, rockery GI - 29 $ 15.00 1 SF Page 3 of 9 Page 9 of 9 614 5th Ave S_KC BQ_REV 4 SUBTOTAL 7,174.00 Check out the DDES Web site at www.kinpcounty.pov/permits 36,139.00 Unit prices updated: 03/02/2015 Version: 03/02/2015 Report Date: 11/10/2023 Site Improvement Bond Quantity Worksheet Web date: 04/03/2015 Existing Right-of-way Future Public Right of Way & Drainage Facilities Private Improvements Unit Price Unit Quant. Cost Quant. Cost Quant. Cost ROAD IMPROVEMENT No. AC Grinding, 4' wide machine < 1000sy RI - 1 $ 30.00 SY 487 $ 14,610.00 AC Grinding, 4' wide machine 1000-2000sy RI - 2 $ 16.00 SY AC Grinding, 4' wide machine > 2000sy RI - 3 $ 10.00 SY AC Removal/Disposal RI - 4 1 $ 35.00 SY 410 14,350.00 Barricade, type III ( Permanent) RI - 6 $ 56.00 LF Curb & Gutter, rolled RI - 7 $ 17.00 LF Curb & Gutter, vertical RI - 8 $ 12.50 LF 162 $ 2,025.00 Curb and Gutter, demolition and disposal RI - 9 $ 18.00 LF 162 $ 2,916.00 Curb, extruded asphalt RI - 10 $ 5.50 LF Curb, extruded concrete RI - 11 $ 7.00 LF Sawcut, asphalt, 3" depth RI - 12 $ 1.85 LF 216 $ 399.60 Sawcut, concrete, per 1" depth RI - 13 $ 3.00 LF Sealant, asphalt RI - 14 $ 2.00 LF 165 $ 330.00 Shoulder, AC, ( see AC road unit price) RI - 15 $ - SY Shoulder, gravel, 4" thick RI - 16 $ 15.00 SY Sidewalk, 4" thick RI - 17 $ 38.00 SY 129 $ 4,902.00 33 $ 1,254.00 Sidewalk, 4" thick, demolition and disposal RI - 18 $ 32.00 SY 129 $ 4,128.00 Sidewalk, 5" thick RI - 19 $ 41.00 SY Sidewalk, 5" thick, demolition and disposal RI - 20 $ 40.00 SY Sign, handicap RI - 21 $ 85.00 Each Striping, per stall RI - 22 $ 7.00 Each 4 $ 28.00 12 84.00 Striping, thermoplastic, ( for crosswalk) RI - 23 $ 3.00 SF Striping, 4" reflectorized line RI - 24 $ 0.50 LF Page 4 of 9 Page 9 of 9 614 5th Ave S_KC BQ_REV 4 SUBTOTAL 43,688.60 Check out the DDES Web site at www.kinpcounty.pov/permits 1,338.00 Unit prices updated: 03/02/2015 Version: 03/02/2015 Report Date: 11/10/2023 Site Improvement Bond Quantity Worksheet Web date: 04/03/2015 Existing Right-of-way Future Public Right of Way & Drainage Facilities Private Improvements Unit Price Unit Quant. Cost Quant, Cost Quant. Cost ROAD SURFACING No. (4" Rock = 2.5 base & 1.5" top course) 9 1/2" Rock= 8" base & 1.5" top course) Additional 2.5" Crushed Surfacing RS - 1 $ 3.60 SY HMA 1/2" Overlay, 1.5" RS - 2 $ 14.00 SY $ - $ - HMA 1/2" Overlay 2" RS - 3 $ 18.00 SY 379 6,822.00 69 1,242.00 HMA Road, 2", 4" rock, First 2500 SY RS - 4 $ 28.00 SY 939 $ 26,292.00 HMA Road, 2", 4" rock, Qty. over 2500 SY RS - 5 $ 21.00 SY HMA Road, 3", 9 1/2" Rock, First 2500 SY RS - 6 $ 42.00 SY $ - 232 $ 9,744.00 HMA Road, 3", 9 1/2" Rock, Qty Over 2500 S RS - 7 $ 35.00 SY Not Used RS - 8 Not Used RS - 9 HMA Road, 6" Depth, First 2500 SY RS - 10 $ 33.10 SY 52 1,721.20 HMA Road, 6" Depth, Qty. Over 2500 SY RS - 11 $ 30.00 SY HMA 3/4" or 1", 4" Depth RS - 12 $ 20.00 SY Gravel Road, 4" rock, First 2500 SY RS - 13 $ 15.00 SY Gravel Road, 4" rock, Qty. over 2500 SY RS - 14 $ 10.00 SY PCC Road (Add Under Write -Ins w/Design) RS - 15 Thickened Edge RS - 17 $ 8.60 LF Page 5 of 9 Page 9 of 9 614 5th Ave S_KC BQ_REV 4 SUBTOTAL 8,543.20 Unit prices updated: 03/02/2015 Check out the DDES Web site at www.kinpcounty.poy/permits Version: 03/02/2015 Report Date: 11/10/2023 Site Improvement Bond Quantity Worksheet Web date: 04/03/2015 Existing Right-of-way Future Public Right of Way & Drainage Facilities Private Improvements Unit Price Unit Quant. Cost Quant. Cost Quant. I Cost DRAINAGE (CPP = Corrugated Plastic Pipe, N12 or Equivalent) For Culvert prices, Average of 4' cover was assumed. Assume perforated PVC is same price as s Access Road, R/D D - 1 $ 21.00 SY Bollards - fixed D - 2 $ 240.74 Each Bollards - removable D - 3 $ 452.34 Each * (CBs include frame and lid) CB Type I D - 4 $ 1,500.00 Each 6 $ 9,000.00 CB Type IL D - 5 $ 1,750.00 Each CB Type II, 48" diameter D - 6 $ 2,300.00 Each for additional depth over 4' D - 7 $ 480.00 FT CB Type II, 54" diameter D - 8 $ 2,500.00 Each for additional depth over 4' D - 9 $ 495.00 FT CB Type II, 60" diameter D - 10 $ 2,800.00 Each for additional depth over 4' D - 11 $ 600.00 FT CB Type II, 72" diameter D - 12 $ 3,600.00 Each for additional depth over 4' D - 13 $ 850.00 FT Through -curb Inlet Framework (Add) D - 14 $ 400.00 Each Cleanout, PVC, 4" D - 15 $ 150.00 Each 8 $ 1,200.00 Cleanout, PVC, 6" D - 16 $ 170.00 Each 8 $ 1,360.00 Cleanout, PVC, 8" D - 17 $ 200.00 Each Culvert, PVC, 4" D - 18 $ 10.00 LF 864 $ 8,640.00 Culvert, PVC, 6' D - 19 $ 13.00 LF 1098 $ 14,274.00 Culvert, PVC, 8" D - 20 $ 15.00 LF 15 $ 225.00 Culvert, PVC, 12" D - 21 $ 23.00 LF Culvert, CMP, 8" D - 22 $ 19.00 LF Culvert, CMP, 12" D - 23 $ 29.00 LF Culvert, CMP, 15" D - 24 $ 35.00 LF Culvert, CMP, 18" D - 25 $ 41.00 LF Culvert, CMP, 24" D - 26 $ 56.00 LF Culvert, CMP, 30" D - 27 $ 78.00 LF Culvert, CMP, 36" D - 28 $ 130.00 LF Culvert, CMP, 48" D - 29 $ 190.00 LF Culvert, CMP, 60" D - 30 $ 270.00 LF Culvert, CMP, 72" D - 31 $ 350.00t LF Page 9 of 9 614 5th Ave S_KC BQ_REV 4 Unit prices updated: 03/02/2015 Check out the DDES Web site at www.kinpcounty.poy/permits Version: 03/02/2015 Report Date: 11/10/2023 Site Improvement Bond Quantity Worksheet Web date: 04/03/2015 Page 6 of 9 SUBTOTAL 34,699.00 Page 9 of 9 Unit prices updated: 03/02/2015 Check out the DDES Web site at www.kinpcounty.pov/permits Version: 03/02/2015 614 5th Ave S_KC BQ_REV 4 Report Date: 11/10/2023 Site Improvement Bond Quantity Worksheet Web date: 04/03/2015 DRAINAGE CONTINUED Existing Right-of-way Future Public Right of Way & Drainage Facilities Private Improvements No. Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Culvert, Concrete, 8" D - 32 $ 25.00 LF Culvert, Concrete, 12" D - 33 $ 36.00 LF Culvert, Concrete, 15" D - 34 $ 42.00 LF Culvert, Concrete, 18" D - 35 $ 48.00 LF Culvert, Concrete, 24" D - 36 $ 78.00 LF Culvert, Concrete, 30" D - 37 $ 125.00 LF Culvert, Concrete, 36" D - 38 $ 150.00 LF Culvert, Concrete, 42" D - 39 $ 175.00 LF Culvert, Concrete, 48" D - 40 $ 205.00 LF Culvert, CPP, 6" D - 41 $ 14.00 LF Culvert, CPP, 8" D - 42 $ 16.00 LF Culvert, CPP, 12" D - 43 $ 24.00 LF Culvert, CPP, 15" D - 44 $ 35.00 LF Culvert, CPP, 18" D - 45 $ 41.00 LF Culvert, CPP, 24" D - 46 $ 56.00 LF Culvert, CPP, 30" D - 47 $ 78.00 LF Culvert, CPP, 36" D -48 $ 130.00 LF Ditching D - 49 $ 9.50 CY Flow Dispersal Trench (1,436 base+) D - 50 $ 28.00 LF French Drain (3' depth) D - 51 $ 26.00 LF Geotextile, laid in trench, polypropylene D - 52 $ 3.00 SY Mid -tank Access Riser, 48" dia, 6' deep D - 54 $ 2,000.00 Each Pond Overflow Spillway D - 55 $ 16.00 SY Restrictor/Oil Separator, 12" D - 56 $ 1,150.00 Each 1 1150 Restrictor/Oil Separator, 15" D - 57 $ 1,350.00 Each Restrictor/Oil Separator, 18" D - 58 $ 1,700.00 Each Riprap, placed D - 59 $ 42.00 CY Tank End Reducer (36" diameter) D - 60 $ 1,200.00 Each Trash Rack, 12' D - 61 $ 350.00 Each Trash Rack, 15" D - 62 $ 410.00 Each Trash Rack, 18" D - 63 $ 480.00 Each Trash Rack, 21" D - 64 $ 550.00 Each Page 7 of 9 SUBTOTAL Page 9 of 9 Check out the DDES Web site at www.kinpcounty.pov/permits 614 5th Ave S_KC BQ_REV 4 1150 Unit prices updated: 03/02/2015 Version: 03/02/2015 Report Date: 11/10/2023 Site Improvement Bond Quantity Worksheet Web date: 04/03/2015 Page 9 of 9 Unit prices updated: 03/02/2015 Check out the DDES Web site at www.kinpcounty.pov/permits Version: 03/02/2015 614 5th Ave S_KC BQ_REV 4 Report Date: 11/10/2023 Site Improvement Bond Quantity Worksheet Web date: 04/03/2015 Existing Right-of-way Future Public Right of Way & Drainage Facilities Private Improvements Unit Price Unit Quant. Price Quant. Cost Quant. Cost PARKING LOT SURFACING Not To Be Used For Roads Or Shoulders No. 2" AC, 2" top course rock & 4" borrow PL - 1 $ 21.00 SY NA NA 2" AC, 1.5" top course & 2.5" base course PL - 2 $ 28.00 SY NA NA 4" select borrow PL - 3 $ 5.00 SY NA NA 1.5" top course rock & 2.5" base course PL - 4 $ 14.00 SY NA NA UTILITY POLES & STREET LIGHTING Utility pole relocation costs must be accompanied by Franchise Utility's Cost Estimate Utility Pole(s) Relocation UP-1 Lump Sum Street Light Poles w/Luminaires UP-2 $ 7,500.00 Each WRITE -IN -ITEMS (Such as detention/water quality vaults.) No. Stormwater Vault WI-1 $ 380,000.00 Each Block Wall WI - 2 $ 16.00 SY BioPod Biofilter System WI - 3 $ 15,000.00 Each 2 30,000.00 Remove OHP, Install UGP WI-4 $ 5,000.00 LS 1 $ 5,000.00 1 $ 5,000.00 New 1" Water Service/Meter/Connection WI-5 $ 1,500.00 LS 14 $ 21,000.00 6" Concrete Driveway WI-6 $ 65.00 SY 30 $ 1,950.00 14 $ 910.00 Trench Drain WI-7 $ 500.00 LS 2 $ 1,000.00 Stormwater Infiltration Trench W 1 - 8 $ 2,000.00 LS 2 $ 4,000.00 Water Service Lines WI - 9 $ 300.00 Each 14 $ 4,200.00 1" Water Meter & Service Tap WI - 10 $ 2,970.00 Each 14 $ 41,580.00 Sanitary Sewer Cleanout, PVC, 6" W 1 - 11 $ 170.00 Each 4 $ 680.00 Sanitary Sewer PVC, 6" W 1 - 12 $ 13.00 LF 287 $ 3,731.00 Street Tree Grate JWI - 13 $ 500.00 Each 4 $ 2,000.00 SUBTOTAL 27, 950.00 47,780.00 SUBTOTAL (SUM ALL PAGES): 87,355.80 47,780.00 Page 9 of 9 Check out the DDES Web site at www.kinpcounty.poy/permits 614 5th Ave S_KC BQ_REV 4 155,925.00 Unit prices updated: 03/02/2015 Version: 03/02/2015 Report Date: 11/10/2023 Page 8 of 9 Page 9 of 9 614 5th Ave S_KC BQ_REV 4 Site Improvement Bond Quantity Worksheet 30% CONTINGENCY & MOBILIZATION: 26,206.74 14,334.00 Web date: 04/03/2015 46,777.50 GRANDTOTAL: 113,562.54 62,114.00 202,702.50 COLUMN: B C D Unit prices updated: 03/02/2015 Check out the DDES Web site at www.kinpcounty.pov/permits Version: 03/02/2015 Report Date: 11/10/2023 Site Improvement Bond Quantity Worksheet Original bond computations prepared by: Name: PE Registration Number: Firm Name: Address: Stabilization/Erosion Sediment Control (ESC) Existing Right -of -Way Improvements Future Public Right of Way & Drainage Facilities Private Improvements Calculated Quantity Completed Pine Park 614 614-616 5th Ave S Edmonds Total Right -of Way and/or Site Restoration Bond*/** (First $7,500 of bond* shall be cash.) Performance Bond* Amount (A+B+C+D) = TOTAL Maintenance/Defect Bond* Total 1►/9��1��]���:i.Y�7►�,:7��1:71►[H:I�7►1�3ii:7��1�I��[�7�F (A) (B) (C) (D) Date: Tel. #: Project No Web date: 04/03/2015 11 /10/2023 BLDG2022-0694 FINANCIAL GUARANTEE REQUIREMENTS PERFORMANCE BOND* MINIMUM BOND* AMOUNT PUBLIC ROAD & DRAINAGE AMOUNT REQUIRED FOR RECORDING OR MAINTENANCE/DEFECT BOND* TEMPORARY OCCUPANCY AT $ 13,697.5 SUBSTANTIAL COMPLETION *** $ 113,562.5 $ 62,114.0 $ 202,702.5 (A+B) $ 127,260.0 (T) $ Minimum is $2000. 392,076.5 T x 0.30 $ 117,622.9 Minimum is $2000. (B+C) x 0.25 = $ 43,919.1 Minimum is $2000. Date: * NOTE: The word "bond" as used in this document means a financial guarantee acceptable to King County. ** NOTE: KCC 27A authorizes right of way and site restoration bonds to be combined when both are required. The restoration requirement shall include the total cost for all TESC as a minimum, not a maximum. In addition, corrective work, both on- and off -site needs to be included. Quantities shall reflect worse case scenarios not just minimum requirements. For example, if a salmonid stream may be damaged, some estimated costs for restoration needs to be reflected in this amount. The 30% contingency and mobilization costs are computed in this quantity. *** NOTE: Per KCC 27A, total bond amounts remaining after reduction shall not be less than 30% of the original amount (T) or as revised by major design changes. REQUIRED BOND* AMOUNTS ARE SUBJECT TO REVIEW AND MODIFICATION BY KING COUNTY Page 9 of 9 Unit prices updated: 03/02/2015 Check out the DDES Web site at www.kinpcounty._poy/permits Version: 03/02/2015 614 5th Ave S_KC BQ_REV 4 Report Date: 11/10/2023