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HomeMy WebLinkAboutRS_Final_TIR_Full_Sapphire_on_Talbot_200128_v4DEVELOPMENT ENGINEERINGNathan Janders 02/07/2020SURFACE WATER UTILITYJFarah 02/07/2020 8/15/19 Page 2 Table of Contents II. CONDITIONS AND REQUIREMENTS SUMMARY.......................................................... 6 III. Level-1 Downstream Analysis ................................................................................................ 8 IV. FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN .. 12 V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN ..................................................... 18 VI. SPECIAL REPORTS AND STUDIES ................................................................................. 18 VII. OTHER PERMITS ................................................................................................................ 18 VIII. CSWPPP ANALYSIS AND DESIGN ............................................................................. 18 IX. BOND QUANTITIES and DECLARATION of COVENANT ............................................ 19 X. OPERATION AND MAINTENANCE MANUAL .............................................................. 19 Appendix A Geotechnical Engineering Report by Migizi Group revised March 29, 2019 Appendix B WWHM Output Appendix C Bond Quantity Worksheet Appendix D Operation and Maintenance Manual Appendix E Arborist Report by American Forest Management dated July 9, 2018 Appendix F Trip Generation Report by DN Traffic Consultants dated September 28, 2018 Appendix G Wetland Reconnaissance by The Watershed Company dated June 11, 2015 Review of Site and Watershed June 11, 2015 Report by Sewall Wetland Consulting, Inc. dated May 6, 2016 Appendix H Biopod Biofilter Underground Vault Details by Oldcastle Infrastructure 8/15/19 Page 3 I. PROJECT OVERVIEW Project: Sapphire on Talbot Tax Parcel #: 312305-9022 Site Area: The project parcel is 1.69 Acres Site Address: 4827 Talbot Road, Renton, WA 98055 (See Vicinity Map) Site Location: The site is in the City of Renton within the SE quarter of Section 31, Township 23 North, Range 5 East, W.M, King County, Washington, at the southwest corner of the intersection of Talbot Road South and South 48th Street. Figure 1: Site Location 8/15/19 Page 5 Figure 2: Soil Map and Legend Pre-developed Site Conditions: The site is developed with an existing single-family residence, detached garage and paved driveway. The site is comprised of grasses, trees and shrubs around the boundaries of the property. The eastern portion of the site slopes to the west at 2-17%. Critical Areas: Based on the available information from King County iMap and the attached Geotech report there are no wetlands, streams or associated buffers located on-site. See full offsite analysis in Section III of this TIR. Soils: Per the US Department of Agriculture (USDA), Natural Resources Conservation Service (NCRS) Web Soil Survey (WSS) information, the entire project site is underlain with Alderwood Gravelly Sandy Loam (AgC). 8/15/19 Page 6 II. CONDITIONS AND REQUIREMENTS SUMMARY The 2017 City of Renton Surface Water Design Manual was utilized for this report per the City of Renton requirements. Core Requirement #1: Discharge at the Natural Location The proposed development runoff will follow existing drainage patterns that flow west towards the adjacent Ashburn Condominium project storm system. Refer to the Downstream Analysis in Section III for a complete description of the existing drainage path. Core Requirement #2: Offsite Analysis A Level 1 Downstream analysis has been completed for the site and no existing or potential problems have been identified. This analysis is included in Section III of this TIR. Core Requirement #3: Flow Control Facilities Based on the City of Renton’s flow control map, the project site is located within the duration flow control area. This means that the existing conditions must be modeled as forested per Section 1.2.3.1.B of the City of Renton 2017 SWDM. Flow control facilities were designed to match the predeveloped rates over the range of flows extending from ½ of the 2-year up the full 50-year flow. Flow shall not exceed predeveloped peak discharge rates for the 2- and 10-year return periods. See Section IV of this TIR for a detailed breakdown of proposed facilities and how they were modeled. Core Requirement #4: Conveyance System Conveyance systems were designed to fully comply with the requirements detailed in Section 1.2.4.1 of the City of Renton 2017 SWDM. Full conveyance system analysis is provided in Section V of this report. Core Requirement #5: Construction Stormwater Pollution Prevention A temporary erosion and sediment control (TESC) plan provides details of BMPs to be implemented during construction and is included in the engineering plan set. A SWPPP has also been prepared by Encompass Engineering and Surveying and is included with this submittal package. Core Requirement #6: Maintenance and Operations See Section X – Operation and Maintenance Manual. Core Requirement #7: Financial Guarantees and Liability The owner will arrange for any financial guarantees and liabilities required by the permit. Bond quantity information is provided in Appendix C. Core Requirement #8: Water Quality Facilities In accordance with the King County Surface Water Design Manual, section 1.2.8.1.A.2, Enhanced Basic water quality treatment is required for this project as the development results in a multifamily land use. A treatment train comprised of an Oldcastle Biopod and infiltration will provide water quality treatment. Further discussion of proposed water quality system is included in Section IV of this report. See geotechnical studies in Appendix A for additional information regarding infiltration rates. 8/15/19 Page 7 Core Requirement #9: Flow Control BMPs This site is located within the UGA and is larger than 22,000 SF. It is therefore subject to the Large Lot BMP Requirements detailed in Section 1.2.9.2.2 in the 2017 City of Renton SWDM. On-site BMPs shall be applied in the following order, if feasible: Full Dispersion, Full Infiltration, Limited Infiltration, Bioretention, Permeable Pavement, Basic Dispersion, Reduced Impervious Surface Credit, Native Growth Retention Credit, and finally, Tree Retention Credit. All flow control BMPs are designed to fully comply with the specifications detailed in the 2017 City of Renton SWDM. See Section IV of this TIR for complete Flow Control details. Full Dispersion: Infeasible, a 100’ Native Vegetated Flowpath at less than 15% slope is not available onsite. Full Infiltration: Infeasible, Geotech Report states that Limited infiltration is feasible at depths between 8’-13’ only. Limited Infiltration: Feasible, Geotech Report states that Limited infiltration is feasible at depths between 8’-13’ only. Limited Infiltration is applied to the the runoff from the site area in the form of a combination Detention/Infiltration Vault. This vault was sized to the specification detailed in Appendix C.2.3. Bioretention: Infeasible, there is little to no room for bioretention onsite and bioretention relies on infiltration which is not feasible above 8’ depths. Permeable Pavement: Infeasible per Geotech Report due to underlying glacial till soil. Basic Dispersion: Feasible, but not for all impervious surfaces. • Basic dispersion is not proposed for this site as limited infiltration will fully serve the site’s needs. Reduced Impervious Surface Credit: Infeasible, developed conditions propose to clear the entire site. Native Growth Retention Credit: Infeasible, there is not sufficient room for Native Growth Retention areas onsite. Tree Retention Credit: Infeasible, minimum canopy area requirements cannot be met. Soil Amendment: Feasible, all disturbed, pervious areas of the project will meet soil amendment requirements. This will be accomplished mostly by retaining the existing topsoil in a stockpile onsite. 8/15/19 Page 8 Special Requirement #1: Other Adopted Area-Specific Requirements Critical Drainage Area – N/A Master Drainage Plan – N/A Basin Plan – N/A Lake management Plan – N/A Shared Facility Drainage Plan – N/A Special Requirement #2: Flood Hazard Area Delineation The limits of this project do not lie in a 100-year floodplain Special Requirement #3: Flood Protection Facilities N/A Special Requirement #4: Source controls This project is subject to structural improvements related to Fueling of Equipment and Vehicles such as cement pads. Special Requirement #5: Oil Control This project is not considered high-use in need of oil control. Special Requirement #6: Aquifer Protection Area The aquifer protection area is not applicable to this site. III. Level-1 Downstream Analysis A Level 1 Downstream Drainage Analysis was performed October 12, 2018 at around 8:00 AM. The weather was clear and roughly 60°. The site is developed with an existing single-family residence, detached garage and paved driveway. The site is comprised of grasses, trees and shrubs around the boundaries of the property. The eastern portion of the site slopes to the west at 2-17%. Task 1: The area of analysis extends downstream from the site to 1/4 mile downstream. Task 2: Per King county resources, there have been no significant drainage complaints. Task 3: There were no apparent downstream drainage issues. Task 4: The site mostly sheet flows (A) west into a wooded tract, part of the adjacent Ashburn Condominium project. There is an existing level spreader (B) of some sort constructed with the Ashburn collecting and routing at least some of the flows into a 12” pipe system in Ashburn that directs these flows around the detention vault constructed for the Ashburn project (E). This bypass pipe (C) discharges into a wooded ravine (H) about 350’ downstream from the site. Flows from the ravine cross under on the Ashburn streets through a 12” pipe (I), continuing west through more wooded ravine (J) then into the SR-167 storm system (G), about ¼ mile downstream from the site. That portion of runoff from the site (A) that doesn’t drain into the bypass pipe mentioned above drains past the existing level spreader (B) into a wooded area south of the site, then into an inlet pipe (D), about 200’ west of the site. The flows drain though the 12” Ashburn pipe system about ¼ mile before discharging into a large underground detention vault (E). The vault discharges into an overgrown bioswale F) draining south, then west towards the SR-167 storm system (G), a distance of greater than ¼ mile downstream from the site. 8/15/19 Page 9 Photo 1: Site Frontage (A) Photo 2: Ashburn Stormwater Vault (E) 8/15/19 Page 10 Photo 3: Ashburn Bioswale (F) Photo 4: Wooded Ravine (J) 8/15/19 Page 11 8/15/19 Page 12 IV. FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN Target Area Swap and Mitigation Trade Sections 1.2.8.C-D and 1.2.3.2.E-G of the 2017 RSWDM outline the requirements for bypass and area swap mitigation for areas that can not be collected due to topographic limitations. There are two such areas associated with this project. 1. Talbot Road frontage improvements south of the access intersection are topographically disconnected from the drainage collection system. This area consists of 2,015 square feet of asphalt and sidewalk and 770 square feet of landscaping. The access road to the project is graded such that an additional 2,240 square feet of asphalt on Talbot Road SE will be collected into the onsite stormwater system. Section 1.2.3.2 G of the RSWDM: G. MITIGATION TRADES A project’s flow control facility may be designed to mitigate an existing developed non-target surface area (either onsite or offsite) in trade for not mitigating part or all of the project’s target surface area, provided that all of the following conditions are met: 1. The existing developed non-target surface area (i.e., an area of existing impervious surface and/or nonnative pervious surface) must have runoff discharge characteristics (i.e., peak flow and volume) equivalent to those of the target surface area for which mitigation is being traded and must not be currently mitigated to the same flow control performance requirement as the target surface area, AND a. The extra asphalt collected has the same runoff as the target area. 2. Runoff from both the target surface area being traded and the flow control facility must converge prior to discharge of the runoff from the target surface area being traded onto private property without an easement or through any area subject to erosion, AND a. The runoff from the bypass area will be conveyed south in the flow line of Talbot Road to S 50th Street, where it will be collected into the public storm drain system and conveyed to the west, arriving approximately 1,700 feet downstream of the project site at Lake Pl South, where it joins the discharge from the developed project. 3. The net effect in terms of flow control at the point of convergence downstream must be the same with or without the mitigation trade, AND a. The traded areas will produce the same amount of runoff. 4. The undetained runoff from the target surface area being traded must not create a significant adverse impact to downstream drainage systems, salmonid habitat, or properties prior to convergence with runoff from the flow control facility. a. The runoff will be conveyed in the public storm drainage system. 8/15/19 Page 13 5. Consideration of an offsite area to be mitigated for must take into account the likelihood of that area redeveloping in the future. Those areas determined by the City to have a high likelihood of future redevelopment that will provide its own mitigation may not be used as a mitigation trade. a. The area mitigated for is a public right of way. Additional development is not anticipated. 6. Mitigation trade proposals must be reviewed and approved with input from the City of Renton a. The mitigation proposal is presented here in the Technical Information Report. 2. 387 square feet of the gravel access road in the southwest corner of the project is topographically disconnected from the detention system. Runoff from this area will sheet flow to the property boundary, follow the existing sewer easement and be collected into a cb within 100 feet of the project. This catch basin is connected to the discharge of the stormwater leaving the onsite detention system. Given the negligible amount of runoff generated by 387 square feet (0.0089 AC), the fact that it is connecting to an existing gravel area, this bypass area will have a negligible effect on the downstream system. See Asbuilt exhibit below. Ashburn Commons As-built Existing sewer connection and existing runoff path Primary Discharge Point 8/15/19 Page 14 Flow Control Calculations Per the City of Renton Stormwater Management Manual, full dispersion and full infiltration must be implemented if feasible. However, the native vegetative flow paths are limited within the development area and the Alderwood soils are not conducive to full infiltration above the depth of 8-feet. Below 8-feet deep, the soils become more conducive to infiltration, but full infiltration is not supported by geotechnical engineering. Therefore, partial infiltration is being proposed for all collected areas. This stormwater management system for this project is designed to comply with the minimum required performance for facilities in Flow Control Duration Standard Areas (Matching Forested) as described in section 1.2.3.1.B of the 2017 City of Renton Surface Water Design Manual. Per the requirements: • Developed discharge durations shall not exceed predeveloped durations for the range of predeveloped discharge rates from 50% of the 2-year peak flow up to the full 50-year peak flow. • Developed peak discharge rates shall not exceed predeveloped peak discharge rates for the 2- and 10-year return periods. • Assume forested (historical) site conditions as the predeveloped condition. Runoff from all remaining, improved site areas will be routed to a combination detention / infiltration vault for flow control. The detention/infiltration vault will release the stormwater at a controlled rate similar to the existing conditions. The vault was designed for the site using WWHM and provides 4.93 feet of active storage depth with a storage volume of 12,700 Cubic Feet. See Appendix B – WWHM Modeling for full calculations and final engineering site plans for dimensions and details. This project proposes to implement the Soil Amendment On-Site BMP per the 2017 SWDM Appendix C.2.13. Establishing a minimum soil quality and depth across the site will improve on- site management of stormwater flow and water quality. Soil amendment is considered infeasible on till soil slopes greater than 33 percent, of which there are none on the site. All landscaped areas on site shall meet the minimum requirements for soil quality detailed in Appendix C.2.13 and are therefore modeled as half “Pasture” and half “Lawn” in WWHM as there are no restrictive covenants protecting the areas. Details are included in the final engineering plan set and modeling is attached in Appendix B. Runoff Flow Rates Produced in WWHM Full WWHM output is included in Appendix B of this TIR. 8/15/19 Page 15 Water Quality Calculations The proposed pollution generating impervious surfaces (20,736 square feet) are greater than the 5,000 SF threshold, therefore water quality treatment is required for this project. See area breakdown and WWHM Analysis results below. Since the land use of the site will be multi- family, enhanced basic water quality is required in accordance with 2017 RSWDM Section 1.2.8.1.A.2. This project proposes to infiltrate runoff per the standards of Section 5.2 and therefore meets exemption 1 in Section 1.2.8.1.B of the 2017 Renton SWDM. An underground Biopod by Oldcastle Infrastructure is proposed to achieve the enhanced portion of the water quality requirements. The design flow modeled by WWHM is 0.1785 cubic feet per second. The table shown on the next page provides sizing requirements of the Biopod based on the design flow rate. At 0.1758 cfs, a Biopod of 6’ by 12’ is required. Pollutant Generating Impervious Area Impervious Area: (SF) (AC) Driveway 7,195 0.1652 Street 13,541 0.3109 Total 20,736 0.4760 8/15/19 Page 16 Biopod Sizing Chart See full bipod details in Appendix H This project proposes a 6’ x 12’ underground Biopod by Oldcastle prior to infiltration to provide Enhanced Basic water quality treatment. Since water quality is provided upstream of infiltration, a settling tank is not proposed prior to infiltration. The Biopod Biofiltration device is a proprietary filtration system that has not been specifically approved by the City of Renton, but has received GULD certification from the Department of Ecology. A Stormwater Adjustment request is included in Appendix H along with the Biopod details. 8/15/19 Page 18 V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN The flow into the vault is 0.9723 CFS for the 100-year flow frequency return period as shown below in the copied information provided by WWHM. A 12” PVC pipe flowing at 0.5% Slope (minimum) has a capacity of 2.729 CFS. This is sufficient to convey the most extreme design flows on the developed site. The pipe capacity was calculated using manning’s equation built into an online Conveyance Calculator (shown below). VI. SPECIAL REPORTS AND STUDIES • Geotechnical Engineering Report by Migizi Group revised August 30, 2018 • Arborist Report by American Forest Management dated July 9, 2018 • Trip Generation Report by DN Traffic Consultants dated September 28, 2018 • Wetland Reconnaissance by The Watershed Company dated June 11, 2015 • Review of Site and Watershed June 11, 2015 Report by Sewall Wetland Consulting, Inc. dated May 6, 2016 VII. OTHER PERMITS Building Permits will be required. NPDES VIII. CSWPPP ANALYSIS AND DESIGN A CSWPPP has been prepared and is included in the civil design package. 8/15/19 Page 19 IX. BOND QUANTITIES and DECLARATION of COVENANT Bond Quantities are provided in Appendix C with this submittal. The Declaration of Covenant will be provided with project approval. X. OPERATION AND MAINTENANCE MANUAL An Operation and Maintenance Manual is provided in Appendix D with this submittal. Sapphire on Talbot Final Technical Information Report Appendix A Geotechnical Engineering Report by Migizi Group revised March 29, 2019 Geotechnical Engineering Report Proposed Talbot Gardens Short Plat 4827 Talbot Rd S Renton, Washington 98055 P/N 3123059022 October 11, 2017 Revised March 29, 2019 prepared for: Sapphire Homes Attention: Troy Schmeil 16834 SE 43rd St Bellevue, Washington 98006 prepared by: Migizi Group, Inc. PO Box 44840 Tacoma, Washington 98448 (253) 537-9400 MGI Project P1389-T18 i TABLE OF CONTENTS Page No. 1.0 SITE AND PROJECT DESCRIPTION............................................................................................... 1 2.0 EXPLORATORY METHODS ............................................................................................................. 2 2.1 Test Pit Procedures ................................................................................................................ 3 2.2 Infiltration Test Procedures .................................................................................................. 3 3.0 SITE CONDITIONS ............................................................................................................................ 4 3.1 Surface Conditions ................................................................................................................. 4 3.2 Soil Conditions ....................................................................................................................... 4 3.3 Groundwater Conditions ...................................................................................................... 5 3.4 Infiltration Conditions and Infiltration Rate ...................................................................... 5 3.5 Seismic Conditions ................................................................................................................. 7 3.6 Liquefaction Potential ............................................................................................................ 7 4.0 CONCLUSIONS AND RECOMMENDATIONS ............................................................................ 7 4.1 Site Preparation ...................................................................................................................... 9 4.2 Spread Footings .................................................................................................................... 11 4.3 Slab-On-Grade-Floors .......................................................................................................... 12 4.4 Asphalt Pavement ................................................................................................................ 12 4.5 Structural Fill ........................................................................................................................ 14 5.0 RECOMMENDED ADDITIONAL SERVICES .............................................................................. 15 6.0 CLOSURE ........................................................................................................................................... 15 List of Tables Table 1. Approximate Locations and Depths of Explorations ............................................................................. 2 Table 2. Laboratory Test Results for Non-Organic Onsite Soils .......................................................................... 6 Table 3. Falling Head Period Test Results .............................................................................................................. 6 List of Figures Figure 1. Topographic and Location Map Figure 2. Site and Exploration Plan APPENDIX A Soil Classification Chart and Key to Test Data .................................................................................................. A-1 Logs of Test Pits TP-1 through TP-11 ...................................................................................................... A-2…A-12 APPENDIX B Laboratory Testing Results .......................................................................................................................... B-1…B-4 Page 1 of 15 MIGIZI GROUP, INC. PO Box 44840 PHONE (253) 537-9400 Tacoma, Washington 98448 FAX (253) 537-9401 October 11, 2017 Revised March 29, 2019 Sapphire Homes 16834 SE 43rd St Bellevue, Washington 98006 Attention: Troy Schmeil Subject: Revised Geotechnical Engineering Report Proposed Talbot Gardens Short Plat 4827 Talbot Rd S Renton, Washington 98055 P/N 3123059022 MGI Project P1389-T18 Dear Mr. Schmeil: Migizi Group, Inc. (MGI) is pleased to submit this revised report describing the results of our geotechnical engineering evaluation of the proposed residential development in Renton, Washington. It is our understanding that since our initial iteration of this report, the subject property has changed hands, and that a new design scheme is being implemented. Additional soils information is needed in order to execute the new design. This report has been prepared for the exclusive use of Sapphire Homes, and their consultants, for specific application to this project, in accordance with generally accepted geotechnical engineering practice. 1.0 SITE AND PROJECT DESCRIPTION The project site consists of a 1.67-acre, residential parcel located immediately southwest of the intersection between S 48th St and Talbot Rd S in Renton, Washington, as shown on the enclosed Topographic and Location Map (Figure 1). The subject property is situated in a densely populated residential area located towards the south end of the city limits of Renton. A single-family residence, originally constructed in 1936, and accompanying detached garage and shed building occupy the central portion of the site, with the northeast corner of the project area containing extensive paved surfaces for overflow parking. The remainder of the parcel is occupied by tall grasses, and various forms of vegetation. Sapphire Homes – Talbot Gardens Short Plat, Renton, WA October 11, 2017 / Revised March 29, 2019 Revised Geotechnical Engineering Report P1389-T18 Migizi Group, Inc. Page 2 of 15 Improvement plans involve the clearing/stripping of the property, demolition of the existing structures, and development of the site for residential purposes. The proposed development will result in approximately 20 buildable lots and contain a primary access road which travels east-west across the length of the property, following the general course of the existing driveway. A supplemental alleyway will also be introduced as part of the proposed development, traveling south from S 48th Street, spanning the full length of the property along this orientation. The southwest corner of the subject property will be utilized as an Open Space / Tree Retention Tract, and will also house stormwater retention facilities, if feasible. 2.0 EXPLORATORY METHODS We explored surface and subsurface conditions at the project site on September 5, 2017, July 24, 2018, and March 15, 2019. Our exploration and evaluation program comprised the following elements: • Surface reconnaissance of the site; • Eleven test pit explorations (designated TP-1 through TP-11) advanced on September 5, 2017, July 24, 2018, March 15, 2019; • Two grain-size analyses performed on soil samples collected from our subsurface explorations; • Two Small-Scale Pilot Infiltration Tests (PIT) (designated INF-1 and INF-2) performed in the vicinity of test pit explorations TP-7 and TP-11; and • A review of published geologic and seismologic maps and literature. Table 1 summarizes the approximate functional locations and termination depths of our subsurface explorations, and Figure 2 depicts their approximate relative locations. The following sections describe the procedures used for excavation of the test pits. TABLE 1 APPROXIMATE LOCATIONS AND DEPTHS OF EXPLORATIONS Exploration Functional Location Termination Depth (feet) TP-1 TP-2 TP-3 TP-4 TP-5 TP-6 TP-7 TP-8 TP-9 TP-10 TP-11 Northwest corner of the project area; southeast of shed building West of southwest corner of existing residence Southeast corner of the project area in small clearing Far southwest corner of the project area Immediately northeast of test pit exploration TP-4 East of southeast corner of the existing residence Grass clearing north of the primary driveway Northeast corner of the project area, within existing paved parking area Far northwest corner of the project area Centrally, west end of the project area West of existing residence, north of TP-2 10 10 10 15 15 10 11 10 10 15 10 Sapphire Homes – Talbot Gardens Short Plat, Renton, WA October 11, 2017 / Revised March 29, 2019 Revised Geotechnical Engineering Report P1389-T18 Migizi Group, Inc. Page 3 of 15 The specific number and locations of our explorations were selected in relation to the existing site features, under the constraints of surface access, underground utility conflicts, and budget considerations. It should be realized that the explorations performed and utilized for this evaluation reveal subsurface conditions only at discrete locations across the project site and that actual conditions in other areas could vary. Furthermore, the nature and extent of any such variations would not become evident until additional explorations are performed or until construction activities have begun. If significant variations are observed at that time, we may need to modify our conclusions and recommendations contained in this report to reflect the actual site conditions. 2.1 Test Pit Procedures Our initial exploratory test pits were excavated with a rubber-tracked mini-excavator operated by an excavation contractor under subcontract to MGI. Deeper explorations, advanced at later mobilizations were excavated with a steel-tracked excavator/operator under subcontract with the client. An engineering geologist from our firm observed the test pit excavations, collected soil samples, and logged the subsurface conditions. The enclosed test pit logs indicate the vertical sequence of soils and materials encountered in our test pits, based on our field classifications. Where a soil contact was observed to be gradational or undulating, our logs indicate the average contact depth. We estimated the relative density and consistency of the in-situ soils by means of the excavation characteristics and the stability of the test pit sidewalls. Our logs also indicate the approximate depths of any sidewall caving or groundwater seepage observed in the test pits. The soils were classified visually in general accordance with the system described in Figure A-1, which includes a key to our exploration logs. Summary logs of our explorations are included as Figures A-2 through A-12. 2.2 Infiltration Test Procedures In-situ field infiltration testing was performed for determination of a Design Infiltration Rate in general accordance with the Small-Scale PIT procedures, as described in Reference 6A, of the 2016 King County Surface Water Design Manual, as adopted by the City of Renton. The first step of this test procedure was to identify a suitable soil stratum for stormwater retention, and once completed, perform an excavation within this soil group with a minimum surface area of 12 square feet (sf). Once the excavation was completed, a vertical measuring rod marked in half-inch increments was installed towards the center of the test area. Water was then introduced into the test area, being conveyed through a 4-inch corrugated pipe to a splash block at the bottom of the excavation. Once 12 inches of water was developed at the bottom of the excavation, the test surface was saturated prior to testing. After the saturation period was completed, a steady state flow rate was developed in order to maintain 12 inches of head at the bottom of the test surface. This steady state rate was maintained for one hour. After completion of the steady state period, water was no longer introduced into the excavation, and infiltration of the existing water was allowed. We recorded the falling head rate for one hour, for comparison with the steady state rate. Sapphire Homes – Talbot Gardens Short Plat, Renton, WA October 11, 2017 / Revised March 29, 2019 Revised Geotechnical Engineering Report P1389-T18 Migizi Group, Inc. Page 4 of 15 3.0 SITE CONDITIONS The following sections present our observations, measurements, findings, and interpretations regarding surface, soil, groundwater, and infiltration conditions. 3.1 Surface Conditions As previously indicated, the project site consists of a fully developed, 1.67-acre residential parcel located immediately southwest of the intersection between S 48th St and Talbot Rd S in Renton, Washington. The project area is roughly square-shaped, spanning approximately 270 feet along its primary boundaries. The central portion of the site is occupied by an existing single-family residence and accompanying detached garage and shed building. Expanded asphalt pavements occupy the northeast corner of the subject property. The primary driveway enters the site from the east along Talbot Rd S, looping to the north to access the aforementioned expanded parking area. Vegetation consists primarily of lawn grass immediately east and west of the existing structures. A thick growth of alder and fir trees are located towards the southern and western margins of the project area, containing a dense understory of fern, blackberry bushes, and other brush. Topographically, the subject property is gently sloped, generally descending from east to west at gradients of less than 10 percent; with a total elevation change of ± 25 feet being observed over the extent of the parcel. The subject parcel is situated along the eastern valley wall of the Duwamish Valley. No hydrologic features were observed on site, such as seeps, springs, ponds and streams. 3.2 Soil Conditions Our test pit explorations revealed relatively consistent subgrade conditions across the project area, generally consisting of a surface mantle of sod/topsoil, underlain by native, Vashon-aged glacial soils. Renton, and the larger Puget Sound area in general, has been glaciated a number of times over the last 2.4 million years. The most recent of these glacial events, the Vashon Stade of the Fraser Glaciation, receded from this region approximately 13,500 years ago. The majority of near surface soils encountered within the Renton area are either directly associated with or have been physically altered by the Vashon glacial event. Glacial till is typically described as being a compact, coherent mixture of gravel, silt, clay and sand-sized clasts deposited along the base of glacial ice during a period of localized advancement. This material is generally encountered in a compact relative consistency given the fact that it was overridden by the ice mass shortly after deposition and is commonly underlain by advance outwash soils. Advance outwash is resultant of pro-glacial rivers and streams which carried sediment ahead of the advancing ice mass. Pockets of fine-grained soils encountered within larger outwash deposits, as observed onsite, indicate that locally, pro-glacial streams were slow-moving to nearly stagnant. In general, our test pit explorations encountered glacial till soils within 12 inches of existing grade. This material was continuous through a depth of approximately 7 to 8 feet below existing grade, being comprised of silty sand with some gravel, to gravelly silty sand. As encountered on site, Sapphire Homes – Talbot Gardens Short Plat, Renton, WA October 11, 2017 / Revised March 29, 2019 Revised Geotechnical Engineering Report P1389-T18 Migizi Group, Inc. Page 5 of 15 glacial till soils were highly weathered and heavily mottled; indicating poor surface drainage. From a depth of 8 feet to 10 feet below existing grade, the termination depth of seven of our subsurface explorations, we encountered advance outwash deposits. Advance outwash is typically comprised of densely consolidated, relatively clean, sands and gravel. However, on site, this soil group was largely comprised of alternating lenses of fine sand and silty sand; with an average relative fines content (percent silt and clay) between 25 to 30 percent. This soil group was found to extend to a depth of ± 11 to 13 feet below existing grade, transitioning to a more homogenous, relatively impervious, dense, silty sand with some gravel. In the Geologic Map of the Renton Quadrangle, King County, Washington, as prepared by the Department of the Interior United States Geological Survey (USGS) (1965), the project site is mapped as containing Qvt, or Vashon-aged glacial till. Our subsurface explorations generally correspond with the geologic mapping prepared by the USGS. The enclosed exploration logs (Appendix A) provide a detailed description of the soil strata encountered in our subsurface explorations. 3.3 Groundwater Conditions We did not encounter actual groundwater in any of our subsurface explorations, which extended to a depth upwards of 15 feet below existing grade. During our later explorations performed in March of 2019, we encountered small amounts of perched groundwater towards the top of the heavily mottled soil column, first encountered within 2½ to 3 feet of surface elevations across the project area. This was indicative of the poorly drained nature of surficial soils across the project area. Deeper soil groups were not encountered in a saturated condition. We do not anticipate that groundwater or perched water will be encountered in project excavations if they are performed during the summer months, nor do we anticipate that groundwater will be a limiting factor in the proposed development. 3.4 Infiltration Conditions and Infiltration Rate As indicated in the Soil Conditions section of the report, the site is underlain by low permeability glacial till soils at shallow depths, extending upwards of 8 feet below existing grade. The extensive soil mottling encountered in this soil group is indicative of poor surface drainage. Encountered at a depth of 8 feet, extending through a depth of ± 13 feet, we encountered advance outwash. As observed in our explorations, this soil group was largely comprised of alternating lenses of fine sand and silty sand. Though not ideal for stormwater retention, it is our opinion that this soil group could support limited infiltration. Additionally, we are of the opinion that groundwater levels are at a sufficient depth so as to not adversely affect stormwater retention. Our grain-size analysis indicates that the advance outwash contains an average relative fines (percent silt/clay) content between 27 to 30 percent. The results of our soil grain size analyses are presented below, and the attached Soil Gradation Graphs (Appendix B) display the grain-size distribution of the samples tested. Sapphire Homes – Talbot Gardens Short Plat, Renton, WA October 11, 2017 / Revised March 29, 2019 Revised Geotechnical Engineering Report P1389-T18 Migizi Group, Inc. Page 6 of 15 TABLE 2 LABORATORY TEST RESULTS FOR NON-ORGANIC ONSITE SOILS Soil Sample, Depth % Coarse Gravel % Fine Gravel % Coarse Sand % Medium Sand % Fine Sand % Fines D10 TP-1, S-3, 9 feet TP-2, S-2, 9 feet TP-4, S-1, 10 feet TP-5, S-1, 9 feet 19.3 3.3 0.0 0.0 5.7 9.2 3.8 4.5 2.6 4.2 3.5 2.6 7.3 13.3 14.2 12.7 33.8 43.1 52.3 50.0 31.3 26.9 26.1 30.3 - - - - On March 15, 2019, an engineering geologist from MGI performed field infiltration testing utilizing the procedures at the onset of this report. The field tests (INF-1 and INF-2) were performed in the vicinity of test pit explorations TP-7 and TP-11, as indicated on the attached Figure 2. As described in the Infiltration Test Procedures section of this report, there are two complementary portions of the Small PIT procedure utilized to determine a field infiltration rate; the steady-state period and the falling head period. In our experience, the falling head period is generally more conservative, and provides a more accurate evaluation of infiltration conditions. The results of the falling head portion of our Small PIT is recorded in Table 3. TABLE 3 FALLING HEAD PERIOD TEST RESULTS Test Pit Exploration Depth of Test Surface (feet) Field Infiltration Rate (in/hr) INF-1 INF-2 10 11 2 3 The design rate is determined by the formula Idesign = Imeasured x Ftesting x Fgeometry x Fplugging. Idesign is the maximum Design Infiltration Rate and Imeasured is the field infiltration rate, or 60 inches per hour in this instance. Ftesting is a safety factor that accounts for uncertainties in the testing method and is accepted as Ftesting =0.50. Fgeometry is a safety factor that accounts for the influence of facility geometry and depth to the water table or impervious strata on the actual infiltration rate and is determined by the following equation: Fgeometry = 4 D/W + 0.05 where D = depth from the bottom of the proposed facility to the maximum wet season water table or nearest impervious layer, whichever is less and W = width of facility. Fplugging is a safety factor that accounts for reductions in infiltration rates over the long term due to plugging of soils. This factor is: • 0.7 for loams and sandy loams • 0.8 for fine sands and loamy sands • 0.9 for medium sands • 1.0 for coarse sands or cobbles. Because the infiltration area is underlain by fine to loamy sands, a value of 0.8 for Fplugging should be used for calculations. The accepted value of 0.5 for Ftesting should be used for calculations as well. A preliminary value of 1.0 should be used for Fgeometry. Using these values, the calculated average Design Infiltration Rate is 1 inch per hour. This value is for the native advance outwash soils which underlie the project area. Retention facilities should have an invert elevation of at least 8 feet below Sapphire Homes – Talbot Gardens Short Plat, Renton, WA October 11, 2017 / Revised March 29, 2019 Revised Geotechnical Engineering Report P1389-T18 Migizi Group, Inc. Page 7 of 15 existing grade. A more homogeneous restrictive layer is encountered at a depth of 13 feet in the proposed stormwater retention area. The presence of this restrictive layer should be evaluated by the Civil Engineer of Record for this project to determine whether it will adversely affect any proposed designs. 3.5 Seismic Conditions Based on our analysis of subsurface exploration logs and our review of published geologic maps, we interpret the onsite soil conditions to generally correspond with site class D, as defined by Table 20.3-1 in ASCE 7, per the 2015 International Building Code (IBC). Using 2015 IBC information on the USGS Design Summary Report website, Risk Category I/II/III seismic parameters for the site are as follows: Ss = 1.394 g SMS = 1.394 g SDS = 0.929 g S1 = 0.520 g SM1 = 0.780 g SD1 = 0.520 g Using the 2015 IBC information, MCER Response Spectrum Graph on the USGS Design Summary Report website, Risk Category I/II/III, Sa at a period of 0.2 seconds is 1.39 g and Sa at a period of 1.0 seconds is 0.78 g. The Design Response Spectrum Graph from the same website, using the same IBC information and Risk Category, Sa at a period of 0.2 seconds is 0.93 g and Sa at a period of 1.0 seconds is 0.52 g. 3.6 Liquefaction Potential Liquefaction is a sudden increase in pore water pressure and a sudden loss of soil shear strength caused by shear strains, as could result from an earthquake. Research has shown that saturated, loose, fine to medium sands with a fines (silt and clay) content less than about 20 percent are most susceptible to liquefaction. Our explorations did not encounter any saturated, or potentially saturated granular soils, and we interpret the site as having a low potential for soil liquefaction during a large-scale seismic event. 4.0 CONCLUSIONS AND RECOMMENDATIONS Improvement plans involve the clearing/stripping of the property, demolition of the existing structures, and development of the site for residential purposes. The proposed development will result in approximately 20 buildable lots and contain a primary access road which travels east-west across the length of the property, following the general course of the existing driveway. A supplemental alleyway will also be introduced as part of the proposed development, traveling south from S 48th Street, spanning the full length of the property along this orientation. The southwest corner of the subject property will be utilized as an Open Space / Tree Retention Tract, and will also house stormwater retention facilities, if feasible. We offer these recommendations: • Feasibility: Based on our field explorations, research and analyses, the proposed structures appear feasible from a geotechnical standpoint. Sapphire Homes – Talbot Gardens Short Plat, Renton, WA October 11, 2017 / Revised March 29, 2019 Revised Geotechnical Engineering Report P1389-T18 Migizi Group, Inc. Page 8 of 15 • Foundation Options: Foundation elements for the proposed residences should be constructed on medium dense or denser undisturbed native soils, or on structural fill bearing pads extending down to these soils. We anticipate that adequate bearing soils will be encountered within two to three feet of existing grade. Recommendations for Spread Footings are provided in Section 4.2. • Floor Options: Floor sections for the proposed residences should bear on medium dense or denser native soils or on properly compacted structural fill extending down to these soils. We anticipate that adequate bearing soils will be encountered within two to three feet of existing grade. Recommendations for slab-on-grade floors are included in Section 4.3. Fill underlying floor slabs should be compacted to 95 percent (ASTM:D-1557). • Pavement Sections: Native, in-situ soil conditions are amenable to the use of soil- supported pavements. We recommend a conventional pavement section comprised of an asphalt concrete pavement over a crushed rock base course over a properly prepared (compacted) subgrade or a granular subbase, depending on subgrade conditions during pavement subgrade preparation. All soil subgrades should be thoroughly compacted, then proof-rolled with a loaded dump truck or heavy compactor. Any localized zones of yielding subgrade disclosed during this proof-rolling operation should be over-excavated to a depth of 12 inches and replaced with a suitable structural fill material. • Infiltration Conditions: Given the geological conditions encountered on site, we do not foresee full-infiltration as being feasible for this project. However, limited infiltration utilizing a system of trenches, likely can be implemented on site, utilizing the advance outwash soils for stormwater retention. We recommend utilizing a design infiltration rate of 1 inch per hour for this soil group. Invert elevations for retention facilities should be located at least 8 feet below existing grade. A more homogeneous restrictive layer is encountered at a depth of 13 feet in the proposed stormwater retention area. The presence of this restrictive layer should be evaluated by the Civil Engineer of Record for this project to determine whether it will adversely affect any proposed designs. Shallower glacial till soils, should be considered impermeable for design purposes. • Geologic Hazards: During our site reconnaissance, advancement of subsurface explorations, and general evaluation of the proposed development, we did not observe any erosional, landslide, seismic, settlement, or other forms of geologic hazards within the subject property. Given this fact, we recommend that no buffers, setbacks, or other forms of site restraints be implemented to address these potential hazards. The following sections of this report present our specific geotechnical conclusions and recommendations concerning site preparation, spread footings, slab-on-grade floors, asphalt pavement, and structural fill. The Washington State Department of Transportation (WSDOT) Standard Specifications and Standard Plans cited herein refer to WSDOT publications M41-10, Sapphire Homes – Talbot Gardens Short Plat, Renton, WA October 11, 2017 / Revised March 29, 2019 Revised Geotechnical Engineering Report P1389-T18 Migizi Group, Inc. Page 9 of 15 Standard Specifications for Road, Bridge, and Municipal Construction, and M21-01, Standard Plans for Road, Bridge, and Municipal Construction, respectively. 4.1 Site Preparation Preparation of the project site should involve erosion control, temporary drainage, clearing, stripping, excavations, cutting, subgrade compaction, and filling. Erosion Control: Before new construction begins, an appropriate erosion control system should be installed. This system should collect and filter all surface water runoff through silt fencing. We anticipate a system of berms and drainage ditches around construction areas will provide an adequate collection system. Silt fencing fabric should meet the requirements of WSDOT Standard Specification 9-33.2 Table 3. In addition, silt fencing should embed a minimum of 6 inches below existing grade. An erosion control system requires occasional observation and maintenance. Specifically, holes in the filter and areas where the filter has shifted above ground surface should be replaced or repaired as soon as they are identified. Temporary Drainage: We recommend intercepting and diverting any potential sources of surface or near-surface water within the construction zones before stripping begins. Because the selection of an appropriate drainage system will depend on the water quantity, season, weather conditions, construction sequence, and contractor's methods, final decisions regarding drainage systems are best made in the field at the time of construction. Based on our current understanding of the construction plans, surface and subsurface conditions, we anticipate that curbs, berms, or ditches placed around the work areas will adequately intercept surface water runoff. Clearing and Stripping: After surface and near-surface water sources have been controlled, sod, topsoil, and root-rich soil should be stripped from the site. Our subsurface explorations indicate that the organic horizon can reach thicknesses of up to 14 inches. Stripping is best performed during a period of dry weather. Site Excavations: Based on our explorations, we expect deeper site excavations will predominately encounter densely consolidated glacial till soils. This soil group can be readily excavated utilizing standard excavation equipment, though special teeth, or “rippers”, may need to be utilized in order to rapidly excavate glacial till soils. Shallower excavations will encounter highly weathered, loosely consolidated soils which can be readily excavated using standard excavation equipment. Dewatering: We did not encounter actual groundwater seepage in any of our subsurface explorations, which extended a maximum depth of 15 feet below existing grade. We do not anticipate that groundwater levels will rise high enough to adversely affect the proposed development; however, seasonally perched groundwater will likely be encountered at relatively shallow depths across the project area during extended precipitation given the presence of low permeability till soils across the subsurface. If groundwater is encountered, we anticipate that an internal system of ditches, sump holes, and pumps will be adequate to temporarily dewater excavations. Sapphire Homes – Talbot Gardens Short Plat, Renton, WA October 11, 2017 / Revised March 29, 2019 Revised Geotechnical Engineering Report P1389-T18 Migizi Group, Inc. Page 10 of 15 Temporary Cut Slopes: All temporary soil slopes associated with site cutting or excavations should be adequately inclined to prevent sloughing and collapse. Temporary cut slopes in site soils should be no steeper than 1½H:1V, and should conform to Washington Industrial Safety and Health Act (WISHA) regulations. Subgrade Compaction: Exposed subgrades for the foundation of the proposed residence should be compacted to a firm, unyielding state before new concrete or fill soils are placed. Any localized zones of looser granular soils observed within a subgrade should be compacted to a density commensurate with the surrounding soils. In contrast, any organic, soft, or pumping soils observed within a subgrade should be overexcavated and replaced with a suitable structural fill material. Site Filling: Our conclusions regarding the reuse of onsite soils and our comments regarding wet- weather filling are presented subsequently. Regardless of soil type, all fill should be placed and compacted according to our recommendations presented in the Structural Fill section of this report. Specifically, building pad fill soil should be compacted to a uniform density of at least 95 percent (based on ASTM:D-1557). Onsite Soils: We offer the following evaluation of these onsite soils in relation to potential use as structural fill: • Surficial Organic Soil and Organic-Rich Fill Soils: Where encountered, surficial organic soils like duff, topsoil, root-rich soil, and organic-rich fill soils are not suitable for use as structural fill under any circumstances, due to high organic content. Consequently, this material can be used only for non-structural purposes, such as in landscaping areas. • Glacial Till: Underlying a surface mantle of sod and topsoil, native glacial till soils were encountered; generally consisting of dense, gravelly silty sand. These soils are moderately moisture sensitive and will be difficult, if not impossible, to reuse during wet weather conditions. If reuse is planned, care should be taken while stockpiling in order to avoid saturation/over-saturation of the material, and moisture conditioning should be expected. Permanent Slopes: All permanent cut slopes and fill slopes should be adequately inclined to reduce long-term raveling, sloughing, and erosion. We generally recommend that no permanent slopes be steeper than 2H:1V. For all soil types, the use of flatter slopes (such as 2½H:1V) would further reduce long-term erosion and facilitate revegetation. Slope Protection: We recommend that a permanent berm, swale, or curb be constructed along the top edge of all permanent slopes to intercept surface flow. Also, a hardy vegetative groundcover should be established as soon as feasible, to further protect the slopes from runoff water erosion. Alternatively, permanent slopes could be armored with quarry spalls or a geosynthetic erosion mat. Sapphire Homes – Talbot Gardens Short Plat, Renton, WA October 11, 2017 / Revised March 29, 2019 Revised Geotechnical Engineering Report P1389-T18 Migizi Group, Inc. Page 11 of 15 4.2 Spread Footings In our opinion, conventional spread footings will provide adequate support for the proposed residences if the subgrade is properly prepared. We offer the following comments and recommendations for spread footing design. Footing Depths and Widths: For frost and erosion protection, the bases of all exterior footings should bear at least 18 inches below adjacent outside grades, whereas the bases of interior footings need bear only 12 inches below the surrounding slab surface level. To reduce post-construction settlements, continuous (wall) and isolated (column) footings should be at least 16 and 24 inches wide, respectively. Bearing Subgrades: Footings should bear on medium dense or denser, undisturbed native soils which have been stripped of surficial organic soils and vigorously surface compacted, or on properly compacted structural fill bearing pads which extend down to soils described above. We anticipate that adequate bearing subgrades will be encountered within 1 to 2 feet of existing grade, within glacial till soils. In general, before footing concrete is placed, any localized zones of loose soils exposed across the footing subgrades should be compacted to a firm, unyielding condition, and any localized zones of soft, organic, or debris-laden soils should be over-excavated and replaced with suitable structural fill. Lateral Overexcavations: Because foundation stresses are transferred outward as well as downward into the bearing soils, all structural fill placed under footings, should extend horizontally outward from the edge of each footing. This horizontal distance should be equal to the depth of placed fill. Therefore, placed fill that extends 3 feet below the footing base should also extend 3 feet outward from the footing edges. Subgrade Observation: All footing subgrades should consist of firm, unyielding, native soils, or structural fill materials that have been compacted to a density of at least 95 percent (based on ASTM:D-1557). Footings should never be cast atop loose, soft, or frozen soil, slough, debris, existing uncontrolled fill, or surfaces covered by standing water. Bearing Pressures: In our opinion, for static loading, footings that bear on medium dense or denser, native, glacial soils can be designed for a maximum allowable soil bearing pressure of 2,000 psf. A one-third increase in allowable soil bearing capacity may be used for short-term loads created by seismic or wind related activities. Footing Settlements: Assuming that structural fill soils are compacted to a medium dense or denser state, we estimate that total post-construction settlements of properly designed footings bearing on properly prepared subgrades will not exceed 1 inch. Differential settlements for comparably loaded elements may approach one-half of the actual total settlement over horizontal distances of approximately 50 feet. Sapphire Homes – Talbot Gardens Short Plat, Renton, WA October 11, 2017 / Revised March 29, 2019 Revised Geotechnical Engineering Report P1389-T18 Migizi Group, Inc. Page 12 of 15 Footing Backfill: To provide erosion protection and lateral load resistance, we recommend that all footing excavations be backfilled on both sides of the footings and stemwalls after the concrete has cured. Either imported structural fill or non-organic onsite soils can be used for this purpose, contingent on suitable moisture content at the time of placement. Regardless of soil type, all footing backfill soil should be compacted to a density of at least 90 percent (based on ASTM:D-1557). Lateral Resistance: Footings that have been properly backfilled as recommended above will resist lateral movements by means of passive earth pressure and base friction. We recommend using an allowable passive earth pressure of 225 psf and an allowable base friction coefficient of 0.35 for site soils. 4.3 Slab-On-Grade Floors In our opinion, soil-supported slab-on-grade floors can be used in the proposed residences if the subgrades are properly prepared. Floor sections for the proposed structures should bear on medium dense or denser native soils or on properly compacted structural fill which extends down to soils described above. We anticipate that adequate bearing soils will be encountered within 1 to 2 feet of existing grade. We offer the following comments and recommendations concerning slab- on-grade floors. Floor Subbase: Surface compaction of all slab subgrades is recommended. If a subbase is required, it should be compacted to a density of at least 95 percent (based on ASTM:D-1557). Capillary Break and Vapor Barrier: To retard the upward wicking of moisture beneath the floor slab, we recommend that a capillary break be placed over the subgrade. Ideally, this capillary break would consist of a 4-inch-thick layer of pea gravel or other clean, uniform, well-rounded gravel, such as “Gravel Backfill for Drains” per WSDOT Standard Specification 9-03.12(4), but clean angular gravel can be used if it adequately prevents capillary wicking. In addition, a layer of plastic sheeting (such as Crosstuff, Visqueen, or Moistop) should be placed over the capillary break to serve as a vapor barrier. During subsequent casting of the concrete slab, the contractor should exercise care to avoid puncturing this vapor barrier. Vertical Deflections: Due to elastic compression of subgrades, soil-supported slab-on-grade floors can deflect downwards when vertical loads are applied. In our opinion, a subgrade reaction modulus of 250 pounds per cubic inch can be used to estimate such deflections. 4.4 Asphalt Pavement Since asphalt pavements will also be used for the proposed communal driveway system, we offer the following comments and recommendations for pavement design and construction. Subgrade Preparation: All soil subgrades should be thoroughly compacted, then proof-rolled with a loaded dump truck or heavy compactor. Any localized zones of yielding subgrade disclosed during this proof-rolling operation should be over excavated to a maximum depth of 12 inches and replaced with a suitable structural fill material. All structural fill should be compacted according to our recommendations given in the Structural Fill section. Specifically, the upper 2 feet of soils Sapphire Homes – Talbot Gardens Short Plat, Renton, WA October 11, 2017 / Revised March 29, 2019 Revised Geotechnical Engineering Report P1389-T18 Migizi Group, Inc. Page 13 of 15 underlying pavement section should be compacted to at least 95 percent (based on ASTM D-1557), and all soils below 2 feet should be compacted to at least 90 percent. Pavement Materials: For the base course, we recommend using imported washed crushed rock, such as "Crushed Surfacing Base Course” per WSDOT Standard Specification 9-03.9(3) but with a fines content of less than 5 percent passing the No. 200 Sieve. Although our explorations do not indicate a need for a pavement subbase, if a subbase course is needed, we recommend using imported, clean, well-graded sand and gravel such as “Ballast” or “Gravel Borrow” per WSDOT Standard Specifications 9-03.9(1) and 9-03.14, respectively. Conventional Asphalt Sections: A conventional pavement section typically comprises an asphalt concrete pavement over a crushed rock base course. We recommend using the following conventional pavement sections: Minimum Thickness Pavement Course Parking Areas High Traffic Driveways and Private Access Roads Asphalt Concrete Pavement 2 inches 4 inches Crushed Rock Base 4 inches 8 inches Granular Fill Subbase (if needed) 6 inches 12 inches Compaction and Observation: All subbase and base course material should be compacted to at least 95 percent of the Modified Proctor maximum dry density (ASTM D-1557), and all asphalt concrete should be compacted to at least 92 percent of the Rice value (ASTM D-2041). We recommend that an MGI representative be retained to observe the compaction of each course before any overlying layer is placed. For the subbase and pavement course, compaction is best observed by means of frequent density testing. For the base course, methodology observations and hand-probing are more appropriate than density testing. Pavement Life and Maintenance: No asphalt pavement is maintenance-free. The above described pavement sections present our minimum recommendations for an average level of performance during a 20-year design life; therefore, an average level of maintenance will likely be required. Furthermore, a 20-year pavement life typically assumes that an overlay will be placed after about 10 years. Thicker asphalt and/or thicker base and subbase courses would offer better long-term performance, but would cost more initially; thinner courses would be more susceptible to “alligator” cracking and other failure modes. As such, pavement design can be considered a compromise between a high initial cost and low maintenance costs versus a low initial cost and higher maintenance costs. Sapphire Homes – Talbot Gardens Short Plat, Renton, WA October 11, 2017 / Revised March 29, 2019 Revised Geotechnical Engineering Report P1389-T18 Migizi Group, Inc. Page 14 of 15 4.5 Structural Fill The term "structural fill" refers to any material placed under foundations, retaining walls, slab-on- grade floors, sidewalks, pavements, and other structures. Our comments, conclusions, and recommendations concerning structural fill are presented in the following paragraphs. Materials: Typical structural fill materials include clean sand, gravel, pea gravel, washed rock, crushed rock, well-graded mixtures of sand and gravel (commonly called "gravel borrow" or "pit- run"), and miscellaneous mixtures of silt, sand, and gravel. Recycled asphalt, concrete, and glass, which are derived from pulverizing the parent materials, are also potentially useful as structural fill in certain applications. Soils used for structural fill should not contain any organic matter or debris, nor any individual particles greater than about 6 inches in diameter. Fill Placement: Clean sand, gravel, crushed rock, soil mixtures, and recycled materials should be placed in horizontal lifts not exceeding 8 inches in loose thickness, and each lift should be thoroughly compacted with a mechanical compactor. Compaction Criteria: Using the Modified Proctor test (ASTM:D-1557) as a standard, we recommend that structural fill used for various onsite applications be compacted to the following minimum densities: Fill Application Minimum Compaction Footing subgrade and bearing pad Foundation backfill Asphalt pavement base Asphalt pavement subgrade (upper 2 feet) Asphalt pavement subgrade (below 2 feet) 95 percent 90 percent 95 percent 95 percent 90 percent Subgrade Observation and Compaction Testing: Regardless of material or location, all structural fill should be placed over firm, unyielding subgrades prepared in accordance with the Site Preparation section of this report. The condition of all subgrades should be observed by geotechnical personnel before filling or construction begins. Also, fill soil compaction should be verified by means of in-place density tests performed during fill placement so that adequacy of soil compaction efforts may be evaluated as earthwork progresses. Soil Moisture Considerations: The suitability of soils used for structural fill depends primarily on their grain-size distribution and moisture content when they are placed. As the "fines" content (that soil fraction passing the U.S. No. 200 Sieve) increases, soils become more sensitive to small changes in moisture content. Soils containing more than about 5 percent fines (by weight) cannot be consistently compacted to a firm, unyielding condition when the moisture content is more than 2 percentage points above or below optimum. For fill placement during wet-weather site work, we recommend using "clean" fill, which refers to soils that have a fines content of 5 percent or less (by weight) based on the soil fraction passing the U.S. No. 4 Sieve. APPROXIMATE SITE LOCATION P.O. Box 44840Tacoma, WA 98448 Location Job Number Figure DateTitle 4827 Talbot Rd SRenton, WAP/N 3123059022 Topographic and Location Map 1 08/28/18 P1389-T18 APPENDIX A SOIL CLASSIFICATION CHART AND KEY TO TEST DATA LOGS OF TEST PITS CLAYEY GRAVELS, POORLY GRADED GRAVEL-SAND-CLAY MIXTURES SILTS AND CLAYSCOARSE GRAINED SOILSMore than Half > #200 sieveLIQUID LIMIT LESS THAN 50 LIQUID LIMIT GREATER THAN 50 CLEAN GRAVELS WITH LITTLE OR NO FINES GRAVELS WITH OVER 15% FINES CLEAN SANDS WITH LITTLE OR NO FINESMORE THAN HALF COARSE FRACTION IS SMALLER THAN NO. 4 SIEVE MORE THAN HALF COARSE FRACTION IS LARGER THAN NO. 4 SIEVE INORGANIC SILTS, MICACEOUS OR DIATOMACIOUS FINE SANDY OR SILTY SOILS, ELASTIC SILTS ORGANIC CLAYS AND ORGANIC SILTY CLAYS OF LOW PLASTICITY OH INORGANIC SILTS AND VERY FINE SANDS, ROCK FLOUR,SILTY OR CLAYEY FINE SANDS, OR CLAYEY SILTS WITH SLIGHT PLASTICITY CH SILTY GRAVELS, POORLY GRADED GRAVEL-SAND-SILT MIXTURES SANDS SILTS AND CLAYS Figure A-1 INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY, GRAVELLY CLAYS, SANDY CLAYS, SILTY CLAYS,LEAN CLAYS R-Value Sieve Analysis Swell Test Cyclic Triaxial Unconsolidated Undrained Triaxial Torvane Shear Unconfined Compression (Shear Strength, ksf) Wash Analysis (with % Passing No. 200 Sieve) Water Level at Time of Drilling Water Level after Drilling(with date measured) RV SA SW TC TX TV UC (1.2) WA (20) Modified California Split Spoon Pushed Shelby Tube Auger Cuttings Grab Sample Sample Attempt with No Recovery Chemical Analysis Consolidation Compaction Direct Shear Permeability Pocket Penetrometer CA CN CP DS PM PP PtHIGHLY ORGANIC SOILS TYPICAL NAMES GRAVELS ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY, ORGANIC SILTS WELL GRADED GRAVELS, GRAVEL-SAND MIXTURES MAJOR DIVISIONS PEAT AND OTHER HIGHLY ORGANIC SOILS WELL GRADED SANDS, GRAVELLY SANDS POORLY GRADED SANDS, GRAVELLY SANDS SILTY SANDS, POORLY GRADED SAND-SILT MIXTURES CLAYEY SANDS, POORLY GRADED SAND-CLAY MIXTURES POORLY GRADED GRAVELS, GRAVEL-SAND MIXTURES SOIL CLASSIFICATION CHART AND KEY TO TEST DATA GW GP GM GC SW SP SM SC ML FINE GRAINED SOILSMore than Half < #200 sieveLGD A NNNN02 GINT US LAB.GPJ 11/4/05INORGANIC CLAYS OF HIGH PLASTICITY, FAT CLAYS CL OL MH SANDS WITH OVER 15% FINES Migizi Group, Inc. SM SM SM SM 0.6 1.5 5.0 8.0 10.0 Sod and topsoil (SM) Gray fine silty sand (medium dense, damp) (Weathered Glacial Till) (SM) Light brown mottled silty sand with gravel (dense, damp) (Weathered Glacial Till) (SM) Gray/brown silty sand with gravel (very dense, moist) (Unweathered Glacial Till) (SM) Brown silty sand with gravel and intermittent lenses of fine sand (medium dense, moist) (Advanced Outwash) No caving observed No groundwater seepage observed The depths on the test pit logs are based on an average of measurements across the test pit and should be considered accurate to 0.5 foot.Bottom of test pit at 10.0 feet. NOTES LOGGED BY ZLL EXCAVATION METHOD Rubber Tracked Mini Excavator EXCAVATION CONTRACTOR Paulman GROUND WATER LEVELS: CHECKED BY JEB DATE STARTED 9/5/17 COMPLETED 9/5/17 AT TIME OF EXCAVATION --- AT END OF EXCAVATION --- AFTER EXCAVATION --- TEST PIT SIZEGROUND ELEVATION SAMPLE TYPENUMBERDEPTH(ft)0.0 2.5 5.0 7.5 10.0 PAGE 1 OF 1 Figure A-2 TEST PIT NUMBER TP-1 CLIENT Monsef Donogh Design Group PROJECT NUMBER P1056-T17 PROJECT NAME Proposed Talbot Gardens Short Plat PROJECT LOCATION 4827 Talbot Rd S, Renton, WA 98055 COPY OF GENERAL BH / TP LOGS - FIGURE.GDT - 10/11/17 10:17 - C:\USERS\JESSICA\DESKTOP\TEST PITS AND BORINGS - GINT\P1056-T17\P1056-T17 TEST PITS.GPJMigizi Group, Inc. PO Box 44840 Tacoma, WA 98448 Telephone: 253-537-9400 Fax: 253-537-9401 U.S.C.S.GRAPHICLOGMATERIAL DESCRIPTION ML SM SM SM 0.6 2.5 5.0 8.0 10.0 Sod and topsoil (ML) Gray/brown mottled sandy silt (medium stiff, damp) (Recessional Outwash) (SM) Gray fine silty sand (medium dense, damp) (Weathered Glacial Till) (SM) Gray/brown silty sand with gravel (dense, moist) (Unweathered Glacial Till) (SM) Brown silty sand with some gravel and intermittent lenses of fine sand (medium dense, moist) (AdvancedOutwash) No caving observed No groundwater seepage observed The depths on the test pit logs are based on an average of measurements across the test pit and should be considered accurate to 0.5 foot.Bottom of test pit at 10.0 feet. NOTES LOGGED BY ZLL EXCAVATION METHOD Rubber Tracked Mini Excavator EXCAVATION CONTRACTOR Paulman GROUND WATER LEVELS: CHECKED BY JEB DATE STARTED 9/5/17 COMPLETED 9/5/17 AT TIME OF EXCAVATION --- AT END OF EXCAVATION --- AFTER EXCAVATION --- TEST PIT SIZEGROUND ELEVATION SAMPLE TYPENUMBERDEPTH(ft)0.0 2.5 5.0 7.5 10.0 PAGE 1 OF 1 Figure A-3 TEST PIT NUMBER TP-2 CLIENT Monsef Donogh Design Group PROJECT NUMBER P1056-T17 PROJECT NAME Proposed Talbot Gardens Short Plat PROJECT LOCATION 4827 Talbot Rd S, Renton, WA 98055 COPY OF GENERAL BH / TP LOGS - FIGURE.GDT - 10/11/17 10:17 - C:\USERS\JESSICA\DESKTOP\TEST PITS AND BORINGS - GINT\P1056-T17\P1056-T17 TEST PITS.GPJMigizi Group, Inc. PO Box 44840 Tacoma, WA 98448 Telephone: 253-537-9400 Fax: 253-537-9401 U.S.C.S.GRAPHICLOGMATERIAL DESCRIPTION SM SM SM SM 1.2 3.0 7.0 8.0 10.0 Sod and topsoil with small roots (SM) Gray fine silty sand (medium dense, damp) (Weathered Glacial Till) (SM) Light brown mottled silty sand with some gravel (medium dense, damp) (Weathered Glacial Till) (SM) Gray/brown silty sand with some gravel (dense, damp) (Unweathered Glacial Till) (SM) Brown silty sand with some gravel and intermittent lenses of fine sand (dense, moist) (Advanced Outwash) No caving observed No groundwater seepage observed The depths on the test pit logs are based on an average of measurements across the test pit and should be considered accurate to 0.5 foot.Bottom of test pit at 10.0 feet. NOTES LOGGED BY ZLL EXCAVATION METHOD Rubber Tracked Mini Excavator EXCAVATION CONTRACTOR Paulman GROUND WATER LEVELS: CHECKED BY JEB DATE STARTED 9/5/17 COMPLETED 9/5/17 AT TIME OF EXCAVATION --- AT END OF EXCAVATION --- AFTER EXCAVATION --- TEST PIT SIZEGROUND ELEVATION SAMPLE TYPENUMBERDEPTH(ft)0.0 2.5 5.0 7.5 10.0 PAGE 1 OF 1 Figure A-4 TEST PIT NUMBER TP-3 CLIENT Monsef Donogh Design Group PROJECT NUMBER P1056-T17 PROJECT NAME Proposed Talbot Gardens Short Plat PROJECT LOCATION 4827 Talbot Rd S, Renton, WA 98055 COPY OF GENERAL BH / TP LOGS - FIGURE.GDT - 10/11/17 10:17 - C:\USERS\JESSICA\DESKTOP\TEST PITS AND BORINGS - GINT\P1056-T17\P1056-T17 TEST PITS.GPJMigizi Group, Inc. PO Box 44840 Tacoma, WA 98448 Telephone: 253-537-9400 Fax: 253-537-9401 U.S.C.S.GRAPHICLOGMATERIAL DESCRIPTION GB S-1 SM SM SM SM 0.8 2.5 8.0 13.0 15.0 Sod and topsoil (SM) Gray/brown fine silty sand (medium dense, damp) (Weathered Glacial Till) (SM) Orange/brown mottled fine silty sand with some gravel (dense, moist) (Unweathered Glacial Till) (SM) Light brown silty sand with some gravel and intermittent lenses of fine sand (medium dense, moist) (Advanced Outwash) (SM) Gray fine silty sand with gravel (dense, moist) No caving observedNo groundwater seepage observed The depths on the test pit logs are based on an average of measurements across the test pit and should beconsidered accurate to 0.5 foot.Bottom of test pit at 15.0 feet. NOTES LOGGED BY ZLL EXCAVATION METHOD Steel Tracked Excavator EXCAVATION CONTRACTOR Dreamline Construction GROUND WATER LEVELS: CHECKED BY JEB DATE STARTED 7/24/18 COMPLETED 7/24/18 AT TIME OF EXCAVATION --- AT END OF EXCAVATION --- AFTER EXCAVATION --- TEST PIT SIZEGROUND ELEVATION SAMPLE TYPENUMBERDEPTH(ft)0.0 2.5 5.0 7.5 10.0 12.5 15.0 PAGE 1 OF 1 Figure A-5 TEST PIT NUMBER TP-4 CLIENT Sapphire Homes PROJECT NUMBER P1389-T18 PROJECT NAME Proposed Talbot Gardens Short Plat PROJECT LOCATION 4827 Talbot Rd S, Renton, WA COPY OF GENERAL BH / TP LOGS - FIGURE.GDT - 3/29/19 14:29 - C:\USERS\JESSICA\DESKTOP\TEST PITS AND BORINGS - GINT\P1389-T18\P1389-T18 TEST PITS.GPJMigizi Group, Inc. PO Box 44840 Tacoma, WA 98448 Telephone: 253-537-9400 Fax: 253-537-9401 U.S.C.S.GRAPHICLOGMATERIAL DESCRIPTION GBS-1 SM SM SM SM 1.0 3.0 8.5 13.0 15.0 Sod and topsoil (SM) Gray/brown fine silty sand (loose, damp) (Weathered Glacial Till) (SM) Orange/brown mottled fine silty sand (dense, moist) (Unweathered Glacial Till) (SM) Light brown silty sand with some gravel and intermittent lenses of fine sand (medium dense, moist) (Advanced Outwash) (SM) Gray fine silty sand with gravel (dense, moist) No caving observedNo groundwater seepage observed The depths on the test pit logs are based on an average of measurements across the test pit and should beconsidered accurate to 0.5 foot.Bottom of test pit at 15.0 feet. NOTES LOGGED BY ZLL EXCAVATION METHOD Steel Tracked Excavator EXCAVATION CONTRACTOR Dreamline Construction GROUND WATER LEVELS: CHECKED BY JEB DATE STARTED 7/24/18 COMPLETED 7/24/18 AT TIME OF EXCAVATION --- AT END OF EXCAVATION --- AFTER EXCAVATION --- TEST PIT SIZEGROUND ELEVATION SAMPLE TYPENUMBERDEPTH(ft)0.0 2.5 5.0 7.5 10.0 12.5 15.0 PAGE 1 OF 1 Figure A-6 TEST PIT NUMBER TP-5 CLIENT Sapphire Homes PROJECT NUMBER P1389-T18 PROJECT NAME Proposed Talbot Gardens Short Plat PROJECT LOCATION 4827 Talbot Rd S, Renton, WA COPY OF GENERAL BH / TP LOGS - FIGURE.GDT - 3/29/19 14:29 - C:\USERS\JESSICA\DESKTOP\TEST PITS AND BORINGS - GINT\P1389-T18\P1389-T18 TEST PITS.GPJMigizi Group, Inc. PO Box 44840 Tacoma, WA 98448 Telephone: 253-537-9400 Fax: 253-537-9401 U.S.C.S.GRAPHICLOGMATERIAL DESCRIPTION SM SM SM 0.7 3.0 7.5 10.0 Sod and topsoil (SM) Dark brown fine silty sand (medium dense, moist) (Weathered Glacial Till) (SM) Orange/brown silty sand with some gravel (medium dense, wet) (Unweathered Glacial Till) (SM) Brown silty sand with some gravel and intermittent lenses of fine sand (medium dense, moist) (AdvancedOutwash) No caving observedNo groundwater seepage observed The depths on the test pit logs are based on an average of measurements across the test pit and should beconsidered accurate to 0.5 foot. Bottom of test pit at 10.0 feet. NOTES LOGGED BY ZLL EXCAVATION METHOD Steel Tracked Excavator EXCAVATION CONTRACTOR Owner-Operator GROUND WATER LEVELS: CHECKED BY JEB DATE STARTED 3/15/19 COMPLETED 3/15/19 AT TIME OF EXCAVATION --- AT END OF EXCAVATION --- AFTER EXCAVATION --- TEST PIT SIZEGROUND ELEVATION SAMPLE TYPENUMBERDEPTH(ft)0.0 2.5 5.0 7.5 10.0 PAGE 1 OF 1 Figure A-7 TEST PIT NUMBER TP-6 CLIENT Sapphire Homes PROJECT NUMBER P1389-T18 PROJECT NAME Proposed Talbot Gardens Short Plat PROJECT LOCATION 4827 Talbot Rd S, Renton, WA COPY OF GENERAL BH / TP LOGS - FIGURE.GDT - 3/29/19 14:29 - C:\USERS\JESSICA\DESKTOP\TEST PITS AND BORINGS - GINT\P1389-T18\P1389-T18 TEST PITS.GPJMigizi Group, Inc. PO Box 44840 Tacoma, WA 98448 Telephone: 253-537-9400 Fax: 253-537-9401 U.S.C.S.GRAPHICLOGMATERIAL DESCRIPTION SM SM SM 0.6 2.5 8.0 11.0 Sod and topsoil (SM) Dark brown fine silty sand (medium dense, moist) (Weathered Glacial Till) (SM) Orange/brown silty sand with some gravel (medium dense, wet) (Unweathered Glacial Till) (SM) Brown silty sand with some gravel and intermittent lenses of fine sand (medium dense, moist) (Advanced Outwash) Small-scale PIT (INF-2) performed at a depth of 11 feet No caving observed No groundwater seepage observed The depths on the test pit logs are based on an average of measurements across the test pit and should be considered accurate to 0.5 foot.Bottom of test pit at 11.0 feet. NOTES LOGGED BY ZLL EXCAVATION METHOD Steel Tracked Excavator EXCAVATION CONTRACTOR Owner-Operator GROUND WATER LEVELS: CHECKED BY JEB DATE STARTED 3/15/19 COMPLETED 3/15/19 AT TIME OF EXCAVATION --- AT END OF EXCAVATION --- AFTER EXCAVATION --- TEST PIT SIZEGROUND ELEVATION SAMPLE TYPENUMBERDEPTH(ft)0.0 2.5 5.0 7.5 10.0 PAGE 1 OF 1 Figure A-8 TEST PIT NUMBER TP-7 CLIENT Sapphire Homes PROJECT NUMBER P1389-T18 PROJECT NAME Proposed Talbot Gardens Short Plat PROJECT LOCATION 4827 Talbot Rd S, Renton, WA COPY OF GENERAL BH / TP LOGS - FIGURE.GDT - 3/29/19 14:29 - C:\USERS\JESSICA\DESKTOP\TEST PITS AND BORINGS - GINT\P1389-T18\P1389-T18 TEST PITS.GPJMigizi Group, Inc. PO Box 44840 Tacoma, WA 98448 Telephone: 253-537-9400 Fax: 253-537-9401 U.S.C.S.GRAPHICLOGMATERIAL DESCRIPTION SM SM ML 0.20.5 3.0 7.5 10.0 Asphaltic concrete 3/8-5/8" minus crushed rock base (SM) Dark brown fine silty sand (medium dense, moist) (Weathered Glacial Till) (SM) Orange/brown silty sand with some gravel (medium dense, wet) (Unweathered Glacial Till) (ML) Light brown sandy silt (medium stiff, moist) (Advanced Outwash) No caving observedNo groundwater seepage observed The depths on the test pit logs are based on an average of measurements across the test pit and should beconsidered accurate to 0.5 foot. Bottom of test pit at 10.0 feet. NOTES LOGGED BY ZLL EXCAVATION METHOD Steel Tracked Excavator EXCAVATION CONTRACTOR Owner-Operator GROUND WATER LEVELS: CHECKED BY JEB DATE STARTED 3/15/19 COMPLETED 3/15/19 AT TIME OF EXCAVATION --- AT END OF EXCAVATION --- AFTER EXCAVATION --- TEST PIT SIZEGROUND ELEVATION SAMPLE TYPENUMBERDEPTH(ft)0.0 2.5 5.0 7.5 10.0 PAGE 1 OF 1 Figure A-9 TEST PIT NUMBER TP-8 CLIENT Sapphire Homes PROJECT NUMBER P1389-T18 PROJECT NAME Proposed Talbot Gardens Short Plat PROJECT LOCATION 4827 Talbot Rd S, Renton, WA COPY OF GENERAL BH / TP LOGS - FIGURE.GDT - 3/29/19 14:29 - C:\USERS\JESSICA\DESKTOP\TEST PITS AND BORINGS - GINT\P1389-T18\P1389-T18 TEST PITS.GPJMigizi Group, Inc. PO Box 44840 Tacoma, WA 98448 Telephone: 253-537-9400 Fax: 253-537-9401 U.S.C.S.GRAPHICLOGMATERIAL DESCRIPTION SM SM SM 0.3 2.0 7.0 10.0 Sod and topsoil (SM) Dark brown fine silty sand (medium dense, wet) (Weathered Glacial Till) (SM) Orange/brown silty sand with some gravel (medium dense, wet) (Unweathered Glacial Till) (SM) Brown silty sand with some gravel and intermittent lenses of fine sand (medium dense, moist) (AdvancedOutwash) No caving observedNo groundwater seepage observed The depths on the test pit logs are based on an average of measurements across the test pit and should beconsidered accurate to 0.5 foot. Bottom of test pit at 10.0 feet. NOTES LOGGED BY ZLL EXCAVATION METHOD Steel Tracked Excavator EXCAVATION CONTRACTOR Owner-Operator GROUND WATER LEVELS: CHECKED BY JEB DATE STARTED 3/15/19 COMPLETED 3/15/19 AT TIME OF EXCAVATION --- AT END OF EXCAVATION --- AFTER EXCAVATION --- TEST PIT SIZEGROUND ELEVATION SAMPLE TYPENUMBERDEPTH(ft)0.0 2.5 5.0 7.5 10.0 PAGE 1 OF 1 Figure A-10 TEST PIT NUMBER TP-9 CLIENT Sapphire Homes PROJECT NUMBER P1389-T18 PROJECT NAME Proposed Talbot Gardens Short Plat PROJECT LOCATION 4827 Talbot Rd S, Renton, WA COPY OF GENERAL BH / TP LOGS - FIGURE.GDT - 3/29/19 14:29 - C:\USERS\JESSICA\DESKTOP\TEST PITS AND BORINGS - GINT\P1389-T18\P1389-T18 TEST PITS.GPJMigizi Group, Inc. PO Box 44840 Tacoma, WA 98448 Telephone: 253-537-9400 Fax: 253-537-9401 U.S.C.S.GRAPHICLOGMATERIAL DESCRIPTION SM SM SM SM 0.5 3.0 8.0 11.0 15.0 Sod and topsoil (SM) Dark brown fine silty sand (medium dense, wet) (Weathered Glacial Till) (SM) Orange/brown silty sand with some gravel (medium dense, wet) (Unweathered Glacial Till) (SM) Brown silty sand with some gravel and intermittent lenses of fine sand (medium dense, moist) (Advanced Outwash) (SM) Gray silty sand with gravel (very dense, moist) No caving observedNo groundwater seepage observed The depths on the test pit logs are based on an average of measurements across the test pit and should beconsidered accurate to 0.5 foot.Bottom of test pit at 15.0 feet. NOTES LOGGED BY ZLL EXCAVATION METHOD Steel Tracked Excavator EXCAVATION CONTRACTOR Owner-Operator GROUND WATER LEVELS: CHECKED BY JEB DATE STARTED 3/15/19 COMPLETED 3/15/19 AT TIME OF EXCAVATION --- AT END OF EXCAVATION --- AFTER EXCAVATION --- TEST PIT SIZEGROUND ELEVATION SAMPLE TYPENUMBERDEPTH(ft)0.0 2.5 5.0 7.5 10.0 12.5 15.0 PAGE 1 OF 1 Figure A-11 TEST PIT NUMBER TP-10 CLIENT Sapphire Homes PROJECT NUMBER P1389-T18 PROJECT NAME Proposed Talbot Gardens Short Plat PROJECT LOCATION 4827 Talbot Rd S, Renton, WA COPY OF GENERAL BH / TP LOGS - FIGURE.GDT - 3/29/19 14:29 - C:\USERS\JESSICA\DESKTOP\TEST PITS AND BORINGS - GINT\P1389-T18\P1389-T18 TEST PITS.GPJMigizi Group, Inc. PO Box 44840 Tacoma, WA 98448 Telephone: 253-537-9400 Fax: 253-537-9401 U.S.C.S.GRAPHICLOGMATERIAL DESCRIPTION SM SM SM 1.0 2.5 7.5 10.0 Sod and topsoil (SM) Dark brown fine silty sand (medium dense, wet) (Weathered Glacial Till) (SM) Orange/brown silty sand with some gravel (medium dense, wet) (Unweathered Glacial Till) (SM) Brown silty sand with some gravel and intermittent lenses of fine sand (medium dense, moist) (AdvancedOutwash) Small-scale PIT (INF-1) performed at a depth of 10 feet No caving observedNo groundwater seepage observed The depths on the test pit logs are based on an average of measurements across the test pit and should beconsidered accurate to 0.5 foot. Bottom of test pit at 10.0 feet. NOTES LOGGED BY ZLL EXCAVATION METHOD Steel Tracked Excavator EXCAVATION CONTRACTOR Owner-Operator GROUND WATER LEVELS: CHECKED BY JEB DATE STARTED 3/15/19 COMPLETED 3/15/19 AT TIME OF EXCAVATION --- AT END OF EXCAVATION --- AFTER EXCAVATION --- TEST PIT SIZEGROUND ELEVATION SAMPLE TYPENUMBERDEPTH(ft)0.0 2.5 5.0 7.5 10.0 PAGE 1 OF 1 Figure A-12 TEST PIT NUMBER TP-11 CLIENT Sapphire Homes PROJECT NUMBER P1389-T18 PROJECT NAME Proposed Talbot Gardens Short Plat PROJECT LOCATION 4827 Talbot Rd S, Renton, WA COPY OF GENERAL BH / TP LOGS - FIGURE.GDT - 3/29/19 14:29 - C:\USERS\JESSICA\DESKTOP\TEST PITS AND BORINGS - GINT\P1389-T18\P1389-T18 TEST PITS.GPJMigizi Group, Inc. PO Box 44840 Tacoma, WA 98448 Telephone: 253-537-9400 Fax: 253-537-9401 U.S.C.S.GRAPHICLOGMATERIAL DESCRIPTION APPENDIX B LABORATORY TESTING RESULTS Sample Distribution Job Name:Talbot Gardens Short-Plat GeotecSample #:3 Job Number:P1389-T18 Date:10/2/17 Figure:B-1 Tested By:ZLL Depth:9 feet Exploration #:TP-1 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.11101001000Percent PassingParticle Size (mm) Sample Distribution Sample Distribution U.S. Standard Sieve Sizes 3"1.5"3/4"3/8"4 10 4020 60 100 200 Sample Distribution Job Name:Talbot Gardens Short-Plat GeotecSample #:1 Job Number:P1389-T18 Date:10/2/17 Figure:B-2 Tested By:ZLL Depth:9 feet Exploration #:TP-2 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.11101001000Percent PassingParticle Size (mm) Sample Distribution Sample Distribution U.S. Standard Sieve Sizes 3"1.5"3/4"3/8"4 10 4020 60 100 200 Sample Distribution Job Name:Talbot Gardens Short-Plat GeotecSample #:1 Job Number:P1389-T18 Date:7/26/18 Figure:B-3 Tested By:LBB Depth:10 feet Exploration #:TP-4 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.11101001000Percent PassingParticle Size (mm) Sample Distribution Sample Distribution U.S. Standard Sieve Sizes 3"1.5"3/4"3/8"4 10 4020 60 100 200 Sample Distribution Job Name:Talbot Gardens Short-Plat GeotecSample #:1 Job Number:P1389-T18 Date:7/26/18 Figure:B-4 Tested By:LBB Depth:9 feet Exploration #:TP-5 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.11101001000Percent PassingParticle Size (mm) Sample Distribution Sample Distribution U.S. Standard Sieve Sizes 3"1.5"3/4"3/8"4 10 4020 60 100 200 Sapphire on Talbot Final Technical Information Report Appendix B WWHM Output WWHM2012 PROJECT REPORT 18615 R 8-1-19 8/15/2019 2:56:30 PM Page 2 General Model Information Project Name:18615 R 8-1-19 Site Name: Site Address: City: Report Date:8/15/2019 Gage:Seatac Data Start:1948/10/01 Data End:2009/09/30 Timestep:15 Minute Precip Scale:0.000 (adjusted) Version Date:2018/10/10 Version:4.2.16 POC Thresholds Low Flow Threshold for POC1:50 Percent of the 2 Year High Flow Threshold for POC1:50 Year 18615 R 8-1-19 8/15/2019 2:56:30 PM Page 3 Landuse Basin Data Predeveloped Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre C, Forest, Mod 1.7882 Pervious Total 1.7882 Impervious Land Use acre Impervious Total 0 Basin Total 1.7882 Element Flows To: Surface Interflow Groundwater 18615 R 8-1-19 8/15/2019 2:56:30 PM Page 4 Mitigated Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre C, Pasture, Flat 0.358 C, Lawn, Flat 0.358 Pervious Total 0.716 Impervious Land Use acre ROADS MOD 0.3109 ROOF TOPS FLAT 0.4715 DRIVEWAYS FLAT 0.1652 SIDEWALKS FLAT 0.1108 Impervious Total 1.0584 Basin Total 1.7744 Element Flows To: Surface Interflow Groundwater DETENTION/INFILTRATION VAULTDETENTION/INFILTRATION VAULT 18615 R 8-1-19 8/15/2019 2:56:30 PM Page 5 GRAVEL ACCESS ROAD Bypass:Yes GroundWater:No Pervious Land Use acre Pervious Total 0 Impervious Land Use acre ROADS MOD 0.0089 Impervious Total 0.0089 Basin Total 0.0089 Element Flows To: Surface Interflow Groundwater 18615 R 8-1-19 8/15/2019 2:56:30 PM Page 6 Routing Elements Predeveloped Routing 18615 R 8-1-19 8/15/2019 2:56:30 PM Page 7 Mitigated Routing DETENTION/INFILTRATION VAULT Width:36 ft. Length:72 ft. Depth:5.9 ft. Infiltration On Infiltration rate:0.5 Infiltration safety factor:1 Total Volume Infiltrated (ac-ft.):117.474 Total Volume Through Riser (ac-ft.):50.292 Total Volume Through Facility (ac-ft.):167.766 Percent Infiltrated:70.02 Total Precip Applied to Facility:0 Total Evap From Facility:0 Discharge Structure Riser Height:4.9 ft. Riser Diameter:12 in. Notch Type:Rectangular Notch Width:0.012 ft. Notch Height:0.250 ft. Orifice 1 Diameter:1.0625 in.Elevation:0 ft. Orifice 2 Diameter:1.125 in.Elevation:2.9 ft. Element Flows To: Outlet 1 Outlet 2 Vault Hydraulic Table Stage(feet)Area(ac.)Volume(ac-ft.)Discharge(cfs)Infilt(cfs) 0.0000 0.059 0.000 0.000 0.000 0.0656 0.059 0.003 0.007 0.030 0.1311 0.059 0.007 0.011 0.030 0.1967 0.059 0.011 0.013 0.030 0.2622 0.059 0.015 0.015 0.030 0.3278 0.059 0.019 0.017 0.030 0.3933 0.059 0.023 0.019 0.030 0.4589 0.059 0.027 0.020 0.030 0.5244 0.059 0.031 0.022 0.030 0.5900 0.059 0.035 0.023 0.030 0.6556 0.059 0.039 0.024 0.030 0.7211 0.059 0.042 0.026 0.030 0.7867 0.059 0.046 0.027 0.030 0.8522 0.059 0.050 0.028 0.030 0.9178 0.059 0.054 0.029 0.030 0.9833 0.059 0.058 0.030 0.030 1.0489 0.059 0.062 0.031 0.030 1.1144 0.059 0.066 0.032 0.030 1.1800 0.059 0.070 0.033 0.030 1.2456 0.059 0.074 0.034 0.030 1.3111 0.059 0.078 0.035 0.030 1.3767 0.059 0.081 0.035 0.030 1.4422 0.059 0.085 0.036 0.030 1.5078 0.059 0.089 0.037 0.030 1.5733 0.059 0.093 0.038 0.030 1.6389 0.059 0.097 0.039 0.030 1.7044 0.059 0.101 0.040 0.030 18615 R 8-1-19 8/15/2019 2:56:30 PM Page 8 1.7700 0.059 0.105 0.040 0.030 1.8356 0.059 0.109 0.041 0.030 1.9011 0.059 0.113 0.042 0.030 1.9667 0.059 0.117 0.043 0.030 2.0322 0.059 0.120 0.043 0.030 2.0978 0.059 0.124 0.044 0.030 2.1633 0.059 0.128 0.045 0.030 2.2289 0.059 0.132 0.045 0.030 2.2944 0.059 0.136 0.046 0.030 2.3600 0.059 0.140 0.047 0.030 2.4256 0.059 0.144 0.047 0.030 2.4911 0.059 0.148 0.048 0.030 2.5567 0.059 0.152 0.049 0.030 2.6222 0.059 0.156 0.049 0.030 2.6878 0.059 0.159 0.050 0.030 2.7533 0.059 0.163 0.050 0.030 2.8189 0.059 0.167 0.051 0.030 2.8844 0.059 0.171 0.052 0.030 2.9500 0.059 0.175 0.060 0.030 3.0156 0.059 0.179 0.064 0.030 3.0811 0.059 0.183 0.068 0.030 3.1467 0.059 0.187 0.071 0.030 3.2122 0.059 0.191 0.074 0.030 3.2778 0.059 0.195 0.076 0.030 3.3433 0.059 0.198 0.078 0.030 3.4089 0.059 0.202 0.081 0.030 3.4744 0.059 0.206 0.083 0.030 3.5400 0.059 0.210 0.085 0.030 3.6056 0.059 0.214 0.087 0.030 3.6711 0.059 0.218 0.088 0.030 3.7367 0.059 0.222 0.090 0.030 3.8022 0.059 0.226 0.092 0.030 3.8678 0.059 0.230 0.094 0.030 3.9333 0.059 0.234 0.095 0.030 3.9989 0.059 0.238 0.097 0.030 4.0644 0.059 0.241 0.098 0.030 4.1300 0.059 0.245 0.100 0.030 4.1956 0.059 0.249 0.101 0.030 4.2611 0.059 0.253 0.103 0.030 4.3267 0.059 0.257 0.104 0.030 4.3922 0.059 0.261 0.106 0.030 4.4578 0.059 0.265 0.107 0.030 4.5233 0.059 0.269 0.108 0.030 4.5889 0.059 0.273 0.110 0.030 4.6544 0.059 0.277 0.111 0.030 4.7200 0.059 0.280 0.113 0.030 4.7856 0.059 0.284 0.116 0.030 4.8511 0.059 0.288 0.118 0.030 4.9167 0.059 0.292 0.144 0.030 4.9822 0.059 0.296 0.371 0.030 5.0478 0.059 0.300 0.715 0.030 5.1133 0.059 0.304 1.115 0.030 5.1789 0.059 0.308 1.516 0.030 5.2444 0.059 0.312 1.864 0.030 5.3100 0.059 0.316 2.121 0.030 5.3756 0.059 0.319 2.286 0.030 5.4411 0.059 0.323 2.447 0.030 5.5067 0.059 0.327 2.585 0.030 18615 R 8-1-19 8/15/2019 2:56:30 PM Page 9 5.5722 0.059 0.331 2.715 0.030 5.6378 0.059 0.335 2.839 0.030 5.7033 0.059 0.339 2.958 0.030 5.7689 0.059 0.343 3.072 0.030 5.8344 0.059 0.347 3.182 0.030 5.9000 0.059 0.351 3.288 0.030 5.9656 0.059 0.355 3.390 0.030 6.0311 0.000 0.000 3.490 0.000 18615 R 8-1-19 8/15/2019 2:56:30 PM Page 10 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area:1.7882 Total Impervious Area:0 Mitigated Landuse Totals for POC #1 Total Pervious Area:0.716 Total Impervious Area:1.0673 Flow Frequency Method:Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.053244 5 year 0.087245 10 year 0.109107 25 year 0.135113 50 year 0.153126 100 year 0.169951 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.039907 5 year 0.055876 10 year 0.068366 25 year 0.086516 50 year 0.101887 100 year 0.118958 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.061 0.037 1950 0.073 0.039 1951 0.116 0.066 1952 0.036 0.032 1953 0.029 0.035 1954 0.045 0.029 1955 0.072 0.047 1956 0.058 0.041 1957 0.047 0.040 1958 0.052 0.038 18615 R 8-1-19 8/15/2019 2:57:02 PM Page 14 Duration Flows The Facility PASSED Flow(cfs)Predev Mit Percentage Pass/Fail 0.0266 17077 12142 71 Pass 0.0279 15494 10530 67 Pass 0.0292 14072 9144 64 Pass 0.0305 12799 7972 62 Pass 0.0317 11567 6866 59 Pass 0.0330 10515 5856 55 Pass 0.0343 9567 5114 53 Pass 0.0356 8752 4357 49 Pass 0.0368 8031 3700 46 Pass 0.0381 7347 3131 42 Pass 0.0394 6731 2744 40 Pass 0.0407 6192 2455 39 Pass 0.0420 5730 2169 37 Pass 0.0432 5309 1876 35 Pass 0.0445 4924 1606 32 Pass 0.0458 4569 1365 29 Pass 0.0471 4235 1165 27 Pass 0.0483 3951 948 23 Pass 0.0496 3643 803 22 Pass 0.0509 3388 672 19 Pass 0.0522 3133 539 17 Pass 0.0535 2915 490 16 Pass 0.0547 2706 467 17 Pass 0.0560 2488 455 18 Pass 0.0573 2314 436 18 Pass 0.0586 2136 428 20 Pass 0.0598 1972 413 20 Pass 0.0611 1822 393 21 Pass 0.0624 1702 377 22 Pass 0.0637 1577 349 22 Pass 0.0650 1442 332 23 Pass 0.0662 1325 308 23 Pass 0.0675 1232 294 23 Pass 0.0688 1147 281 24 Pass 0.0701 1085 264 24 Pass 0.0713 1020 251 24 Pass 0.0726 947 234 24 Pass 0.0739 885 220 24 Pass 0.0752 824 208 25 Pass 0.0765 760 197 25 Pass 0.0777 725 183 25 Pass 0.0790 674 169 25 Pass 0.0803 623 160 25 Pass 0.0816 589 155 26 Pass 0.0828 549 147 26 Pass 0.0841 506 138 27 Pass 0.0854 469 131 27 Pass 0.0867 427 121 28 Pass 0.0880 388 113 29 Pass 0.0892 356 107 30 Pass 0.0905 328 97 29 Pass 0.0918 297 89 29 Pass 0.0931 270 85 31 Pass 18615 R 8-1-19 8/15/2019 2:57:02 PM Page 15 0.0943 241 80 33 Pass 0.0956 218 77 35 Pass 0.0969 197 74 37 Pass 0.0982 173 68 39 Pass 0.0995 152 65 42 Pass 0.1007 130 63 48 Pass 0.1020 119 54 45 Pass 0.1033 106 52 49 Pass 0.1046 95 47 49 Pass 0.1058 84 45 53 Pass 0.1071 74 35 47 Pass 0.1084 69 29 42 Pass 0.1097 61 26 42 Pass 0.1110 54 22 40 Pass 0.1122 46 20 43 Pass 0.1135 39 14 35 Pass 0.1148 31 12 38 Pass 0.1161 25 11 44 Pass 0.1173 22 10 45 Pass 0.1186 20 8 40 Pass 0.1199 17 6 35 Pass 0.1212 14 6 42 Pass 0.1225 12 5 41 Pass 0.1237 8 4 50 Pass 0.1250 7 4 57 Pass 0.1263 7 4 57 Pass 0.1276 7 4 57 Pass 0.1288 6 3 50 Pass 0.1301 6 3 50 Pass 0.1314 6 2 33 Pass 0.1327 6 2 33 Pass 0.1340 6 1 16 Pass 0.1352 5 0 0 Pass 0.1365 5 0 0 Pass 0.1378 5 0 0 Pass 0.1391 5 0 0 Pass 0.1403 5 0 0 Pass 0.1416 5 0 0 Pass 0.1429 5 0 0 Pass 0.1442 4 0 0 Pass 0.1455 4 0 0 Pass 0.1467 3 0 0 Pass 0.1480 3 0 0 Pass 0.1493 3 0 0 Pass 0.1506 3 0 0 Pass 0.1518 3 0 0 Pass 0.1531 3 0 0 Pass 18615 R 8-1-19 8/15/2019 2:57:02 PM Page 16 Water Quality Water Quality BMP Flow and Volume for POC #1 On-line facility volume:0.1304 acre-feet On-line facility target flow:0.1785 cfs. Adjusted for 15 min:0.1785 cfs. Off-line facility target flow:0.1006 cfs. Adjusted for 15 min:0.1006 cfs. 18615 R 8-1-19 8/15/2019 2:57:02 PM Page 17 LID Report 18615 R 8-1-19 8/15/2019 2:57:24 PM Page 18 Model Default Modifications Total of 0 changes have been made. PERLND Changes No PERLND changes have been made. IMPLND Changes No IMPLND changes have been made. 18615 R 8-1-19 8/15/2019 2:57:24 PM Page 19 Appendix Predeveloped Schematic 18615 R 8-1-19 8/15/2019 2:57:25 PM Page 20 Mitigated Schematic 18615 R 8-1-19 8/15/2019 2:57:27 PM Page 21 Predeveloped UCI File 18615 R 8-1-19 8/15/2019 2:57:27 PM Page 22 Mitigated UCI File RUN GLOBAL WWHM4 model simulation START 1948 10 01 END 2009 09 30 RUN INTERP OUTPUT LEVEL 3 0 RESUME 0 RUN 1 UNIT SYSTEM 1 END GLOBAL FILES <File> <Un#> <-----------File Name------------------------------>*** <-ID-> *** WDM 26 18615 R 8-1-19.wdm MESSU 25 Mit18615 R 8-1-19.MES 27 Mit18615 R 8-1-19.L61 28 Mit18615 R 8-1-19.L62 30 POC18615 R 8-1-191.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 13 PERLND 16 IMPLND 2 IMPLND 4 IMPLND 5 IMPLND 8 RCHRES 1 COPY 1 COPY 501 COPY 601 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 DETENTION/INFILTRATION VA MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 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 <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 13 C, Pasture, Flat 1 1 1 1 27 0 16 C, Lawn, Flat 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** 18615 R 8-1-19 8/15/2019 2:57:27 PM Page 23 # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 13 0 0 1 0 0 0 0 0 0 0 0 0 16 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 ********* 13 0 0 4 0 0 0 0 0 0 0 0 0 1 9 16 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 *** 13 0 0 0 0 0 0 0 0 0 0 0 16 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 13 0 4.5 0.06 400 0.05 0.5 0.996 16 0 4.5 0.03 400 0.05 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 13 0 0 2 2 0 0 0 16 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 13 0.15 0.4 0.3 6 0.5 0.4 16 0.1 0.25 0.25 6 0.5 0.25 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 13 0 0 0 0 2.5 1 0 16 0 0 0 0 2.5 1 0 END PWAT-STATE1 END PERLND IMPLND GEN-INFO <PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 2 ROADS/MOD 1 1 1 27 0 4 ROOF TOPS/FLAT 1 1 1 27 0 5 DRIVEWAYS/FLAT 1 1 1 27 0 8 SIDEWALKS/FLAT 1 1 1 27 0 END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** 2 0 0 1 0 0 0 4 0 0 1 0 0 0 5 0 0 1 0 0 0 8 0 0 1 0 0 0 END ACTIVITY 18615 R 8-1-19 8/15/2019 2:57:27 PM Page 24 PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* 2 0 0 4 0 0 0 1 9 4 0 0 4 0 0 0 1 9 5 0 0 4 0 0 0 1 9 8 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 *** 2 0 0 0 0 0 4 0 0 0 0 0 5 0 0 0 0 0 8 0 0 0 0 0 END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC 2 400 0.05 0.1 0.08 4 400 0.01 0.1 0.1 5 400 0.01 0.1 0.1 8 400 0.01 0.1 0.1 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN 2 0 0 4 0 0 5 0 0 8 0 0 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 2 0 0 4 0 0 5 0 0 8 0 0 END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Basin 1*** PERLND 13 0.358 RCHRES 1 2 PERLND 16 0.358 RCHRES 1 2 IMPLND 2 0.3109 RCHRES 1 5 IMPLND 4 0.4715 RCHRES 1 5 IMPLND 5 0.1652 RCHRES 1 5 IMPLND 8 0.1108 RCHRES 1 5 GRAVEL ACCESS ROAD*** IMPLND 2 0.0089 COPY 501 15 IMPLND 2 0.0089 COPY 601 15 ******Routing****** PERLND 13 0.358 COPY 1 12 PERLND 16 0.358 COPY 1 12 IMPLND 2 0.3109 COPY 1 15 IMPLND 4 0.4715 COPY 1 15 IMPLND 5 0.1652 COPY 1 15 IMPLND 8 0.1108 COPY 1 15 RCHRES 1 1 COPY 501 17 END SCHEMATIC 18615 R 8-1-19 8/15/2019 2:57:27 PM Page 25 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 *** 1 DETENTION/INFILT-011 2 1 1 1 28 0 1 END GEN-INFO *** Section RCHRES*** 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 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 END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** 1 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 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 <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> 1 0 4.0 5.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES FTABLE 1 92 5 Depth Area Volume Outflow1 Outflow2 Velocity Travel Time*** (ft) (acres) (acre-ft) (cfs) (cfs) (ft/sec) (Minutes)*** 0.000000 0.059504 0.000000 0.000000 0.000000 0.065556 0.059504 0.003901 0.007844 0.030000 0.131111 0.059504 0.007802 0.011093 0.030000 0.196667 0.059504 0.011702 0.013586 0.030000 0.262222 0.059504 0.015603 0.015687 0.030000 0.327778 0.059504 0.019504 0.017539 0.030000 0.393333 0.059504 0.023405 0.019213 0.030000 0.458889 0.059504 0.027306 0.020752 0.030000 18615 R 8-1-19 8/15/2019 2:57:27 PM Page 26 0.524444 0.059504 0.031207 0.022185 0.030000 0.590000 0.059504 0.035107 0.023531 0.030000 0.655556 0.059504 0.039008 0.024804 0.030000 0.721111 0.059504 0.042909 0.026015 0.030000 0.786667 0.059504 0.046810 0.027171 0.030000 0.852222 0.059504 0.050711 0.028281 0.030000 0.917778 0.059504 0.054612 0.029348 0.030000 0.983333 0.059504 0.058512 0.030379 0.030000 1.048889 0.059504 0.062413 0.031375 0.030000 1.114444 0.059504 0.066314 0.032340 0.030000 1.180000 0.059504 0.070215 0.033278 0.030000 1.245556 0.059504 0.074116 0.034190 0.030000 1.311111 0.059504 0.078017 0.035078 0.030000 1.376667 0.059504 0.081917 0.035944 0.030000 1.442222 0.059504 0.085818 0.036790 0.030000 1.507778 0.059504 0.089719 0.037617 0.030000 1.573333 0.059504 0.093620 0.038426 0.030000 1.638889 0.059504 0.097521 0.039219 0.030000 1.704444 0.059504 0.101421 0.039995 0.030000 1.770000 0.059504 0.105322 0.040757 0.030000 1.835556 0.059504 0.109223 0.041505 0.030000 1.901111 0.059504 0.113124 0.042240 0.030000 1.966667 0.059504 0.117025 0.042962 0.030000 2.032222 0.059504 0.120926 0.043672 0.030000 2.097778 0.059504 0.124826 0.044371 0.030000 2.163333 0.059504 0.128727 0.045059 0.030000 2.228889 0.059504 0.132628 0.045736 0.030000 2.294444 0.059504 0.136529 0.046404 0.030000 2.360000 0.059504 0.140430 0.047062 0.030000 2.425556 0.059504 0.144331 0.047711 0.030000 2.491111 0.059504 0.148231 0.048352 0.030000 2.556667 0.059504 0.152132 0.048984 0.030000 2.622222 0.059504 0.156033 0.049608 0.030000 2.687778 0.059504 0.159934 0.050224 0.030000 2.753333 0.059504 0.163835 0.050833 0.030000 2.818889 0.059504 0.167736 0.051435 0.030000 2.884444 0.059504 0.171636 0.052029 0.030000 2.950000 0.059504 0.175537 0.060297 0.030000 3.015556 0.059504 0.179438 0.064874 0.030000 3.081111 0.059504 0.183339 0.068390 0.030000 3.146667 0.059504 0.187240 0.071400 0.030000 3.212222 0.059504 0.191140 0.074097 0.030000 3.277778 0.059504 0.195041 0.076573 0.030000 3.343333 0.059504 0.198942 0.078883 0.030000 3.408889 0.059504 0.202843 0.081062 0.030000 3.474444 0.059504 0.206744 0.083134 0.030000 3.540000 0.059504 0.210645 0.085115 0.030000 3.605556 0.059504 0.214545 0.087019 0.030000 3.671111 0.059504 0.218446 0.088856 0.030000 3.736667 0.059504 0.222347 0.090634 0.030000 3.802222 0.059504 0.226248 0.092359 0.030000 3.867778 0.059504 0.230149 0.094036 0.030000 3.933333 0.059504 0.234050 0.095670 0.030000 3.998889 0.059504 0.237950 0.097264 0.030000 4.064444 0.059504 0.241851 0.098823 0.030000 4.130000 0.059504 0.245752 0.100348 0.030000 4.195556 0.059504 0.249653 0.101842 0.030000 4.261111 0.059504 0.253554 0.103307 0.030000 4.326667 0.059504 0.257455 0.104745 0.030000 4.392222 0.059504 0.261355 0.106158 0.030000 4.457778 0.059504 0.265256 0.107547 0.030000 4.523333 0.059504 0.269157 0.108914 0.030000 4.588889 0.059504 0.273058 0.110259 0.030000 4.654444 0.059504 0.276959 0.111596 0.030000 4.720000 0.059504 0.280860 0.113620 0.030000 4.785556 0.059504 0.284760 0.116118 0.030000 4.851111 0.059504 0.288661 0.118907 0.030000 4.916667 0.059504 0.292562 0.144281 0.030000 4.982222 0.059504 0.296463 0.371938 0.030000 5.047778 0.059504 0.300364 0.715787 0.030000 18615 R 8-1-19 8/15/2019 2:57:27 PM Page 27 5.113333 0.059504 0.304264 1.115779 0.030000 5.178889 0.059504 0.308165 1.516327 0.030000 5.244444 0.059504 0.312066 1.864028 0.030000 5.310000 0.059504 0.315967 2.121277 0.030000 5.375556 0.059504 0.319868 2.286300 0.030000 5.441111 0.059504 0.323769 2.447830 0.030000 5.506667 0.059504 0.327669 2.585294 0.030000 5.572222 0.059504 0.331570 2.715559 0.030000 5.637778 0.059504 0.335471 2.839656 0.030000 5.703333 0.059504 0.339372 2.958389 0.030000 5.768889 0.059504 0.343273 3.072401 0.030000 5.834444 0.059504 0.347174 3.182219 0.030000 5.900000 0.059504 0.351074 3.288275 0.030000 5.965556 0.059504 0.354975 3.390932 0.030000 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 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP END EXT SOURCES EXT TARGETS <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** RCHRES 1 HYDR RO 1 1 1 WDM 1004 FLOW ENGL REPL RCHRES 1 HYDR O 1 1 1 WDM 1005 FLOW ENGL REPL RCHRES 1 HYDR O 2 1 1 WDM 1006 FLOW ENGL REPL RCHRES 1 HYDR STAGE 1 1 1 WDM 1007 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 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 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 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 18615 R 8-1-19 8/15/2019 2:57:27 PM Page 28 Predeveloped HSPF Message File 18615 R 8-1-19 8/15/2019 2:57:27 PM Page 29 Mitigated HSPF Message File 18615 R 8-1-19 8/15/2019 2:57:27 PM Page 30 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. 2005-2019; 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 Sapphire on Talbot Final Technical Information Report Appendix C Bond Quantity Worksheet CED Permit #:C19-003341UnitReference #PriceUnitQuantity CostBackfill & compaction-embankmentESC-16.50$ CY Check dams, 4" minus rockESC-2SWDM 5.4.6.380.00$ Each9720.00Catch Basin ProtectionESC-335.50$ Each8284.00Crushed surfacing 1 1/4" minusESC-4WSDOT 9-03.9(3)95.00$ CY252,375.00DitchingESC-59.00$ CYExcavation-bulkESC-62.00$ CY Fence, siltESC-7SWDM 5.4.3.11.50$ LF345517.50Fence, Temporary (NGPE)ESC-81.50$ LF Geotextile FabricESC-92.50$ SY Hay Bale Silt TrapESC-100.50$ Each HydroseedingESC-11SWDM 5.4.2.40.80$ SY36782,942.40Interceptor Swale / DikeESC-121.00$ LF405405.00Jute MeshESC-13SWDM 5.4.2.23.50$ SY Level SpreaderESC-141.75$ LF Mulch, by hand, straw, 3" deepESC-15SWDM 5.4.2.12.50$ SY Mulch, by machine, straw, 2" deepESC-16SWDM 5.4.2.12.00$ SY12102,420.00Piping, temporary, CPP, 6"ESC-1712.00$ LF Piping, temporary, CPP, 8"ESC-1814.00$ LF Piping, temporary, CPP, 12"ESC-1918.00$ LF Plastic covering, 6mm thick, sandbaggedESC-20SWDM 5.4.2.34.00$ SY100400.00Rip Rap, machine placed; slopesESC-21WSDOT 9-13.1(2)45.00$ CY Rock Construction Entrance, 50'x15'x1'ESC-22SWDM 5.4.4.11,800.00$ Each Rock Construction Entrance, 100'x15'x1'ESC-23SWDM 5.4.4.13,200.00$ Each13,200.00Sediment pond riser assemblyESC-24SWDM 5.4.5.22,200.00$ Each12,200.00Sediment trap, 5' high berm ESC-25SWDM 5.4.5.119.00$ LF Sed. trap, 5' high, riprapped spillway berm section ESC-26SWDM 5.4.5.170.00$ LFSeeding, by handESC-27SWDM 5.4.2.41.00$ SY Sodding, 1" deep, level groundESC-28SWDM 5.4.2.58.00$ SY Sodding, 1" deep, sloped groundESC-29SWDM 5.4.2.510.00$ SY TESC SupervisorESC-30110.00$ HR404,400.00Water truck, dust controlESC-31SWDM 5.4.7140.00$ HR101,400.00UnitReference #PriceUnitQuantity Cost EROSION/SEDIMENT SUBTOTAL:21,263.90SALES TAX @ 10%2,126.39EROSION/SEDIMENT TOTAL:23,390.29(A)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR EROSION & SEDIMENT CONTROLDescription No.(A)WRITE-IN-ITEMS Page 2 of 13Ref 8-H Bond Quantity WorksheetSECTION II.a EROSION_CONTROLUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 11/14/2019 CED Permit #:C19-003341ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostGENERAL ITEMS Backfill & Compaction- embankmentGI-16.00$ CYBackfill & Compaction- trenchGI-29.00$ CY56504.008427,578.0089801.00Clear/Remove Brush, by hand (SY)GI-31.00$ SYBollards - fixedGI-4240.74$ EachBollards - removableGI-5452.34$ Each31,357.02Clearing/Grubbing/Tree RemovalGI-610,000.00$ Acre1.6916,900.00Excavation - bulkGI-72.00$ CYExcavation - TrenchGI-85.00$ CY56280.008424,210.0089445.00Fencing, cedar, 6' highGI-920.00$ LFFencing, chain link, 4'GI-1038.31$ LFFencing, chain link, vinyl coated, 6' highGI-1120.00$ LFFencing, chain link, gate, vinyl coated, 20' GI-121,400.00$ EachFill & compact - common barrowGI-1325.00$ CY103525,875.00207051,750.00Fill & compact - gravel baseGI-1427.00$ CY33891.002225,994.00381,026.00Fill & compact - screened topsoilGI-1539.00$ CYGabion, 12" deep, stone filled mesh GI-1665.00$ SYGabion, 18" deep, stone filled mesh GI-1790.00$ SYGabion, 36" deep, stone filled meshGI-18150.00$ SYGrading, fine, by handGI-192.50$ SYGrading, fine, with graderGI-202.00$ SY226452.0012152,430.0075150.00Monuments, 3' LongGI-21250.00$ Each1250.0051,250.00Sensitive Areas SignGI-227.00$ EachSodding, 1" deep, sloped groundGI-238.00$ SYSurveying, line & gradeGI-24850.00$ DaySurveying, lot location/linesGI-251,800.00$ AcreTopsoil Type A (imported)GI-2628.50$ CYTraffic control crew ( 2 flaggers )GI-27120.00$ HR161,920.00Trail, 4" chipped woodGI-288.00$ SYTrail, 4" crushed cinderGI-299.00$ SYTrail, 4" top courseGI-3012.00$ SYConduit, 2"GI-315.00$ LFWall, retaining, concreteGI-3255.00$ SFWall, rockeryGI-3315.00$ SF1752,625.00SUBTOTAL THIS PAGE:4,297.0048,694.0273,697.00(B)(C)(D)(E)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR STREET AND SITE IMPROVEMENTSQuantity Remaining (Bond Reduction) (B)(C)Page 3 of 13Ref 8-H Bond Quantity WorksheetSECTION II.b TRANSPORTATIONUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 11/14/2019 CED Permit #:C19-003341ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostSITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR STREET AND SITE IMPROVEMENTSQuantity Remaining (Bond Reduction) (B)(C)ROAD IMPROVEMENT/PAVEMENT/SURFACINGAC Grinding, 4' wide machine < 1000syRI-130.00$ SYAC Grinding, 4' wide machine 1000-2000syRI-216.00$ SY5308,480.00AC Grinding, 4' wide machine > 2000syRI-310.00$ SYAC Removal/DisposalRI-435.00$ SY1043,640.00361,260.0070724,745.00Barricade, Type III ( Permanent )RI-556.00$ LF201,120.00Guard RailRI-630.00$ LFCurb & Gutter, rolledRI-717.00$ LFCurb & Gutter, verticalRI-812.50$ LF2553,187.505506,875.0046575.00Curb and Gutter, demolition and disposalRI-918.00$ LF25450.00Curb, extruded asphaltRI-105.50$ LFCurb, extruded concreteRI-117.00$ LFSawcut, asphalt, 3" depthRI-121.85$ LF710113,136.85Sawcut, concrete, per 1" depthRI-133.00$ LFSealant, asphaltRI-142.00$ LF305610.00Shoulder, gravel, 4" thickRI-1515.00$ SYSidewalk, 4" thickRI-1638.00$ SY12456.0075228,576.00803,040.00Sidewalk, 4" thick, demolition and disposalRI-1732.00$ SYSidewalk, 5" thickRI-1841.00$ SYSidewalk, 5" thick, demolition and disposalRI-1940.00$ SYSign, Handicap RI-2085.00$ EachStriping, per stallRI-217.00$ EachStriping, thermoplastic, ( for crosswalk )RI-223.00$ SFStriping, 4" reflectorized lineRI-230.50$ LFAdditional 2.5" Crushed SurfacingRI-243.60$ SYHMA 1/2" Overlay 1.5" RI-2514.00$ SYHMA 1/2" Overlay 2"RI-2618.00$ SY5309,540.00HMA Road, 2", 4" rock, First 2500 SYRI-2728.00$ SY1975,516.00HMA Road, 2", 4" rock, Qty. over 2500SYRI-2821.00$ SYHMA Road, 4", 6" rock, First 2500 SYRI-2945.00$ SY84237,890.0049022,050.00HMA Road, 4", 6" rock, Qty. over 2500 SYRI-3037.00$ SYHMA Road, 4", 4.5" ATBRI-3138.00$ SYGravel Road, 4" rock, First 2500 SYRI-3215.00$ SY2003,000.00Gravel Road, 4" rock, Qty. over 2500 SYRI-3310.00$ SYThickened EdgeRI-348.60$ LFSUBTOTAL THIS PAGE:45,016.3574,601.0054,530.00(B)(C)(D)(E)Page 4 of 13Ref 8-H Bond Quantity WorksheetSECTION II.b TRANSPORTATIONUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 11/14/2019 CED Permit #:C19-003341ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostSITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR STREET AND SITE IMPROVEMENTSQuantity Remaining (Bond Reduction) (B)(C)PARKING LOT SURFACINGNo.2" AC, 2" top course rock & 4" borrowPL-121.00$ SY2" AC, 1.5" top course & 2.5" base coursePL-228.00$ SY4" select borrowPL-35.00$ SY1.5" top course rock & 2.5" base coursePL-414.00$ SYSUBTOTAL PARKING LOT SURFACING:(B)(C)(D)(E)LANDSCAPING & VEGETATIONNo.Street TreesLA-1Median LandscapingLA-2Right-of-Way LandscapingLA-3Wetland LandscapingLA-4SUBTOTAL LANDSCAPING & VEGETATION:(B)(C)(D)(E)TRAFFIC & LIGHTINGNo.SignsTR-1Street Light System ( # of Poles)TR-2268Traffic SignalTR-3Traffic Signal ModificationTR-4SUBTOTAL TRAFFIC & LIGHTING:(B)(C)(D)(E)WRITE-IN-ITEMSSUBTOTAL WRITE-IN ITEMS:STREET AND SITE IMPROVEMENTS SUBTOTAL:49,313.35123,295.02128,227.00SALES TAX @ 10%4,931.3412,329.5012,822.70STREET AND SITE IMPROVEMENTS TOTAL:54,244.69135,624.52141,049.70(B)(C)(D)(E)Page 5 of 13Ref 8-H Bond Quantity WorksheetSECTION II.b TRANSPORTATIONUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 11/14/2019 CED Permit #:C19-003341ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostDRAINAGE (CPE = Corrugated Polyethylene Pipe, N12 or Equivalent) For Culvert prices, Average of 4' cover was assumed. Assume perforated PVC is same price as solid pipe.) Access Road, R/DD-126.00$ SY2275,902.00* (CBs include frame and lid)BeehiveD-290.00$ EachThrough-curb Inlet FrameworkD-3400.00$ EachCB Type ID-41,500.00$ Each23,000.00CB Type ILD-51,750.00$ EachCB Type II, 48" diameterD-62,300.00$ Each920,700.00 for additional depth over 4' D-7480.00$ FT12.626,057.60CB Type II, 54" diameterD-82,500.00$ Each for additional depth over 4'D-9495.00$ FTCB Type II, 60" diameterD-102,800.00$ Each for additional depth over 4'D-11600.00$ FTCB Type II, 72" diameterD-126,000.00$ Each for additional depth over 4'D-13850.00$ FTCB Type II, 96" diameterD-1414,000.00$ Each for additional depth over 4'D-15925.00$ FTTrash Rack, 12"D-16350.00$ EachTrash Rack, 15"D-17410.00$ EachTrash Rack, 18"D-18480.00$ EachTrash Rack, 21"D-19550.00$ EachCleanout, PVC, 4"D-20150.00$ EachCleanout, PVC, 6"D-21170.00$ EachCleanout, PVC, 8"D-22200.00$ EachCulvert, PVC, 4" D-2310.00$ LFCulvert, PVC, 6" D-2413.00$ LFCulvert, PVC, 8" D-2515.00$ LFCulvert, PVC, 12" D-2623.00$ LF4209,660.001062,438.00Culvert, PVC, 15" D-2735.00$ LFCulvert, PVC, 18" D-2841.00$ LFCulvert, PVC, 24"D-2956.00$ LFCulvert, PVC, 30" D-3078.00$ LFCulvert, PVC, 36" D-31130.00$ LFCulvert, CMP, 8"D-3219.00$ LFCulvert, CMP, 12"D-3329.00$ LFSUBTOTAL THIS PAGE:42,319.605,438.00(B)(C)(D)(E)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESQuantity Remaining (Bond Reduction) (B)(C)Page 6 of 13Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 11/14/2019 CED Permit #:C19-003341ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostSITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESQuantity Remaining (Bond Reduction) (B)(C)DRAINAGE (Continued)Culvert, CMP, 15"D-3435.00$ LFCulvert, CMP, 18"D-3541.00$ LFCulvert, CMP, 24"D-3656.00$ LFCulvert, CMP, 30"D-3778.00$ LFCulvert, CMP, 36"D-38130.00$ LFCulvert, CMP, 48"D-39190.00$ LFCulvert, CMP, 60"D-40270.00$ LFCulvert, CMP, 72"D-41350.00$ LFCulvert, Concrete, 8"D-4242.00$ LFCulvert, Concrete, 12"D-4348.00$ LF904,320.00Culvert, Concrete, 15"D-4478.00$ LFCulvert, Concrete, 18"D-4548.00$ LFCulvert, Concrete, 24"D-4678.00$ LFCulvert, Concrete, 30"D-47125.00$ LFCulvert, Concrete, 36"D-48150.00$ LFCulvert, Concrete, 42"D-49175.00$ LFCulvert, Concrete, 48"D-50205.00$ LFCulvert, CPE Triple Wall, 6" D-5114.00$ LFCulvert, CPE Triple Wall, 8" D-5216.00$ LFCulvert, CPE Triple Wall, 12" D-5324.00$ LFCulvert, CPE Triple Wall, 15" D-5435.00$ LFCulvert, CPE Triple Wall, 18" D-5541.00$ LFCulvert, CPE Triple Wall, 24" D-5656.00$ LFCulvert, CPE Triple Wall, 30" D-5778.00$ LFCulvert, CPE Triple Wall, 36" D-58130.00$ LFCulvert, LCPE, 6"D-5960.00$ LFCulvert, LCPE, 8"D-6072.00$ LFCulvert, LCPE, 12"D-6184.00$ LFCulvert, LCPE, 15"D-6296.00$ LFCulvert, LCPE, 18"D-63108.00$ LFCulvert, LCPE, 24"D-64120.00$ LFCulvert, LCPE, 30"D-65132.00$ LFCulvert, LCPE, 36"D-66144.00$ LFCulvert, LCPE, 48"D-67156.00$ LFCulvert, LCPE, 54"D-68168.00$ LFSUBTOTAL THIS PAGE:4,320.00(B)(C)(D)(E)Page 7 of 13Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 11/14/2019 CED Permit #:C19-003341ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostSITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESQuantity Remaining (Bond Reduction) (B)(C)DRAINAGE (Continued)Culvert, LCPE, 60"D-69180.00$ LFCulvert, LCPE, 72"D-70192.00$ LFCulvert, HDPE, 6"D-7142.00$ LFCulvert, HDPE, 8"D-7242.00$ LFCulvert, HDPE, 12"D-7374.00$ LFCulvert, HDPE, 15"D-74106.00$ LFCulvert, HDPE, 18"D-75138.00$ LFCulvert, HDPE, 24"D-76221.00$ LFCulvert, HDPE, 30"D-77276.00$ LFCulvert, HDPE, 36"D-78331.00$ LFCulvert, HDPE, 48"D-79386.00$ LFCulvert, HDPE, 54"D-80441.00$ LFCulvert, HDPE, 60"D-81496.00$ LFCulvert, HDPE, 72"D-82551.00$ LFPipe, Polypropylene, 6"D-8384.00$ LFPipe, Polypropylene, 8"D-8489.00$ LFPipe, Polypropylene, 12"D-8595.00$ LFPipe, Polypropylene, 15"D-86100.00$ LFPipe, Polypropylene, 18"D-87106.00$ LFPipe, Polypropylene, 24"D-88111.00$ LFPipe, Polypropylene, 30"D-89119.00$ LFPipe, Polypropylene, 36"D-90154.00$ LFPipe, Polypropylene, 48"D-91226.00$ LFPipe, Polypropylene, 54"D-92332.00$ LFPipe, Polypropylene, 60"D-93439.00$ LFPipe, Polypropylene, 72"D-94545.00$ LFCulvert, DI, 6"D-9561.00$ LFCulvert, DI, 8"D-9684.00$ LFCulvert, DI, 12"D-97106.00$ LFCulvert, DI, 15"D-98129.00$ LFCulvert, DI, 18"D-99152.00$ LFCulvert, DI, 24"D-100175.00$ LFCulvert, DI, 30"D-101198.00$ LFCulvert, DI, 36"D-102220.00$ LFCulvert, DI, 48"D-103243.00$ LFCulvert, DI, 54"D-104266.00$ LFCulvert, DI, 60"D-105289.00$ LFCulvert, DI, 72"D-106311.00$ LFSUBTOTAL THIS PAGE:(B)(C)(D)(E)Page 8 of 13Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 11/14/2019 CED Permit #:C19-003341ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostSITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESQuantity Remaining (Bond Reduction) (B)(C)Specialty Drainage ItemsDitching SD-19.50$ CYFlow Dispersal Trench (1,436 base+)SD-328.00$ LF French Drain (3' depth)SD-426.00$ LFGeotextile, laid in trench, polypropyleneSD-53.00$ SYMid-tank Access Riser, 48" dia, 6' deepSD-62,000.00$ EachPond Overflow SpillwaySD-716.00$ SYRestrictor/Oil Separator, 12"SD-81,150.00$ EachRestrictor/Oil Separator, 15"SD-91,350.00$ EachRestrictor/Oil Separator, 18"SD-101,700.00$ EachRiprap, placedSD-1142.00$ CYTank End Reducer (36" diameter)SD-121,200.00$ EachInfiltration pond testingSD-13125.00$ HR4500.00Permeable PavementSD-14Permeable Concrete SidewalkSD-15Culvert, Box __ ft x __ ftSD-16SUBTOTAL SPECIALTY DRAINAGE ITEMS:500.00(B)(C)(D)(E)STORMWATER FACILITIES (Include Flow Control and Water Quality Facility Summary Sheet and Sketch)Detention PondSF-1Each Detention TankSF-2Each Detention VaultSF-3Each Infiltration PondSF-4Each Infiltration TankSF-5Each Infiltration VaultSF-6181,000.00$ Each 1181,000.00Infiltration TrenchesSF-7Each Basic Biofiltration SwaleSF-8Each Wet Biofiltration SwaleSF-9Each WetpondSF-10Each WetvaultSF-11Each Sand FilterSF-12Each Sand Filter VaultSF-13Each Linear Sand FilterSF-14Each Proprietary FacilitySF-1520,000.00$ Each 120,000.00Bioretention FacilitySF-16Each SUBTOTAL STORMWATER FACILITIES:201,000.00(B)(C)(D)(E)Page 9 of 13Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 11/14/2019 CED Permit #:C19-003341ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostSITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESQuantity Remaining (Bond Reduction) (B)(C)WRITE-IN-ITEMS (INCLUDE ON-SITE BMPs)WI-1WI-2WI-3WI-4WI-5WI-6WI-7WI-8WI-9WI-10WI-11WI-12WI-13WI-14WI-15SUBTOTAL WRITE-IN ITEMS:DRAINAGE AND STORMWATER FACILITIES SUBTOTAL:248,139.605,438.00SALES TAX @ 10%24,813.96543.80DRAINAGE AND STORMWATER FACILITIES TOTAL:272,953.565,981.80(B) (C) (D) (E)Page 10 of 13Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 11/14/2019 CED Permit #:C19-003341ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostConnection to Existing WatermainW-12,000.00$ Each24,000.00Ductile Iron Watermain, CL 52, 4 Inch DiameterW-250.00$ LFDuctile Iron Watermain, CL 52, 6 Inch DiameterW-356.00$ LFDuctile Iron Watermain, CL 52, 8 Inch DiameterW-460.00$ LFDuctile Iron Watermain, CL 52, 10 Inch DiameterW-570.00$ LF251,750.0024617,220.00Ductile Iron Watermain, CL 52, 12 Inch DiameterW-680.00$ LF36929,520.00Gate Valve, 4 inch DiameterW-7500.00$ EachGate Valve, 6 inch DiameterW-8700.00$ EachGate Valve, 8 Inch DiameterW-9800.00$ EachGate Valve, 10 Inch DiameterW-101,000.00$ Each11,000.0022,000.00Gate Valve, 12 Inch DiameterW-111,200.00$ Each22,400.0022,400.00Fire Hydrant AssemblyW-124,000.00$ Each312,000.00Permanent Blow-Off AssemblyW-131,800.00$ Each11,800.00Air-Vac Assembly, 2-Inch DiameterW-142,000.00$ EachAir-Vac Assembly, 1-Inch DiameterW-151,500.00$ EachCompound Meter Assembly 3-inch DiameterW-168,000.00$ EachCompound Meter Assembly 4-inch DiameterW-179,000.00$ EachCompound Meter Assembly 6-inch DiameterW-1810,000.00$ EachPressure Reducing Valve Station 8-inch to 10-inchW-1920,000.00$ EachWATER SUBTOTAL:9,150.0064,940.00SALES TAX @ 10%915.006,494.00WATER TOTAL:10,065.0071,434.00(B) (C) (D) (E)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR WATERQuantity Remaining (Bond Reduction) (B)(C)Page 11 of 13Ref 8-H Bond Quantity WorksheetSECTION II.d WATERUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 11/14/2019 CED Permit #:C19-003341ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostClean OutsSS-11,000.00$ Each2020,000.00Grease Interceptor, 500 gallonSS-28,000.00$ EachGrease Interceptor, 1000 gallonSS-310,000.00$ EachGrease Interceptor, 1500 gallonSS-415,000.00$ EachSide Sewer Pipe, PVC. 4 Inch DiameterSS-580.00$ LFSide Sewer Pipe, PVC. 6 Inch DiameterSS-695.00$ LF30028,500.00Sewer Pipe, PVC, 8 inch DiameterSS-7105.00$ LF66369,615.00Sewer Pipe, PVC, 12 Inch DiameterSS-8120.00$ LFSewer Pipe, DI, 8 inch DiameterSS-9115.00$ LFSewer Pipe, DI, 12 Inch DiameterSS-10130.00$ LFManhole, 48 Inch DiameterSS-116,000.00$ Each636,000.00Manhole, 54 Inch DiameterSS-136,500.00$ EachManhole, 60 Inch DiameterSS-157,500.00$ EachManhole, 72 Inch DiameterSS-178,500.00$ EachManhole, 96 Inch DiameterSS-1914,000.00$ EachPipe, C-900, 12 Inch DiameterSS-21180.00$ LFOutside DropSS-241,500.00$ LSInside DropSS-251,000.00$ LSSewer Pipe, PVC, ____ Inch DiameterSS-26Lift Station (Entire System)SS-27LSSANITARY SEWER SUBTOTAL:134,115.0020,000.00SALES TAX @ 10%13,411.502,000.00SANITARY SEWER TOTAL:147,526.5022,000.00(B) (C) (D) (E)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR SANITARY SEWERQuantity Remaining (Bond Reduction) (B)(C)Page 12 of 13Ref 8-H Bond Quantity WorksheetSECTION II.e SANITARY SEWERUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 11/14/2019 Planning Division |1055 South Grady Way – 6th Floor | Renton, WA 98057 (425) 430-7200Date:Name:Project Name: PE Registration No:CED Plan # (LUA):Firm Name:CED Permit # (U):Firm Address:Site Address:Phone No.Parcel #(s):Email Address:Project Phase: Site Restoration/Erosion Sediment Control Subtotal (a)Existing Right-of-Way Improvements Subtotal (b)(b)64,309.69$ Future Public Improvements Subtotal(c)354,585.02$ Stormwater & Drainage Facilities (Public & Private) Subtotal(d)(d)278,935.36$ (e)(f)Site RestorationCivil Construction PermitMaintenance Bond139,566.01$ Bond Reduction2Construction Permit Bond Amount 3Minimum Bond Amount is $10,000.001 Estimate Only - May involve multiple and variable components, which will be established on an individual basis by Development Engineering.2 The City of Renton allows one request only for bond reduction prior to the maintenance period. Reduction of not more than 70% of the original bond amount, provided that the remaining 30% willcover all remaining items to be constructed. 3 Required Bond Amounts are subject to review and modification by Development Engineering.* Note: The word BOND as used in this document means any financial guarantee acceptable to the City of Renton.** Note: All prices include labor, equipment, materials, overhead and profit. 425-392-0250emecum@encompasses.netSapphire on Talbot18-0006654827 Talbot Road South, Renton, WA 980593123059022FOR APPROVALC19-003341165 NE Juniper St. #201, Issaquah, WA 98027398,790.18$ P (a) x 100%SITE IMPROVEMENT BOND QUANTITY WORKSHEET BOND CALCULATIONS8/21/2019Edward Mecum39374Encompass Engineering & SurveyingR((b x 150%) + (d x 100%))S(e) x 150% + (f) x 100%Bond Reduction: Existing Right-of-Way Improvements (Quantity Remaining)2Bond Reduction: Stormwater & Drainage Facilities (Quantity Remaining)2T(P +R - S)Prepared by:Project InformationCONSTRUCTION BOND AMOUNT */**(prior to permit issuance)EST1((b) + (c) + (d)) x 20%-$ MAINTENANCE BOND */**(after final acceptance of construction)23,390.29$ 64,309.69$ 375,399.89$ 23,390.29$ -$ 278,935.36$ -$ Page 13 of 13Ref 8-H Bond Quantity WorksheetSECTION III. BOND WORKSHEETUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 11/14/2019 Sapphire on Talbot Final Technical Information Report Appendix D Operation and Maintenance Manual APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2017 City of Renton Surface Water Design Manual 12/12/2016 A-3 NO. 1 – DETENTION PONDS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash and debris which exceed 1 cubic foot per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Trash and debris cleared from site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive growth of grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Top or Side Slopes of Dam, Berm or Embankment Rodent holes Any evidence of rodent holes if facility is acting as a dam or berm, or any evidence of water piping through dam or berm via rodent holes. Rodents removed or destroyed and dam or berm repaired. Tree growth Tree growth threatens integrity of slopes, does not allow maintenance access, or interferes with maintenance activity. If trees are not a threat or not interfering with access or maintenance, they do not need to be removed. Trees do not hinder facility performance or maintenance activities. Erosion Eroded damage over 2 inches deep where cause of damage is still present or where there is potential for continued erosion. Any erosion observed on a compacted slope. Slopes stabilized using appropriate erosion control measures. If erosion is occurring on compacted slope, a licensed civil engineer should be consulted to resolve source of erosion. Settlement Any part of a dam, berm or embankment that has settled 4 inches lower than the design elevation. Top or side slope restored to design dimensions. If settlement is significant, a licensed civil engineer should be consulted to determine the cause of the settlement. Storage Area Sediment accumulation Accumulated sediment that exceeds 10% of the designed pond depth. Sediment cleaned out to designed pond shape and depth; pond reseeded if necessary to control erosion. Liner damaged (If applicable) Liner is visible or pond does not hold water as designed. Liner repaired or replaced. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Emergency Overflow/Spillway Tree growth Tree growth impedes flow or threatens stability of spillway. Trees removed. Rock missing Only one layer of rock exists above native soil in area five square feet or larger or any exposure of native soil on the spillway. Spillway restored to design standards. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-4 NO. 2 – INFILTRATION FACILITIES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash and debris which exceed 1 cubic foot per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Trash and debris cleared from site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive growth of grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Infiltration Pond, Top or Side Slopes of Dam, Berm or Embankment Rodent holes Any evidence of rodent holes if facility is acting as a dam or berm, or any evidence of water piping through dam or berm via rodent holes. Rodents removed or destroyed and dam or berm repaired. Tree growth Tree growth threatens integrity of dams, berms or slopes, does not allow maintenance access, or interferes with maintenance activity. If trees are not a threat to dam, berm, or embankment integrity or not interfering with access or maintenance, they do not need to be removed. Trees do not hinder facility performance or maintenance activities. Erosion Eroded damage over 2 inches deep where cause of damage is still present or where there is potential for continued erosion. Any erosion observed on a compacted slope. Slopes stabilized using appropriate erosion control measures. If erosion is occurring on compacted slope, a licensed civil engineer should be consulted to resolve source of erosion. Settlement Any part of a dam, berm or embankment that has settled 4 inches lower than the design elevation. Top or side slope restored to design dimensions. If settlement is significant, a licensed civil engineer should be consulted to determine the cause of the settlement. Infiltration Pond, Tank, Vault, Trench, or Small Basin Storage Area Sediment accumulation If two inches or more sediment is present or a percolation test indicates facility is working at or less than 90% of design. Facility infiltrates as designed. Liner damaged (If applicable) Liner is visible or pond does not hold water as designed. Liner repaired or replaced. Infiltration Tank Structure Plugged air vent Any blockage of the vent. Tank or vault freely vents. Tank bent out of shape Any part of tank/pipe is bent out of shape more than 10% of its design shape. Tank repaired or replaced to design. Gaps between sections, damaged joints or cracks or tears in wall A gap wider than ½-inch at the joint of any tank sections or any evidence of soil particles entering the tank at a joint or through a wall. No water or soil entering tank through joints or walls. Infiltration Vault Structure Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch, any evidence of soil entering the structure through cracks or qualified inspection personnel determines that the vault is not structurally sound. Vault is sealed and structurally sound. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2017 City of Renton Surface Water Design Manual 12/12/2016 A-5 NO. 2 – INFILTRATION FACILITIES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Inlet/Outlet Pipes Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Access Manhole Cover/lid not in place Cover/lid is missing or only partially in place. Any open manhole requires immediate maintenance. Manhole access covered. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. Large access doors/plate Damaged or difficult to open Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat; covers access opening completely. Lifting rings missing, rusted Lifting rings not capable of lifting weight of door or plate. Lifting rings sufficient to lift or remove door or plate. Infiltration Pond, Tank, Vault, Trench, or Small Basin Filter Bags Plugged filter bag (if applicable) Filter bag more than 1/2 full. Replace filter bag or redesign system. Infiltration Pond, Tank, Vault, Trench, or Small Basin Pre- settling Ponds and Vaults Sediment accumulation 6" or more of sediment has accumulated. Pre-settling occurs as designed Infiltration Pond, Rock Filter Plugged rock filter High water level on upstream side of filter remains for extended period of time or little or no water flows through filter during heavy rain storms. Rock filter replaced evaluate need for filter and remove if not necessary. Infiltration Pond Emergency Overflow Spillway Rock missing Only one layer of rock exists above native soil in area five square feet or larger, or any exposure of native soil at the top of out flow path of spillway. Rip-rap on inside slopes need not be replaced. Spillway restored to design standards. Tree growth Tree growth impedes flow or threatens stability of spillway. Trees removed. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-6 NO. 3 – DETENTION TANKS AND VAULTS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash and debris which exceed 1 cubic foot per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Trash and debris cleared from site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive growth of grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Tank or Vault Storage Area Trash and debris Any trash and debris accumulated in vault or tank (includes floatables and non- floatables). No trash or debris in vault. Sediment accumulation Accumulated sediment depth exceeds 10% of the diameter of the storage area for ½ length of storage vault or any point depth exceeds 15% of diameter. Example: 72-inch storage tank would require cleaning when sediment reaches depth of 7 inches for more than ½ length of tank. All sediment removed from storage area. Tank Structure Plugged air vent Any blockage of the vent. Tank or vault freely vents. Tank bent out of shape Any part of tank/pipe is bent out of shape more than 10% of its design shape. Tank repaired or replaced to design. Gaps between sections, damaged joints or cracks or tears in wall A gap wider than ½-inch at the joint of any tank sections or any evidence of soil particles entering the tank at a joint or through a wall. No water or soil entering tank through joints or walls. Vault Structure Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch, any evidence of soil entering the structure through cracks or qualified inspection personnel determines that the vault is not structurally sound. Vault is sealed and structurally sound. Inlet/Outlet Pipes Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipes Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Access Manhole Cover/lid not in place Cover/lid is missing or only partially in place. Any open manhole requires immediate maintenance. Manhole access covered. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2017 City of Renton Surface Water Design Manual 12/12/2016 A-7 NO. 3 – DETENTION TANKS AND VAULTS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Access Manhole (cont.) Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. Large access doors/plate Damaged or difficult to open Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat; covers access opening completely. Lifting rings missing, rusted Lifting rings not capable of lifting weight of door or plate. Lifting rings sufficient to lift or remove door or plate. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-10 NO. 5 – CATCH BASINS AND MANHOLES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Structure Sediment accumulation Sediment exceeds 60% of the depth from the bottom of the catch basin to the invert of the lowest pipe into or out of the catch basin or is within 6 inches of the invert of the lowest pipe into or out of the catch basin. Sump of catch basin contains no sediment. Trash and debris Trash or debris of more than ½ cubic foot which is located immediately in front of the catch basin opening or is blocking capacity of the catch basin by more than 10%. No Trash or debris blocking or potentially blocking entrance to catch basin. Trash or debris in the catch basin that exceeds 1/3 the depth from the bottom of basin to invert the lowest pipe into or out of the basin. No trash or debris in the catch basin. Dead animals or vegetation that could generate odors that could cause complaints or dangerous gases (e.g., methane). No dead animals or vegetation present within catch basin. Deposits of garbage exceeding 1 cubic foot in volume. No condition present which would attract or support the breeding of insects or rodents. Damage to frame and/or top slab Corner of frame extends more than ¾ inch past curb face into the street (If applicable). Frame is even with curb. Top slab has holes larger than 2 square inches or cracks wider than ¼ inch. Top slab is free of holes and cracks. Frame not sitting flush on top slab, i.e., separation of more than ¾ inch of the frame from the top slab. Frame is sitting flush on top slab. Cracks in walls or bottom Cracks wider than ½ inch and longer than 3 feet, any evidence of soil particles entering catch basin through cracks, or maintenance person judges that catch basin is unsound. Catch basin is sealed and is structurally sound. Cracks wider than ½ inch and longer than 1 foot at the joint of any inlet/outlet pipe or any evidence of soil particles entering catch basin through cracks. No cracks more than 1/4 inch wide at the joint of inlet/outlet pipe. Settlement/ misalignment Catch basin has settled more than 1 inch or has rotated more than 2 inches out of alignment. Basin replaced or repaired to design standards. Damaged pipe joints Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering the catch basin at the joint of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of inlet/outlet pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2017 City of Renton Surface Water Design Manual 12/12/2016 A-11 NO. 5 – CATCH BASINS AND MANHOLES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Inlet/Outlet Pipe (cont.) Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Metal Grates (Catch Basins) Unsafe grate opening Grate with opening wider than 7/8 inch. Grate opening meets design standards. Trash and debris Trash and debris that is blocking more than 20% of grate surface. Grate free of trash and debris. footnote to guidelines for disposal Damaged or missing grate Grate missing or broken member(s) of the grate. Any open structure requires urgent maintenance. Grate is in place and meets design standards. Manhole Cover/Lid Cover/lid not in place Cover/lid is missing or only partially in place. Any open structure requires urgent maintenance. Cover/lid protects opening to structure. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs. of lift. Cover/lid can be removed and reinstalled by one maintenance person. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-12 NO. 6 – CONVEYANCE PIPES AND DITCHES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Pipes Sediment & debris accumulation Accumulated sediment or debris that exceeds 20% of the diameter of the pipe. Water flows freely through pipes. Vegetation/root growth in pipe Vegetation/roots that reduce free movement of water through pipes. Water flows freely through pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Damage to protective coating or corrosion Protective coating is damaged; rust or corrosion is weakening the structural integrity of any part of pipe. Pipe repaired or replaced. Damaged pipes Any dent that decreases the cross section area of pipe by more than 20% or is determined to have weakened structural integrity of the pipe. Pipe repaired or replaced. Ditches Trash and debris Trash and debris exceeds 1 cubic foot per 1,000 square feet of ditch and slopes. Trash and debris cleared from ditches. Sediment accumulation Accumulated sediment that exceeds 20% of the design depth. Ditch cleaned/flushed of all sediment and debris so that it matches design. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive vegetation growth Vegetation that reduces free movement of water through ditches. Water flows freely through ditches. Erosion damage to slopes Any erosion observed on a ditch slope. Slopes are not eroding. Rock lining out of place or missing (If applicable) One layer or less of rock exists above native soil area 5 square feet or more, any exposed native soil. Replace rocks to design standards. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2017 City of Renton Surface Water Design Manual 12/12/2016 A-15 NO. 9 – FENCING MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Erosion or holes under fence Erosion or holes more than 4 inches high and 12-18 inches wide permitting access through an opening under a fence. No access under the fence. Wood Posts, Boards and Cross Members Missing or damaged parts Missing or broken boards, post out of plumb by more than 6 inches or cross members broken No gaps on fence due to missing or broken boards, post plumb to within 1½ inches, cross members sound. Weakened by rotting or insects Any part showing structural deterioration due to rotting or insect damage All parts of fence are structurally sound. Damaged or failed post foundation Concrete or metal attachments deteriorated or unable to support posts. Post foundation capable of supporting posts even in strong wind. Metal Posts, Rails and Fabric Damaged parts Post out of plumb more than 6 inches. Post plumb to within 1½ inches. Top rails bent more than 6 inches. Top rail free of bends greater than 1 inch. Any part of fence (including post, top rails, and fabric) more than 1 foot out of design alignment. Fence is aligned and meets design standards. Missing or loose tension wire. Tension wire in place and holding fabric. Deteriorated paint or protective coating Part or parts that have a rusting or scaling condition that has affected structural adequacy. Structurally adequate posts or parts with a uniform protective coating. Openings in fabric Openings in fabric are such that an 8-inch diameter ball could fit through. Fabric mesh openings within 50% of grid size. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-16 NO. 10 – GATES/BOLLARDS/ACCESS BARRIERS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Chain Link Fencing Gate Damaged or missing members Missing gate. Gates in place. Broken or missing hinges such that gate cannot be easily opened and closed by a maintenance person. Hinges intact and lubed. Gate is working freely. Gate is out of plumb more than 6 inches and more than 1 foot out of design alignment. Gate is aligned and vertical. Missing stretcher bar, stretcher bands, and ties. Stretcher bar, bands, and ties in place. Locking mechanism does not lock gate Locking device missing, no-functioning or does not link to all parts. Locking mechanism prevents opening of gate. Openings in fabric Openings in fabric are such that an 8-inch diameter ball could fit through. Fabric mesh openings within 50% of grid size. Bar Gate Damaged or missing cross bar Cross bar does not swing open or closed, is missing or is bent to where it does not prevent vehicle access. Cross bar swings fully open and closed and prevents vehicle access. Locking mechanism does not lock gate Locking device missing, no-functioning or does not link to all parts. Locking mechanism prevents opening of gate. Support post damaged Support post does not hold cross bar up. Cross bar held up preventing vehicle access into facility. Bollards Damaged or missing bollards Bollard broken, missing, does not fit into support hole or hinge broken or missing. No access for motorized vehicles to get into facility. Bollards do not lock Locking assembly or lock missing or cannot be attached to lock bollard in place. No access for motorized vehicles to get into facility. Boulders Dislodged boulders Boulders not located to prevent motorized vehicle access. No access for motorized vehicles to get into facility. Evidence of vehicles circumventing boulders Motorized vehicles going around or between boulders. No access for motorized vehicles to get into facility. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2017 City of Renton Surface Water Design Manual 12/12/2016 A-17 NO. 11 – GROUNDS (LANDSCAPING) MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash and debris which exceed 1 cubic foot per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Trash and debris cleared from site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive growth of grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Trees and Shrubs Hazard tree identified Any tree or limb of a tree identified as having a potential to fall and cause property damage or threaten human life. A hazard tree identified by a qualified arborist must be removed as soon as possible. No hazard trees in facility. Damaged tree or shrub identified Limbs or parts of trees or shrubs that are split or broken which affect more than 25% of the total foliage of the tree or shrub. Trees and shrubs with less than 5% of total foliage with split or broken limbs. Trees or shrubs that have been blown down or knocked over. No blown down vegetation or knocked over vegetation. Trees or shrubs free of injury. Trees or shrubs which are not adequately supported or are leaning over, causing exposure of the roots. Tree or shrub in place and adequately supported; dead or diseased trees removed. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-18 NO. 12 – ACCESS ROADS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Trash and debris exceeds 1 cubic foot per 1,000 square feet (i.e., trash and debris would fill up one standards size garbage can). Roadway drivable by maintenance vehicles. Debris which could damage vehicle tires or prohibit use of road. Roadway drivable by maintenance vehicles. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Blocked roadway Any obstruction which reduces clearance above road surface to less than 14 feet. Roadway overhead clear to 14 feet high. Any obstruction restricting the access to a 10- to 12 foot width for a distance of more than 12 feet or any point restricting access to less than a 10 foot width. At least 12-foot of width on access road. Road Surface Erosion, settlement, potholes, soft spots, ruts Any surface defect which hinders or prevents maintenance access. Road drivable by maintenance vehicles. Vegetation on road surface Trees or other vegetation prevent access to facility by maintenance vehicles. Maintenance vehicles can access facility. Shoulders and Ditches Erosion Erosion within 1 foot of the roadway more than 8 inches wide and 6 inches deep. Shoulder free of erosion and matching the surrounding road. Weeds and brush Weeds and brush exceed 18 inches in height or hinder maintenance access. Weeds and brush cut to 2 inches in height or cleared in such a way as to allow maintenance access. Modular Grid Pavement Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Damaged or missing blocks/grids Access surface compacted because of broken on missing modular block. Access road surface restored so road infiltrates. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-24 NO. 17 – WETVAULT MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Trash and debris accumulated on facility site. Trash and debris removed from facility site. Treatment Area Trash and debris Any trash and debris accumulated in vault (includes floatables and non-floatables). No trash or debris in vault. Sediment accumulation Sediment accumulation in vault bottom exceeds the depth of the sediment zone plus 6 inches. No sediment in vault. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Vault Structure Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch, any evidence of soil entering the structure through cracks, vault does not retain water or qualified inspection personnel determines that the vault is not structurally sound. Vault is sealed and structurally sound. Baffles damaged Baffles corroding, cracking, warping and/or showing signs of failure or baffle cannot be removed. Repair or replace baffles or walls to specifications. Ventilation area blocked/plugged Ventilation area blocked or plugged. No reduction of ventilation area exists. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Gravity Drain Inoperable valve Valve will not open and close. Valve opens and closes normally. Valve won’t seal Valve does not seal completely. Valve completely seals closed. Access Manhole Access cover/lid damaged or difficult to open Access cover/lid cannot be easily opened by one person. Corrosion/deformation of cover/lid. Access cover/lid can be opened by one person. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Access doors/plate has gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat; covers access opening completely. Lifting rings missing, rusted Lifting rings not capable of lifting weight of door or plate. Lifting rings sufficient to lift or remove door or plate. Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2017 City of Renton Surface Water Design Manual 12/12/2016 A-33 NO. 22 – BAFFLE OIL/WATER SEPARATOR MAINTENANCE COMPONENT DEFECT CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash or debris which impairs the function of the facility. Trash and debris removed from facility. Contaminants and pollution Floating oil in excess of 1 inch in first chamber, any oil in other chambers or other contaminants of any type in any chamber. No contaminants present other than a surface oil film. Vault Treatment Area Sediment accumulation Sediment accumulates exceeds 6 inches in the vault. No sediment in the vault. Discharge water not clear Inspection of discharge water shows obvious signs of poor water quality- effluent discharge from vault shows thick visible sheen. Effluent discharge is clear. Trash or debris accumulation Any trash and debris accumulation in vault (floatables and non-floatables). Vault is clear of trash and debris. Oil accumulation Oil accumulations that exceed 1 inch, at the surface of the water in the oil/water separator chamber. No visible oil depth on water. Vault Structure Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch or evidence of soil particles entering the structure through the cracks, or maintenance/inspection personnel determines that the vault is not structurally sound. Vault replaced or repaired to design specifications. Baffles damaged Baffles corroding, cracking, warping and/or showing signs of failure as determined by maintenance inspection personnel. Repair or replace baffles to specifications. Gravity Drain Inoperable valve Valve will not open and close. Valve opens and closes normally. Valve won’t seal Valve does not seal completely. Valve completely seals closed. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Access Manhole Cover/lid not in place Cover/lid is missing or only partially in place. Any open manhole requires immediate maintenance. Manhole access covered. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-34 NO. 22 – BAFFLE OIL/WATER SEPARATOR MAINTENANCE COMPONENT DEFECT CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Large Access Doors/Plate Damaged or difficult to open Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat and cover access opening completely. Lifting rings missing, rusted Lifting rings not capable of lifting weight of door or cover/lid. Lifting rings sufficient to lift or remove cover/lid. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-38 NO. 25 – DRYWELL BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Preventive Plugging, obstructions Any cause limiting flow into drywell. Drywell able to receive full flow prior to and during wet season. Site Trash and debris Trash or debris that could end up in the drywell is evident. No trash or debris that could get into the drywell can be found. Pipes Plugged inlet The entrance to the pipe is restricted due to sediment, trash, or debris. The entrance to the pipe is not restricted. Vegetation/root growth in pipes Vegetation/roots that reduce free movement of water through pipes. Water flows freely through pipes. Plugged pipe Sediment or other material prevents free flow of water through the pipe. Water flows freely through pipes. Broken pipe or joint leaks Damage to the pipe or pipe joints allowing water to seep out. Pipe does not allow water to exit other than at the outlet. Structure Basin leaks Holes or breaks in the basin allow water to leave the basin at locations other than per design. Basin is sealed and allows water to exit only where designed. Filter Media Plugged filter media Filter media plugged. Flow through filter media is normal. NO. 26 – GRAVEL FILLED INFILTRATION TRENCH BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Preventive Blocking, obstructions Debris or trash limiting flow to infiltration trench. Infiltration trench able to receive full flow prior to and during wet season. Site Trash and debris Trash or debris that could end up in the infiltration trench is evident. No trash or debris that could get into the infiltration trench can be found. Pipes Plugged inlet The entrance to the pipe is restricted due to sediment, trash, or debris. The entrance to the pipe is not restricted. Vegetation/root growth in pipes Vegetation/roots that reduce free movement of water through pipes. Water flows freely through pipes. Plugged pipes Sediment or other material prevents free flow of water through the pipe. Water flows freely through pipes. Broken pipe or joint leaks Damage to the pipe or pipe joints allowing water to seep out. Pipe does not allow water to exit other than at the outlet to the trench. Structure Flow not reaching trench Flows are not getting into the trench as designed. Water enters and exits trench as designed. Cleanout/inspection access does not allow cleaning or inspection of trench The cleanout/inspection access is not available. Cleanout/inspection access is available. Filter Media Plugged filter media Filter media plugged. Flow through filter media is normal. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2017 City of Renton Surface Water Design Manual 12/12/2016 A-47 NO. 38 – SOIL AMENDMENT BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Soil Media Unhealthy vegetation Vegetation not fully covering ground surface or vegetation health is poor. Yellowing: possible Nitrogen (N) deficiency. Poor growth: possible Phosphorous (P) deficiency. Poor flowering, spotting or curled leaves, or weak roots or stems: possible Potassium (K) deficiency. Plants are healthy and appropriate for site conditions Inadequate soil nutrients and structure In the fall, return leaf fall and shredded woody materials from the landscape to the site when possible Soil providing plant nutrients and structure Excessive vegetation growth Grass becomes excessively tall (greater than 10 inches); nuisance weeds and other vegetation start to take over. Healthy turf- “grasscycle” (mulch-mow or leave the clippings) to build turf health Weeds Preventive maintenance Avoid use of pesticides (bug and weed killers), like “weed & feed,” which damage the soil Fertilizer needed Where fertilization is needed (mainly turf and annual flower beds), a moderate fertilization program should be used which relies on compost, natural fertilizers or slow-release synthetic balanced fertilizers Integrated Pest Management (IPM) protocols for fertilization followed Bare spots Bare spots on soil No bare spots, area covered with vegetation or mulch mixed into the underlying soil. Compaction Poor infiltration due to soil compaction To remediate compaction, aerate soil, till to at least 8-inch depth, or further amend soil with compost and re-till If areas are turf, aerate compacted areas and top dress them with 1/4 to 1/2 inch of compost to renovate them If drainage is still slow, consider investigating alternative causes (e.g., high wet season groundwater levels, low permeability soils) Also consider site use and protection from compacting activities No soil compaction Poor infiltration Soils become waterlogged, do not appear to be infiltrating. Facility infiltrating properly Erosion/Scouring Erosion Areas of potential erosion are visible Causes of erosion (e.g., concentrate flow entering area, channelization of runoff) identified and damaged area stabilized (regrade, rock, vegetation, erosion control matting).For deep channels or cuts (over 3 inches in ponding depth), temporary erosion control measures in place until permanent repairs can be made Grass/Vegetation Unhealthy vegetation Less than 75% of planted vegetation is healthy with a generally good appearance. Healthy vegetation. Unhealthy plants removed/replaced. Appropriate vegetation planted in terms of exposure, soil and soil moisture. Noxious Weeds Noxious weeds Listed noxious vegetation is present (refer to current County noxious weed list). No noxious weeds present. Sapphire on Talbot Final Technical Information Report Appendix E Arborist Report by American Forest Management dated July 9, 2018 11415 NE 128th St., Suite 110, Kirkland, WA 98034 | Phone: 425.820.3420 | Fax: 425.820.3437 americanforestmanagement.com ARBORIST REPORT for Sapphire Homes Inc. 4827 Talbot RD S Renton, WA July 9, 2018 American Forest Management 7/9/2018 Table of Contents 1. Introduction .............................................................................................................. 1 2. Description ............................................................................................................... 1 3. Methodology ............................................................................................................ 1 4. Observations ........................................................................................................... 2 5. Discussion ............................................................................................................... 2 6. Tree Protection Measures ........................................................................................ 3 7. Tree Replacement ................................................................................................... 3 Appendix Site/Tree Photos – pages 5 – 8 Tree Summary Table – attached Tree Conditions Map - attached General Tree Protection Fencing Detail - attached Talbot Road S Arborist Report Page 1 American Forest Management 7/9/2018 1. Introduction American Forest Management, Inc. was contacted by Troy Schmeil of Sapphire Homes Inc., and was asked to compile an ‘Arborist Report’ for a property located within the City of Renton. The proposed townhome project encompasses property located at 4827 Talbot Rd S. Our assignment is to prepare a written report on present tree conditions, which is to be filed with the preliminary permit application. This report encompasses all of the criteria set forth under City of Renton code section 4-8-120. The tree retention requirement is 30% of significant trees. Date of Field Examination: July 3rd, 2018 2. Description 71 significant trees were identified and assessed on the property. These are comprised of a mix of native species and planted ornamental species. A numbered aluminum tag was placed on the lower trunks of the subject trees located in the southeast corner of the site, within the proposed tree retention/open space tract. Significant trees outside of this area were identified with a numbered piece of flagging attached the lower trunk. These tree numbers correspond with the numbers on the Tree Summary Tables and attached maps. There are only a few potential issues with neighboring or off-site trees. Three neighboring trees were identified, assessed and included in this report. 3. Methodology Each tree in this report was visited. Tree diameters were measured by tape. The tree heights were measured using a Spiegel Relaskop. Each tree was visually examined for defects and vigor. The tree assessment procedure involves the examination of many factors: • The crown of the tree is examined for current vigor. This is comprised of inspecting the crown (foliage, buds and branches) for color, density, form, and annual shoot growth, limb dieback and disease. The percentage of live crown is estimated for coniferous species only and scored appropriately. • The bole or main stem of the tree is inspected for decay, which includes cavities, wounds, fruiting bodies of decay (conks or mushrooms), seams, insects, bleeding, callus development, broken or dead tops, structural defects and unnatural leans. Structural defects include crooks, forks with V-shaped crotches, multiple attachments, and excessive sweep. • The root collar and roots are inspected for the presence of decay, insects and/or damage, as well as if they have been injured, undermined or exposed, or original grade has been altered. Based on these factors a determination of viability is made. Trees considered ‘non-viable’ are trees that are in poor condition due to disease, extensive decay and/or cumulative structural defects, which exacerbate failure potential. A ‘viable’ tree is a tree found to be in good health, in a sound condition with minimal defects and is suitable for its location. Also, it will be wind firm if isolated or left as part of a grouping or grove of trees. A ‘borderline’ viable tree is a tree where its viability is in question. These are trees that are beginning to display symptoms of decline due to age and or species related problems. Borderline trees are not expected to positively contribute to the landscape for the long-term and are not recommended for retention. The attached Tree Conditions Map indicates the viability of the subject trees. Talbot Road S Arborist Report Page 2 American Forest Management 7/9/2018 4. Observations The subject trees are comprised of a mix of native and planted species. Native species are comprised of Oregon Ash, Pacific Willow, Western Red Cedar, Big Leaf Maple, Douglas-fir and Black Cottonwood. Planted species include Black Pine, Lombardi Poplar, Leyland Cypress, Fruit Trees, European Paper Birch, Lawson Cypress, Elm, and Windmill Palms. 6 of the 71 assessed trees on the subject property are in poor condition and considered non-viable. These are described as follows: Tree #33 is a Pacific Willow (Salix lasiandra). It has a broken leader and is suppressed by nearby Cottonwoods. Tree #35 is a Pacific Willow dominated by nearby trees with a severe lean reaching for light. Tree #36 is another Pacific Willow dominated by nearby trees with a severe lean and broken leader. Tree #50 is an overly mature Apple (Malus spp.) shaded by taller trees with a history of large heading cuts resulting in an abundance of regrowth and dead and decaying wood. (See photo #1) Tree #69 is a European White Elm (Ulmus laevis). It is severely damaged by Elm Leafminer (Fenusa ulmi), and its form is poor. Tree #70 is another overly mature Apple with a history of growing in the shade and harsh pruning resulting in a large amount of dead wood in the canopy. There are several native neighboring trees on the west perimeter. These are primarily comprised of black cottonwood trees. These are mostly young to semi-mature specimens. 5. Discussion There are several trees in the southeast corner of the site where retention may be feasible. Trees #1-20, 24, 25 roughly fall within the proposed tree retention tract on the site plan. The number of trees that can be retained will depend on the storm water retention design. In order to properly protect retained trees, existing grades shall be maintained around them to the fullest extent possible. After review of the proposed design, the subject trees selected for retention can be successfully preserved in good condition, so long as the proper tree protection measures are taken. The drip-lines (farthest reaching branches) for the trees within the proposed tree retention tract can be found on the tree summary table. These have also been delineated on a copy of the development plan for trees proposed for retention. The information plotted on the attached plan may need to be transferred to a final tree retention/protection plan to meet City submittal requirements. The trees that are to be removed shall be shown “X’d” out on the final plan. The Limits of Disturbance (LOD) measurements can also be found on the tree summary table. This is the recommended distance of the closest impact (soil excavation or fill) to the trunk face. These should be referenced when determining tree retention feasibility. The LOD measurements are based on species, age, condition, drip-line, prior improvements, proposed impacts and the anticipated cumulative impacts to the entire root zone. Tree Protection fencing shall be initially located a few feet beyond the drip-line edge of retained trees per the attached plan, and only moved back to the LOD when work is authorized and ready to commence. Talbot Road S Arborist Report Page 3 American Forest Management 7/9/2018 Neighboring Tree Issues: Tree #201 is a Black Cottonwood (Populus trichocarpa) in fair condition just over the west fence line. This tree is likely to develop into a hazard tree as it matures. Removal now to avoid future problems would be prudent. Tree # 202 is an Oregon Ash (Fraxinus latifolia) in fair condition just over the north fence line. This tree will likely be significantly impacted by the development. Removal and replacement would be prudent. Tree # 203 is a Big Leaf Maple (Acer macrophyllum) in poor condition near the south east corner of the property near Talbot Road S. This tree is under utility lines and has been topped many times over the years resulting in multiple leader regrowth. (See photo #3) Removal is recommended. Finished landscaping work within the drip-lines of retained trees shall maintain existing grades and not disturb fine root mass at the ground surface. Finish landscape with mulch or new lawn on top of existing grade. Add no more than 2” to 4” of mulch or 2” of composted soil to establish new lawn. Raising the grade more than a few inches will have adverse impacts on fine roots by cutting off oxygen causing suffocation. 6. Tree Protection Measures The following general guidelines are recommended to ensure that the designated space set aside for the preserved trees are protected and construction impacts are kept to a minimum. 1. Tree protection fencing should be erected around retained trees and positioned just beyond the drip-line edge prior to moving any heavy equipment on site. Doing this will set clearing limits and avoid compaction of soils within root zones of retained trees. 2. Any existing infrastructure to be removed within the drip-line or tree protection zone shall be removed by hand or utilizing a tracked mini-excavator. 3. Excavation limits should be laid out in paint on the ground to avoid over excavating. 4. Excavations within the drip-lines shall be monitored by a qualified tree professional so necessary precautions can be taken to decrease impacts to tree parts. A qualified tree professional shall monitor excavations when work is required and allowed within the “limits of disturbance”. 5. To establish sub grade for foundations, curbs and pavement sections near the trees, soil should be removed parallel to the roots and not at 90 degree angles to avoid breaking and tearing roots that lead back to the trunk within the drip-line. Any roots damaged during these excavations should be exposed to sound tissue and cut cleanly with a saw. Cutting tools should be sterilized with alcohol. 6. Areas excavated within the drip-line of retained trees should be thoroughly irrigated weekly during dry periods. 7. Preparations for final landscaping shall be accomplished by hand within the drip-lines of retained trees. Large equipment shall be kept outside of the tree protection zones at all times. Simply finish landscape within 10’ of retained trees with a 2” to 4” layer of organic mulch. 7. Tree Replacement Supplemental trees will likely be necessary to meet the retention requirement, given the low potential for successful tree retention. The tree retention calculation is based on 65, healthy significant trees, not including poor condition or non-viable trees. The retention requirement for the site is 30%, therefore, a total of 20 trees are required for retention per code. Talbot Road S Arborist Report Page 4 American Forest Management 7/9/2018 The following replacement requirements are necessary when retained/protected trees do not meet the minimum requirement per RMC 4-4-130 H. Performance Standards for Land Development/Building Permits: e. Replacement Requirements: As an alternative to retaining trees, the Administrator may authorize the planting of replacement trees on the site if it can be demonstrated to the Administrator’s satisfaction that an insufficient number of trees can be retained. i. Replacement Ratio: When the required number of protected trees cannot be retained, replacement trees, with at least a two-inch (2") caliper or an evergreen at least six feet (6') tall, shall be planted at a rate of twelve (12) caliper inches of new trees to replace each protected tree removed. Up to fifty percent (50%) of trees required pursuant to RMC 4-4-070, Landscaping, may contribute to replacement trees. The City may require a surety or bond to ensure the survival of replacement trees. New or supplemental trees will likely need to be planted to meet the municipal code. New tree plantings shall be given the appropriate space for the species and their growing characteristics. Confer with the City’s Urban Forester for appropriate replacement species. Consult with your City planner to determine the number of replacement trees required once the tree retention plan has been finalized. For planting and maintenance specifications, refer to municipal code 4-4-070 Landscaping. There is no warranty suggested for any of the trees subject to this report. Weather, latent tree conditions, and future man-caused activities could cause physiologic changes and deteriorating tree condition. Over time, deteriorating tree conditions may appear and there may be conditions, which are not now visible which, could cause tree failure. This report or the verbal comments made at the site in no way warrant the structural stability or long term condition of any tree, but represent my opinion based on the observations made. Nearly all trees in any condition standing within reach of improvements or human use areas represent hazards that could lead to damage or injury. Please call if you have any questions or if we can be of further assistance. Sincerely, Bob Layton ISA Certified Arborist #PN-2714A Tree Risk Assessment Qualified (TRAQ) Ben Mark ISA Certified Arborist #PN-6976A Tree Risk Assessment Qualified (TRAQ) Talbot Road S Arborist Report Page 5 American Forest Management 7/9/2018 Photo #1, Tree #50 – Non-viable Photo #2, Trees #8,9 – Good condition Talbot Road S Arborist Report Page 6 American Forest Management 7/9/2018 Photo #3, Neighboring tree #203, Poor condition Photo #4 Trees along west side Talbot Road S Arborist Report Page 7 American Forest Management 7/9/2018 Photo #5, Trees #53,54 Photo #6, Looking south Talbot Road S Arborist Report Page 8 American Forest Management 7/9/2018 Photo #7, Looking west 1 Sapphire Homes TREE SUMMARY TABLE Ben Mark, Bob Layton 4827 Talbot Road South Renton, WA Jul 3, 2018 Tree #Species DBH (in)Height (ft)North South East West Condition Comments Proposal 1 Black Pine 16 47 13 12 13 10 Good Typical TBD 2 Pear 11 36 14 10 12 16 Fair Shade, dead wood TBD 3 Apple *20 caliper 36 12 16 12 20 Fair History of poor pruning TBD 4 Lombardi poplar 23 110 14 14 14 12 Good Typical TBD 5 Lombardi poplar 17 85 12 12 10 10 Good Typical TBD 6 Oregon Ash 18, 20 85 14 18 16 16 Fair Forked, crown dieback TBD 7 Black Cottonwood 21 94 20 20 20 20 Good Typical TBD 8 Black Pine 12 43 8 12 12 10 Good Suppressed TBD 9 Black Pine 14 53 10 8 12 8 Good Forked top TBD 10 Pacific Willow 11, 7 50 10 12 8 20 Good Natural lean TBD 11 Pacific Willow 10 50 10 20 8 10 Good Natural lean TBD 12 Plum 7 22 Fair Volunteer TBD 13 Plum 7 20 Fair Volunteer TBD 14 Pacific Willow 14, 10, 7 60 16 12 14 25 Fair Multi, broken TBD 15 Douglas Fir 7 32 10 8 8 8 Good Suppressed TBD 16 Leyland Cypress 7 30 8 8 10 8 Good Suppressed TBD 17 Black pine 15 40 12 12 8 12 Fair Shade TBD 18 Black pine 11 40 6 8 8 10 Good Forked top TBD 19 Black pine 13 50 10 8 12 12 Good Forked top TBD 20 Plum 11 36 8 12 10 12 Fair Mature TBD 21 Plum 6, 5, 5 Good Typical REMOVE 22 Plum 6, 5, 3, 4 Good Typical REMOVE 23 Lombardi poplar 28 Good Typical REMOVE 24 Leyland cypress 6 Good Typical TBD 25 Pacific Willow 10, 6, 8 Fair Split REMOVE 26 Pacific Willow 8 Fair Natural lean REMOVE 27 Black Cottonwood 9, 7 Fair Suppressed REMOVE 28 Pacific willow 12 Fair Suppressed REMOVE 29 Pacific willow 11 Fair Suppressed REMOVE 30 Black Cottonwood 17 Fair Typical REMOVE 31 Black Cottonwood 8 Fair Typical REMOVE 32 Black Cottonwood 8 Fair Typical REMOVE 33 Pacific Willow 10, 9 Poor Broken leader REMOVE 34 Pacific Willow 10, 12 Fair Broken Leader REMOVE 35 Pacific Willow 13 Poor Lean REMOVE 36 Pacific Willow 11 Poor Broken Leader, severe lean REMOVE 37 Western red cedar 7 fair Typical REMOVE 38 Western red cedar 8 Good Typical REMOVE 39 Western red cedar 5,5,5,Good Multi REMOVE 2 Sapphire Homes TREE SUMMARY TABLE Ben Mark, Bob Layton 4827 Talbot Road South Renton, WA Jul 3, 2018 Tree #Species DBH (in)Height (ft)North South East West Condition Comments Proposal 40 Oregon Ash 9, 8, 7, 6, 5 Fair Multi REMOVE 41 Black Cottonwood 16 Good Typical REMOVE 42 Oregon Ash 16, 7 Fair Forked, multi REMOVE 43 Douglas Fir 10 Good Typical REMOVE 44 Oregon Ash 15, 13, 12 70 Good Forked, included bark REMOVE 45 Windmill Palm 10 Good Typical REMOVE 46 Windmill Palm 10 Good Typical REMOVE 47 Leyland Cypress 22 Good Typical REMOVE 48 European Paper Birch 28 Good Mature REMOVE 49 Lawson Cypress 18 Good Typical REMOVE 50 Apple 7 Poor Shade, poor pruning REMOVE 51 Cherry 9, 9, 8, 8, 6 Good Typical REMOVE 52 Zelkova 7, 7, 6, 6 Fair Multi, broken tops REMOVE 53 Lombardi poplar 28 Fair Sending shoots through pavement REMOVE 54 Leyland Cypress 28 Good Typical REMOVE 55 Douglas Fir 12 Fair Suppressed REMOVE 56 Douglas Fir 12 Good Typical REMOVE 57 Douglas Fir 7 Good Typical REMOVE 58 Douglas Fir 14 Good Typical REMOVE 59 Douglas Fir 12 Good Ivy REMOVE 60 Black Pine 11 Good Typical REMOVE 61 Black Pine 12 Fair Forked leader REMOVE 62 Black Pine 13 Fair Forked leader REMOVE 63 Black Pine 12 Fair Broken leader, suppressed REMOVE 64 Western red cedar 22 Good Typical REMOVE 65 Douglas Fir 12 Good Young REMOVE 66 Douglas Fir 12 Good Young REMOVE 67 Leyland Cypress 20 Good Vigorous REMOVE 68 Leyland Cypress 18 Good Typical REMOVE 69 Elm 10 Poor Leaf miner REMOVE 70 Apple 14 Poor Shade, pruning REMOVE 71 European Paper Birch 11 Fair Significant lean REMOVE Neighboring Trees 201 Black Cottonwood 16 85 18,18 16, 10 Lod Fair Forked, broken branches REMOVE 202 Oregon Ash 16, 14 80 24, 14 Lod 18 18 Fair Typical REMOVE 203 BLM 8 Poor Forked leader, under utility lines REMOVE Sapphire on Talbot Final Technical Information Report Appendix F Trip Generation Report by DN Traffic Consultants dated September 28, 2018 Sapphire on Talbot Final Technical Information Report Appendix G Wetland Reconnaissance by The Watershed Company dated June 11, 2015 Review of Site and Watershed June 11, 2015 Report by Sewall Wetland Consulting, Inc. dated May 6, 2016 June 11, 2015 Alun Vick 4827 Talbot Road S. Renton, WA 98055 Re: 4827 Talbot Road Wetland Reconnaissance The Watershed Company Reference Number: 150537 Dear Alun: On June 3, 2015, I visited an area located on the Ashburn Condominiums property (Ashburn Property) directly west of your property located at 4827 Talbot Road S. in Renton, Washington. The purpose of the visit was to determine the approximate location of the mapped wetland boundary on the Ashburn Property. We understand you were given verbal permission to enter the property by the Ashburn HOA. This letter summarizes the findings of this study. The following attachments are included: • Wetland Reconnaissance Sketch • Wetland Determination Data Forms • Sewall Wetland Consulting, Inc. Report Methods Public-domain information on the subject properties was reviewed for this study. These sources include USDA Natural Resources Conservation Service Soil maps, U.S. Fish and Wildlife Service National Wetland Inventory maps, Washington Department of Fish and Wildlife interactive mapping programs (PHS on the Web), City of Renton GIS mapping website (COR Maps), and King County’s GIS mapping website (iMAP). An existing conditions report prepared for the Vick property was also reviewed as part of this study (Vick/Wright Property Existing Conditions Stream Analysis Report, Sewall Wetland Consulting, Inc., March 14, 2007) (Sewall Report). The study area was evaluated for wetlands using methodology from the Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region Version 2.0 (Regional Supplement) (US Army Corps of Engineers [Corps] May 2010). Wetland presence was determined on the basis of an examination of vegetation, soils, and hydrology. Only areas meeting the criteria set forth in the Regional Supplement were determined to be wetland. Soil, vegetation, and hydrologic parameters were sampled at several locations make the determination. Data Wetland Reconnaissance Report Alun Vick June 11, 2015 Page 2 were recorded at two of these locations. Findings The study area is composed of a forested plant community dominated by black cottonwood, red alder, Oregon ash, red-osier dogwood, Himalayan blackberry, and reed canarygrass. The dominant vegetation satisfies the criteria for a hydrophytic plant community, as more than 50 percent of the dominant vegetation is composed of facultative or facultative-wetland species. However, much of the vegetation, with the exception of the larger cottonwood trees, appears to be a managed plant community. Many of the sapling trees and shrubs appear to be of similar age, and remnant irrigation piping is still present in many areas. Additionally, many of the dominant species, especially the weed species, have a wide ecological tolerance and are commonly found in both wetlands and non-wetlands alike. The soil in the study area is variable, satisfying the criteria for the hydric soil indicator Redox Dark Surface (F6) at DP-1, but not satisfying hydric soil criteria at DP-2. There was no observed wetland hydrology (ground- or surface-water) present in the study area at the time of the inspection, and no primary hydrology indicators were observed. Hydrology sampling pits were dug to approximately 30 inches below the ground surface, with no detectable soil moisture observed. DP-1 is located in the lowest point of the study area, in the former drainage feature connecting to the Vick property (see below). The study area is mapped as a wetland, per the City of Renton wetland inventory. Previously, much of the Vick property was mapped as part of the same wetland. However, the wetland designation for the Vick property was changed upon verification in the Sewall Report that the wetland was a man-made landscape pond. We understand the hydrologic input to the wetland came from a man-made drainage feature that was controlled by a water-flow control valve adjacent to Talbot Road. The flow was captured in a lined pond on the Vick property, then discharged into the mapped wetland on the Ashburn property. Following the determination that the pond on the Vick property was not a jurisdictional wetland, and the drainage feature was not a jurisdictional stream, flow into the drainage feature was permanently disconnected, and the Vick wetland subsequently dried up and was completely filled. This action appears to have had the unanticipated effect of partially or completely dewatering the Ashburn wetland, as well. The effect that discontinuing a substantial hydrologic source for the wetland mapped on the Ashburn property cannot be entirely quantified at this time of year since we are past the historically wettest portion of the growing season (typically early March). However, hydrology appears to have been substantially diminished. There was no dry-season water table below the root zone as of the June inspection, and there are no indicators of recent ponding, such as an algal mat, iron deposits, surface soil cracks, water-stained Wetland Reconnaissance Report Alun Vick June 11, 2015 Page 3 leaves, or a sparsely vegetated concave surface. The soil throughout the study area does not consistently exhibit hydric soil characteristics; the plant community is not a reliable indicator, as it is a managed community; and wetland hydrology was not observed as of the date of this study. Therefore, based on the combined evidence available, it appears that mapped wetland located on the Ashburn property just west of the Vick property no longer satisfies all three wetland criteria. Wetland hydrology indicators are often the most transitory of wetland parameters. Direct hydrology observations are often only present during the normal wet portion of the growing season and may be absent during the dry season or during drier-than-normal years. Areas that have hydrophytic vegetation and hydric soils generally also have wetland hydrology, unless the hydrologic regime has changed due to natural events or human activities. In instances, particularly during the dry season, when hydrophytic vegetation and hydric soils are present but hydrology indicators are absent, best professional judgment is used to determine wetland presence and boundaries. In some situations, it may be necessary to conduct additional inspections during the normal wet portion of the growing season to determine if wetland hydrology is present in a particular area. Disclaimer The information contained in this letter or report is based on the application of technical guidelines currently accepted as the best available science and in conjunction with the manuals and criteria outlined in the methods section. All discussions, conclusions and recommendations reflect the best professional judgment of the author(s) and are based upon information available to us at the time the study was conducted. All work was completed within the constraints of budget, scope, and timing. The findings of this report are subject to verification and agreement by the appropriate local, State and Federal regulatory authorities. No other warranty, expressed or implied, is made. Please call if you have any questions or if we can provide you with any additional information. Sincerely, Ryan Kahlo, PWS Ecologist Enclosures DP-2 DP-1 Wetland Reconnaissance Sketch 4827 Talbot Road S. and Ashburn Condominiums Prepared for Alun Vick June 10, 2015 TWC Project #150537 Legend: Former Man-made Pond (filled) (approx.) Former Piped Drainage Segment (disconnected) (approx.) Former Open-channel Drainage Feature (disconnected) (approx.) Data Point Ashburn Condominiums Property Vick Property US Army Corps of Engineers Western Mountains, Valleys, and Coast – Interim Version WETLAND DETERMINATION DATA FORM Western Mountains, Valleys, and Coast Supplement to the 1987 COE Wetlands Delineation Manual Project Site: 4827 Talbot Road S Sampling Date: 6/3/2015 Applicant/Owner: Ashburn Condominiums Sampling Point: DP- 1 Investigator: Kahlo, R. PWS City/County: Renton Sect., Township, Range S 31 T 23N R 05E State: WA Landform (hillslope, terrace, etc) Swale Slope (%) 5 Local relief (concave, convex, none) Concave Subregion (LRR) A Lat Long Datum Soil Map Unit Name Alderwood gravelly sandy loam, 8-15% slopes NWI classification None Are climatic/hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in remarks.) Are “Normal Circumstances” present on the site? Yes No (If needed, explain any answers in Remarks.) Are Vegetation , Soil, , or Hydrology significantly disturbed? Are Vegetation , Soil, , or Hydrology naturally problematic? SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc. Hydrophytic Vegetation Present? Yes No Is this Sampling Point within a Wetland? Yes No Hydric Soils Present? Yes No Wetland Hydrology Present? Yes No Remarks: VEGETATION – Use scientific names of plants. Tree Stratum (Plot size 5m diam. ) Absolute % Cover Dominant Species? Indicator Status Dominance Test Worksheet 1. Fraxinus latifolia 70 Yes FACW Number of Dominant Species that are OBL, FACW, or FAC: 4 (A) 2. Populus balsamifera 50 Yes FAC 3. Total Number of Dominant Species Across All Strata: 5 (B) 4. = Total Cover Percent of Dominant Species that are OBL, FACW, or FAC: 80 (A/B) Sapling/Shrub Stratum (Plot size 3m diam. ) 1. Salix sitchensis 25 Yes FACW Prevalence Index Worksheet 2. Total % Cover of Multiply by 3. OBL species x 1 = 4. FACW species x 2 = 5. FAC species x 3 = = Total Cover FACU species x 4 = UPL species x 5 = Herb Stratum (Plot size 1m diam. ) Column totals (A) (B) 1. Phalaris arundinacea 15 Yes FACW 2. Prevalence Index = B / A = 3. 4. Hydrophytic Vegetation Indicators 5. X Dominance test is > 50% 6. Prevalence test is ≤ 3.0 * 7. Morphological Adaptations * (provide supporting 8. data in remarks or on a separate sheet) 9. Wetland Non-Vascular Plants * 10. Problematic Hydrophytic Vegetation * (explain) 11. = Total Cover * Indicators of hydric soil and wetland hydrology must be present, unless disturbed or problematic Woody Vine Stratum (Plot size ) Hydrophytic Vegetation Present? Yes No 1. Rubus armeniacus 10 Yes FACU 2. = Total Cover % Bare Ground in Herb Stratum ______ Remarks: This is a weedy plant assemblage with wide ecological tolerance. 750 Sixth Street South Kirkland, Washington 98033 (425) 822-5242 watershedco.com DP-1 US Army Corps of Engineers Western Mountains, Valleys, and Coast – Interim Version SOIL Sampling Point – DP-1 Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) Depth Matrix Redox Features (inches) Color (moist) % Color (moist) % Type1 Loc2 Texture Remarks 0-2 10YR 2/2 95 10YR 3/6 5 C M Sandy loam 5-24 2.5Y 3/3 90 10YR 4/6 10 C M Sandy loam 1Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains 2Loc: PL=Pore Lining, M=Matrix Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils3 Histosol (A1) Sandy Redox (S5) 2cm Muck (A10) Histic Epipedon (A2) Stripped Matrix (S6) Red Parent Material (TF2) Black Histic (A3) Loamy Mucky Mineral (F1) (except MLRA 1) Other (explain in remarks) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Depleted Below Dark Surface (A11) Depleted Matrix (F3) Thick Dark Surface (A12) Redox Dark Surface (F6) 3 Indicators of hydrophytic vegetation and wetland hydrology must be present, unless disturbed or problematic Sandy Mucky Mineral (S1) Depleted Dark Surface (F7) Sandy Gleyed Matrix (S4) Redox Depressions (F8) Restrictive Layer (if present): Hydric soil present? Type: ________________________________________ Yes No Depth (inches): _____________________________________ Remarks: HYDROLOGY Wetland Hydrology Indicators: Primary Indicators (minimum of one required: check all that apply): Secondary Indicators (2 or more required): Surface water (A1) Sparsely Vegetated Concave Surface (B8) Water-Stained Leaves (B9) (MLRA 1, 2, 4A & 4B) High Water Table (A2) Water-Stained Leaves (except MLRA 1, 2, 4A & 4B) (B9) Drainage Patterns (B10) Saturation (A3) Salt Crust (B11) Dry-Season Water Table (C2) Water Marks (B1) Aquatic Invertebrates (B13) Saturation Visible on Aerial Imagery (C9) Sediment Deposits (B2) Hydrogen Sulfide Odor (C1) Geomorphic Position (D2) Drift Deposits (B3) Oxidized Rhizospheres along Living Roots (C3) Shallow Aquitard (D3) Algal Mat or Crust (B4) Presence of Reduced Iron (C4) FAC-Neutral Test (D5) Iron Deposits (B5) Recent Iron Reduction in Tilled Soils (C6) Raised Ant Mounds (D6) (LRR A) Surface Soil Cracks (B6) Stunted or Stressed Plants (D1) (LRR A) Frost-Heave Hummocks Inundation Visible on Aerial Imagery (B7) Other (explain in remarks) Field Observations Wetland Hydrology Present? Surface Water Present? Yes No Depth (in): Water Table Present? Yes No Depth (in): Yes No Saturation Present? (includes capillary fringe) Yes No Depth (in): Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available: Remarks: Soil was completely dry to 30” below ground surface US Army Corps of Engineers Western Mountains, Valleys, and Coast – Interim Version WETLAND DETERMINATION DATA FORM Western Mountains, Valleys, and Coast Supplement to the 1987 COE Wetlands Delineation Manual Project Site: 4827 Talbot Road S Sampling Date: 6/3/2015 Applicant/Owner: Ashburn Condominiums Sampling Point: DP- 2 Investigator: Kahlo, R. PWS City/County: Renton Sect., Township, Range S 31 T 23N R 05E State: WA Landform (hillslope, terrace, etc) Depression Slope (%) flat Local relief (concave, convex, none) Concave Subregion (LRR) A Lat Long Datum Soil Map Unit Name Alderwood gravelly sandy loam, 8-15% slopes NWI classification None Are climatic/hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in remarks.) Are “Normal Circumstances” present on the site? Yes No (If needed, explain any answers in Remarks.) Are Vegetation , Soil, , or Hydrology significantly disturbed? Are Vegetation , Soil, , or Hydrology naturally problematic? SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc. Hydrophytic Vegetation Present? Yes No Is this Sampling Point within a Wetland? Yes No Hydric Soils Present? Yes No Wetland Hydrology Present? Yes No Remarks: VEGETATION – Use scientific names of plants. Tree Stratum (Plot size 5m diam. ) Absolute % Cover Dominant Species? Indicator Status Dominance Test Worksheet 1. Populus balsamifera 20 Yes FAC Number of Dominant Species that are OBL, FACW, or FAC: 3 (A) 2. 3. Total Number of Dominant Species Across All Strata: 5 (B) 4. = Total Cover Percent of Dominant Species that are OBL, FACW, or FAC: 60 (A/B) Sapling/Shrub Stratum (Plot size 3m diam. ) 1. Fraxinus latifolia 100 Yes FACW Prevalence Index Worksheet 2. Symphoricarpos albus 5 No FACU Total % Cover of Multiply by 3. OBL species x 1 = 4. FACW species x 2 = 5. FAC species x 3 = = Total Cover FACU species x 4 = UPL species x 5 = Herb Stratum (Plot size 1m diam. ) Column totals (A) (B) 1. Galium aparine 5 Yes FACU 2. Phalaris arundinacea 10 Yes FACW Prevalence Index = B / A = 3. 4. Hydrophytic Vegetation Indicators 5. X Dominance test is > 50% 6. Prevalence test is ≤ 3.0 * 7. Morphological Adaptations * (provide supporting 8. data in remarks or on a separate sheet) 9. Wetland Non-Vascular Plants * 10. Problematic Hydrophytic Vegetation * (explain) 11. = Total Cover * Indicators of hydric soil and wetland hydrology must be present, unless disturbed or problematic Woody Vine Stratum (Plot size ) Hydrophytic Vegetation Present? Yes No 1. Hedera helix 5 Yes FACU 2. Rubus armeniacus 2 No FACU = Total Cover % Bare Ground in Herb Stratum ______ Remarks: 750 Sixth Street South Kirkland, Washington 98033 (425) 822-5242 watershedco.com DP-2 US Army Corps of Engineers Western Mountains, Valleys, and Coast – Interim Version SOIL Sampling Point – DP-2 Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) Depth Matrix Redox Features (inches) Color (moist) % Color (moist) % Type1 Loc2 Texture Remarks 0-12 10YR 2/2 100 Sandy loam 12-24 10YR 3/1 98 10YR 3/6 2 C M Sandy loam 1Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains 2Loc: PL=Pore Lining, M=Matrix Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils3 Histosol (A1) Sandy Redox (S5) 2cm Muck (A10) Histic Epipedon (A2) Stripped Matrix (S6) Red Parent Material (TF2) Black Histic (A3) Loamy Mucky Mineral (F1) (except MLRA 1) Other (explain in remarks) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Depleted Below Dark Surface (A11) Depleted Matrix (F3) Thick Dark Surface (A12) Redox Dark Surface (F6) 3 Indicators of hydrophytic vegetation and wetland hydrology must be present, unless disturbed or problematic Sandy Mucky Mineral (S1) Depleted Dark Surface (F7) Sandy Gleyed Matrix (S4) Redox Depressions (F8) Restrictive Layer (if present): Hydric soil present? Type: ________________________________________ Yes No Depth (inches): _____________________________________ Remarks: HYDROLOGY Wetland Hydrology Indicators: Primary Indicators (minimum of one required: check all that apply): Secondary Indicators (2 or more required): Surface water (A1) Sparsely Vegetated Concave Surface (B8) Water-Stained Leaves (B9) (MLRA 1, 2, 4A & 4B) High Water Table (A2) Water-Stained Leaves (except MLRA 1, 2, 4A & 4B) (B9) Drainage Patterns (B10) Saturation (A3) Salt Crust (B11) Dry-Season Water Table (C2) Water Marks (B1) Aquatic Invertebrates (B13) Saturation Visible on Aerial Imagery (C9) Sediment Deposits (B2) Hydrogen Sulfide Odor (C1) Geomorphic Position (D2) Drift Deposits (B3) Oxidized Rhizospheres along Living Roots (C3) Shallow Aquitard (D3) Algal Mat or Crust (B4) Presence of Reduced Iron (C4) FAC-Neutral Test (D5) Iron Deposits (B5) Recent Iron Reduction in Tilled Soils (C6) Raised Ant Mounds (D6) (LRR A) Surface Soil Cracks (B6) Stunted or Stressed Plants (D1) (LRR A) Frost-Heave Hummocks Inundation Visible on Aerial Imagery (B7) Other (explain in remarks) Field Observations Wetland Hydrology Present? Surface Water Present? Yes No Depth (in): Water Table Present? Yes No Depth (in): Yes No Saturation Present? (includes capillary fringe) Yes No Depth (in): Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available: Remarks: May 6, 2016 Alun Vick 4827 Talbot Road Renton, WA 98055 RE: Review of site and Watershed June 11, 2015 report City of Renton, Washington SWC Job #16-110 Dear Alun, I have reviewed the “4827 Talbot Road South Wetland Reconnaissance” report, dated 6/11//2015 prepared by The Watershed Company. I visited the site on February 11, and March 9, 2016 in the early part of the growing season that had a record high rainfall well above average. My observations concur with those described in the June 11, 2015 Watershed reconnaissance letter. It appears that the removal of the pond and its water source on your property have have resulted in the wetland on the Ashburn parcel to have dried up significantly. During my site visits no areas meeting wetland hydrology were found on your property or the area immediately to the west on the Ashburn site on these dates. If you have any questions in regards to this report or need additional information, please feel free to contact me at (253) 859-0515 or at esewall@sewallwc.com . Sincerely, Sewall Wetland Consulting, Inc. Ed Sewall Senior Wetlands Ecologist PWS #212 Sewall Wetland Consulting, Inc. PO Box 880 Phone: 253-859-0515 Fall City, WA 98024 Appendix H Biopod Biofilter Underground Vault Details By Oldcastle Infrastructure And Stormwater Adjustment DEPARTMENT OF COMMUNITY AND ECONOMIC DEVELOPMENT Page 1 of 2 | Published: 2/1/2018 Planning Division | 1055 South Grady Way, 6th Floor | Renton, WA 98057 | 425-430-7200 Website: rentonwa.gov STORMWATER ADJUSTMENT REQUEST APPLICATION Published: 2/1/2018 1.Submit the completed Stormwater Adjustment Request Application form. 2.Submit sufficient documentation in order for the City to evaluate the request, including, but not limited to: ☐Electronic Copy of the Adjustment Request Justification – A written statement separately addressing and justifying each of the issues to be considered by the City. The burden of proof as to the appropriateness of the adjustment request lies with the applicant. Criteria for granting adjustments are outlined in detail in Section 1.4.2 of the City of Renton Surface Water Design Manual (RSWDM). ☐Electronic Copy of all Plans and supporting reports and studies applicable to the adjustment request. ☐Draft Electronic copy of any easements and/or Declarations of Covenants. ☐Electronic Copy of the Maintenance and Operations information for the proposed Stormwater Facilities. 3.Pay all Stormwater Adjustment Review Fees. Multiple Stormwater Adjustments can be requested in a single Application; however, a separate fee is applied to each Adjustment. Reference the current City of Renton Fee Schedule for the current Stormwater Adjustment Review Fees. 4.Upon determination of a successful and complete application, the City will review and either approve or deny the adjustment request. Note: Requests for standard adjustments will be accepted only for permits pending approval or approved permits that have not yet expired. Specific Code Section(s) related to this document RMC Ch 4-6 Street and Utility Standards RMC Ch 4-8 Permits – General and Appeals RSWDM Section 1.4 – Adjustment Review Process Additional Design Resources and City Standards City of Renton Surface Water Design Manual (RSWDM) City of Renton Standard Details City of Renton Forms DEPARTMENT OF COMMUNITY AND ECONOMIC DEVELOPMENT Page 2 of 2 | Published: 2/01/2018 Planning Division | 1055 South Grady Way, 6th Floor | Renton, WA 98057 | 425-430-7200 Website: rentonwa.gov STORMWATER ADJUSTMENT REQUEST APPLICATION Project Name: Project Address/Location: Description of Project: Related Permit(s): C#: B#: LUA#: Type of Construction: ☐Short Plat (9 or fewer lots)☐Subdivision (10+ Lots)☐Commercial / Multi-Family ☐Tenant Improvement ☐Addition to Existing - Approximate Value of Addition: $________________ The proposed stormwater facilities subject to the adjustment request will be: ☐public (owned and maintained by the City)☐privately owned and maintained Applicant Information: Engineer Information: Name: Firm: Address: Address: City: State: Zip: City: State: Zip: Phone: Phone: Email: Contact: Email: Applicable Section(s) of Design Standard(s) being modified: Description of Adjustment Request and Justification (Reference Section 1.4 – Adjustment Review Process): Provide information on additional sheet as necessary For Staff Use Only Determination: ☐Approved ☐Denied Stormwater Adjustment No.: Enclosed Written Decision dated: Sapphire on Talbot 4827 Talbot Rd S 20 lot unit subdivision 407201 18-000665 4 4 4 Troy Schmeil 16805 SE 43rd Ct Bellevue WA 98006 206-954-4945 callidusland@comcast.net Encompass Engineering & Surveying 165 NE Juniper St; Ste 201 Issaquah WA 98027 425-392-0250 Edward Mecum emecum@encompasses.net 6.7.2 Proprietary Facility Designs Biopod biofilter by Oldcastle Infrastructure is not approved by the City of Renton, but has GULD certification through Ecology. The Biopod is necessary due to the drop required by other facilities and presettling is not required with the Biopod, easing the need for additional facilities. May 2019 GENERAL USE LEVEL DESIGNATION FOR BASIC (TSS), DISSOLVED METALS (ENHANCED), AND PHOSPHORUS TREATMENT For Oldcastle Infrastructure, Inc.’s The BioPod™ Biofilter (Formerly the TreePod Biofilter) Ecology’s Decision: Based on Oldcastle Infrastructure, Inc. application submissions for the The BioPod™ Biofilter (BioPod), Ecology hereby issues the following use level designation: 1. General Use Level Designation (GULD) for Basic, Enhanced, and Phosphorus Treatment:  Sized at a hydraulic loading rate of 1.6 gallons per minute (gpm) per square foot (sq ft) of media surface area.  Constructed with a minimum media thickness of 18-inches (1.5-feet). 2. Ecology approves the BioPod at the hydraulic loading rate listed above, to achieve the maximum water quality design flow rate. The water quality design flow rates are calculated using the following procedures:  Western Washington: For treatment installed upstream of detention or retention, the water quality design flow rate is the peak 15-minute flow rate as calculated using the latest version of the Western Washington Hydrology Model or other Ecology- approved continuous runoff model.  Eastern Washington: For treatment installed upstream of detention or retention, the water quality design flow rate is the peak 15-minute flow rate as calculated using one of the three methods described in Chapter 2.2.5 of the Stormwater Management Manual for Eastern Washington (SWMMEW) or local manual.  Entire State: For treatment installed downstream of detention, the water quality design flow rate is the full 2-year release rate of the detention facility. 3. The GULD has no expiration date, but may be amended or revoked by Ecology. Ecology’s Conditions of Use: The BioPod shall comply with these conditions: 1) Applicants shall design, assemble, install, operate, and maintain the BioPod installations in accordance with Oldcastle Infrastructure, Inc.’s applicable manuals and the Ecology Decision. 2) BioPod media shall conform to the specifications submitted to and approved by Ecology 3) Maintenance: The required inspection/maintenance interval for stormwater treatment devices is often dependent on the efficiency of the device and the degree of pollutant loading from a particular drainage basin. Therefore, Ecology does not endorse or recommend a “one size fits all” maintenance cycle for a particular model/size of manufactured filter treatment device.  The BioPod is designed for a target maintenance interval of 1 year. Maintenance includes replacing the mulch, assessing plant health, removal of trash, and raking the top few inches of engineered media.  A BioPod system tested at the Lake Union Ship Canal Test Facility in Seattle, WA required maintenance after 1.5 months, or 6.3% of a water year. Monitoring personnel observed similar maintenance issues with other systems evaluated at the Test Facility. The runoff from the Test Facility may be unusual and maintenance requirements of systems installed at the Test Facility may not be indicative of maintenance requirements for all sites.  Test results provided to Ecology from a BioPod System evaluated in a lab following New Jersey Department of Environmental Protection Laboratory Protocol for Filtration MTDs have indicated the BioPod System is capable of longer maintenance intervals.  Owners/operators must inspect BioPod systems for a minimum of twelve months from the start of post-construction operation to determine site-specific inspection/maintenance schedules and requirements. Owners/operators must conduct inspections monthly during the wet season, and every other month during the dry season. (According to the SWMMWW, the wet season in western Washington is October 1 to April 30. According to the SWMMEW, the wet season in eastern Washington is October 1 to June 30.) After the first year of operation, owners/operators must conduct inspections based on the findings during the first year of inspections.  Conduct inspections by qualified personnel, follow manufacturer’s guidelines, and use methods capable of determining either a decrease in treated effluent flow rate and/or a decrease in pollutant removal ability. 4) Install the BioPod in such a manner that you bypass flows exceeding the maximum operating rate and you will not resuspend captured sediment. 5) Discharges from the BioPod shall not cause or contribute to water quality standards violations in receiving waters. Applicant: Oldcastle Infrastructure, Inc. Applicant’s Address: 7100 Longe St, Suite 100 Stockton, CA 95206 Application Documents: Technical Evaluation Report TreePod™ BioFilter System Performance Certification Project, Prepared for Oldcastle, Inc., Prepared by Herrera Environmental Consultants, Inc. February 2018 Technical Memorandum: Response to Board of External Reviewers’ Comments on the Technical Evaluation Report for the TreePod™ Biofilter System Performance Certification Project, Oldcastle, Inc. and Herrera Environmental Consultants, Inc., February 2018 Technical Memorandum: Response to Board of External Reviewers’ Comments on the Technical Evaluation Report for the TreePod™ Biofilter System Performance Certification Project, Oldcastle, Inc. and Herrera Environmental Consultants, Inc., January 2018 Application for Pilot Use Level Designation, TreePod™ Biofilter – Stormwater Treatment System, Oldcastle Stormwater Solutions, May 2016 Emerging Stormwater Treatment Technologies Application for Certification: The TreePod™ Biofilter, Oldcastle Stormwater Solutions, April 2016 Applicant’s Use Level Request:  General Use Level Designation as a Basic, Enhanced, and Phosphorus Treatment device in accordance with Ecology’s Stormwater Management Manual for Western Washington Applicant’s Performance Claims: Based on results from laboratory and field-testing, the applicant claims the BioPod™ Biofilter operating at a hydraulic loading rate of 153 inches per hour is able to remove:  80% of Total Suspended Solids (TSS) for influent concentrations greater than 100 mg/L and achieve a 20 mg/L effluent for influent concentrations less than 100 mg/L.  60% dissolved zinc for influent concentrations 0.02 to 0.3 mg/L.  30% dissolved copper for influent concentrations 0.005 to 0.02 mg/L.  50% or greater total phosphorus for influent concentrations 0.1 to 0.5 mg/L. Ecology’s Recommendations: Ecology finds that:  Oldcastle Infrastructure, Inc. has shown Ecology, through laboratory and field testing, that the BioPod™ Biofilter is capable of attaining Ecology’s Basic, Total Phosphorus, and Enhanced treatment goals. Findings of Fact: Field Testing 1. Herrera Environmental Consultants, Inc. conducted monitoring of the BioPod™ Biofilter at the Lake Union Ship Canal Test Facility in Seattle Washington between November 2016 and April 2018. Herrera collected flow-weight composite samples during 14 separate storm events and peak flow grab samples during 3 separate storm events. The system was sized at an infiltration rate of 153 inches per hour or a hydraulic loading rate of 1.6 gpm/ft2. 2. The D50 of the influent PSD ranged from 3 to 292 microns, with an average D50 of 28 microns. 3. Influent TSS concentrations ranged from 17 mg/L to 666 mg/L, with a mean concentration of 98 mg/L. For all samples (influent concentrations above and below 100 mg/L) the bootstrap estimate of the lower 95 percent confidence limit (LCL 95) of the mean TSS reduction was 84% and the bootstrap estimate of the upper 95 percent confidence limit (UCL95) of the mean TSS effluent concentration was 8.2 mg/L. 4. Dissolved copper influent concentrations from the 17 events ranged from 9.0 µg/L to 21.1 µg/L. The 21.1 µg/L data point was reduced to 20.0 µg/L, the upper limit to the TAPE allowed influent concentration range, prior to calculating the pollutant removal. A bootstrap estimate of the LCL95 of the mean dissolved copper reduction was 35%. 5. Dissolved zinc influent concentrations from the 17 events ranged from 26.1 µg/L to 43.3 µg/L. A bootstrap estimate of the LCL95 of the mean dissolved zinc reduction was 71%. 6. Total phosphorus influent concentrations from the 17 events ranged from 0.064 mg/L to 1.56 mg/L. All influent data greater than 0.5 mg/L were reduced to 0.5 mg/L, the upper limit to the TAPE allowed influent concentration range, prior to calculating the pollutant removal. A bootstrap estimate of the LCL95 of the mean total phosphorus reduction was 64%. 7. The system experienced rapid sediment loading and needed to be maintained after 1.5 months. Monitoring personnel observed similar sediment loading issues with other systems evaluated at the Test Facility. The runoff from the Test Facility may not be indicative of maintenance requirements for all sites. Laboratory Testing 1. Good Harbour Laboratories (GHL) conducted laboratory testing at their site in Mississauga, Ontario in October 2017 following the New Jersey Department of Environmental Protection Laboratory Protocol for Filtration MTDs. The testing evaluated a 4-foot by 6-foot standard biofiltration chamber and inlet contour rack with bypass weir. The test sediment used during the testing was custom blended by GHL using various commercially available silica sands, which had an average d50 of 69 µm. Based on the lab test results: a. GHL evaluated removal efficiency over 15 events at a Maximum Treatment Flow Rate (MTFR) of 37.6 gpm, which corresponds to a MTFR to effective filtration treatment area ratio of 1.80 gpm/ft2. The system, operating at 100% of the MTFR with an average influent concentration of 201.3 mg/L, had an average removal efficiency of 99 percent. b. GHL evaluated sediment mass loading capacity over an additional 16 events using an influent SSC concentration of 400 mg/L. The first 11 runs were evaluated at 100% of the MTFR. The BioPod began to bypass, so the remaining 5 runs were evaluated at 90% of the MTFR. The total mass of the sediment captured was 245.0 lbs and the cumulative mass removal efficiency was 96.3%. 2. Herrera Environmental Consultants Inc. conducted laboratory testing in September 2014 at the Seattle University Engineering Laboratory. The testing evaluated the flushing characteristics, hydraulic conductivity, and pollutant removal ability of twelve different media blends. Based on this testing, Oldcastle Infrastructure, Inc. selected one media blend, Mix 8, for inclusion in their TAPE evaluation of the BioPod™ Biofilter. a. Herrera evaluated Mix 8 in an 8-inch diameter by 36-inch tall polyvinyl chloride (PVC) column. The column contained 18-inches of Mix 8 on top of 6-inches of pea gravel. The BioPod will normally include a 3-inch mulch layer on top of the media layer; however, this was not included in the laboratory testing. b. Mix 8 has a hydraulic conductivity of 218 inches per hour; however, evaluation of the pollutant removal ability of the media was based on an infiltration rate of 115 inches per hour. The media was tested at 75%, 100%, and 125% of the infiltration rate. Based on the lab test results:  The system was evaluated using natural stormwater. The dissolved copper and dissolved zinc concentrations in the natural stormwater were lower than the TAPE influent standards; therefore, the stormwater was spiked with 66.4 mL of 100 mg/L Cu solution and 113.6 mL of 1,000 mg/L Zn solution.  The BioPod removed an average of 81% of TSS, with a mean influent concentration of 48.4 mg/L and a mean effluent concentration of 9.8 mg/L.  The BioPod removed an average of 94% of dissolved copper, with a mean influent concentration of 10.6 µg/L and a mean effluent concentration of 0.6 µg/L.  The BioPod removed an average of 97% of dissolved zinc, with a mean influent concentration of 117 µg/L and a mean effluent concentration of 4 µg/L.  The BioPod removed an average of 97% of total phosphorus, with a mean influent concentration of 2.52 mg/L and a mean effluent concentration of 0.066 mg/L. When total phosphorus influent concentrations were capped at the TAPE upper limit of 0.5 mg/L, calculations showed an average removal of 87%. Other BioPod Related Issues to be Addressed By the Company: 1. Conduct hydraulic testing to obtain information about maintenance requirements on a site with runoff that is more typical of the Pacific Northwest. Technology Description: Download at https://oldcastleprecast.com/stormwater/bioretention- biofiltration-applications/bioretention-biofiltration- solutions/ Contact Information: Applicant: Chris Demarest Oldcastle Infrastructure, Inc. (925) 667-7100 Chris.demarest@oldcastle.com Applicant website: https://oldcastleprecast.com/stormwater/ Ecology web link: https://ecology.wa.gov/Regulations-Permits/Guidance-technical- assistance/Stormwater-permittee-guidance-resources/Emerging-stormwater-treatment- technologies Ecology: Douglas C. Howie, P.E. Department of Ecology Water Quality Program (360) 407-6444 douglas.howie@ecy.wa.gov Revision History Date Revision March 2018 GULD granted for Basic Treatment March 2018 Provisional GULD granted for Enhanced and Phosphorus Treatment June 2016 PULD Granted April 2018 GULD for Basic and Provisional GULD for Enhanced and Phosphorus granted, changed name to BioPod from TreePod July 2018 GULD for Enhanced and Phosphorus granted September 2018 Changed Address for Oldcastle December 2018 Added minimum media thickness requirement May 2019 Changed language on who must Install and maintain the device from Oldcastle to Applicants