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Home My WebLink AboutTIR-4128 Western Washington Division Eastern Washington Division 165 NE Juniper St., Ste 201, Issaquah, WA 98027 108 East 2nd Street, Cle Elum, WA 98922 Phone: (425) 392-0250 Fax: (425) 391-3055 Phone: (509) 674-7433 Fax: (509) 674-7419 www.EncompassES.net TECHNICAL INFORMATION REPORT For Cherie Lane Short Plat 34XX Talbot Road S Renton, WA 98055 Preliminary March 27, 2018 Civil Construction: July 31, 2020 (Revised September 2, 2020) 9/2/2020 Prepared by: Briana Bennington Encompass Engineering Job No. 20521 Prepared For: Ram Singh 10616 SE 268th Street Kent, WA 98030 APPROVED 10/14/2020 msippo DEVELOPMENT ENGINEERING DIVISION SURFACE WATER UTILITY jfarah 10/15/2020 Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | i Table of Contents List of Figures ................................................................................................................................... i I. PROJECT OVERVIEW ................................................................................................................ 1 II. CONDITIONS AND REQUIREMENTS SUMMARY ...................................................................... 8 III. DOWNSTREAM ANALYSIS ...................................................................................................... 16 IV. FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN ........................... 22 V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN ..................................................................... 27 VI. SPECIAL REPORTS AND STUDIES ............................................................................................ 30 VII. OTHER PERMITS ..................................................................................................................... 30 VIII. CONSTRUCTION STORMWATER GENERAL PERMIT............................................................... 30 IX. BOND QUANTITIES and DECLARATION of COVENANT .......................................................... 30 X. OPERATION AND MAINTENANCE MANUAL .......................................................................... 30 List of Figures Figure 1 – TIR Worksheet Figure 2 – Vicinity Map Figure 3 – Soils Map and Legend Figure 4 – Existing Conditions Map Figure 5 – Developed Conditions Map Figure 6 – Drainage Review Flow Chart Figure 7 – Downstream Map Figure 8 – Off-Site Tributary Basin Appendix A Geotechnical Engineering Study by Earth Solutions NW, LLC dated July 15, 2016. Appendix B Coal Mine Hazard Assessment by Icicle Creek Engineers, Inc. dated December 27, 2016. Appendix C Wetland Delineation and Classification by Altman Oliver Associates, LLC dated December 14, 2017. Appendix D Tree Health Report by Arborists NW, LLC dated December 27, 2016. Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | ii Appendix E WWHM Output Appendix F Bond Quantity Worksheet Appendix G Operation and Maintenance Manual Appendix H Oldcastle BioPod Design Information KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 1 PROJECT OWNER AND PROJECT ENGINEER Part 2 PROJECT LOCATION AND DESCRIPTION Project Owner ___________________________ Phone _________________________________ Address _______________________________ _______________________________________ Project Engineer _________________________ Company ______________________________ Phone _________________________________ Project Name _________________________ DPER Permit # ________________________ Location Township ______________ Range ________________ Section ________________ Site Address __________________________ _____________________________________ Part 3 TYPE OF PERMIT APPLICATION Part 4 OTHER REVIEWS AND PERMITS  Landuse (e.g.,Subdivision / Short Subd. / UPD)  Building (e.g.,M/F / Commercial / SFR)  Clearing and Grading  Right-of-Way Use  Other _______________________  DFW HPA  COE 404  DOE Dam Safety  FEMA Floodplain  COE Wetlands  Other ________  Shoreline Management  Structural Rockery/Vault/_____  ESA Section 7 Part 5 PLAN AND REPORT INFORMATION Technical Information Report Site Improvement Plan (Engr. Plans) Type of Drainage Review (check one): Date (include revision dates): Date of Final:  Full  Targeted  Simplified  Large Project  Directed ____________________________________ __________________ Plan Type (check one): Date (include revision dates): Date of Final:  Full  Modified  Simplified ____________________________________ __________________ Part 6 SWDM ADJUSTMENT APPROVALS Type (circle one): Standard / Experimental / Blanket Description: (include conditions in TIR Section 2) ____________________________________________________________________________________ ____________________________________________________________________________________ ____________________________________________________________________________________ Approved Adjustment No. ______________________ Date of Approval: ______________________ 2016 Surface Water Design Manual 4/24/2016 1 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 7 MONITORING REQUIREMENTS Monitoring Required: Yes / No Start Date: _______________________ Completion Date: _______________________ Describe: _________________________________ _________________________________________ _________________________________________ Re: KCSWDM Adjustment No. ________________ Part 8 SITE COMMUNITY AND DRAINAGE BASIN Community Plan : ____________________________________________________________________ Special District Overlays: ______________________________________________________________ Drainage Basin: _____________________________________________________________________ Stormwater Requirements: ____________________________________________________________ Part 9 ONSITE AND ADJACENT SENSITIVE AREAS  River/Stream ________________________  Lake ______________________________  Wetlands ____________________________  Closed Depression ____________________  Floodplain ___________________________  Other _______________________________ _______________________________  Steep Slope __________________________  Erosion Hazard _______________________  Landslide Hazard ______________________  Coal Mine Hazard ______________________  Seismic Hazard _______________________  Habitat Protection ______________________  _____________________________________ Part 10 SOILS Soil Type _________________ _________________ _________________ _________________ Slopes _________________ _________________ _________________ _________________ Erosion Potential _________________ _________________ _________________ _________________  High Groundwater Table (within 5 feet)  Other ________________________________  Sole Source Aquifer  Seeps/Springs  Additional Sheets Attached 2016 Surface Water Design Manual 4/24/2016 2 TBD Alderwood gravelly sandy loam KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 11 DRAINAGE DESIGN LIMITATIONS REFERENCE  Core 2 – Offsite Analysis_________________  Sensitive/Critical Areas__________________  SEPA________________________________  LID Infeasibility________________________  Other________________________________  _____________________________________ LIMITATION / SITE CONSTRAINT _______________________________________ _______________________________________ _______________________________________ _______________________________________ _______________________________________ _______________________________________  Additional Sheets Attached Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet per Threshold Discharge Area) Threshold Discharge Area: (name or description) Core Requirements (all 8 apply): Discharge at Natural Location Number of Natural Discharge Locations: Offsite Analysis Level: 1 / 2 / 3 dated:__________________ Flow Control (include facility summary sheet) Level: 1 / 2 / 3 or Exemption Number ____________ Flow Control BMPs _______________________________ Conveyance System Spill containment located at: _________________________ Erosion and Sediment Control / Construction Stormwater Pollution Prevention CSWPP/CESCL/ESC Site Supervisor: _____________________ Contact Phone: _________________________ After Hours Phone: _________________________ Maintenance and Operation Responsibility (circle one): Private / Public If Private, Maintenance Log Required: Yes / No Financial Guarantees and Liability Provided: Yes / No Water Quality (include facility summary sheet) Type (circle one): Basic / Sens. Lake / Enhanced Basic / Bog or Exemption No. ______________________ Landscape Management Plan: Yes / No Special Requirements (as applicable): Area Specific Drainage Requirements Type: CDA / SDO / MDP / BP / LMP / Shared Fac. / None Name: ________________________ Floodplain/Floodway Delineation Type (circle one): Major / Minor / Exemption / None 100-year Base Flood Elevation (or range): ______________ Datum: Flood Protection Facilities Describe: 2016 Surface Water Design Manual 4/24/2016 3 TBD KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet per Threshold Discharge Area) Source Control (commercial / industrial land use) Describe land use: Describe any structural controls: Oil Control High-use Site: Yes / No Treatment BMP: ________________________________ Maintenance Agreement: Yes / No with whom? ____________________________________ Other Drainage Structures Describe: Part 13 EROSION AND SEDIMENT CONTROL REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION  Clearing Limits  Cover Measures  Perimeter Protection  Traffic Area Stabilization  Sediment Retention  Surface Water Collection  Dewatering Control  Dust Control  Flow Control  Protection of Flow Control BMP Facilities (existing and proposed)  Maintain BMPs / Manage Project MINIMUM ESC REQUIREMENTS AFTER CONSTRUCTION  Stabilize exposed surfaces  Remove and restore Temporary ESC Facilities  Clean and remove all silt and debris, ensure operation of Permanent Facilities, restore operation of Flow Control BMP Facilities as necessary  Flag limits of SAO and open space preservation areas  Other ______________________ Part 14 STORMWATER FACILITY DESCRIPTIONS (Note: Include Facility Summary and Sketch) Flow Control Type/Description Water Quality Type/Description  Detention  Infiltration  Regional Facility  Shared Facility  Flow Control BMPs  Other ________________ ________________ ________________ ________________ ________________ ________________  Vegetated Flowpath  Wetpool  Filtration  Oil Control  Spill Control  Flow Control BMPs  Other ________________ ________________ ________________ ________________ ________________ ________________ ________________ 2016 Surface Water Design Manual 4/24/2016 4 09/02/2020 Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 1 I. PROJECT OVERVIEW Project: Cherie Lane Short Plat Site Address: 34XX Talbot Road S, Renton, WA 98055 (See Vicinity Map) Tax Parcel #: 302305-9108 Zoning District: R-8, Single Family Residential Site Area: 114,813 SF (2.64 Acres) Site Location: The site is in the City of Renton within the SE quarter of Section 30, Township 23 North, Range 5 East, W.M, King County, Washington. The site is located on the east side of Talbot Road South, south of the intersection of Talbot Road South and South 32nd Street. Figure 2: Vicinity Map Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 2 Pre-developed Site Conditions The project site is located in the City of Renton on a 114,813 SF (2.64 Acres) lot that is zoned R-8 (single-family residential). The site is accessed via an existing 30-foot utility easement between Talbot Road South and South 34th Place. The easement contains storm, sewer, and gas utilities extending from Talbot Road South to the Cherie Lane II housing development located east of the project site. The site is bordered to the north, east and west by single-family residences and to the south by an undeveloped parcel. The site is currently undeveloped and predominately forested. The existing utility easement along the north 30-feet of the site is cleared and partially covered with an existing gravel driveway. The property is located within a single drainage basin that slopes to the west at grades between 8 and 25%. Runoff from the existing site generally sheet flows toward Talbot Road South where it is collected in a shallow channel that conveys water to the south along the eastern roadway shoulder. Stormwater is ultimately discharged to Panther Creek, located approximately 900-feet west of the site. See full downstream analysis in Chapter III of this Technical Information Report (TIR). An Existing Conditions Map is included as Figure 4 at the end of this Chapter. Critical Areas The parcel contains an extensive unsubmerged Category IV wetland and associated 50-foot buffer located centrally on the property. This wetland experiences a high groundwater table seasonally, but no ponding was observed during numerous site visits during the wet season. In addition, two off-site wetlands have been identified. A smaller Category IV wetland with associated 50-foot buffer is located north of the site, and a Category III wetland with associated 75-foot buffer has been identified south of the site. A Wetland Delineation and Classification Report has been prepared by Altmann Olives Associates and is provided in Appendix C of this TIR. The southwest portion of the site is located within a Coal Mine Hazard Area and contains four (4) small underground coal mines ranging from low to higher risk. Higher risk areas present a potential risk for subsidence or collapse; therefore, no development should take place in these areas unless proper structural controls are in place. Appurtenances such as driveways, outbuilding, and cleared lawn may be constructed within the moderate hazard areas. Structural development for the proposed residence is allowed within the low hazard areas with proper mitigation. The Coal Mine Hazards Assessment prepared by Icicle Creek Engineers has been included in Appendix B 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 (See Figure 3 on the following page). The Geotechnical Engineering Study prepared by Earth Solutions NW (Appendix A) confirms this soil classification across the site. Bedrock was encountered on-site as depths ranging from 8 to 12-feet below ground surface (BGS). Due to the Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 3 presence of coal mine hazards and the shallow bedrock, the underlying glacial till was found to be unsuitable for stormwater infiltration. Figure 2: Soil Map and Legend Developed Site Conditions The project proposes the development of two (2) single-family lots and a Private Critical Area Tract (Tract A) within the 114,813 SF (2.64 Acres) parcel. Lot 1 is 10,665 SF (0.24 Acres) and is located along the eastern portion of the site with driveway access off of South 34th Place. The 973 SF concrete driveway for Lot 1 is currently being constructed under a separate approved building permit for Parcel # 302305-9022. As part of the Cherie Lane project, frontage improvements for South 34th Place, including a 4.5’ concrete sidewalk, 6” curb, and gutter, are proposed. Lot 2 is 40,197 SF (0.92 Acres) and is located on the western portion of the site with driveway access off of Talbot Road South. A 7,538 SF asphalt driveway with a slope of 15% will be constructed off of Talbot Road South for access to Lot 2. In addition, structural retaining walls and fences will be installed along the northern and southern limits of the proposed driveway cut for Lot 2. The remaining 63,951 SF (1.47 Acres) located centrally on the site will be designated as a Private Critical Area Tract (Tract A). Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 4 The parcel is zoned R-8, which allows for a maximum building coverage of 50% and a maximum impervious surface coverage of 65%. The maximum allowable building/impervious surface for each lot is discussed below: • Lot 1: The maximum allowable building coverage for Lot 1 is 10,665 SF*0.5 = 5,332 SF, and the maximum impervious surface coverage is 10,665 SF*0.65 = 6,932 SF. Approximately 677 SF of the concrete driveway is located within the Lot 1 property limits; therefore approximately 6,255 SF of allowable impervious surface remains for the future construction of a residence and additional impervious surface. However, it is anticipated that the future impervious surface will be much less than this due to the required property line and stormwater BMP setbacks. This report assumes that the future impervious surface required to construct the residence on Lot 1 will be limited to 5,000 SF. • Lot 2: The maximum building coverage for Lot 2 is 40,197 SF*0.5 = 20,099 SF, and the maximum impervious surface coverage is 40,197 SF*0.65 = 26,128 SF. Approximately 7,205 SF of the proposed driveway is located within the Lot 2 property limits; therefore approximately 18,923 SF of allowable impervious surface remains for the future construction of a residence and additional impervious surface. However, it is anticipated that the future impervious surface will be much less than this due to the required property line setbacks and building restrictions over the designated coal mine hazard areas. This report assumes that the future impervious surface required to construct the residence on Lot 2 will be limited to 2,800 SF. • Critical Area Tract A: No development is proposed within the Private Critical Area Tract (Tract A). Stormwater runoff from the proposed development of Lots 1 and 2 will be managed as follows: • Lot 1: A 973 SF concrete driveway on Lot 1 is being constructed under a separate approved building permit for Parcel # 302305-9022. Based on the available records, the driveway is being constructed to drain to the South 34th Place stormwater system, east of Lot 1. In addition, runoff from the proposed frontage improvements for South 34th Place (4.5’ sidewalk, 6” curb, and gutter) will be routed to the existing stormwater system. A future 50-foot full dispersion trench with notched board and 100-foot native vegetated flowpath is proposed on Lot 1 to mitigate stormwater from the future residence and driveway extension. This report assumes that the future impervious surface required to construct the residence on Lot 1 will be limited to 5,000 SF. If the future impervious surface exceeds 5,000 SF on Lot 1, additional stormwater BMPs may be required for building permit approval. Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 5 All new pervious surface created on Lot 1 will be fully dispersed over the 50-foot wetland buffer downstream of the lot. All disturbed, pervious areas of the project will meet soil amendment requirements. • Lot 2: No stormwater BMPs are feasible for Lot 2 due to the presence of steep slopes and coal mine hazards. Runoff from the proposed 7,538 SF asphalt driveway and future residence (up to a maximum of 2,800 SF of additional impervious surface) will be conveyed and discharged to the existing storm system for Talbot Road South. The roof drains will also utilize a perforated pipe connection. If the future impervious surface exceeds 2,800 SF on Lot 2, additional stormwater BMPs may be required for building permit approval. All new pervious surface created on Lot 2 will follow the natural drainage patterns and sheet flow toward Talbot Road South. All disturbed, pervious areas of the project will meet soil amendment requirements. Although no stormwater BMPs are feasible for the Lot 2 driveway, runoff will be treated for basic water quality via an Oldcastle BioPod Biofilter Vault with Internal Bypass (unit BPU-IB-48). Further discussion of the proposed water quality system is included in Chapter IV of this TIR. • Critical Area Tract A: No development is proposed within the Private Critical Area Tract (Tract A). Stormwater will follow the natural drainage pattern and sheet flow toward Talbot Road South. A total Native Growth Retention Area (NGRA) of 52,830 SF has been designated on the engineering plan set. The proposed NGRA encompasses approximately 675 SF of Lot 1 and 52,155 SF of the Private Critical Area Tract (Tract A). Please refer to Core Requirement # 9 in Chapter II and Chapter IV of this TIR for additional discussion on stormwater BMPs and NGRA calculations. A Developed Conditions Map is provided as Figure 5 at this end of this Chapter. Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 8 II. CONDITIONS AND REQUIREMENTS SUMMARY The 2017 City of Renton Surface Water Design Manual (RSWDM) was utilized to determine and address all core and special requirements. Based on the criteria specified in Figure 1.1.2.A of the RSWDM, the project falls under Full Drainage Review. Per Section 1.1.2.4 of the RSWDM, the project must meet all nine (9) core and all six (6) special requirements. See Figure 6 below for more information on how the type of drainage review was determined. Figure 6: Drainage Review Flow Chart Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 9 Core Requirements Core Requirement #1: Discharge at the Natural Location The proposed development runoff will follow existing drainage patterns that flow west towards the adjacent Talbot Road South storm system. Refer to the Level 1 Downstream Analysis in Chapter III of this TIR for a complete description of the existing drainage path. Core Requirement #2: Downstream 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 Chapter 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 (forested condition). Flow control facilities are required 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. The proposed stormwater BMPs result in a 0.1472 CFS increase in the 100-year flow using 15-minutes time steps. This is below the allowable threshold of a 0.15 CFS maximum increase per Section 1.2.3.1.B of the RSWDM; therefore, the project meets flow control exemption 2. No formal flow control facilities are proposed at this time; however, flow control BMPs will be implemented as described in Core Requirement #9. Please refer to Chapter IV of this TIR for additional discussion. Core Requirement #4: Conveyance System The existing conveyance system was analyzed to determine compliance with the requirements detailed in Section 1.2.4.1 of the City of Renton 2017 SWDM. Full conveyance system analysis for the 25-year storm is provided in Chapter V of this TIR. Core Requirement #5: Construction Stormwater Pollution Prevention The limits of construction for the project are less than 1 acre. A temporary erosion and sediment control (TESC) plan providing details on best management practices (BMPs) to be implemented during construction is included in the engineering plan set. A Construction Stormwater Pollution Prevention Plan (CSWPPP) has also been prepared by Encompass Engineering. Please refer to Chapter VIII of this TIR for additional discussion. Core Requirement #6: Maintenance and Operations An Operation and Maintenance Manual has been prepared for the project. Please refer to Chapter X of this TIR for additional discussion. Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 10 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 F. Core Requirement #8: Water Quality Facilities In accordance with Section 1.2.8.1.A of the RSWDM, Basic Water Quality Treatment is required for this project. An Oldcastle BioPod Biofilter Vault with Internal Bypass (unit BPU-IB-48) is proposed to treat runoff from the 7,538 SF Lot 2 driveway. Please refer to Appendix H for the DOE GULD approval and Oldcastle BioPod Details and sizing tables. Further discussion of the proposed water quality system is included in Chapter IV of this TIR. Core Requirement #9: Flow Control BMPs This project is classified as a small urban subdivision; therefore, it is subject to the Small Road Improvement and Urban Road Improvement Project BMP Requirements detailed in Section 1.2.9.3.2 in the RSWDM. Although implementation of individual lot BMPs is not required until building permit application, BMPs have been considered for the future improvements on Lots 1 and 2 based on Section 1.2.9.2 and of the RSWDM. See Chapter IV of this TIR for further discussion and flow control analysis. Impervious Surface BMPs Full Dispersion: Feasible for Lot 1; Infeasible for Lot 2. • Lot 1: A 973 SF concrete driveway on Lot 1 is being constructed under a separate approved building permit for Parcel # 302305-9022. Based on the available records, the driveway is being constructed to drain to the South 34th Place stormwater system. Therefore, collection and conveyance for full dispersion is not proposed. A future 50-foot full dispersion trench with notched board and 100-foot native vegetated flowpath is feasible to mitigate stormwater from the future construction of a residence and driveway extension on Lot 1. This report assumes that the future impervious surface required to construct the residence and driveway extension on Lot 1 will be limited to 5,000 SF. If the future impervious surface exceeds 5,000 SF on Lot 1, additional stormwater BMPs may be required for building permit approval. The trench will fully disperse 5,000 SF of tributary impervious surface; therefore, a (5,000 SF)/.15 = 33,333 SF Native Growth Retention Area (NGRA) for full dispersion is required for Lot 1. Approximately 675 SF of the required NGRA will be on Lot 1, and the remaining area will be designated within the Private Critical Area Tract (Tract A). • Lot 2: Per conversations with the City of Renton on March 4, 2020, dispersion will not be considered as a feasible BMP for Lot 2 due to the presence of steep slopes greater than 20% and high coal mine hazards downstream of the proposed development. In Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 11 addition, the required 100-foot flowpath is not available downstream of the proposed driveway. Full Infiltration: Infeasible for Lots 1 and 2 • Lots 1 and 2: The Geotechnical Engineering Study prepared by Earth Solutions Northwest (Appendix A) states that infiltration is infeasible at the site due to the shallow bedrock layer and the presence of coal mine hazards. Limited Infiltration: Infeasible for Lots 1 and 2 • Lots 1 and 2: The Geotechnical Engineering Study prepared by Earth Solutions Northwest (Appendix A) states that infiltration is infeasible at the site due to the shallow bedrock layer and the presence of coal mine hazards. Bioretention: Infeasible for Lots 1 and 2 • Lots 1 and 2: Bioretention relies on infiltration to function properly. The Geotechnical Engineering Study prepared by Earth Solutions Northwest (Appendix A) states that infiltration is infeasible at the site due to the shallow bedrock layer and the presence of coal mine hazards. Permeable Pavement: Infeasible for Lots 1 and 2 • Lots 1 and 2: The Geotechnical Engineering Study prepared by Earth Solutions Northwest (Appendix A) states that infiltration is infeasible at the site due to the shallow bedrock layer and the presence of coal mine hazards. Basic Dispersion: Infeasible for Lots 1 and 2 • Lot 1: A 973 SF concrete driveway on Lot 1 is being constructed under a separate approved building permit for Parcel # 302305-9022. Based on the available records, the driveway is being constructed to drain to the South 34th Place stormwater system. Therefore, collection and conveyance for basic dispersion is not proposed. • Lot 2: Per conversations with the City of Renton on March 4, 2020, dispersion will not be considered as a feasible BMP for Lot 2 due to the presence of steep slopes greater than 20% and high coal mine hazards downstream of the proposed development. Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 12 Reduced Impervious Surface Credit: Infeasible for Lot 2 • Lot 2: The required driveway for Lot 2 exceeds the maximum impervious area threshold of 4,000 SF, which is required for eligibility for a reduced impervious surface credit. Native Growth Retention Credit: Feasible for Lots 1 and 2 • Per Section 1.2.9.3.2 of the RSWDM, NGRA credits are not an allowable BMP for improvements within the right-of-way for Talbot Road South and South 34th Place that do not drain to a pervious surface. However, it is feasible to utilize NGRA credits for the proposed/future residence on Lot 2 if a perforated pipe connection is utilized. This report assumes that the future impervious surface required to construct the residence on Lot 2 will be limited to 2,800 SF. If the future impervious surface exceeds 2,800 SF on Lot 2, additional stormwater BMPs may be required for building permit approval. This total impervious area seeking an NGRA credit is 2,800 SF; therefore, a 2,800 SF*3.5 = 9,800 SF NGRA is required for the proposed NGRA credits. The total NGRA required to mitigate stormwater from Lots 1 and 2 is 33,333 SF + 9,800 SF = 43,133 SF. A 52,830 SF NGRA is proposed, which exceeds the minimum requirement. The proposed NGRA encompasses approximately 675 SF of Lot 1 and 52,155 SF of the Private Critical Area Tract (Tract A). Pervious Surface BMPs Full Dispersion: Feasible for Lot 1; Infeasible for Lot 2 • Lot 1: All new pervious surface created on Lot 1 will be fully dispersed over the 50- foot wetland buffer downstream of the lot. • Lot 2: The required native vegetated flowpath is not available downstream of the new pervious surface on Lot 2. Soil Amendment: Feasible for Lots 1 and 2 • Lots 1 and 2: All disturbed, pervious areas of the project will meet soil amendment requirements as detailed in Section C.2.13 of the RSWDM. Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 13 Special Requirements 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 within a delineated FEMA 100-year floodplain. Special Requirement #3: Flood Protection Facilities This project does not rely on or propose to modify/construct a new flood protection facility. Special Requirement #4: Source controls The project is a single-family residential development; therefore, this requirement is not applicable. Special Requirement #5: Oil Control This project is not considered high-use in need of oil control. Special Requirement #6: Aquifer Protection Area The site is not located within an aquifer protection area; therefore, this requirement is not applicable. Conditions of Approval Per the Administrative Report and Decision received from the City of Renton Department of Community and Economic Development on April 27, 2018, the following conditions of approval were identified: 1. A detailed landscape plan meeting the requirements of RMC 4-8-120D.12 shall be submitted at the time of Construction Permit review for review and approval by the Current Planning Project Manager. A Landscape Plan has been prepared and is included in the civil design plans. 2. A final Tree Retention and Replacement Plan shall be submitted at the time of Construction Permit application for review and approval by the Current Planning Project Manager. The final Tree Retention and Replacement Plan shall include the planting of a minimum of 24 minimum 2 inch caliper replacement trees and a minimum of two trees per 5,000 square feet of lot area for compliance with the minimum tree density Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 14 requirements and shall include a tree protection tract for those trees that do not count towards an individual lot’s minimum tree density requirements. The NGPA tract may be extended to encompass the additional protected trees if feasible. A Tree Retention and Replacement Plan has been prepared and is included in the civil design plans. 3. Development of the project site shall comply with the recommendation provided in the Coal Mine Hazard Assessment, prepared by Icicle Creek Engineers, Inc., dated December, 27, 2016. The proposed development has been designed to comply with the recommendations in the Coal Mine Hazards Assessment. Per Section 8.0 of the Icicle Creek Report, no development shall occur within the Higher Risk Zones, with the exception of driveways that have been designed to structurally bridge or otherwise mitigate for the coal mine hazards. Roads, driveways, outbuildings, yards and periodic use are permitted to be developed within the Moderate Risk Zones. Structural development within the Low Hazard Zone is permitted with the recommended mitigation measures. The following mitigation strategies have been implemented for the proposed house footprints: • Small, square-shaped building pads. • A note has been added to the civil design plans specifying that future houses are required to be constructed on conventional reinforced-concrete spread footings with crawl-space construction, rather than slab-on-grade. No basement construction is permitted. • Underground utilities within the Low Hazard Areas have been designed with flexible couplings and fittings. 4. A note shall be recorded on the face of the final short plat map identifying and delineating the coal mine hazard areas on the project site. A note has been recorded on the final short plat map identifying the coal mine hazard areas and associated risks on the project site. 5. The applicant shall include the required frontage improvements along Talbot Road South on the construction plan submittal or submit a modification request and obtain approval of the modification to reduce the required improvements along Talbot Road South. The modification request or modified civil plans shall be submitted at the time of Construction Permit review to the City’s Plan Reviewer for review and approval. The project does not propose to construct frontage improvements for Talbot Road South. There is no adequate space along the site’s 30-feet of frontage to install the necessary Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 15 improvements. However, the proposed driveway has been designed to accommodate the future construction of frontage improvements along Talbot Road South. A modification to reduce the required improvements along Talbot Road South has been submitted under separate cover with this submittal. 6. The applicant shall include the required frontage improvements along S 34th Place. S 34th Place is classified as a Residential Access Street, per RMC 4-6-060, half street frontage improvements will be required to be built along the S 34th Place frontage, including paving, curb and gutter, and sidewalk. The project proposes to install frontage improvements along South 34th Place, which includes a 4.5’ sidewalk with 6” curb/gutter. The proposed frontage improvements are consistent with the existing frontage for the Cherie Lane II housing development located off of South 34th Street. Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 16 III. DOWNSTREAM ANALYSIS A Level 1 Downstream analysis has been conducted per the requirements in Section 1.2.2.1 of the RSWDM. Please see Tasks 1 through 4 below for a summary of the results. Task 1: Define and Map the Study Area The area of analysis extends from the site discharge point along Talbot Road South to approximately a quarter-mile downstream of the site in Panther Creek. A Downstream Map is provided in Figure 7 below. Figure 7: Downstream Map Task 2: Review All Available Information on the Study Area Per King county resources, there have been no significant drainage complaints since 1992 within a quarter-mile downstream of the site. The only drainage complaint on record with King County is from the neighboring parcel located immediately to the west of the subject site. The complaint dated back to 1992 and was for flooding of the ditch along Talbot Road South. Task 3: Field Inspect the Study Area A field inspection was performed by Encompass Engineering & Surveying on May 11, 2016. Please refer to Task 4 for a detailed description of the downstream drainage system and analysis. Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 17 Task 4: Describe the Drainage System Runoff from the site generally sheet flows to the west toward the Talbot Road South right-of-way (A). From there, runoff is conveyed to the south along the eastern roadway shoulder via a shallow channel toward a Type 1 Catch Basin (B). Note that there is also an 18-inch storm pipe sloped at 1.5% buried beneath the shallow channel that conveys offsite flows to Catch Basin Element B. The flows from the channel and the storm pipe converge at this point. Flow is then conveyed to the west underneath Talbot Road South via a buried 12-inch concrete pipe (C) to a heavily wooded lot owned by the City of Renton (D). Flow is discharged at Outfall OUT-0498 into the wooded lot where it is then conveyed via a shallow channel until it ultimately discharges into Panther Creek (E). Panther Creek continues to flow to the north. This is where the analysis was completed, approximately a quarter-mile downstream of the site. Please refer to Figure 7 above, for the approximate location of identified drainage features. If conveyance system nuisance, severe erosion, severe flooding, or wetland hydrology problems are identified downstream of the site under Core Requirement #2, additional impact analysis and/or mitigation may be required. As discussed in Task 2, there have been no recent significant drainage complaints within a quarter-mile downstream of the site. The only drainage complaint on record with King County dates back to 1992 and is for flooding of the ditch along Talbot Road South near the neighboring parcel. During the site visit completed by Encompass Engineering & Surveying on May 11, 2016, there were no apparent on-site or downstream drainage issues observed. It appears that the drainage complaint from 1992 has been corrected, as no signs of erosion or standing water were observed along the Talbot Road South ditch or associated drainage systems. As no existing drainage or conveyance issues have been recently identified, further impact analysis and mitigation of the downstream stormwater system is not required. Please refer to the conveyance analysis in Section V of this TIR for additional discussion and evaluation of the on-site conveyance system capacity. Photographs from the site visit are included below. Photo 1: Eastern property limit (looking west) Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 18 Photo 2: Heavily wooded region of the property Photo 3: Cleared zone containing lawn along drainage easement location. Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 19 Photo 4: Western property limit and Talbot Rd S right-of-way Photo 5: Shallow channel along east side of Talbot Rd S Shallow Channel Downstream flow path Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 20 Photo 6: Shallow channel along east side of Talbot Rd S Photo 7: Catch Basin downstream of subject property (within Talbot Rd S right-of-way) Approx. location of Catch Basin Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 21 Photo 8: Wooded area owned by City of Renton along west side of Talbot Rd S Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 22 IV. FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN Part A: Existing Site Hydrology The 114,813 SF (2.64 Acres) site is currently undeveloped and predominately forested. The existing utility easement along the north 30-feet of the site is cleared and partially covered with a gravel driveway. The property is located within a single drainage basin that slopes to the west at grades between 8 and 15%. Runoff from the existing site generally sheet flows toward Talbot Road South where it is collected in a shallow channel that conveys water to the south along the eastern roadway shoulder. Stormwater is ultimately discharged to Panther Creek, located approximately 900-feet west of the site. See full downstream analysis in Chapter III of this TIR. Per the Geotechnical Engineering Study prepared by Earth Solutions NW (Appendix A) on-site soils have been classified as Alderwood Gravelly Sandy Loam. WWHM 2012 was used to model the existing condition within the 34,591 SF (0.793 AC) limits of disturbance as 100% forested with moderate slopes over Type C soils. Note that the off-site frontage improvements along S 34th Place have been excluded from the model, as the S 34th Place Detention Vault was originally designed to accommodate the runoff from the improved frontage. Part B: Developed Site Hydrology The project proposes the development of two (2) single-family lots with a Private Critical Area Tract (Tract A) within the 114,813 SF (2.64 Acres) parcel. Lot 1 is 10,665 SF (0.24 Acres) and is located along the eastern portion of the site with driveway access off of South 34th. Lot 2 is 40,197 SF (0.92 Acres) and is located on the western portion of the site with driveway access off of Talbot Road South. The remaining 63,951 SF (1.47 Acres) located centrally on the site will be designated as a Private Critical Area Tract (Tract A). An additional 1,645 SF (0.04 AC) of off-site area will be improved as part of this project. Stormwater runoff from the proposed development of Lots 1 and 2 will be managed as follows: • Lot 1: A 973 SF concrete driveway for Lot 1 is being constructed under a separate approved building permit for Parcel # 302305-9022. Based on the available records, the driveway is being constructed to drain to the South 34th Place stormwater system, east of Lot 1. In addition, runoff from the proposed 353 SF of off-site frontage improvements for South 34th Place (4.5’ sidewalk, 6” curb, and gutter) will be routed to the existing stormwater system. A future 50-foot full dispersion trench with notched board and 100-foot native vegetated flowpath is proposed on Lot 1 to mitigate stormwater from the future residence/driveway extension. This report assumes that the future impervious surface required to construct the residence on Lot 1 will be limited to 5,000 SF. If the future impervious surface exceeds 5,000 SF on Lot 1, additional stormwater BMPs may be required for building permit approval. Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 23 All new pervious surface created on Lot 1 will be fully dispersed over the 50-foot wetland buffer downstream of the lot. All disturbed, pervious areas of the project will meet soil amendment requirements. • Lot 2: No stormwater BMPs are feasible for Lot 2 due to the presence of steep slopes and coal mine hazards. Runoff from the proposed 7,538 SF asphalt driveway and future residence (up to a maximum of 2,800 SF of additional impervious surface) will be conveyed and discharged to the existing storm system for Talbot Road South. A perforated pipe connection to the stormwater system will be utilized for the roof-top drainage. If the future impervious surface exceeds 2,800 SF on Lot 2, additional stormwater BMPs may be required for building permit approval. All new pervious surface created on Lot 2 will follow the natural drainage patterns and sheet flow toward Talbot Road South. All disturbed, pervious areas of the project will meet soil amendment requirements. • Critical Area Tract A: No development is proposed within the Private Critical Area Tract (Tract A). Stormwater will follow the natural drainage pattern and sheet flow toward Talbot Road South. WWHM 2012 was used to model the proposed condition as follows: • Lot 1: The modeled limits of disturbance for Lot 1 is 10,206 SF. The 5,000 SF of future impervious surface being fully dispersed has been modeled as forest per Table 1.2.9.A in the RSWDM. A 973 SF concrete driveway is being discharged to the South 34th Place storm system and has been modeled as flat road. The remaining 4,233 SF of new pervious surface created on Lot 1 will be fully dispersed over the 50-foot wetland buffer downstream of the lot; therefore, it has been modeled as forest. Note that the off-site frontage improvements along S 34th Place have been excluded from the modeled limits of disturbance, as the S 34th Place Detention Vault was originally designed to accommodate the runoff from the improved frontage. • Lot 2: The modeled limits of disturbance for Lot 2 is 24,385 SF. The 2,800 SF of future house footprint being discharged to the Talbot Road South storm system via a perforated pipe connection will receive an NGRA credit. The future roof area has therefore been modeled as 50% lawn and 50% impervious per Table 1.2.9.A in the RSWDM. The 7,538 SF of asphalt driveway being discharged to the Talbot Road South storm system has been modeled as moderate road. The remaining 14,047 SF of new pervious surface on Lot 2 will meet the soil amendment requirements as detailed in Section C.2.13 of the RSWDM; therefore, it has been modeled as 100% pasture. Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 24 Please refer to Core Requirement #9 in Chapter II of the TIR for additional discussion and NGRA credit calculations. A Developed Conditions Map is provided as Figure 5. A summary of the existing and developed analyses is provided in the table below: WWHM Model Area Description Size Existing Condition Developed Condition Lot 1 Potential House Footprint (Full Dispersion) 5,000 SF (0.115 AC) Modeled as 100% Forest Modeled as 100% Moderate Forest (0.115 AC) Lot 1 Driveway 973 SF (0.022 AC) Modeled as 100% Forest Modeled as 100% Flat Driveway (0.022 AC) Lot 1 Lawn (Full Dispersion) 4,233 SF (0.097 AC) Modeled as 100% Forest Modeled as 100% Moderate Forest (0.097 AC) Lot 2 Potential House Footprint (NGRA Credit) 2,800 SF (0.064 AC) Modeled as 100% Forest Modeled as 50% Flat Roof (0.032 AC) and 50% Moderate Lawn (0.032 AC) Lot 2 Driveway 7,538 SF (0.173 AC) Modeled as 100% Forest Modeled as 100% Moderate Driveway (0.173 AC) Lot 2 Lawn (Soil Amendment) 14,047 SF (0.322 AC) Modeled as 100% Forest Modeled as 100% Moderate Pasture (0.322 Acres) TOTAL LIMITS OF DISTURBANCE 34,591 SF (0.793 AC) See Above See Above Part C: Performance Standards Based on the City of Renton’s flow control map, the project site is located within the Duration Flow Control Area (forested condition). 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 are required 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. In addition, the site is located within the UGA and is larger than 22,000 SF. Therefore, the site is subject to the Large Lot BMP Requirements detailed in Section 1.2.9.2.2 of the RSWDM. In accordance with Section 1.2.8.1.A of the RSWDM, Basic Water Quality Treatment is required for this project. Part D: Flow Control System As shown in the table on the following page, the proposed stormwater BMPs result in a 0.1472 CFS increase in the 100-year flow using 15-minutes time steps. This is below the allowable threshold of a 0.15 CFS maximum increase per Section 1.2.3.1.B of the RSWDM; therefore, the Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 25 project meets flow control exemption 2. No formal flow control facilities are proposed at this time; however, flow control BMPs will be implemented as described in Core Requirement #9 in Chapter II of this TIR. Please refer to Appendix E for a copy of the full WWHM data output. Part E: Water Quality System The project proposes 8,511 SF of pollution generating impervious surface (PGIS), which is greater than the 5,000 SF threshold. Water quality treatment is therefore required for this project. The 973 SF of new PGIS for the Lot 1 driveway is being constructed under a separate approved building permit for Parcel # 302305-9022. Based on the available records, the Lot 1 driveway will drain directly to the existing stormwater system in South 34h Place; therefore, water quality measures are not proposed for the 973 SF of new PGIS for Lot 1. Basic water quality treatment will be provided for the 7,538 SF (0.173 AC) of new PGIS for Lot 2 in accordance with Section 1.2.8.1.A of the RSWDM. The 7,538 SF (0.173 AC) of PGIS from the driveway on Lot 2 has been modeled in WWHM to determine the design flow rate for the proposed water quality treatment system. Please refer to the table below for a summary of the results. The full WWHM output has been included in Appendix E. The standard water quality flow rate for the on-line facility was determined using WWHM to be 0.0313 cfs. As required in Section 6.2.1 of the 2017 RSWDM, the standard flow rate must be corrected in accordance with Table 6.2.1.A of the 2017 RSWDM. Based on the 2-Year 24-hour isopluvial map for western Washington, the 2-year 24-hour precipitation is approximately 1.95 Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 26 inches. The 6-month 24-hour precipitation is 1.95-inches x 72% = 1.40-inches. Per the equation provided in Table 6.2.1.A of the 2017 RSWDM: 𝑘=1.4366(𝑃6−𝑚𝑚𝑚𝑡ℎ)−0.1369 = 1.4366(1.40)−0.1369 =1.87 Therefore, the corrected design water quality flow rate is (0.0313)(1.87) = 0.0585 cfs. This is the flow rate that was used to size the water quality treatment system for the project. The PGIS created from the Lot 2 driveway will be treated with an Oldcastle BioPod Biofilter Vault with Internal Bypass. This treatment method has received DOE GULD approval for basic water quality and does not require a pre-settling facility. Per the Oldcastle BioPod details, unit BPU-IB- 48 has been selected. This unit has exterior dimensions of 5-feet wide, 9-feet long, and 5’ deep, and it has a treatment capacity of 0.086 cfs. This capacity exceeds the corrected design flow rate of 0.0585 cfs for the Lot 2 driveway. Please refer to Appendix H for the DOE GULD approval and Oldcastle BioPod Details and sizing tables. Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 27 V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN A conveyance system analysis was conducted for the on-site and off-site stormwater conveyance system to determine if the increase in flow due to the proposed Cherie Lane development is able to be conveyed by the existing storm system. Detailed stormwater records for the adjacent Cherie Lane II housing development were unavailable from the City of Renton; therefore, the tributary drainage basin has been estimated using King County iMap and City or Renton (COR) Stormwater Utility Maps. As illustrated in Figure 8 below, COR Maps were used to determine that the upstream tributary area to the site is approximately 860,942 SF (19.8 AC). King County iMap contours were also used to confirm the tributary area. Figure 8: Off-Site Tributary Area WWHM was used to model the existing tributary basin. Within the off-site tributary basin, there are approximately 2,943 linear feet of roadway with an approximately 45-foot-wide right-of-way. Therefore, 132,435 SF (3.040 AC) of the basin has been modeled as road/sidewalk. In addition, there is approximately 71,450 SF (1.640 AC) of existing off-site forest within the tributary basin. The remaining off-site basin area was divided equally between 328,529 SF (7.542 AC) of lawn and 328,529 SF (7.542 AC) of rooftop/driveway. The 11,311 SF (0.260 AC) on-site basin was modeled as 100% steep forest in the existing condition. WWHM was also utilized to model the developed conditions. For the purposes of this conveyance analysis, the NGRA credits that were applied for the flow control analysis in Chapter V have not been included. Only the new impervious/pervious surfaces that are proposed to be direct discharged to the existing storm system have been included for the developed condition. Fully dispersed pervious surfaces and replaced impervious surfaces have been excluded from the conveyance analysis model. SITE Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 28 In the developed condition, the following new impervious surfaces were modeled for the on-site basin: the 973 SF (0.022 AC) Lot 1 driveway (modeled as road), the 7,538 SF (0.173 AC) Lot 2 driveway (modeled as road), and the 2,800 SF (0.064 AC) future Lot 2 house footprint (modeled as roof). These are the new impervious areas that are proposed to be directly discharged to the existing storm system. It should also be noted that if the future house on Lot 2 is greater than the estimated 2,800 SF, this conveyance analysis should be updated as part of the individual lot building permit. A summary of the existing and proposed flows into the on-site and off-site stormwater system are provided below. Full WWHM output is provided in Appendix E. Based on the WWHM analysis, the developed discharge during the 25-Year storm is approximately 35.0124 CFS and during the 100-year storm is approximately 51.3938 CFS. As shown in the figures on the following pages, the on-site 18” pipe flowing at 15% slope has a maximum capacity of 51.71 CFS. In accordance with Section 1.2.4.2 of the 2017 RSWDM, the existing on-site pipe shall be capable of conveying the developed 25-year peak flow. The on-site pipe capacity exceeds the 25-year peak flow of 35.0124 CFS by approximately 16.7 CFS. This is more than sufficient to convey the 25-year storm flows from the developed tributary basin. In addition, Section 1.2.4.2 of the RSWDM requires that the applicant demonstrate that the 100- year peak flow will not aggravate a severe flooding or erosion problem. The on-site 18” pipe is capable of conveying the 100-year peak flow of 51.3938 CFS; therefore, no downstream erosion or flooding issues are anticipated. The on-site pipe capacity was calculated using manning’s equation built into an online Conveyance Calculator (shown on the following page). Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 29 In accordance with Section 1.2.4.2 of the 2017 RSWDM, the existing off-site stormwater conveyance system downstream of the site does not need to be evaluated for conveyance capacity except as required by Core Requirement #2. If conveyance system nuisance, severe erosion, severe flooding, or wetland hydrology problems are identified downstream of the site under Core Requirement #2, additional impact analysis and/or mitigation may be required. As described in Section III of this TIR, there have been no recent significant drainage complaints within a quarter-mile downstream of the site. The only drainage complaint on record with King County dates back to 1992 and is for flooding of the ditch along Talbot Road South near the neighboring parcel. During the site visit completed by Encompass Engineering & Surveying on May 11, 2016, there were no apparent on-site or downstream drainage issues observed. It appears that the drainage complaint from 1992 has been corrected, as no signs of erosion or standing water were observed along the Talbot Road South ditch or associated drainage systems. As no existing drainage or conveyance issues have been recently identified, further conveyance analysis of the off-site stormwater conveyance system is not required for this project. Please refer to Section III for additional discussion on the downstream analysis. Cherie Lane Short Plat Technical Information Report 9/2/2020 P a g e | 30 VI. SPECIAL REPORTS AND STUDIES • Geotechnical Engineering Study by Earth Solutions NW, LLC dated July 15, 2016. • Coal Mine Hazard Assessment by Icicle Creek Engineers, Inc. dated December 27, 2016. • Wetland Delineation and Classification by Altman Oliver Associates, LLC dated December 14, 2017. • Tree Health Report by Arborists NW, LLC dated December 27, 2016. VII. OTHER PERMITS • Clearing and Grading Permit • Right-of-Way Use Permit VIII. CONSTRUCTION STORMWATER GENERAL PERMIT A CSWPPP has been prepared and has been included with the civil design package under separate cover. The construction limits for the project are less than 1 acre; therefore, a Construction Stormwater General Permit is not required. IX. BOND QUANTITIES and DECLARATION of COVENANT Bond Quantities are provided in Appendix F of this TIR. The Declaration of Covenant will be provided with project approval. X. OPERATION AND MAINTENANCE MANUAL An Operation and Maintenance Manual is provided in Appendix G of this TIR. Cherie Lane Short Plat Technical Information Report Appendix A Geotechnical Engineering Study by Earth Solutions NW, LLC dated July 15, 2016 EarthSolutionsNWLLC EarthSolutionsNWLLC Geotechnical Engineering Geology Environmental Scientists Construction Monitoring 1805 -136th Place N.E.,Suite 201 Bellevue,WA 98005 (425)449-4704 Fax (425)449-4711 www.earthsolutionsnw.com GEOTECHNICAL ENGINEERING STUDY CHERIE LANE NO.3 RESIDENTIAL SHORT PLAT TALBOT ROAD SOUTH RENTON,WASHINGTON ES-4490 Drwn. Checked Date Date Proj.No. Plate Earth Solutions NWLLC Geotechnical Engineering,Construction Monitoring EarthSolutionsNWLLC EarthSolutionsNWLLC and Environmental Sciences Vicinity Map Cherie Lane #3 Renton,Washington GLS 07/05/2016 4490 BJP July 2016 1 NOTE:This plate may contain areas of color.ESNW cannot be responsible for any subsequent misinterpretation of the information resulting from black &white reproductions of this plate. Reference: King County,Washington Map 656 By The Thomas Guide Rand McNally 32nd Edition NORTH SITE Plate Proj.No. Date Checked By Drwn.ByEarthSolutionsNWLLCGeotechnicalEngineering,ConstructionMonitoringandEnvironmentalSciencesEarthSolutionsNWLLCEarthSolutionsNWLLCTestPitLocationPlanCherieLane#3Renton,WashingtonGLS BJP 07/05/2016 4490 2 LEGEND Approximate Location of ESNW Test Pit,Proj.No. ES-4490,June 2016 Subject Site Proposed Lot Number Areas Delineated By Icicle Engineers,Report ICE File No.1096-001: Higher Risk -High Coal Mine Hazard Area Moderate Risk -High Coal Mine Hazard Area Lower Risk -High Coal Mine Hazard Area Declassified Coal Mine Area NORTH 0 50 100 2 00 Scale in Feet1"=100' NOTE:This plate may contain areas of color.ESNW cannot be responsible for any subsequent misinterpretation of the information resulting from black &white reproductions of this plate. NOTE:The graphics shown on this plate are not intended for design purposes or precise scale measurements,but only to illustrate the approximate test locations relative to the approximate locations of existing and /or proposed site features.The information illustrated is largely based on data provided by the client at the time of our study.ESNW cannot be responsible for subsequent design changes or interpretation of the data by others. TP-1 TP-2 TP-3 TP-4TP-5 TP-6 1 2 3 4 Tract A TP-1 2talbotroadsouth Drwn. Checked Date Date Proj.No. Plate Earth Solutions NWLLC Geotechnical Engineering,Construction MonitoringandEnvironmentalSciences EarthSolutionsNWLLC EarthSolutionsNWLLC RETAINING WALL DRAINAGE DETAIL NOTES: Free Draining Backfill should consist of soil having less than 5 percent fines. Percent passing #4 should be 25 to 75 percent. Sheet Drain may be feasible in lieu of Free Draining Backfill,per ESNW recommendations. Drain Pipe should consist of perforated, rigid PVC Pipe surrounded with 1" Drain Rock. LEGEND: Free Draining Structural Backfill 1 inch Drain Rock 18"Min. Structural Fill Perforated Drain Pipe (Surround In Drain Rock) SCHEMATIC ONLY -NOT TO SCALE NOT A CONSTRUCTION DRAWING Cherie Lane #3 Renton,Washington GLS 07/05/2016 4490 BJP July 2016 3 Drwn. Checked Date Date Proj.No. Plate Earth Solutions NWLLC Geotechnical Engineering,Construction Monitoring and Environmental Sciences EarthSolutionsNWLLC EarthSolutionsNWLLC FOOTING DRAIN DETAIL Slope Perforated Rigid Drain Pipe (Surround with 1"Rock) 18"(Min.) NOTES: Do NOT tie roof downspouts to Footing Drain. Surface Seal to consist of 12"of less permeable,suitable soil.Slope away from building. LEGEND: Surface Seal;native soil or other low permeability material. 1"Drain Rock SCHEMATIC ONLY -NOT TO SCALE NOT A CONSTRUCTION DRAWING Cherie Lane #3 Renton,Washington GLS 07/05/2016 4490 BJP July 2016 4 Cherie Lane Short Plat Technical Information Report Appendix B Coal Mine Hazard Assessment by Icicle Creek Engineers, Inc. dated December 27, 2016 Report of Geological Engineering Services Proposed Property Development Coal Mine Hazard Assessment and Ground Proofing Program Newfourth LLC Property King County Parcel No. 302305-9108 Renton, Washington December 27, 2016 ICE File No. 1096-001 Prepared For: Newfourth LLC Prepared By: Icicle Creek Engineers, Inc. 29335 NE 20th Street, Carnation, Washington 98014-9632  www.iciclecreekengineers.com  w 425.333.0093  f 425.996.4036 December 27, 2016 Steve Beck, Manager Newfourth LLC 19244 - 39th Avenue South SeaTac, Washington 98188 Report Geological Engineering Services Proposed Property Development Coal Mine Hazard Assessment and Ground Proofing Program Newfourth LLC Property King County Parcel No. 302305-9108 Renton, Washington ICE File No. 1096-001 1.0 INTRODUCTION This report presents the results of Icicle Creek Engineers’ (ICE’s) geological engineering services regarding a coal mine hazard assessment and ground proofing program of the Newfourth LLC property located at King County Parcel No. 302305-9108 in Renton, Washington. The Newfourth LLC property is shown relative to nearby physical features on the Vicinity Map, Figure 1. The property area, including site topography, is shown on the Site Plan, Figure 2. Our services were completed in general accordance with our Revised Scope of Services and Fee Estimate dated September 14, 2015 and were authorized in writing by Steven A. Beck, Manager for Newfourth LLC, on September 17, 2015. ICE previously completed a preliminary coal mine hazard assessment of the Newfourth LLC property; the results are presented in our report dated May 23, 2014. 2.0 BACKGROUND INFORMATION As described in ICE’s May 2014 Preliminary Coal Mine Hazard Assessment (Report), the southwest part of the Newfourth LLC property is located in a “High Coal Mine Hazard” area by definition based on the Renton Municipal Code (RMC) 4-3-050J.1.e, and our site and historical review. Four abandoned underground coal mines underlie the general area of the Newfourth LLC property including the Johnson Mine, the King Mine, the Hi-Grade Mine and the Old Springbrook Mine as shown on the Abandoned Underground Coal Mine Map, Figure 3. The mines were active in the 1930s and were considered small, “backyard” operations compared with the other large coal mines in the Renton area such as the nearby Renton and Springbrook Mines. The Johnson and King Mines underlie the west and southwest part of the Newfourth LLC property. The south-central part of the Newfourth LLC property is also underlain by an abandoned underground coal mine (the Hi- Grade Mine), but is in an area identified (by others) as a wetland so was not targeted for further evaluation (ground proofing) as future development is not planned in that area. Steve Beck, Manager Newfourth LLC December 27, 2016 Page 2 I c i c l e C r e e k E n g i n e e r s 1096001/122716 This report does not restate review details for surface conditions, historical aerial photograph review, Morrison Knudsen (outside report) review and detailed description of the abandoned underground coal mines that underlie the Newfourth LLC property, as these details are already documented in ICE’s May 2014 report. A summary description of the abandoned underground coal mines is restated in this report. The primary focus of this evaluation was to explore the subsurface condition of the abandoned underground mine workings (referred to as “ground proofing”), in order to reclassify, as appropriate, the High Coal Mine Hazard area shown on Figure 5 of ICE’s May 2014 report. 3.0 SCOPE OF SERVICES The purpose of our services was to complete a coal mine hazard assessment and ground proofing program at the Newfourth LLC property. Specifically, our services included the following: • Review readily available historic coal mine records from the City of Renton, Washington State Department of Natural Resources and ICE’s May 2014 report. • Drill 19 test borings in the southwest part of the Newfourth LLC property using track-mounted drilling equipment. • Re-classify the High Coal Mine Hazard area, as appropriate, based on the results of the ground proofing program. • Re-evaluate the potential for regional subsidence based on the results of the ground proofing program. • Develop mitigation for building design and construction. 4.0 ABANDONED UNDERGROUND COAL MINES As previously described, four abandoned underground coal mines including the Johnson, King, Hi-Grade and Old Springbrook Mines underlie the Newfourth LLC property and adjacent areas as shown on Figure 3. The mines were active in the 1930s and were considered small, “backyard” operations compared with the other large coal mines in the Renton area such as the nearby Renton and Springbrook Mines. However, even for the small mines that were operated during the 1930s, the owners were still required to submit underground survey records to the Washington State Mine Inspectors Office in order to market their coal. For this reason, the historical mine records that we reviewed appeared to be relatively detailed showing surface and subsurface elevations, areas mined out, inclination of the coal seam and other mining-related features typical of a well-documented mining operation. All the mines were developed by opening a “slope” down the coal seam that served as the main haulageway for coal to the surface. From the main haulageway, “chutes” (or tunnels) were driven up the coal seam toward the ground surface. These chutes were then connected by a series of “cross-cuts” (tunnels that connect the chutes). This type of mining is referred to as “room-and-pillar” mining. Upon retreat from the mine, the support pillars of coal between the chutes and cross-cuts were removed (called “pillar-robbing”) to maximize the removal of coal from the mine. The effect of pillar-robbing was to dramatically destabilize the mined-out area, therefore, natural collapse (“room caving”) of the mine usually occurred within a few weeks or years. The “structure” of the coal seam in the area of the Newfourth LLC property forms a “bowl-shape” in cross- section. The coal seam in the abandoned mines near the ground surface dips down to the south at about 45 to 50 degrees for the Johnson, King and Hi-Grade Mines. The Old Springbrook Mine, which underlies the property to the south, dips down to the north at about 40 to 45 degrees. Each of the abandoned coal Steve Beck, Manager Newfourth LLC December 27, 2016 Page 3 I c i c l e C r e e k E n g i n e e r s 1096001/122716 mines was worked on the same coal seam. The Johnson and King Mines underlie the southwest part of the Newfourth LLC property at a depth of zero (at mine entries) to over 125 feet as shown on the Mine Depth Map, Figure 4 and Geologic Cross-Sections A-A’ and B-B’, Figure 5. The locations of the geologic cross-sections are shown on Figure 4. 5.0 GROUND PROOFING PROGRAM SUMMARY Subsurface conditions in the southwest part of the Newfourth LLC property area were explored by drilling 19, three-inch-diameter borings (Borings B-1 through B-19) at the approximate locations shown on Figures 2 and 3. Exploration locations were established by measuring from physical features at the site and with a hand-held GPS. The number of borings was determined such that the probability of drilling through “support pillars” was reduced to an acceptable level. The results of our coal mine hazard assessment and ground proofing program are presented in the Coal Mine Hazards Map, Figure 6; these results are described in Section 7 of this report. During our ground proofing program, we observed evidence in the field that a single-lane road crossed the property from west to east as shown on Figure 3; this was substantiated by review of the 1936 aerial photograph. Currently the only visible feature in the field is a shallow cut slot in the vicinity of Boring B- 8. The borings were drilled on September 25 and 28, 2015 to depths ranging from 35 to 95 feet below the ground surface in the area likely underlain by the Johnson and King Mines. The borings were advanced using track-mounted, hydraulic/air-percussion drilling equipment owned and operated by McCallum Rock Drilling, Inc. of Chehalis, Washington. Soil and bedrock samples (drill cuttings) were observed continuously as the borings were advanced. The subsurface explorations were continuously logged by an engineering geologist from our firm. Soils were classified in general accordance with ASTM Test Method D 2488 as shown on the Explanation for Boring Logs, Figure 7. Bedrock was classified in general accordance with Chapter 4 of the May 2015 WSDOT Geotechnical Design Manual. The boring logs are presented in Figures 8 through 26. A summary of the subsurface conditions observed in the borings is presented below. Steve Beck, Manager Newfourth LLC December 27, 2016 Page 4 I c i c l e C r e e k E n g i n e e r s 1096001/122716 Test Boring Number Total Depth (feet)(1) Depth to Bedrock (feet)(2) Depth to Coal Seam/Mine (feet) Thickness of Collapsed Mine Workings (feet) Unmined - Intact Coal Thickness Intact Coal (feet) Depth to Groundwater (feet) B-1 80 10 60 - Yes 20+ 60 B-2 57 10 16 - Yes 9 53 B-3 90 10 58 32+ No - 60 B-4 80 11 57 23+ No - 57 B-5 95 10 75 15.5 No - 70 B-6 62 10 62+ 5 No - 50 B-7 57 10 55 2+ No - 52 B-8 80 12 52 28+ No - 52 B-9 35 10 10 25+ No - >35 B-10 50 12 41 9+ No - 45 B-11 58 9 45 13+ No - 45 B-12 70 12 55 5 No - 55 B-13 66 8 37 13 No - 55 B-14 75 8 60 13+ No - 70 B-15 58 10 45 - Yes 10 58 B-16 53 12 29 - Yes 25 >53 B-17 58 10 32 - Yes 13 55 B-18 56 10 35 - Yes 11 55 B-19 70 7 60 10+ No - 60 Most of the borings were completed because of the drill bit plugging where groundwater and caved coal/rock were encountered. Borings B-1, B-2 and B-8 through B-19 (excluding Borings B-11 and B-13) encountered 3 to 12 feet of Fill consisting of silty sand with variable amounts of gravel and/or coal fines. The fill is evidence that the property area where these borings were completed was modified by grading and stockpiling of waste coal and other soil material. The top of the mined-out coal seam appeared to be altered by roof caving which created larger than expected “soft coal zones” where the abandoned mine had been filled with caved coal and rock. No open voids were encountered in the test borings although soft zones of coal and rock rubble were encountered based on the drill action and rate, as shown in column 5 above. Intact coal was also encountered in Borings B-1, B-2 and B-15 through B-18. We observed that the thickness of the intact coal varied from 9 to 25 feet. The thinner sections of intact coal (Borings B-2, B-15, B-17 and B-18) may suggest that the coal seam was mined, and the roof had collapsed completely in to the floor of the mined-out area without creating a rubble zone (pancaked). Steve Beck, Manager Newfourth LLC December 27, 2016 Page 5 I c i c l e C r e e k E n g i n e e r s 1096001/122716 Groundwater was consistently encountered at the coal seam zone, as expected, especially in the caved, rubble zones that suggest “collapsed mine workings” as shown on the boring logs. During the process of the ground proofing program, we observed Mine Rock Fill (waste rock from underground mining consisting of coal fines and broken rock) in the area of Borings B-1, B-2, B-14, B-15 and B-16. Other areas of Mine Rock Fill may exist which were not observed because of dense blackberry vines that cover most of the southwest corner of the Newfourth LLC property. 6.0 REGULATORY CONSIDERATIONS The Renton Municipal Code (RMC) 4-3-050J.1.e defines coal mine hazards as follows: High Coal Mine Hazards - Areas with abandoned and improperly sealed mine openings and areas underlain by mine workings shallower than two hundred feet (200') in depth for steeply dipping seams, or shallower than fifteen (15) times the thickness of the seam or workings for gently dipping seams. These areas may be affected by collapse or other subsidence. Medium Coal Mine Hazards – Areas where the mine workings are deeper than two hundred feet (200’) for steeply dipping seams, or deeper than fifteen (15) times the thickness of the seam for gently dipping seams. These areas may be affected by subsidence. Low Coal Mine Hazards – Areas with no known mine workings and no predicted subsidence. While no mines are known in these areas, undocumented mining is known to have occurred. In addition, RMC 4-3-050J.1.i. provides the following regulatory considerations related to coal mine hazards: i. Mitigation – Additional Engineering Design and Remediation Specifications: After approval of the mitigation approach proposed as a result of RMC 4-3-050D, and prior to construction, the applicant shall complete engineering design drawings and specifications for remediation. Upon approval of the plans and specifications, the applicant shall complete the remediation. Hazard mitigation shall be performed by or under the direction of a licensed geotechnical engineer or engineering geologist. The applicant shall document the hazard mitigation by submitting as-builts and a remediation construction report. ii. Hazards Found during Construction: Any hazards found during any development activities shall be immediately reported to the Development Services Division. Any coal mine hazards shall be mitigated prior to recommencing construction based upon supplemental recommendations or reports by the applicant’s geotechnical professional. iii. Construction in Areas with Combustion: Construction shall not be permitted where surface or subsurface investigations indicate the possible presence of combustion in the underlying seam or seams, unless the impact is adequately mitigated in accordance with the recommendations of the applicant’s geotechnical professional. According to RMC 4-3-050G.2 (Development Standards), there are no specific buffers to coal mine hazards. However, based on the findings of a geotechnical report (subject to this report) the Conditions of Approval may require a buffer and/or setbacks. Steve Beck, Manager Newfourth LLC December 27, 2016 Page 6 I c i c l e C r e e k E n g i n e e r s 1096001/122716 7.0 ANALYSIS OF COAL MINE HAZARDS 7.1 GENERAL Our analysis of Coal Mine Hazards is based on definitions and methodologies described within RMC 4-3- 050. Our analysis includes the findings developed from the ground proofing program which details subsurface conditions including 1) the accuracy of the historic mine maps relative to the plan and depth of mine workings observed in our borings, 2) the thickness and character of the overburden soils/bedrock and 3) the status of collapse of the abandoned underground coal mines. This new information allowed for consideration of development within RMC defined “High Coal Mine Hazard” areas because the risk of surface collapse (health and safety concern) and/or regional subsidence (property damage concern) was more confidently evaluated. 7.2 HIGH COAL MINE HAZARDS 7.2.1 General As described in ICE’s May 2014 report, the southwest part of the Newfourth LLC property is within a High Coal Mine Hazard area as defined by RMC 4-3-050J.1.e. ICE completed ground proofing (subsurface exploration) to further evaluate the location and condition of the abandoned underground coal mines. Based on the results of the ground proofing program, we were able to better identify the location of the abandoned underground coal mines and to evaluate the status of collapse of the mine workings. The borings suggest that the historic mine maps are reasonably accurate for location and that the mines are filled with coal fines and rock rubble, or have completely collapsed (pancaked). From a hazard evaluation perspective, it would have been more favorable if the mine had collapsed by “pancaking.” However, our ground proofing program indicates that much of the mine is filled with caved rock instead. While this has a benefit of filling voids, it does not eliminate the risk of sinkhole occurrence. For this reason, we have created three high coal mine hazard risk subareas, as described in the following sections of this report, to qualify risk levels based on the mine depth and location within the Newfourth LLC property. 7.2.2 Higher Risk High Coal Mine Hazard Area As described in ICE’s May 2014 report and confirmed by the ground proofing program completed for this study, portions of the Johnson and King Mines underlie the west and southwest part of the Newfourth LLC property. Four surface entries to these mines occur within or adjacent to the property; one of which is centrally located in this area; the other three are less of a factor as they occur in a known wetland area or are adjacent to, or are in a limited access area of the property. Mine entry areas, even if covered or collapsed, which is the current condition at the Newfourth LLC property, should be avoided. Borings B-9, B-10, B-11 and B-13 encountered relatively shallow collapsed mine workings (less than 50 feet below the ground surface); this is consistent with shallow mine workings shown on the historic maps. The area of Borings B-9, B-10, B-11and B-13 should be avoided for development. These areas of covered mine entries and shallow mine workings are shown as Higher Risk High Coal Mine Hazard Areas on the Figure 6. In these areas the risk of sinkhole occurrence is high. Based on current subsurface information, no development should be allowed in the Higher Risk High Coal Mine Hazard Areas unless the area is “bridged” (structurally spanned) or additional subsurface exploration is completed on a site specific basis, depending on the development plan, in order to develop alternative mitigation. Steve Beck, Manager Newfourth LLC December 27, 2016 Page 7 I c i c l e C r e e k E n g i n e e r s 1096001/122716 7.2.3 Moderate Risk High Coal Mine Hazard Area The remaining portion of the Newfourth LLC property where test borings encountered either intact coal or collapsed mine workings at depths less than 50 feet should be considered a Moderate Risk High Coal Mine Hazard Area. No open voids were encountered. The collapsed mine workings encountered in the test borings were characterized as the mined-out zone being filled with coal and rock fragments, and usually saturated (flooded). Drilling was relatively soft in the mine collapse zone, but the drill rods did not “free fall” which would suggest the mined out area is filled with rock fragments. The soft drilling occurred with little down-pressure as the weight of the drill stem (which is considerable) was sufficient to advance the boring through the coal and rock fragments. Where intact coal was encountered in the test borings (the thickness of coal was unusually thin), it is possible that the mine has “pancaked” in these areas (“plastic deformation” - roof and floor come together by overburden pressures without rock fracture). Our evaluation of this area is such that we concluded that 1) the mined-out areas are less than 50-feet deep, 2) the mined-out areas are overlain by at least 30 feet of bedrock, 3) the mined-out areas are filled with coal and rock fragments, 4) the mined-out areas have pancaked, or 5) the coal seam is intact (not mined). These areas are referred to as Moderate Risk High Coal Mine Hazard Areas as shown on Figure 6. In these areas, the risk of sinkhole occurrence is low to moderate. Roads, driveways, outbuildings (sheds), yard and passive use should be allowed in the Moderate Risk High Coal Mine Hazard Areas. 7.2.4 Lower Risk High Coal Mine Hazard Area Lower Risk High Coal Mine Hazards include areas where the risk of sinkhole occurrence is low. These areas include 1) mined-out areas that are more than 50-feet deep, 2) mined-out areas that are overlain by at least 40 feet of bedrock, 3) mined-out areas that are filled with coal and rock fragments, 4) mined-out areas that have pancaked, or 5) areas where the coal seam is intact (not mined). These areas are referred to as Lower Risk High Coal Mine Hazard Areas as shown on Figure 6. Structure development, with mitigation, should be allowed in the Lower Risk High Coal Mine Hazard Areas. 8.0 CONCLUSIONS In our opinion, sufficient subsurface exploration (ground proofing) has been completed to define the locations of the Johnson and King Mines that underlie the west and southwest part of the Newfourth LLC property. ICE’s May 2014 preliminary coal mine hazard assessment concluded that these mine underlie this area at a depth of less than 100 feet and are therefore RMC-defined High Coal Mine Hazard areas. Based on the 19 test borings completed for our ground proofing program, we concluded that 1) the underground mines were accurately located, and the depth to mine workings (0 to over 100 feet) is generally consistent with the historic mine maps, 2) the mined-out zone is filled with coal and rock fragments, 4) the mined-out area has pancaked, or 5) the coal seam is intact (not mined). Because of these favorable conditions observed in the test borings, it is our opinion that development options can occur on a site-specific basis within the High Coal Mine Hazard areas as shown on Figure 6. Our analysis resulted in identifying higher to lower risk areas that provides development option subareas within the overall High Coal Mine Hazard area. These subareas are defined as follows: Higher Risk High Coal Mine Hazard Area – No development; cleared open space is okay. Driveway access could be allowed provided that the area is “bridged” (structurally spanned) or that additional subsurface exploration is completed in order to develop alternative mitigation. Steve Beck, Manager Newfourth LLC December 27, 2016 Page 8 I c i c l e C r e e k E n g i n e e r s 1096001/122716 Moderate Risk High Coal Mine Hazard Area – Roads, driveways, outbuildings (sheds), yards and periodic use with no structures is okay. Lower Risk High Coal Mine Hazard Area – Structures with mitigation is okay (see Section 9.2 of this report). The area shown as “Declassified Coal Mine Area” on Figure 6 is not underlain by abandoned underground coal mines and can be developed using standard building practices. 9.0 RECOMMENDATIONS 9.1 MODERATE RISK HIGH COAL MINE HAZARD AREA We recommend the following regarding development in the Moderate Risk High Coal Mine Hazard areas. Roads, driveways, outbuildings (sheds) and yards may extend across the Moderate Risk High Coal Mine Hazard areas. We expect that the City of Renton will require a statement indicating that the property owner will accept the risk related to safety and potential damage to the road/driveway in these areas. Roads/driveways should be designed to be able to free-span a distance of 10 feet (the typical sinkhole is 3- to 10-feet in diameter). This can be done using a reinforced-concrete slab. Alternatively, gravel- surfacing could be used for the roads/driveways which is easier to repair. Many adjacent properties and sections of City of Renton streets in this area (such as Renton Hill) are of equal risk related to safety concerns and potential sinkholes. 9.2 LOWER RISK HIGH COAL MINE HAZARD AREA We recommend the following regarding development in the Lower Risk High Coal Mine Hazard areas: • Small, square or nearly square-shaped building pads should be favored over large, irregularly-shaped building pads. • Use of rigid foundations (conventional reinforced-concrete spread footings) supporting a flexible superstructure (wood-frame). Foundations should extend across the inside of the building footprint rather than using individual column footings. • Crawl-space construction rather than slab-on-grade. However, slab-on-grade may be used in garage areas. • No brick or basement construction. • Underground utilities should be designed with flexible and/or telescopic couplings or fittings. • ICE should be contacted immediately should house distortion or a ground surface sag/sinkhole be observed. • Prospective owners that may occupy structures within Lower Risk High Coal Mine Hazard areas should be made aware that an abandoned underground coal mine exists at a depth of 50+ feet although subsurface exploration suggests that the abandoned mine working have filled with coal and rock fragments or have otherwise collapsed. However, there still is some risk that a sinkhole could occur which could be a safety issue and/or cause damage. Based on our experience in Renton, Issaquah and other cities that have coal mine hazards, this risk of sinkhole occurrence is low although hundreds of houses are located in areas with similar and even more risky conditions. However, the risk remains for this site. Steve Beck, Manager Newfourth LLC December 27, 2016 Page 9 I c i c l e C r e e k E n g i n e e r s 1096001/122716 9.3 MINE ROCK FILL Mine Rock Fill was observed at the ground surface in the vicinity of Borings B-1, B-15 and B-16, and at a depth of 5 to 10 feet in Boring B-9 and a depth of 6 to 12 feet in Boring B-10. We recommend against development of structures including houses in areas of Mine Rock Fill (coal fines and rock fragments). However, the Mine Rock Fill can be removed from these areas to allow for development. Mine Rock Fill can be placed in open space areas or be removed from the site. Mine Rock Fill that contains only broken rock (no coal - sandstone, siltstone and shale), may be reused for structural fill provided the moisture content is conditioned for adequate compaction. 10.0 USE OF THIS REPORT We have prepared this report for use by Newfourth LLC. The data and report should be provided to permitting agencies for their information, but our report conclusions and interpretations should not be construed as a warranty of the subsurface conditions. There are probable variations in subsurface conditions between the explorations and also that may occur with time. A contingency for unanticipated conditions should be included in the budget and schedule. There are always risks to public health and safety and property damage related to development in areas of Coal Mine Hazards which includes part of the Talbot and Springbrook areas in Renton. However, this risk can be reduced by following the recommendations presented in this report, but the risk cannot be eliminated. Potential owner(s) of this property should be informed of the hazards that do exist and be provided a copy of this report. Within the limitations of scope, schedule and budget, our services have been executed in accordance with generally accepted practices in this area at the time the report was prepared. No warranty or other conditions, express or implied, should be understood. ******************** Steve Beck, Manager Newfourth LLC December 27, 2016 Page 10 I c i c l e C r e e k E n g i n e e r s 1096001/122716 We trust this report meets your present needs. Please call if you have any questions concerning this report. Yours very truly, Icicle Creek Engineers, Inc. Kathy S. Killman, LEG Principal Engineering Geologist Brian R. Beaman, PE, LEG, LHG Principal Engineer/Geologist/Hydrogeologist Document ID: 1096001.REP Attachments: Vicinity Map – Figure 1 Site Plan – Figure 2 Abandoned Underground Coal Mine Map – Figure 3 Mine Depth Map – Figure 4 Cross-Section A-A’ / B-B’ – Figure 5 Coal Mine Hazard Map – Figure 6 Explanation for Boring Logs – Figure 7 Boring Logs – Figures 8 through 26 Submitted via email (pdf) and surface mail (one original copy) cc: Bill Kombol, Newfourth LLC (email and one original copy) Chad Allen, Encompass Engineering & Surveying (email) I c i c l e C r e e k E n g i n e e r s 1096001/122716 FIGURES ICE FILE NO. FigureCHECKED: KSK DRAWN: BRB DESIGNED: SCALE: As Shown DATE: 12/27/16 VICINITY MAP 1 1096-001 -- King County Parcel No. 302305-9108 29335 NE 20th Street Carnation, Washington 98014 (425) 333-0093 NEWFOURTH LLC PROPERTY KING COUNTY PARCEL NO. 302305-9108, RENTON, WASHINGTON ICE FILE NO. Figure 1096-001 CHECKED: DRAWN: DESIGNED: SCALE: DATE: AS SHOWN BRB BRB KSK 12/27/16 29335 NE 20th Street Carnation, Washington 98014 (425) 333-0093 NEWFOURTH LLC PROPERTY KING COUNTY PARCEL NO. 302305-9108, RENTON, WASHINGTON Base map obtained from King County iMAPTalbot Road SouthScale in Feet 0 100 200 Scale in Feet 0 100 200 Newfourth LLC Property SITE PLAN 2 EXPLANATION Test Boring LocationB-1 B-7 B-2B-3 B-13B-10 B-14 B-1 B-16 B-15 B-11 B-9 B-12 B-4 B-6 B-5 B-19 B-18 B-17 B-8 ICE FILE NO. Figure 1096-001 CHECKED: DRAWN: DESIGNED: SCALE: DATE: AS SHOWN BRB BRB KSK 12/27/16 29335 NE 20th Street Carnation, Washington 98014 (425) 333-0093 NEWFOURTH LLC PROPERTY KING COUNTY PARCEL NO. 302305-9108, RENTON, WASHINGTON Base map obtained from King County iMAPTalbot Road SouthEXPLANATION Test Boring LocationB-1 Historic Road (1936 Aerial Photograph) B-7 B-2B-3 B-13B-10 B-14 B-1 B-16 B-15 B-11 B-9 B-12 B-4 B-6 B-5 B-19 B-18 B-17 B-8 Newfourth LLC Property Scale in Feet 0 100 200 Scale in Feet 0 100 200 Johnson Mine King Mine Hi-Grade Mine Old Springbrook Mine ABANDONED UNDERGROUND COAL MINE MAP 3 Mine mapping based on Washington State Department of Natural Resources, 1932, 1934 through 1938, 1940, 1942 through 1948, historic coal mine maps of the Talbot Road area mines including surface features and underground mine workings.Historic Mine Entry (covered, but not formally reclaimed) ICE FILE NO. Figure 1096-001 CHECKED: DRAWN: DESIGNED: SCALE: DATE: AS SHOWN BRB BRB KSK 12/27/16 29335 NE 20th Street Carnation, Washington 98014 (425) 333-0093 NEWFOURTH LLC PROPERTY KING COUNTY PARCEL NO. 302305-9108, RENTON, WASHINGTON Base map obtained from King County iMAPTalbot Road South0 25 50 100 125 0 EXPLANATION Newfourth LLC Property Depth in Feet to Abandoned Underground Coal Mines Scale in Feet 0 100 200 Scale in Feet 0 100 200 MINE DEPTH MAP A A’ Geologic Cross-Section (see Figure 5)A A’ 4 B B’ Important Note: The depth to mine workings is based on fixed elevations as shown on the historic mine maps along with the elevation of the interpreted top of mine workings encountered in the test borings. The elevation of the top of mine workings from the test borings does not necessarily align exactly with the mine depth map shown on this figure. This is because the plan location of test borings was established using a hand held GPS which is only accurate to within a 20-foot circular area. Considering the high dip of the coal seam (up to 60 degrees) the north (shallow) part of the mine small variations in surface location of the test borings can make a large difference; the test borings are used as “best fit” for mine depth contouring. ICE FILE NO. FigureCHECKED: KSK DRAWN: BRB DESIGNED: BRB SCALE: As shown DATE: 12/27/16 1096-001 5 GEOLOGIC CROSS-SECTIONS A-A’ AND B-B’ Horizontal Scale = Vertical Scale 0 100 200 Newfourth LLC Property200 100 0 200 100 Elevation in FeetElevation in FeetA(north)A'(south) 29335 NE 20th Street Carnation, Washington 98014 (425) 333-0093 Newfourth LLC Property 200 100 0 0Elevation in FeetA(north) Fill/Weathered Bedrock Jo h n s o n / K i n g M i n e 0 25 feet 50 feet 75 feet 100 feet Renton Formation Bedrock Renton Formation Bedrock Fill/Weathered Bedrock Kin g M i n e 200 100 Elevation in FeetA'(south) 25 feet 50 feet 75 feet NEWFOURTH LLC PROPERTY KING COUNTY PARCEL NO. 302305-9108, RENTON, WASHINGTON ICE FILE NO. Figure 1096-001 CHECKED: DRAWN: DESIGNED: SCALE: DATE: AS SHOWN BRB BRB KSK 12/27/16 29335 NE 20th Street Carnation, Washington 98014 (425) 333-0093 NEWFOURTH LLC PROPERTY KING COUNTY PARCEL NO. 302305-9108, RENTON, WASHINGTON Base map obtained from King County iMAPTalbot Road SouthEXPLANATION Moderate Risk High Coal Mine Hazard Area (driveways, yard, active use with no structures is OK) Higher Risk High Coal Mine Hazard Area (no development - cleared open space is OK; bridge (structural span) or additional subsurface exploration can be completed in order to evaluate alternative mitigation) Declassified Coal Mine Area (no development restrictions associated with coal mine hazards) Lower Risk High Coal Mine Hazard Area (structures with mitigation OK - see report text for mitigation) Scale in Feet 0 100 200 Scale in Feet 0 100 200 COAL MINE HAZARD MAP 6 MAJOR DIVISIONS Soil Classification and Generalized Group Description Coarse- Grained Soils More than 50% retained on the No. 200 sieve Fine- Grained Soils More than 50% passing the No. 200 sieve Highly Organic Soils GRAVEL More than 50% of coarse fraction retained on the No. 4 sieve SAND More than 50% of coarse fraction passes the No. 4 sieve SILT AND CLAY Liquid Limit less than 50 SILT AND CLAY Liquid Limit greater than 50 CLEAN GRAVEL GRAVEL WITH FINES CLEAN SAND SAND WITH FINES INORGANIC ORGANIC INORGANIC ORGANIC GW GP GM GC SW SP SM SC ML CL OL MH CH OH PT Well-graded gravels Poorly-graded gravels Gravel and silt mixtures Gravel and clay mixtures Well-graded sand Poorly-graded sand Sand and silt mixtures Sand and clay mixtures Low-plasticity silts Low-plasticity clays Low plasicity organic silts and organic clays High-plasticity silts High-plasticity clays High-plasticity organic silts and organic clays PeatPrimarily organic matter with organic odor Unified Soil Classification System Component Size Range Boulders Coarser than 12 inch Cobbles 3 inch to 12 inch Gravel 3 inch to No. 4 (4.78 mm) Coarse 3 inch to 3/4 inch Fine 3/4 inch to No. 4 (4.78 mm) Sand Coarse No. 4 (4.78 mm) to No. 200 (0.074mm) No. 4 (4.78 mm) to No. 10 (2.0 mm) Medium No. 10 (2.0 mm) to No. 40 (0.42 mm) Fine No. 40 (0.42 mm) to No. 200 (0.074 mm) Silt and Clay Finer than No. 200 (0.074 mm) Soil Particle Size Definitions Soil Moisture Description Dry Moist Wet Absence of moisture Damp, but no visible water Visible water Soil Moisture ModifiersNotes: 1) Soil classification based on visual classification of soil is based on ASTM D 2488. 2) Soil classification using laboratory tests is based on ASTM D 2487. 3) Description of soil density or consistency is based on interpretation of blow count data and/or test data. Sampling Method Boring Log Symbol Description Blows required to drive a 2.4 inch I.D. split-barrel sampler 12-inches or other indicated distance using a 300-pound hammer falling 30 inches. Blows required to drive a 1.5- inch I.D. split barrel sampler (SPT - Standard Penetration Test) 12-inches or other indicated distance using a 140-pound hammer falling 30 inches. 34 12 21 14 30 P Location of relatively undisturbed sample Location of disturbed sample Location of sample attempt with no recovery Location of sample obtained in general accordance with Standard Penetration Test (ASTM D-1586) test procedures. Location of SPT sampling attempt with no recovery. Pushed Sampler Grab Sample Sampler pushed with the weight of the hammer or against weight of the drilling rig. Sample obtained from drill cuttings.G Key to Boring Log Symbols Test Symbol Density Grain Size Percent Fines Atterberg Limits Hydrometer Analysis Consolidation Compaction Permeability Unconfined Compression Consolidated Undrained TX Consolidated Drained TX Chemical Analysis Laboratory Tests DN GS PF AL HA CN CP PM UC CU CD CA Icicle Creek Engineers Explanation for Boring Logs - Figure 7 Unconsolidated Undrained TX UU Note: The lines separating soil types on the logs represents approximate boundaries only. The actual boundaries may vary or be gradual. Moisture Content MC 0 5 10 15 20 25 30 35 40 45 50 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-1 Approximate Ground Surface Elevation: 155 feet Page 1 of 2 Boring Log - Figure 8 Comments Groundwater Observations 0 5 10 15 20 25 30 35 40 45 50Depth in FeetSoilClassificationSymbolSampleLocationIcicle Creek Engineers See Figure 7 for explanation of symbols ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15Unweathered bedrock encountered at 9½ feet SM Rock Rock Rock Rock Rock Rock Rock Rock Brown silty fine to medium SAND with gravel (Fill) Light gray to gray fine-grained SANDSTONE (Renton Formation) Coal fines (Fill) 50 55 60 65 70 75 80 85 90 95 100 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-1 Page 2 of 2 Comments 50 55 60 65 70 75 80 85 90 95 100Depth in FeetSoilClassificationSymbolSampleLocationBoring Log - Figure 8 Groundwater Observations Icicle Creek Engineers See Figure 7 for explanation of symbols Rock Rock Boring completed at 80 feet on September 25, 2015 Groundwater encountered at 60 feet at the time of drilling Black COAL (Renton Formation) Dark brown CARBONACEOUS SHALE (Renton Formation) Light gray to gray fine-grained SANDSTONE (Renton Formation) Rock Rock Rock Rock Rock ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 0 5 10 15 20 25 30 35 40 45 50 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-2 Approximate Ground Surface Elevation: 150 feet Page 1 of 2 Boring Log - Figure 9 Comments Groundwater Observations 0 5 10 15 20 25 30 35 40 45 50Depth in FeetSoilClassificationSymbolSampleLocationIcicle Creek Engineers See Figure 7 for explanation of symbols Unweathered bedrock encountered at 10 feet SM Rock Rock Rock Rock Rock Rock Rock Rock Brown silty fine SAND with coal fragments (Fill) Reddish-yellow silty fine SAND (weathered bedrock) Dark brown CARBONACEOUS SHALE (Renton Formation) Dark brown CARBONACEOUS SHALE (Renton Formation) Light brown fine-grained SANDSTONE (Renton Formation) Black COAL (Renton Formation) Dark brown CARBONACEOUS SHALE with thin layers of COAL (Renton Formation) Light grayish-brown fine-grained SANDSTONE (Renton Formation) SM ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 50 55 60 65 70 75 80 85 90 95 100 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-2 Page 2 of 2 Comments 50 55 60 65 70 75 80 85 90 95 100Depth in FeetSoilClassificationSymbolSampleLocationGroundwater Observations Icicle Creek Engineers See Figure 7 for explanation of symbols Rock Rock Boring completed at 57 feet on September 25, 2015 Groundwater encountered at 53 feet at the time of drillingBlack Coal (Renton Formation) Dark brown CARBONACEOUS SHALE (Renton Formation) Boring Log - Figure 9ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 0 5 10 15 20 25 30 35 40 45 50 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-3 Approximate Ground Surface Elevation: 135 feet Page 1 of 2 Boring Log - Figure 10 Comments Groundwater Observations 0 5 10 15 20 25 30 35 40 45 50Depth in FeetSoilClassificationSymbolSampleLocationIcicle Creek Engineers See Figure 7 for explanation of symbols Unweathered bedrock encountered at 10 feet SM Rock Rock Rock Rock Rock Rock Rock Rock Reddish-yellow and light grayish-brown fine-grained SANDSTONE (Renton Formation) Reddish-yellow silty fine SAND (weathered bedrock) Dark brown CARBONACEOUS SHALE (Renton Formation) Black COAL (Renton Formation) grades to reddish-yellow grades to light gray to gray ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 50 55 60 65 70 75 80 85 90 95 100 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-3 Page 2 of 2 Comments 50 55 60 65 70 75 80 85 90 95 100Depth in FeetSoilClassificationSymbolSampleLocationBoring Log - Figure 10 Groundwater Observations Icicle Creek Engineers See Figure 7 for explanation of symbols Rock Rock Boring completed at 90 feet on September 25, 2015 Groundwater encountered at 58 feet at the time of drilling Black COAL (Renton Formation) Soft drilling from 58 to 60 feet; wood fragments in drill cuttings; lost air circulation at 60 feet; possible collapsed coal mine workings. COAL and ROCK FRAGMENTS? (collapsed mine workings?) Rock? Rock? Rock? Rock? Rock? Rock?ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 0 5 10 15 20 25 30 35 40 45 50 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-4 Approximate Ground Surface Elevation: 145 feet Page 1 of 2 Boring Log - Figure 11 Comments Groundwater Observations 0 5 10 15 20 25 30 35 40 45 50Depth in FeetSoilClassificationSymbolSampleLocationIcicle Creek Engineers See Figure 7 for explanation of symbols Unweathered bedrock encountered at 11 feet SM Rock Rock Rock Rock Rock Rock Rock RockLight gray to gray fine-grained SANDSTONE (Renton Formation) Reddish-yellow silty fine SAND (weathered bedrock) Black COAL (Renton Formation) Dark brown CARBONACEOUS SHALE (Renton Formation) Grayish-brown fine-grained SANDSTONE (Renton Formation) grades to light brown to grayish-brown ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 50 55 60 65 70 75 80 85 90 95 100 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-4 Page 2 of 2 Comments 50 55 60 65 70 75 80 85 90 95 100Depth in FeetSoilClassificationSymbolSampleLocationBoring Log - Figure 11 Groundwater Observations Icicle Creek Engineers See Figure 7 for explanation of symbols Rock Rock Boring completed at 80 feet on September 25, 2015 Groundwater encountered at 57 feet at the time of drilling Black COAL (Renton Formation) Soft drilling from 57 to 60 feet; wood fragments in drill cuttings; lost air circulation at 60 feet, possible collapsed coal mine workings. COAL and ROCK FRAGMENTS? (collapsed mine workings?) Rock? Rock? Rock? Rock?ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 0 5 10 15 20 25 30 35 40 45 50 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-5 Approximate Ground Surface Elevation: 145 feet Page 1 of 2 Boring Log - Figure 12 Comments Groundwater Observations 0 5 10 15 20 25 30 35 40 45 50Depth in FeetSoilClassificationSymbolSampleLocationIcicle Creek Engineers See Figure 7 for explanation of symbols Unweathered bedrock encountered at 10 feet SM Rock Rock Rock Rock Rock Rock Rock Rock Light brown fine-grained SANDSTONE (Renton Formation) Reddish-yellow silty fine SAND (weathered bedrock) grades to gray grades to gray to white grades to grayish-brown to gray grades to grayish-brown to gray ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 50 55 60 65 70 75 80 85 90 95 100 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-5 Page 2 of 2 Comments 50 55 60 65 70 75 80 85 90 95 100Depth in FeetSoilClassificationSymbolSampleLocationBoring Log - Figure 12 Groundwater Observations Icicle Creek Engineers See Figure 7 for explanation of symbols Rock Rock Boring completed at 95 feet on September 25, 2015 Groundwater encountered at 70 feet at the time of drilling Gray fine-grained SANDSTONE (Renton Formation) COAL and ROCK FRAGMENTS? (collapsed mine workings?) SANDSTONE? (Renton Formation) Soft drilling from 75 to 90.5 feet; partial air circulation restored; possible collapsed coal mine workings. Lost air circulation at 90 feet; Hard drilling from 90.5 to 95 feet Drill action suggests fractured bedrock from 64 to 66 feet Lost air circulation at 70 feet Rock Rock Rock Rock Rock Rock Rock? Rock?ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 0 5 10 15 20 25 30 35 40 45 50 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-6 Approximate Ground Surface Elevation: 142 feet Page 1 of 2 Boring Log - Figure 13 Comments Groundwater Observations 0 5 10 15 20 25 30 35 40 45 50Depth in FeetSoilClassificationSymbolSampleLocationIcicle Creek Engineers See Figure 7 for explanation of symbols Unweathered bedrock encountered at 10 feet SM Rock Rock Rock Rock Rock Rock Rock Rock Gray fine-grained SANDSTONE (Renton Formation) Reddish-yellow silty fine SAND (weathered bedrock) grades to light gray to white grades to gray grades to light gray to white grades to gray Soft drilling from 45 to 50 feet ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 50 55 60 65 70 75 80 85 90 95 100 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-6 Page 2 of 2 Comments 50 55 60 65 70 75 80 85 90 95 100Depth in FeetSoilClassificationSymbolSampleLocationBoring Log - Figure 13 Groundwater Observations Icicle Creek Engineers See Figure 7 for explanation of symbols Rock Rock Boring completed at 62 feet on September 25, 2015 Groundwater encountered at 50 feet at the time of drillingDark brown CARBONACEOUS SHALE (Renton Formation) Rock ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 0 5 10 15 20 25 30 35 40 45 50 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-7 Approximate Ground Surface Elevation: 150 feet Page 1 of 2 Boring Log - Figure 14 Comments Groundwater Observations 0 5 10 15 20 25 30 35 40 45 50Depth in FeetSoilClassificationSymbolSampleLocationIcicle Creek Engineers See Figure 7 for explanation of symbols Unweathered bedrock encountered at 10 feet SM Rock Rock Rock Rock Rock Rock Rock Rock Light grayish-brown fine-grained SANDSTONE (Renton Formation) Reddish-brown silty fine SAND (weathered bedrock) grades to light gray to white grades to light grayish-brown grades to light gray to white grades to gray Dark brown CARBONACEOUS SHALE (Renton Formation)ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 50 55 60 65 70 75 80 85 90 95 100 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-7 Page 2 of 2 Comments 50 55 60 65 70 75 80 85 90 95 100Depth in FeetSoilClassificationSymbolSampleLocationBoring Log - Figure 14 Groundwater Observations Icicle Creek Engineers See Figure 7 for explanation of symbols Rock Boring completed at 57 feet on September 25, 2015 Groundwater encountered at 52 feet at the time of drillingDark brown CARBONACEOUS SHALE (Renton Formation) Grayish-brown fine-grained SANDSTONE (Renton Formation) Lost air circulation at 55 feet; possible collapsed coal mine workings. COAL and ROCK FRAGMENTS? (collapsed mine workings?)Rock?ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 0 5 10 15 20 25 30 35 40 45 50 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-8 Approximate Ground Surface Elevation: 129 feet Page 1 of 2 Boring Log - Figure 15 Comments Groundwater Observations 0 5 10 15 20 25 30 35 40 45 50Depth in FeetSoilClassificationSymbolSampleLocationIcicle Creek Engineers See Figure 7 for explanation of symbols Unweathered bedrock encountered at 12 feet SM Rock Rock Rock Rock Rock Rock Rock SM Grayish-brown fine-grained SANDSTONE (Renton Formation) Brown silty fine to medium SAND (Fill) grades to gray Reddish-yellow silty fine SAND (weathered bedrock) Dark brown CARBONACEOUS SHALE with thin layers of coal (Renton Formation) Black COAL (Renton Formation)ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 50 55 60 65 70 75 80 85 90 95 100 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-8 Page 2 of 2 Comments 50 55 60 65 70 75 80 85 90 95 100Depth in FeetSoilClassificationSymbolSampleLocationBoring Log - Figure 15 Groundwater Observations Icicle Creek Engineers See Figure 7 for explanation of symbols Rock Boring completed at 80 feet on September 28, 2015 Groundwater encountered at 52 feet at the time of drillingCOAL and ROCK FRAGMENTS? (collapsed mine workings?)Lost air circulation at 52 feet; possible collapsed coal mine workings. Black COAL (Renton Formation) Rock? Rock? Rock? Rock? Rock?ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 0 5 10 15 20 25 30 35 40 45 50 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-9 Approximate Ground Surface Elevation: 140 feet Page 1 of 1 Boring Log - Figure 16 Comments Groundwater Observations 0 5 10 15 20 25 30 35 40 45 50Depth in FeetSoilClassificationSymbolSampleLocationIcicle Creek Engineers See Figure 7 for explanation of symbols COAL and ROCK FRAGMENTS? (collapsed mine workings?) Brown silty fine to medium SAND with gravel (Fill)SM Black COAL FINES (Fill) Boring completed at 35 feet on September 28, 2015 Lost air circulation at 10 feet; possible collapsed coal mine workings. Soft drilling from 27 to 29 feet Rock? Rock? Rock? Rock? Rock? No groundwater encountered at the time of drilling ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 0 5 10 15 20 25 30 35 40 45 50 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-10 Approximate Ground Surface Elevation: 140 feet Page 1 of 1 Boring Log - Figure 17 Comments Groundwater Observations 0 5 10 15 20 25 30 35 40 45 50Depth in FeetSoilClassificationSymbolSampleLocationIcicle Creek Engineers See Figure 7 for explanation of symbols Unweathered bedrock encountered at 12 feet SM Rock Rock Rock Rock Rock Rock Rock? Dark brown to grayish-brown fine-grained SANDSTONE (Renton Formation) Brown silty fine to medium SAND with gravel (Fill) Soft drilling from 41 to 50 feet; Lost air circulation; possible collapsed coal mine workings. Dark brown SILT and black COAL FINES (Fill) Black COAL FINES (Fill) Dark brown to black CARBONACEOUS SHALE (Renton Formation) Black COAL (Renton Formation) COAL and ROCK FRAGMENTS? (collapsed mine workings?) Boring completed at 50 feet on September 28, 2015 Grayish-brown fine-grained SANDSTONE (Renton Formation) Dark brown to black CARBONACEOUS SHALE (Renton Formation) Groundwater encountered at 45 feet at the time of drilling ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 0 5 10 15 20 25 30 35 40 45 50 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-11 Approximate Ground Surface Elevation: 143 feet Page 1 of 2 Boring Log - Figure 18 Comments Groundwater Observations 0 5 10 15 20 25 30 35 40 45 50Depth in FeetSoilClassificationSymbolSampleLocationIcicle Creek Engineers See Figure 7 for explanation of symbols Unweathered bedrock encountered at 9 feet SM Rock Rock Rock Rock Rock Rock Rock Dark brown CARBONACEOUS SHALE (Renton Formation) Reddish-brown silty fine SAND (weathered bedrock) Dark brown CARBONACEOUS SHALE (Renton Formation) Grayish-brown fine-grained SANDSTONE (Renton Formation) Black COAL (Renton Formation) COAL and ROCK FRAGMENTS? (collapsed mine workings?)Soft drilling from 45 to 58 feet; lost air circulation; possible collapsed coal mine workings. Rock?Groundwater encountered at 45 feet at the time of drilling ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 50 55 60 65 70 75 80 85 90 95 100 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-11 Page 2 of 2 Comments 50 55 60 65 70 75 80 85 90 95 100Depth in FeetSoilClassificationSymbolSampleLocationBoring Log - Figure 18 Groundwater Observations Icicle Creek Engineers See Figure 7 for explanation of symbols Boring completed at 58 feet on September 28, 2015 COAL and ROCK FRAGMENTS? (collapsed mine workings?)Soft drilling from 45 to 58 feet; lost air circulation; possible collapsed coal mine workings. Rock? Rock?ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 0 5 10 15 20 25 30 35 40 45 50 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-12 Approximate Ground Surface Elevation: 141 feet Page 1 of 2 Boring Log - Figure 19 Comments Groundwater Observations 0 5 10 15 20 25 30 35 40 45 50Depth in FeetSoilClassificationSymbolSampleLocationIcicle Creek Engineers See Figure 7 for explanation of symbols Unweathered bedrock encountered at 12 feet SM Rock Rock Rock Rock Rock Rock Rock Gray to light gray fine-grained SANDSTONE (Renton Formation) Brown silty fine to medium SAND with gravel (Fill) grades to gray to brownish-gray Reddish-brown silty fine SAND (weathered bedrock) SM SM grades to gray to light gray grades to grayish-brown Very soft drilling from 48 to 60 feet;lost air circulation; possible collapsed coal mine workings.ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 50 55 60 65 70 75 80 85 90 95 100 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-12 Page 2 of 2 Comments 50 55 60 65 70 75 80 85 90 95 100Depth in FeetSoilClassificationSymbolSampleLocationBoring Log - Figure 19 Groundwater Observations Icicle Creek Engineers See Figure 7 for explanation of symbols Rock? Rock Boring completed at 70 feet on September 28, 2015 Black COAL (Renton Formation) Very soft drilling from 48 to 60 feet: possible collapsed coal mine workings. Grayish-brown fine-grained SANDSTONE (Renton Formation) COAL and ROCK FRAGMENTS? (collapsed mine workings?) Grayish-brown fine-grained SANDSTONE? (Renton Formation) Lost air circulation at 55 feet Groundwater encountered at 55 feet at the time of drilling hard drilling at 60 feetRock? Rock?ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 0 5 10 15 20 25 30 35 40 45 50 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-13 Approximate Ground Surface Elevation: 148 feet Page 1 of 2 Boring Log - Figure 20 Comments Groundwater Observations 0 5 10 15 20 25 30 35 40 45 50Depth in FeetSoilClassificationSymbolSampleLocationIcicle Creek Engineers See Figure 7 for explanation of symbols Unweathered bedrock encountered at 8 feet Rock Rock Rock Rock Rock Grayish-brown fine-grained SANDSTONE (Renton Formation) Grayish-brown to reddish-yellow silty fine SAND (weathered bedrock) SM SM Dark-brown CARBONACEOUS SHALE (Renton Formation) Black COAL (Renton Formation) Very soft drilling from 37 to 50 feet; lost air circulation; possible collapsed coal mine workings. Alternating hard and soft drilling from 27 to 37 feet COAL and ROCK FRAGMENTS (collapsed mine workings?) Rock? Rock?ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 50 55 60 65 70 75 80 85 90 95 100 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-13 Page 2 of 2 Comments 50 55 60 65 70 75 80 85 90 95 100Depth in FeetSoilClassificationSymbolSampleLocationBoring Log - Figure 20 Groundwater Observations Icicle Creek Engineers See Figure 7 for explanation of symbols Boring completed at 66 feet on September 28, 2015 Hard drilling 50 to 55 feetSANDSTONE? (Renton Formation) Rock? Rock? Rock? Rock?Groundwater encountered at 55 feet at the time of drillingSoft drilling 55 to 60 feet ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 0 5 10 15 20 25 30 35 40 45 50 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-14 Approximate Ground Surface Elevation: 151 feet Page 1 of 2 Boring Log - Figure 21 Comments Groundwater Observations 0 5 10 15 20 25 30 35 40 45 50Depth in FeetSoilClassificationSymbolSampleLocationIcicle Creek Engineers See Figure 7 for explanation of symbols Unweathered bedrock encountered at 8 feet SM Rock Rock Rock Rock Rock Rock Rock Rock Light brown fine-grained SANDSTONE (Renton Formation) Brown silty fine to medium SAND with gravel (Fill) grades to dark gray grades to gray Dark brown CARBONACEOUS SHALE (Renton Formation) Black COAL (Renton Formation)Smooth drilling from 41 to 50 feet Alternating slow and fast drilling from 35 to 40 feet ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 50 55 60 65 70 75 80 85 90 95 100 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-14 Page 2 of 2 Comments 50 55 60 65 70 75 80 85 90 95 100Depth in FeetSoilClassificationSymbolSampleLocationBoring Log - Figure 21 Groundwater Observations Icicle Creek Engineers See Figure 7 for explanation of symbols Rock Rock Boring completed at 75 feet on September 28, 2015 Groundwater encountered at 70 feet at the time of drilling Black Coal (Renton Formation) very soft drilling from 70 to 72 feet; hard drilling from 73 to 75 feet Slow drilling from 50 to 53 feet Slow drilling from 58 to 60 feet; Lost air circulation at 60 feet; possible collapsed coal mine workings. COAL and ROCK FRAGMENTS (collapsed mine workings?) SANDSTONE? (Renton Formation)ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 0 5 10 15 20 25 30 35 40 45 50 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-15 Approximate Ground Surface Elevation: 155 feet Page 1 of 2 Boring Log - Figure 22 Comments Groundwater Observations 0 5 10 15 20 25 30 35 40 45 50Depth in FeetSoilClassificationSymbolSampleLocationIcicle Creek Engineers See Figure 7 for explanation of symbols Unweathered bedrock encountered at 10 feet SM Rock Rock Rock Rock Rock Rock Rock Rock Black COAL FINES (Fill) Brown silty fine to medium SAND with gravel (Fill) Soft drilling from 45 to 50 feet Dark brown CARBONACEOUS SHALE (Renton Formation) Black COAL (Renton Formation) Alternating hard and soft drilling from 31 to 41 feet Gray fine-grained SANDSTONE (Renton Formation) Dark brown CARBONACEOUS SHALE (Renton Formation) Grayish-brown fine-grained SANDSTONE (Renton Formation) Dark brown CARBONACEOUS SHALE with thin layers of coal (Renton Formation)ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 50 55 60 65 70 75 80 85 90 95 100 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-15 Page 2 of 2 Comments 50 55 60 65 70 75 80 85 90 95 100Depth in FeetSoilClassificationSymbolSampleLocationBoring Log - Figure 22 Groundwater Observations Icicle Creek Engineers See Figure 7 for explanation of symbols Rock Rock Boring completed at 58 feet on September 28, 2015 Black Coal (Renton Formation) Light gray fine-grained SANDSTONE (Renton Formation) Groundwater encountered at 58 feet at the time of drilling ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 0 5 10 15 20 25 30 35 40 45 50 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-16 Approximate Ground Surface Elevation: 158 feet Page 1 of 2 Boring Log - Figure 23 Comments Groundwater Observations 0 5 10 15 20 25 30 35 40 45 50Depth in FeetSoilClassificationSymbolSampleLocationIcicle Creek Engineers See Figure 7 for explanation of symbols Unweathered bedrock encountered at 10 feet SM Rock Rock Rock Rock Rock Rock Rock SM Brown silty fine to medium SAND with gravel (Fill) Black COAL (Renton Formation) Gray fine-grained SANDSTONE (Renton Formation) Dark brown CARBONACEOUS SHALE (Renton Formation) Reddish-yellow silty fine SAND (weathered bedrock) Dark gray fine-grained SANDSTONE (Renton Formation) Dark brown CARBONACEOUS SHALE (Renton Formation)ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 50 55 60 65 70 75 80 85 90 95 100 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-16 Page 2 of 2 Comments 50 55 60 65 70 75 80 85 90 95 100Depth in FeetSoilClassificationSymbolSampleLocationBoring Log - Figure 23 Groundwater Observations Icicle Creek Engineers See Figure 7 for explanation of symbols Rock Rock Boring completed at 55 feet on September 28, 2015 Black Coal (Renton Formation) Gray fine-grained SANDSTONE (Renton Formation) No groundwater encountered at the time of drilling ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 0 5 10 15 20 25 30 35 40 45 50 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-17 Approximate Ground Surface Elevation: 122 feet Page 1 of 2 Boring Log - Figure 24 Comments Groundwater Observations 0 5 10 15 20 25 30 35 40 45 50Depth in FeetSoilClassificationSymbolSampleLocationIcicle Creek Engineers See Figure 7 for explanation of symbols Unweathered bedrock encountered at 10 feet SM Rock Rock Rock Rock Rock Rock Rock Rock Brown silty fine to medium SAND with gravel (Fill) Black COAL (Renton Formation) Gray fine-grained SANDSTONE (Renton Formation) Dark brown CARBONACEOUS SHALE (Renton Formation) Reddish-yellow silty fine SAND (weathered bedrock) grades to dark gray grades to light gray Light grayish-brown fine-grained SANDSTONE (Renton Formation)ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15SM 50 55 60 65 70 75 80 85 90 95 100 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-17 Page 2 of 2 Comments 50 55 60 65 70 75 80 85 90 95 100Depth in FeetSoilClassificationSymbolSampleLocationBoring Log - Figure 24 Groundwater Observations Icicle Creek Engineers See Figure 7 for explanation of symbols Rock Rock Boring completed at 65 feet on September 28, 2015 grades to gray Light grayish-brown fine-grained SANDSTONE (Renton Formation) Groundwater encountered at 55 feet at the time of drilling ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 0 5 10 15 20 25 30 35 40 45 50 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-18 Approximate Ground Surface Elevation: 120 feet Page 1 of 2 Boring Log - Figure 25 Comments Groundwater Observations 0 5 10 15 20 25 30 35 40 45 50Depth in FeetSoilClassificationSymbolSampleLocationIcicle Creek Engineers See Figure 7 for explanation of symbols Unweathered bedrock encountered at 10 feet SM Rock Rock Rock Rock Rock Rock Rock SM Brown silty fine to medium SAND with gravel (Fill) Black COAL (Renton Formation) Gray fine-grained SANDSTONE (Renton Formation) Dark brown CARBONACEOUS SHALE (Renton Formation) Reddish-yellow silty fine SAND (weathered bedrock) grades to gray Light grayish-brown fine-grained SANDSTONE (Renton Formation) grades to light gray ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15SM 50 55 60 65 70 75 80 85 90 95 100 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-18 Page 2 of 2 Comments 50 55 60 65 70 75 80 85 90 95 100Depth in FeetSoilClassificationSymbolSampleLocationBoring Log - Figure 25 Groundwater Observations Icicle Creek Engineers See Figure 7 for explanation of symbols Rock Rock Boring completed at 56 feet on September 28, 2015 Light grayish-brown fine-grained SANDSTONE (Renton Formation) Groundwater encountered at 55 feet at the time of drilling ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 0 5 10 15 20 25 30 35 40 45 50 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-19 Approximate Ground Surface Elevation: 125 feet Page 1 of 2 Boring Log - Figure 26 Comments Groundwater Observations 0 5 10 15 20 25 30 35 40 45 50Depth in FeetSoilClassificationSymbolSampleLocationIcicle Creek Engineers See Figure 7 for explanation of symbols Unweathered bedrock encountered at 7 feet SM Rock Rock Rock Rock Rock Rock Rock Brown silty fine to medium SAND with gravel (Fill) Black COAL (Renton Formation) Gray fine-grained SANDSTONE (Renton Formation) Dark brown CARBONACEOUS SHALE (Renton Formation) Reddish-yellow silty fine SAND (weathered bedrock) grades to gray grades to light gray grades to gray Rock ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15SM 50 55 60 65 70 75 80 85 90 95 100 Soil/Rock Profile Description Graphic Log Depth in FeetBoring B-19 Page 2 of 2 Comments 50 55 60 65 70 75 80 85 90 95 100Depth in FeetSoilClassificationSymbolSampleLocationBoring Log - Figure 26 Groundwater Observations Icicle Creek Engineers See Figure 7 for explanation of symbols Rock Rock Boring completed at 70 feet on September 28, 2015 Black Coal (Renton Formation) Groundwater encountered at 60 feet at the time of drillingVery soft drilling from 60 to 70 feet; lost air circulation; possible collapsed coal mine workings. COAL and ROCK FRAGMENTS? (collapsed mine workings?)Rock Rock ICE Project No. 1096-001Project Name: Newfourth LLC PropertyLogged by: JMS BRB:11/16/15 Cherie Lane Short Plat Technical Information Report Appendix C Wetland Delineation and Classification by Altman Oliver Associates, LLC dated December 14, 2017 December 14, 2017 AOA-1773 Steve Beck Newfourth LLC 19244 39th Ave. S. SeaTac, WA 98188-5316 SUBJECT: Wetland Delineation and Classification for Cherie Lane (Revised) Parcel 302305-9108, Renton, WA Dear Steve: We have updated this critical areas report to incorporate the results of a site review meeting that was conducted on July 10, 2017 with Jill Ding, Senior Planner with the City of Renton and Jeff Gray, Senior Wetland Scientist with Otak, the City’s peer review consultant. Background On January 20, 2016 I conducted a wetland delineation on the undeveloped subject property utilizing the methodology outlined in the May 2010 Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region (Version 2.0). Additional field investigations were conducted on September 14 and November 1, 2016. Wetland Flags AA-4 through AA-8 were added during the July 10, 2017 site review meeting. These flags are intended to show the connection between Wetland Areas A and AA. 1.0 EXISTING WETLANDS One wetland (Wetland A) was identified as a mosaic throughout the central portion of the property. The wetland boundary (including the newer AA flags) was surveyed by Encompass Engineering & Surveying. A second wetland (Wetland B) is located off-site to the southeast. The approximate location of this wetland was taken from a map prepared by the Jay Group in 2010 (Attachment A) and the approximate location confirmed during the November 1, 2016 field review. It is my understanding that a third wetland has been identified by Sewall Wetland Consulting, Inc. off-site to the northeast. This wetland has also been added to the Encompass plans. Steve Beck December 14, 2017 Page 2 It is also my understanding that the seepage observed within the excavated ditch in the northwest portion of the site was considered artificial and would not be considered a regulated wetland by the City. However, if the ditch were to be filled then the Corps of Engineers would need to be notified to make a determination. 1.1 Wetland A Mosaic Vegetation within the wetland mosaic includes hydrophytic trees such as black cottonwood (Populus trichocarpa), Pacific willow (Salix lasiandra), and Oregon ash (Fraxinus latifolia). Understory vegetation was dominated by a mix of hydrophytic and mesic species including dense Himalayan blackberry (Rubus armeniacus), snowberry (Symphoricarpos albus), black twinberry (Lonicera involucrata), and sword fern (Polystichum munitum). Soils throughout the wetland generally consisted of a low chroma clay loam mixed with charcoal. Soil profiles were highly variable and have likely been disturbed by historic mining activities. Hydrology within the wetland consists of a seasonal high groundwater table and no significant ponding has been observed during numerous “wet season” reviews conducted over the past 15 years. The wetland appears to generally drain off-site to the southwest within a small swale. Attachment B contains data sheets prepared for a representative location along the wetland and upland interface of Wetland A. These data sheets document the vegetation, soils, and hydrology information that aided in the wetland boundary delineation. Wetland A is a Depressional Hydrogeomorphic (HGM) class wetland. Per the current City of Renton rating system (2014 DOE methodology) and the Otak peer review comments, Wetland A meets the criteria for a Category IV wetland with 4 habitat points (Attachment C) and would therefore require a standard 50-foot buffer plus additional 15-foot structure setback adjacent moderate to high impact land uses. 1.2 Wetland B Wetland B consists of a topographic depression and gentle slope located off-site to the southeast. Runoff within the wetland drains west and at the time of the November 1, 2016 field investigation, soils within the wetland were generally saturated to the surface. Vegetation within the Wetland B consisted of a deciduous forested that included black cottonwood, Oregon ash, and red alder (Alnus rubra), salmonberry (Rubus spectabilis), snowberry, black twinberry, red-osier dogwood (Cornus sericea), lady fern (Athyrium filix-femina), and climbing nightshade (Solanum dulcamara). Steve Beck December 14, 2017 Page 3 Per the peer review comments Wetland B meets the criteria for a Category III wetland with 4 habitat points (Attachment C) and would therefore require a standard 75-foot buffer plus additional 15-foot structure setback adjacent moderate to high impact land uses. 1.3 Wetland Per Sewell Report The wetland off-site to the northeast has been identified within the Sewell report as a Category IV wetland that requires a standard 50-foot buffer adjacent moderate to high impact land uses. 2.0 PROPOSED PROJECT IMPACTS The proposed project has been revised and now consists of a reduced 2-lot Short Plat and the access road along the north property line has been removed. There are no longer any proposed impacts to wetland buffers on the site and buffer averaging will no longer be utilized. It is my understanding that there are no plans to widen the existing driveway to Lot 1 and the artificial seepage area within the ditch in the northwest corner of the site will not be filled. If you have any questions, please give me a call. Sincerely, ALTMANN OLIVER ASSOCIATES, LLC John Altmann Ecologist Attachments Confirmed 07/10/17 Confirmed 07/10/17 King County, Pictometry International Corp., King County King County iMap Date: 8/2/2016 Notes: ±The information included on this map has been compiled by King County staff from a variety of sources and is subject to changewithout notice. King County makes no representations or warranties, express or implied, as to accuracy, completeness, timeliness,or rights to the use of such information. This document is not intended for use as a survey product. King County shall not be liablefor any general, special, indirect, incidental, or consequential damages including, but not limited to, lost revenues or lost profitsresulting from the use or misuse of the information contained on this map. Any sale of this map or information on this map isprohibited except by written permission of King County. PROJECTDRAWNDATESCALEREVISEDLandscapeArchitectureAOAEnvironmentalPlanning &Office (425) 333-4535PO Box 578Carnation, WA 98014Fax (425) 333-4509Altmann Oliver Associates, LLC1773-MIT-11-30-16.dwg 8/2/2016 Water Quality Atlas Start Page | Washington State Department of Ecology, 303(d), 305(b), assessed waters, assessed sediments, permitted outfa… https://fortress.wa.gov/ecy/waterqualityatlas/map.aspx?CustomMap=y&RT=0&Layers=23,29&Filters=n,n,n,n 1/1 Washington State Water Quality Atlas Ecology home | Water Quality Program home | Disclaimer | Privacy notice | Accessibility | Contact admin | Water Quality Atlas Version: 1.0.0.0 Copyright © Washington State Department of Ecology 2016. All rights reserved. Home Add Map Data Clear Map Data + – Basemap Assessment Standards Outfalls WQI Projects SITE 12/14/2017 TMDL Project Information for WRIA 9 | WA State Department of Ecology http://www.ecy.wa.gov/programs/wq/tmdl/TMDLsbyWria/tmdl-wria09.html 1/1 About us | Contact usCustom Search Search Search results now have ads — here's why Home Water Quality & Supply Waste & Toxics Air & Climate Cleanup & Spills Water Quality Improvement > Water Quality Improvement Projects by WRIA > WRIA 9: Duwamish-Green WRIA 9: Duwamish-Green The following table lists overview information for water quality improvement projects (including total maximum daily loads, or TMDLs) for this water resource inventory area (WRIA). Please use links (where available) for more information on a project. Counties King Waterbody Name Pollutants Status**TMDL Lead Duwamish and Lower Green River Ammonia-N Approved by EPA Joan Nolan 425-649-4425 Fauntleroy Creek Fecal Coliform Approved by EPA Has an implementation plan Joan Nolan 425-649-4425 Fenwick Lake Total Phosphorus Approved by EPA (1993, Clean Lakes Program) Category 5, 2008 Water Quality Assessment Tricia Shoblom 425-649-7288 Green River and Newaukum Creek Temperature Dissolved Oxygen Green River TMDL Approved by EPA Newaukum Creek TMDL Approved by EPA Has an implementation plan Joan Nolan 425-649-4425 Lake Sawyer Total Phosphorus Approved by EPA Has an implementation plan Tricia Shoblom 425-649-7288 Newaukum Creek Bacteria Under development Joan Nolan 425-649-4425 Soos Creek Fecal Coliform Under development Joan Nolan 425-649-4425 Aquatic Habitat Dissolved Oxygen Temperature ** Status will be listed as one of the following: Approved by EPA, Under Development or Implementation For more information about WRIA 9: Waterbodies in WRIA 9 - using the Water Quality Assessment Query Tool Watershed Information for WRIA 9 * The Department of Ecology and other state resource agencies frequently use a system of 62 "Water Resource Inventory Areas" or "WRIAs" to refer to the state's major watershed basins. 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WETLAND CATEGORY IV WETLAND CATEGORY IV WETLAND CATEGORY III 50' SITE PLAN A Cherie Lane Short Plat Technical Information Report Appendix D Tree Health Report by Arborists NW, LLC dated December 27, 2016 Cherie Lane Short Plat Technical Information Report Appendix E WWHM Output WWHM2012 PROJECT REPORT WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:11:23 PM Page 2 General Model Information Project Name:WWHM Model_Flow Control_UPDATES 8-14-2020 Site Name: Site Address: City: Report Date:8/14/2020 Gage:Seatac Data Start:1948/10/01 Data End:2009/09/30 Timestep:15 Minute Precip Scale:1.000 Version Date:2019/09/13 Version:4.2.17 POC Thresholds Low Flow Threshold for POC1:50 Percent of the 2 Year High Flow Threshold for POC1:50 Year WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:11:23 PM Page 3 Landuse Basin Data Predeveloped Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre C, Forest, Steep 0.793 Pervious Total 0.793 Impervious Land Use acre Impervious Total 0 Basin Total 0.793 Element Flows To: Surface Interflow Groundwater WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:11:23 PM Page 4 Mitigated Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre C, Forest, Mod 0.212 C, Lawn, Mod 0.032 C, Pasture, Mod 0.322 Pervious Total 0.566 Impervious Land Use acre ROOF TOPS FLAT 0.032 DRIVEWAYS FLAT 0.022 DRIVEWAYS MOD 0.173 Impervious Total 0.227 Basin Total 0.793 Element Flows To: Surface Interflow Groundwater WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:11:23 PM Page 5 Routing Elements Predeveloped Routing WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:11:23 PM Page 6 Mitigated Routing WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:11:23 PM Page 7 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area:0.793 Total Impervious Area:0 Mitigated Landuse Totals for POC #1 Total Pervious Area:0.566 Total Impervious Area:0.227 Flow Frequency Method:Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.035486 5 year 0.056525 10 year 0.070185 25 year 0.086706 50 year 0.098374 100 year 0.109469 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.110636 5 year 0.145061 10 year 0.169631 25 year 0.202772 50 year 0.229029 100 year 0.25667 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.040 0.157 1950 0.044 0.133 1951 0.069 0.100 1952 0.026 0.072 1953 0.020 0.077 1954 0.028 0.091 1955 0.051 0.098 1956 0.038 0.092 1957 0.036 0.115 1958 0.034 0.087 WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:11:57 PM Page 8 1959 0.028 0.087 1960 0.051 0.115 1961 0.027 0.096 1962 0.020 0.073 1963 0.026 0.099 1964 0.032 0.089 1965 0.024 0.112 1966 0.022 0.080 1967 0.052 0.147 1968 0.029 0.151 1969 0.031 0.097 1970 0.027 0.104 1971 0.028 0.121 1972 0.055 0.129 1973 0.028 0.070 1974 0.027 0.114 1975 0.043 0.119 1976 0.029 0.099 1977 0.005 0.084 1978 0.028 0.116 1979 0.014 0.144 1980 0.065 0.200 1981 0.021 0.106 1982 0.053 0.160 1983 0.037 0.114 1984 0.025 0.080 1985 0.014 0.095 1986 0.062 0.107 1987 0.055 0.129 1988 0.023 0.079 1989 0.014 0.126 1990 0.117 0.259 1991 0.068 0.184 1992 0.029 0.088 1993 0.028 0.086 1994 0.009 0.076 1995 0.034 0.094 1996 0.078 0.153 1997 0.069 0.113 1998 0.022 0.102 1999 0.061 0.204 2000 0.029 0.106 2001 0.007 0.112 2002 0.033 0.133 2003 0.044 0.147 2004 0.064 0.206 2005 0.041 0.096 2006 0.041 0.092 2007 0.089 0.229 2008 0.117 0.192 2009 0.054 0.135 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.1173 0.2586 2 0.1171 0.2287 3 0.0886 0.2058 WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:11:57 PM Page 9 4 0.0779 0.2039 5 0.0694 0.1995 6 0.0693 0.1918 7 0.0680 0.1843 8 0.0651 0.1600 9 0.0641 0.1566 10 0.0624 0.1526 11 0.0614 0.1509 12 0.0555 0.1469 13 0.0546 0.1467 14 0.0540 0.1437 15 0.0532 0.1354 16 0.0522 0.1327 17 0.0512 0.1327 18 0.0508 0.1294 19 0.0437 0.1292 20 0.0436 0.1256 21 0.0428 0.1206 22 0.0411 0.1186 23 0.0410 0.1161 24 0.0398 0.1150 25 0.0385 0.1146 26 0.0367 0.1142 27 0.0363 0.1137 28 0.0343 0.1131 29 0.0341 0.1120 30 0.0334 0.1118 31 0.0323 0.1069 32 0.0310 0.1058 33 0.0294 0.1056 34 0.0293 0.1042 35 0.0293 0.1018 36 0.0292 0.1003 37 0.0282 0.0987 38 0.0281 0.0985 39 0.0280 0.0976 40 0.0278 0.0974 41 0.0276 0.0961 42 0.0276 0.0960 43 0.0275 0.0949 44 0.0275 0.0940 45 0.0275 0.0924 46 0.0259 0.0916 47 0.0258 0.0907 48 0.0254 0.0894 49 0.0245 0.0877 50 0.0235 0.0874 51 0.0223 0.0869 52 0.0220 0.0858 53 0.0213 0.0844 54 0.0200 0.0801 55 0.0196 0.0801 56 0.0142 0.0788 57 0.0142 0.0766 58 0.0141 0.0763 59 0.0094 0.0733 60 0.0066 0.0723 61 0.0051 0.0702 WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:11:57 PM Page 10 WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:11:57 PM Page 11 Duration Flows Flow(cfs)Predev Mit Percentage Pass/Fail 0.0177 11407 34243 300 Fail 0.0186 10371 31570 304 Fail 0.0194 9439 29132 308 Fail 0.0202 8635 26928 311 Fail 0.0210 7937 24811 312 Fail 0.0218 7276 22950 315 Fail 0.0226 6678 21196 317 Fail 0.0234 6100 19650 322 Fail 0.0243 5612 18157 323 Fail 0.0251 5150 16792 326 Fail 0.0259 4772 15625 327 Fail 0.0267 4410 14523 329 Fail 0.0275 4072 13526 332 Fail 0.0283 3764 12596 334 Fail 0.0291 3544 11721 330 Fail 0.0300 3290 10960 333 Fail 0.0308 3069 10241 333 Fail 0.0316 2862 9574 334 Fail 0.0324 2667 8962 336 Fail 0.0332 2479 8410 339 Fail 0.0340 2306 7869 341 Fail 0.0348 2158 7424 344 Fail 0.0357 1970 6971 353 Fail 0.0365 1827 6536 357 Fail 0.0373 1684 6151 365 Fail 0.0381 1573 5801 368 Fail 0.0389 1460 5463 374 Fail 0.0397 1362 5146 377 Fail 0.0405 1269 4842 381 Fail 0.0414 1173 4564 389 Fail 0.0422 1100 4310 391 Fail 0.0430 1030 4053 393 Fail 0.0438 962 3807 395 Fail 0.0446 904 3583 396 Fail 0.0454 849 3364 396 Fail 0.0462 802 3161 394 Fail 0.0471 750 2986 398 Fail 0.0479 715 2830 395 Fail 0.0487 679 2676 394 Fail 0.0495 638 2537 397 Fail 0.0503 605 2408 398 Fail 0.0511 572 2289 400 Fail 0.0520 542 2165 399 Fail 0.0528 503 2082 413 Fail 0.0536 469 1984 423 Fail 0.0544 435 1880 432 Fail 0.0552 391 1786 456 Fail 0.0560 351 1698 483 Fail 0.0568 321 1625 506 Fail 0.0577 293 1561 532 Fail 0.0585 264 1486 562 Fail 0.0593 230 1409 612 Fail 0.0601 203 1352 666 Fail 0.0609 177 1288 727 Fail WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:11:57 PM Page 12 0.0617 160 1224 765 Fail 0.0625 141 1172 831 Fail 0.0634 130 1121 862 Fail 0.0642 116 1068 920 Fail 0.0650 103 1019 989 Fail 0.0658 95 969 1020 Fail 0.0666 78 924 1184 Fail 0.0674 71 882 1242 Fail 0.0682 58 843 1453 Fail 0.0691 49 802 1636 Fail 0.0699 46 771 1676 Fail 0.0707 44 737 1675 Fail 0.0715 43 714 1660 Fail 0.0723 42 681 1621 Fail 0.0731 41 646 1575 Fail 0.0739 40 618 1545 Fail 0.0748 39 593 1520 Fail 0.0756 36 572 1588 Fail 0.0764 34 548 1611 Fail 0.0772 34 528 1552 Fail 0.0780 30 511 1703 Fail 0.0788 28 491 1753 Fail 0.0796 26 468 1800 Fail 0.0805 25 442 1768 Fail 0.0813 22 418 1900 Fail 0.0821 20 404 2020 Fail 0.0829 18 388 2155 Fail 0.0837 14 374 2671 Fail 0.0845 13 362 2784 Fail 0.0853 11 345 3136 Fail 0.0862 10 330 3300 Fail 0.0870 10 317 3170 Fail 0.0878 8 296 3700 Fail 0.0886 6 289 4816 Fail 0.0894 4 274 6850 Fail 0.0902 4 265 6625 Fail 0.0910 4 258 6450 Fail 0.0919 3 247 8233 Fail 0.0927 3 243 8100 Fail 0.0935 3 235 7833 Fail 0.0943 3 228 7600 Fail 0.0951 3 219 7300 Fail 0.0959 3 212 7066 Fail 0.0967 3 204 6800 Fail 0.0976 3 198 6600 Fail 0.0984 3 193 6433 Fail The development has an increase in flow durations from 1/2 Predeveloped 2 year flow to the 2 year flow or more than a 10% increase from the 2 year to the 50 year flow. The development has an increase in flow durations for more than 50% of the flows for the range of the duration analysis. WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:11:57 PM Page 13 Water Quality Water Quality BMP Flow and Volume for POC #1 On-line facility volume:0.0537 acre-feet On-line facility target flow:0.0354 cfs. Adjusted for 15 min:0.0354 cfs. Off-line facility target flow:0.0195 cfs. Adjusted for 15 min:0.0195 cfs. WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:11:57 PM Page 14 LID Report WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:12:20 PM Page 15 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. WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:12:20 PM Page 16 Appendix Predeveloped Schematic WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:12:22 PM Page 17 Mitigated Schematic WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:12:24 PM Page 18 Predeveloped UCI File RUN GLOBAL WWHM4 model simulation START 1948 10 01 END 2009 09 30 RUN INTERP OUTPUT LEVEL 3 0 RESUME 0 RUN 1 UNIT SYSTEM 1 END GLOBAL FILES <File> <Un#> <-----------File Name------------------------------>*** <-ID-> *** WDM 26 WWHM Model_Flow Control_UPDATES 8-14-2020.wdm MESSU 25 PreWWHM Model_Flow Control_UPDATES 8-14-2020.MES 27 PreWWHM Model_Flow Control_UPDATES 8-14-2020.L61 28 PreWWHM Model_Flow Control_UPDATES 8-14-2020.L62 30 POCWWHM Model_Flow Control_UPDATES 8-14-20201.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 12 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Basin 1 MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 12 C, Forest, Steep 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 12 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 ********* 12 0 0 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:12:24 PM Page 19 PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 12 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 12 0 4.5 0.08 400 0.15 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 12 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 12 0.2 0.3 0.35 6 0.3 0.7 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 12 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 *** END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS END IWAT-STATE1 WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:12:24 PM Page 20 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Basin 1*** PERLND 12 0.793 COPY 501 12 PERLND 12 0.793 COPY 501 13 ******Routing****** END SCHEMATIC NETWORK <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** END NETWORK RCHRES GEN-INFO RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out *** END GEN-INFO *** Section RCHRES*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** END HYDR-PARM1 HYDR-PARM2 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES END FTABLES EXT SOURCES <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:12:24 PM Page 21 WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP END EXT SOURCES EXT TARGETS <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** COPY 501 OUTPUT MEAN 1 1 48.4 WDM 501 FLOW ENGL REPL END EXT TARGETS MASS-LINK <Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 12 PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12 MASS-LINK 13 PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13 END MASS-LINK END RUN WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:12:24 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 WWHM Model_Flow Control_UPDATES 8-14-2020.wdm MESSU 25 MitWWHM Model_Flow Control_UPDATES 8-14-2020.MES 27 MitWWHM Model_Flow Control_UPDATES 8-14-2020.L61 28 MitWWHM Model_Flow Control_UPDATES 8-14-2020.L62 30 POCWWHM Model_Flow Control_UPDATES 8-14-20201.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 11 PERLND 17 PERLND 14 IMPLND 4 IMPLND 5 IMPLND 6 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Basin 1 MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 11 C, Forest, Mod 1 1 1 1 27 0 17 C, Lawn, Mod 1 1 1 1 27 0 14 C, Pasture, Mod 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 11 0 0 1 0 0 0 0 0 0 0 0 0 17 0 0 1 0 0 0 0 0 0 0 0 0 WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:12:24 PM Page 23 14 0 0 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 11 0 0 4 0 0 0 0 0 0 0 0 0 1 9 17 0 0 4 0 0 0 0 0 0 0 0 0 1 9 14 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 *** 11 0 0 0 0 0 0 0 0 0 0 0 17 0 0 0 0 0 0 0 0 0 0 0 14 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 11 0 4.5 0.08 400 0.1 0.5 0.996 17 0 4.5 0.03 400 0.1 0.5 0.996 14 0 4.5 0.06 400 0.1 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 11 0 0 2 2 0 0 0 17 0 0 2 2 0 0 0 14 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 11 0.2 0.5 0.35 6 0.5 0.7 17 0.1 0.25 0.25 6 0.5 0.25 14 0.15 0.4 0.3 6 0.5 0.4 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 11 0 0 0 0 2.5 1 0 17 0 0 0 0 2.5 1 0 14 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 *** 4 ROOF TOPS/FLAT 1 1 1 27 0 5 DRIVEWAYS/FLAT 1 1 1 27 0 6 DRIVEWAYS/MOD 1 1 1 27 0 END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** 4 0 0 1 0 0 0 5 0 0 1 0 0 0 6 0 0 1 0 0 0 WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:12:24 PM Page 24 END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* 4 0 0 4 0 0 0 1 9 5 0 0 4 0 0 0 1 9 6 0 0 4 0 0 0 1 9 END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** 4 0 0 0 0 0 5 0 0 0 0 0 6 0 0 0 0 0 END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC 4 400 0.01 0.1 0.1 5 400 0.01 0.1 0.1 6 400 0.05 0.1 0.08 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN 4 0 0 5 0 0 6 0 0 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 4 0 0 5 0 0 6 0 0 END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Basin 1*** PERLND 11 0.212 COPY 501 12 PERLND 11 0.212 COPY 501 13 PERLND 17 0.032 COPY 501 12 PERLND 17 0.032 COPY 501 13 PERLND 14 0.322 COPY 501 12 PERLND 14 0.322 COPY 501 13 IMPLND 4 0.032 COPY 501 15 IMPLND 5 0.022 COPY 501 15 IMPLND 6 0.173 COPY 501 15 ******Routing****** END SCHEMATIC NETWORK <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:12:24 PM Page 25 END NETWORK RCHRES GEN-INFO RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out *** END GEN-INFO *** Section RCHRES*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** END HYDR-PARM1 HYDR-PARM2 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES END FTABLES EXT SOURCES <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP END EXT SOURCES EXT TARGETS <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** COPY 1 OUTPUT MEAN 1 1 48.4 WDM 701 FLOW ENGL REPL COPY 501 OUTPUT MEAN 1 1 48.4 WDM 801 FLOW ENGL REPL END EXT TARGETS MASS-LINK <Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 12 PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12 MASS-LINK 13 PERLND PWATER IFWO 0.083333 COPY INPUT MEAN WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:12:24 PM Page 26 END MASS-LINK 13 MASS-LINK 15 IMPLND IWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 15 END MASS-LINK END RUN WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:12:24 PM Page 27 Predeveloped HSPF Message File WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:12:24 PM Page 28 Mitigated HSPF Message File WWHM Model_Flow Control_UPDATES 8-14-2020 8/14/2020 3:12:24 PM Page 29 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. 2005-2020; 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 WWHM2012 PROJECT REPORT WWHM Model_Water Quality 6/16/2020 11:58:17 AM Page 2 General Model Information Project Name:WWHM Model_Water Quality Site Name: Site Address: City: Report Date:6/16/2020 Gage:Seatac Data Start:1948/10/01 Data End:2009/09/30 Timestep:15 Minute Precip Scale:1.000 Version Date:2019/09/13 Version:4.2.17 POC Thresholds Low Flow Threshold for POC1:50 Percent of the 2 Year High Flow Threshold for POC1:50 Year WWHM Model_Water Quality 6/16/2020 11:58:17 AM Page 3 Landuse Basin Data Predeveloped Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre C, Forest, Steep 0.173 Pervious Total 0.173 Impervious Land Use acre Impervious Total 0 Basin Total 0.173 Element Flows To: Surface Interflow Groundwater WWHM Model_Water Quality 6/16/2020 11:58:17 AM Page 4 Mitigated Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre Pervious Total 0 Impervious Land Use acre ROADS MOD 0.173 Impervious Total 0.173 Basin Total 0.173 Element Flows To: Surface Interflow Groundwater WWHM Model_Water Quality 6/16/2020 11:58:17 AM Page 5 Routing Elements Predeveloped Routing WWHM Model_Water Quality 6/16/2020 11:58:17 AM Page 6 Mitigated Routing WWHM Model_Water Quality 6/16/2020 11:58:17 AM Page 7 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area:0.173 Total Impervious Area:0 Mitigated Landuse Totals for POC #1 Total Pervious Area:0 Total Impervious Area:0.173 Flow Frequency Method:Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.007742 5 year 0.012331 10 year 0.015312 25 year 0.018916 50 year 0.021461 100 year 0.023882 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.07681 5 year 0.097525 10 year 0.111656 25 year 0.130044 50 year 0.144156 100 year 0.158642 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.009 0.097 1950 0.010 0.101 1951 0.015 0.058 1952 0.006 0.050 1953 0.004 0.060 1954 0.006 0.062 1955 0.011 0.074 1956 0.008 0.070 1957 0.008 0.072 1958 0.007 0.063 WWHM Model_Water Quality 6/16/2020 11:58:48 AM Page 8 1959 0.006 0.069 1960 0.011 0.066 1961 0.006 0.064 1962 0.004 0.055 1963 0.006 0.066 1964 0.007 0.067 1965 0.005 0.075 1966 0.005 0.055 1967 0.011 0.088 1968 0.006 0.118 1969 0.007 0.069 1970 0.006 0.070 1971 0.006 0.085 1972 0.012 0.085 1973 0.006 0.056 1974 0.006 0.079 1975 0.009 0.085 1976 0.006 0.064 1977 0.001 0.064 1978 0.006 0.094 1979 0.003 0.114 1980 0.014 0.117 1981 0.005 0.073 1982 0.012 0.105 1983 0.008 0.087 1984 0.006 0.056 1985 0.003 0.072 1986 0.014 0.063 1987 0.012 0.099 1988 0.005 0.066 1989 0.003 0.104 1990 0.026 0.122 1991 0.015 0.108 1992 0.006 0.057 1993 0.006 0.072 1994 0.002 0.063 1995 0.007 0.067 1996 0.017 0.086 1997 0.015 0.067 1998 0.005 0.072 1999 0.013 0.153 2000 0.006 0.071 2001 0.001 0.089 2002 0.007 0.090 2003 0.010 0.091 2004 0.014 0.149 2005 0.009 0.058 2006 0.009 0.054 2007 0.019 0.140 2008 0.026 0.099 2009 0.012 0.109 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.0256 0.1535 2 0.0255 0.1492 3 0.0193 0.1404 WWHM Model_Water Quality 6/16/2020 11:58:48 AM Page 9 4 0.0170 0.1216 5 0.0151 0.1180 6 0.0151 0.1174 7 0.0148 0.1135 8 0.0142 0.1091 9 0.0140 0.1078 10 0.0136 0.1053 11 0.0134 0.1038 12 0.0121 0.1014 13 0.0119 0.0994 14 0.0118 0.0991 15 0.0116 0.0972 16 0.0114 0.0942 17 0.0112 0.0912 18 0.0111 0.0905 19 0.0095 0.0887 20 0.0095 0.0884 21 0.0093 0.0873 22 0.0090 0.0857 23 0.0089 0.0851 24 0.0087 0.0850 25 0.0084 0.0845 26 0.0080 0.0793 27 0.0079 0.0753 28 0.0075 0.0735 29 0.0074 0.0735 30 0.0073 0.0723 31 0.0070 0.0720 32 0.0068 0.0718 33 0.0064 0.0716 34 0.0064 0.0708 35 0.0064 0.0700 36 0.0064 0.0696 37 0.0062 0.0693 38 0.0061 0.0692 39 0.0061 0.0672 40 0.0061 0.0667 41 0.0060 0.0665 42 0.0060 0.0663 43 0.0060 0.0662 44 0.0060 0.0659 45 0.0060 0.0639 46 0.0056 0.0638 47 0.0056 0.0638 48 0.0055 0.0632 49 0.0053 0.0626 50 0.0051 0.0625 51 0.0049 0.0615 52 0.0048 0.0600 53 0.0046 0.0584 54 0.0044 0.0578 55 0.0043 0.0566 56 0.0031 0.0563 57 0.0031 0.0557 58 0.0031 0.0552 59 0.0021 0.0545 60 0.0014 0.0542 61 0.0011 0.0502 WWHM Model_Water Quality 6/16/2020 11:58:48 AM Page 10 WWHM Model_Water Quality 6/16/2020 11:58:48 AM Page 11 Duration Flows Flow(cfs)Predev Mit Percentage Pass/Fail 0.0039 11405 100763 883 Fail 0.0040 10365 97618 941 Fail 0.0042 9437 94645 1002 Fail 0.0044 8628 91694 1062 Fail 0.0046 7940 88764 1117 Fail 0.0048 7270 86004 1182 Fail 0.0049 6669 83416 1250 Fail 0.0051 6100 80892 1326 Fail 0.0053 5608 78540 1400 Fail 0.0055 5150 76187 1479 Fail 0.0056 4770 74005 1551 Fail 0.0058 4408 71802 1628 Fail 0.0060 4072 69813 1714 Fail 0.0062 3764 67802 1801 Fail 0.0064 3542 65856 1859 Fail 0.0065 3285 63910 1945 Fail 0.0067 3069 62028 2021 Fail 0.0069 2862 60252 2105 Fail 0.0071 2667 58584 2196 Fail 0.0072 2479 56894 2295 Fail 0.0074 2306 55290 2397 Fail 0.0076 2158 53771 2491 Fail 0.0078 1970 52274 2653 Fail 0.0080 1827 50820 2781 Fail 0.0081 1682 49408 2937 Fail 0.0083 1572 48061 3057 Fail 0.0085 1459 46777 3206 Fail 0.0087 1362 45473 3338 Fail 0.0088 1268 44296 3493 Fail 0.0090 1173 43077 3672 Fail 0.0092 1100 41901 3809 Fail 0.0094 1030 40810 3962 Fail 0.0096 962 39740 4130 Fail 0.0097 905 38650 4270 Fail 0.0099 849 37687 4438 Fail 0.0101 804 36660 4559 Fail 0.0103 750 35655 4754 Fail 0.0104 715 34714 4855 Fail 0.0106 680 33837 4976 Fail 0.0108 638 32960 5166 Fail 0.0110 607 32147 5296 Fail 0.0112 572 31292 5470 Fail 0.0113 543 30436 5605 Fail 0.0115 503 29623 5889 Fail 0.0117 469 28918 6165 Fail 0.0119 436 28148 6455 Fail 0.0120 391 27378 7002 Fail 0.0122 351 26693 7604 Fail 0.0124 322 26073 8097 Fail 0.0126 293 25431 8679 Fail 0.0128 264 24811 9398 Fail 0.0129 230 24212 10526 Fail 0.0131 203 23613 11632 Fail 0.0133 177 23079 13038 Fail WWHM Model_Water Quality 6/16/2020 11:58:48 AM Page 12 0.0135 161 22501 13975 Fail 0.0136 142 22009 15499 Fail 0.0138 130 21474 16518 Fail 0.0140 117 20989 17939 Fail 0.0142 103 20452 19856 Fail 0.0144 95 19954 21004 Fail 0.0145 78 19492 24989 Fail 0.0147 72 19023 26420 Fail 0.0149 59 18572 31477 Fail 0.0151 49 18174 37089 Fail 0.0152 46 17727 38536 Fail 0.0154 44 17327 39379 Fail 0.0156 43 16936 39386 Fail 0.0158 42 16551 39407 Fail 0.0160 41 16191 39490 Fail 0.0161 40 15808 39520 Fail 0.0163 39 15451 39617 Fail 0.0165 36 15111 41975 Fail 0.0167 34 14754 43394 Fail 0.0168 34 14412 42388 Fail 0.0170 31 14091 45454 Fail 0.0172 28 13781 49217 Fail 0.0174 26 13505 51942 Fail 0.0176 25 13214 52856 Fail 0.0177 22 12951 58868 Fail 0.0179 20 12632 63159 Fail 0.0181 18 12356 68644 Fail 0.0183 14 12065 86178 Fail 0.0184 13 11813 90869 Fail 0.0186 11 11539 104900 Fail 0.0188 10 11240 112400 Fail 0.0190 10 10970 109700 Fail 0.0192 8 10735 134187 Fail 0.0193 6 10502 175033 Fail 0.0195 4 10269 256725 Fail 0.0197 4 10051 251275 Fail 0.0199 4 9837 245925 Fail 0.0200 3 9642 321400 Fail 0.0202 3 9435 314500 Fail 0.0204 3 9238 307933 Fail 0.0206 3 9039 301300 Fail 0.0208 3 8846 294866 Fail 0.0209 3 8656 288533 Fail 0.0211 3 8470 282333 Fail 0.0213 3 8286 276200 Fail 0.0215 3 8126 270866 Fail The development has an increase in flow durations from 1/2 Predeveloped 2 year flow to the 2 year flow or more than a 10% increase from the 2 year to the 50 year flow. The development has an increase in flow durations for more than 50% of the flows for the range of the duration analysis. WWHM Model_Water Quality 6/16/2020 11:58:48 AM Page 13 Water Quality Water Quality BMP Flow and Volume for POC #1 On-line facility volume:0.0209 acre-feet On-line facility target flow:0.0313 cfs. Adjusted for 15 min:0.0313 cfs. Off-line facility target flow:0.0176 cfs. Adjusted for 15 min:0.0176 cfs. WWHM Model_Water Quality 6/16/2020 11:58:48 AM Page 14 LID Report WWHM Model_Water Quality 6/16/2020 11:59:10 AM Page 15 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. WWHM Model_Water Quality 6/16/2020 11:59:10 AM Page 16 Appendix Predeveloped Schematic WWHM Model_Water Quality 6/16/2020 11:59:13 AM Page 17 Mitigated Schematic WWHM Model_Water Quality 6/16/2020 11:59:15 AM Page 18 Predeveloped UCI File RUN GLOBAL WWHM4 model simulation START 1948 10 01 END 2009 09 30 RUN INTERP OUTPUT LEVEL 3 0 RESUME 0 RUN 1 UNIT SYSTEM 1 END GLOBAL FILES <File> <Un#> <-----------File Name------------------------------>*** <-ID-> *** WDM 26 WWHM Model_Water Quality.wdm MESSU 25 PreWWHM Model_Water Quality.MES 27 PreWWHM Model_Water Quality.L61 28 PreWWHM Model_Water Quality.L62 30 POCWWHM Model_Water Quality1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 12 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Basin 1 MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 12 C, Forest, Steep 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 12 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 ********* 12 0 0 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO WWHM Model_Water Quality 6/16/2020 11:59:15 AM Page 19 PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 12 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 12 0 4.5 0.08 400 0.15 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 12 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 12 0.2 0.3 0.35 6 0.3 0.7 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 12 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 *** END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS END IWAT-STATE1 WWHM Model_Water Quality 6/16/2020 11:59:15 AM Page 20 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Basin 1*** PERLND 12 0.173 COPY 501 12 PERLND 12 0.173 COPY 501 13 ******Routing****** END SCHEMATIC NETWORK <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** END NETWORK RCHRES GEN-INFO RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out *** END GEN-INFO *** Section RCHRES*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** END HYDR-PARM1 HYDR-PARM2 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES END FTABLES EXT SOURCES <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC WWHM Model_Water Quality 6/16/2020 11:59:15 AM Page 21 WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP END EXT SOURCES EXT TARGETS <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** COPY 501 OUTPUT MEAN 1 1 48.4 WDM 501 FLOW ENGL REPL END EXT TARGETS MASS-LINK <Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 12 PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12 MASS-LINK 13 PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13 END MASS-LINK END RUN WWHM Model_Water Quality 6/16/2020 11:59:15 AM 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 WWHM Model_Water Quality.wdm MESSU 25 MitWWHM Model_Water Quality.MES 27 MitWWHM Model_Water Quality.L61 28 MitWWHM Model_Water Quality.L62 30 POCWWHM Model_Water Quality1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 IMPLND 2 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Basin 1 MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* END PRINT-INFO PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** WWHM Model_Water Quality 6/16/2020 11:59:15 AM Page 23 END PWAT-PARM1 PWAT-PARM2 <PLS > PWATER input info: Part 2 *** # - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 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 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 END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** 2 0 0 1 0 0 0 END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* 2 0 0 4 0 0 0 1 9 END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** 2 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 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN 2 0 0 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 2 0 0 END IWAT-STATE1 END IMPLND WWHM Model_Water Quality 6/16/2020 11:59:15 AM Page 24 SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Basin 1*** IMPLND 2 0.173 COPY 501 15 ******Routing****** END SCHEMATIC NETWORK <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** END NETWORK RCHRES GEN-INFO RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out *** END GEN-INFO *** Section RCHRES*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** END HYDR-PARM1 HYDR-PARM2 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES END FTABLES EXT SOURCES <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP WWHM Model_Water Quality 6/16/2020 11:59:15 AM Page 25 END EXT SOURCES EXT TARGETS <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** COPY 1 OUTPUT MEAN 1 1 48.4 WDM 701 FLOW ENGL REPL COPY 501 OUTPUT MEAN 1 1 48.4 WDM 801 FLOW ENGL REPL END EXT TARGETS MASS-LINK <Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 15 IMPLND IWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 15 END MASS-LINK END RUN WWHM Model_Water Quality 6/16/2020 11:59:15 AM Page 26 Predeveloped HSPF Message File WWHM Model_Water Quality 6/16/2020 11:59:15 AM Page 27 Mitigated HSPF Message File WWHM Model_Water Quality 6/16/2020 11:59:15 AM Page 28 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. 2005-2020; 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 WWHM2012 PROJECT REPORT WWHM Model_Conveyance Flow 6/22/2020 10:12:29 AM Page 2 General Model Information Project Name:WWHM Model_Conveyance Flow Site Name: Site Address: City: Report Date:6/22/2020 Gage:Landsburg Data Start:1948/10/01 Data End:2009/09/30 Timestep:15 Minute Precip Scale:1.429 Version Date:2019/09/13 Version:4.2.17 POC Thresholds Low Flow Threshold for POC1:50 Percent of the 2 Year High Flow Threshold for POC1:50 Year WWHM Model_Conveyance Flow 6/22/2020 10:12:29 AM Page 3 Landuse Basin Data Predeveloped Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre C, Forest, Mod 1.64 C, Forest, Steep 0.26 C, Lawn, Mod 7.542 Pervious Total 9.442 Impervious Land Use acre ROADS MOD 3.04 ROOF TOPS FLAT 7.542 Impervious Total 10.582 Basin Total 20.024 Element Flows To: Surface Interflow Groundwater WWHM Model_Conveyance Flow 6/22/2020 10:12:29 AM Page 4 Mitigated Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre C, Lawn, Mod 7.542 C, Forest, Mod 1.64 Pervious Total 9.182 Impervious Land Use acre ROADS MOD 3.235 ROOF TOPS FLAT 7.607 Impervious Total 10.842 Basin Total 20.024 Element Flows To: Surface Interflow Groundwater WWHM Model_Conveyance Flow 6/22/2020 10:12:29 AM Page 5 Routing Elements Predeveloped Routing WWHM Model_Conveyance Flow 6/22/2020 10:12:29 AM Page 6 Mitigated Routing WWHM Model_Conveyance Flow 6/22/2020 10:12:29 AM Page 7 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area:9.442 Total Impervious Area:10.582 Mitigated Landuse Totals for POC #1 Total Pervious Area:9.182 Total Impervious Area:10.842 Flow Frequency Method:Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 12.863549 5 year 20.02813 10 year 25.864057 25 year 34.62234 50 year 42.245549 100 year 50.892372 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 13.055262 5 year 20.294003 10 year 26.183102 25 year 35.012363 50 year 42.69062 100 year 51.393811 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 14.226 14.409 1950 15.345 15.475 1951 12.023 12.206 1952 7.547 7.673 1953 9.346 9.492 1954 16.783 17.002 1955 8.282 8.405 1956 9.328 9.454 1957 10.948 11.092 1958 6.799 6.934 WWHM Model_Conveyance Flow 6/22/2020 10:13:03 AM Page 8 1959 9.363 9.509 1960 9.321 9.486 1961 8.107 8.249 1962 6.095 6.194 1963 12.481 12.656 1964 24.930 25.103 1965 13.219 13.511 1966 7.860 8.009 1967 23.110 23.648 1968 8.114 8.244 1969 17.639 17.854 1970 7.297 7.427 1971 13.082 13.290 1972 23.938 24.382 1973 6.891 7.002 1974 12.093 12.272 1975 12.110 12.257 1976 8.578 8.708 1977 11.836 12.042 1978 8.580 8.717 1979 6.911 7.064 1980 8.929 9.076 1981 15.887 16.067 1982 6.679 6.813 1983 11.510 11.704 1984 22.331 22.599 1985 9.058 9.215 1986 16.266 16.539 1987 28.709 29.113 1988 9.781 9.986 1989 10.806 10.991 1990 16.005 16.188 1991 31.426 31.722 1992 24.472 24.708 1993 7.644 7.756 1994 33.577 34.205 1995 13.758 13.945 1996 15.070 15.183 1997 62.279 62.772 1998 17.807 18.271 1999 30.396 30.683 2000 13.500 13.656 2001 15.569 15.830 2002 17.388 17.580 2003 17.244 17.433 2004 29.324 29.631 2005 10.982 11.095 2006 10.293 10.404 2007 27.428 27.715 2008 20.548 20.699 2009 17.922 18.275 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 62.2794 62.7722 2 33.5765 34.2050 3 31.4259 31.7216 WWHM Model_Conveyance Flow 6/22/2020 10:13:03 AM Page 9 4 30.3959 30.6826 5 29.3242 29.6306 6 28.7091 29.1125 7 27.4283 27.7151 8 24.9297 25.1030 9 24.4721 24.7084 10 23.9379 24.3817 11 23.1102 23.6480 12 22.3314 22.5991 13 20.5481 20.6994 14 17.9220 18.2750 15 17.8065 18.2706 16 17.6386 17.8539 17 17.3880 17.5797 18 17.2437 17.4331 19 16.7830 17.0023 20 16.2656 16.5386 21 16.0049 16.1875 22 15.8867 16.0668 23 15.5693 15.8297 24 15.3453 15.4746 25 15.0696 15.1827 26 14.2260 14.4093 27 13.7575 13.9449 28 13.4996 13.6555 29 13.2188 13.5109 30 13.0815 13.2899 31 12.4813 12.6555 32 12.1104 12.2724 33 12.0926 12.2565 34 12.0227 12.2058 35 11.8360 12.0415 36 11.5098 11.7038 37 10.9816 11.0949 38 10.9475 11.0916 39 10.8058 10.9914 40 10.2932 10.4044 41 9.7813 9.9864 42 9.3633 9.5094 43 9.3465 9.4921 44 9.3276 9.4858 45 9.3211 9.4537 46 9.0582 9.2146 47 8.9289 9.0762 48 8.5803 8.7173 49 8.5785 8.7082 50 8.2819 8.4053 51 8.1136 8.2487 52 8.1066 8.2444 53 7.8603 8.0086 54 7.6444 7.7558 55 7.5474 7.6732 56 7.2969 7.4274 57 6.9115 7.0640 58 6.8907 7.0020 59 6.7992 6.9335 60 6.6791 6.8128 61 6.0949 6.1944 WWHM Model_Conveyance Flow 6/22/2020 10:13:03 AM Page 10 WWHM Model_Conveyance Flow 6/22/2020 10:13:03 AM Page 11 Duration Flows Flow(cfs)Predev Mit Percentage Pass/Fail 6.4318 841 877 104 Fail 6.7935 698 743 106 Fail 7.1553 609 636 104 Fail 7.5170 534 558 104 Fail 7.8788 454 477 105 Fail 8.2406 393 409 104 Fail 8.6023 334 352 105 Fail 8.9641 299 311 104 Fail 9.3258 273 281 102 Fail 9.6876 244 254 104 Fail 10.0493 220 225 102 Fail 10.4111 204 210 102 Fail 10.7728 178 185 103 Fail 11.1346 161 165 102 Fail 11.4963 146 153 104 Fail 11.8581 138 141 102 Fail 12.2199 127 133 104 Fail 12.5816 114 121 106 Fail 12.9434 109 111 101 Pass 13.3051 102 104 101 Pass 13.6669 97 98 101 Pass 14.0286 92 96 104 Pass 14.3904 89 91 102 Pass 14.7521 82 85 103 Pass 15.1139 77 80 103 Pass 15.4757 73 74 101 Pass 15.8374 63 68 107 Pass 16.1992 55 58 105 Pass 16.5609 51 52 101 Pass 16.9227 49 50 102 Pass 17.2844 43 48 111 Fail 17.6462 39 41 105 Pass 18.0079 35 38 108 Pass 18.3697 33 34 103 Pass 18.7315 33 33 100 Pass 19.0932 31 31 100 Pass 19.4550 28 30 107 Pass 19.8167 26 26 100 Pass 20.1785 25 26 104 Pass 20.5402 24 25 104 Pass 20.9020 22 23 104 Pass 21.2637 22 22 100 Pass 21.6255 22 22 100 Pass 21.9873 22 22 100 Pass 22.3490 20 21 104 Pass 22.7108 20 20 100 Pass 23.0725 19 19 100 Pass 23.4343 17 19 111 Fail 23.7960 15 15 100 Pass 24.1578 13 14 107 Pass 24.5195 12 13 108 Pass 24.8813 12 12 100 Pass 25.2430 11 11 100 Pass 25.6048 11 11 100 Pass WWHM Model_Conveyance Flow 6/22/2020 10:13:03 AM Page 12 25.9666 11 11 100 Pass 26.3283 9 10 111 Fail 26.6901 9 9 100 Pass 27.0518 9 9 100 Pass 27.4136 9 9 100 Pass 27.7753 8 8 100 Pass 28.1371 7 7 100 Pass 28.4988 7 7 100 Pass 28.8606 6 7 116 Fail 29.2224 6 6 100 Pass 29.5841 5 6 120 Fail 29.9459 5 5 100 Pass 30.3076 5 5 100 Pass 30.6694 4 5 125 Fail 31.0311 4 4 100 Pass 31.3929 4 4 100 Pass 31.7546 3 3 100 Pass 32.1164 3 3 100 Pass 32.4782 3 3 100 Pass 32.8399 3 3 100 Pass 33.2017 3 3 100 Pass 33.5634 3 3 100 Pass 33.9252 2 3 150 Fail 34.2869 2 2 100 Pass 34.6487 2 2 100 Pass 35.0104 2 2 100 Pass 35.3722 2 2 100 Pass 35.7340 2 2 100 Pass 36.0957 2 2 100 Pass 36.4575 2 2 100 Pass 36.8192 2 2 100 Pass 37.1810 2 2 100 Pass 37.5427 2 2 100 Pass 37.9045 2 2 100 Pass 38.2662 2 2 100 Pass 38.6280 2 2 100 Pass 38.9898 2 2 100 Pass 39.3515 2 2 100 Pass 39.7133 2 2 100 Pass 40.0750 2 2 100 Pass 40.4368 2 2 100 Pass 40.7985 2 2 100 Pass 41.1603 2 2 100 Pass 41.5220 2 2 100 Pass 41.8838 2 2 100 Pass 42.2455 2 2 100 Pass The development has an increase in flow durations from 1/2 Predeveloped 2 year flow to the 2 year flow or more than a 10% increase from the 2 year to the 50 year flow. WWHM Model_Conveyance Flow 6/22/2020 10:13:03 AM Page 13 Water Quality Water Quality BMP Flow and Volume for POC #1 On-line facility volume:0.0212 acre-feet On-line facility target flow:0.0318 cfs. Adjusted for 15 min:0.0318 cfs. Off-line facility target flow:0.0179 cfs. Adjusted for 15 min:0.0179 cfs. WWHM Model_Conveyance Flow 6/22/2020 10:13:03 AM Page 14 LID Report WWHM Model_Conveyance Flow 6/22/2020 10:13:27 AM Page 15 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. WWHM Model_Conveyance Flow 6/22/2020 10:13:27 AM Page 16 Appendix Predeveloped Schematic WWHM Model_Conveyance Flow 6/22/2020 10:13:29 AM Page 17 Mitigated Schematic WWHM Model_Conveyance Flow 6/22/2020 10:13:31 AM Page 18 Predeveloped UCI File RUN GLOBAL WWHM4 model simulation START 1948 10 01 END 2009 09 30 RUN INTERP OUTPUT LEVEL 3 0 RESUME 0 RUN 1 UNIT SYSTEM 1 END GLOBAL FILES <File> <Un#> <-----------File Name------------------------------>*** <-ID-> *** WDM 26 WWHM Model_Conveyance Flow.wdm MESSU 25 PreWWHM Model_Conveyance Flow.MES 27 PreWWHM Model_Conveyance Flow.L61 28 PreWWHM Model_Conveyance Flow.L62 30 POCWWHM Model_Conveyance Flow1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 11 PERLND 12 PERLND 17 IMPLND 2 IMPLND 4 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Basin 1 MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 11 C, Forest, Mod 1 1 1 1 27 0 12 C, Forest, Steep 1 1 1 1 27 0 17 C, Lawn, Mod 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 11 0 0 1 0 0 0 0 0 0 0 0 0 12 0 0 1 0 0 0 0 0 0 0 0 0 17 0 0 1 0 0 0 0 0 0 0 0 0 WWHM Model_Conveyance Flow 6/22/2020 10:13:31 AM Page 19 END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 11 0 0 4 0 0 0 0 0 0 0 0 0 1 9 12 0 0 4 0 0 0 0 0 0 0 0 0 1 9 17 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 *** 11 0 0 0 0 0 0 0 0 0 0 0 12 0 0 0 0 0 0 0 0 0 0 0 17 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 11 0 4.5 0.08 400 0.1 0.5 0.996 12 0 4.5 0.08 400 0.15 0.5 0.996 17 0 4.5 0.03 400 0.1 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 11 0 0 2 2 0 0 0 12 0 0 2 2 0 0 0 17 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 11 0.2 0.5 0.35 6 0.5 0.7 12 0.2 0.3 0.35 6 0.3 0.7 17 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 11 0 0 0 0 2.5 1 0 12 0 0 0 0 2.5 1 0 17 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 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 END ACTIVITY PRINT-INFO WWHM Model_Conveyance Flow 6/22/2020 10:13:31 AM Page 20 <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 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 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 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN 2 0 0 4 0 0 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 2 0 0 4 0 0 END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Basin 1*** PERLND 11 1.64 COPY 501 12 PERLND 11 1.64 COPY 501 13 PERLND 12 0.26 COPY 501 12 PERLND 12 0.26 COPY 501 13 PERLND 17 7.542 COPY 501 12 PERLND 17 7.542 COPY 501 13 IMPLND 2 3.04 COPY 501 15 IMPLND 4 7.542 COPY 501 15 ******Routing****** END SCHEMATIC NETWORK <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** END NETWORK RCHRES GEN-INFO RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out *** END GEN-INFO *** Section RCHRES*** WWHM Model_Conveyance Flow 6/22/2020 10:13:31 AM Page 21 ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** END HYDR-PARM1 HYDR-PARM2 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES END FTABLES EXT SOURCES <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1.429 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1.429 IMPLND 1 999 EXTNL PREC WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP END EXT SOURCES EXT TARGETS <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** COPY 501 OUTPUT MEAN 1 1 48.4 WDM 501 FLOW ENGL REPL END EXT TARGETS MASS-LINK <Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 12 PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12 MASS-LINK 13 PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13 MASS-LINK 15 IMPLND IWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 15 END MASS-LINK END RUN WWHM Model_Conveyance Flow 6/22/2020 10:13:31 AM Page 22 WWHM Model_Conveyance Flow 6/22/2020 10:13:31 AM Page 23 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 WWHM Model_Conveyance Flow.wdm MESSU 25 MitWWHM Model_Conveyance Flow.MES 27 MitWWHM Model_Conveyance Flow.L61 28 MitWWHM Model_Conveyance Flow.L62 30 POCWWHM Model_Conveyance Flow1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 17 PERLND 11 IMPLND 2 IMPLND 4 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Basin 1 MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 17 C, Lawn, Mod 1 1 1 1 27 0 11 C, Forest, Mod 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 17 0 0 1 0 0 0 0 0 0 0 0 0 11 0 0 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO WWHM Model_Conveyance Flow 6/22/2020 10:13:31 AM Page 24 <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 17 0 0 4 0 0 0 0 0 0 0 0 0 1 9 11 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 *** 17 0 0 0 0 0 0 0 0 0 0 0 11 0 0 0 0 0 0 0 0 0 0 0 END PWAT-PARM1 PWAT-PARM2 <PLS > PWATER input info: Part 2 *** # - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC 17 0 4.5 0.03 400 0.1 0.5 0.996 11 0 4.5 0.08 400 0.1 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 17 0 0 2 2 0 0 0 11 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 17 0.1 0.25 0.25 6 0.5 0.25 11 0.2 0.5 0.35 6 0.5 0.7 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 17 0 0 0 0 2.5 1 0 11 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 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 END ACTIVITY 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 END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** WWHM Model_Conveyance Flow 6/22/2020 10:13:31 AM Page 25 2 0 0 0 0 0 4 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 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN 2 0 0 4 0 0 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 2 0 0 4 0 0 END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Basin 1*** PERLND 17 7.542 COPY 501 12 PERLND 17 7.542 COPY 501 13 PERLND 11 1.64 COPY 501 12 PERLND 11 1.64 COPY 501 13 IMPLND 2 3.235 COPY 501 15 IMPLND 4 7.607 COPY 501 15 ******Routing****** END SCHEMATIC NETWORK <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** END NETWORK RCHRES GEN-INFO RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out *** END GEN-INFO *** Section RCHRES*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* END PRINT-INFO WWHM Model_Conveyance Flow 6/22/2020 10:13:31 AM Page 26 HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** END HYDR-PARM1 HYDR-PARM2 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES END FTABLES EXT SOURCES <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1.429 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1.429 IMPLND 1 999 EXTNL PREC WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP END EXT SOURCES EXT TARGETS <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** COPY 1 OUTPUT MEAN 1 1 48.4 WDM 701 FLOW ENGL REPL COPY 501 OUTPUT MEAN 1 1 48.4 WDM 801 FLOW ENGL REPL END EXT TARGETS MASS-LINK <Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 12 PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12 MASS-LINK 13 PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13 MASS-LINK 15 IMPLND IWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 15 END MASS-LINK END RUN WWHM Model_Conveyance Flow 6/22/2020 10:13:31 AM Page 27 Predeveloped HSPF Message File WWHM Model_Conveyance Flow 6/22/2020 10:13:31 AM Page 28 Mitigated HSPF Message File WWHM Model_Conveyance Flow 6/22/2020 10:13:31 AM Page 29 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. 2005-2020; 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 Cherie Lane Short Plat Technical Information Report Appendix F Bond Quantity Worksheet Planning Division |1055 South Grady Way – 6th Floor | Renton, WA 98057 (425) 430-7200Date Prepared: Name:PE Registration No:Firm Name:Firm Address:Phone No.Email Address:Project Name: Project Owner:CED Plan # (LUA):Phone:CED Permit # (U):Address: Site Address:Street Intersection:Addt'l Project Owner:Parcel #(s):Phone:Address: Clearing and grading greater than or equal to 5,000 board feet of timber? Yes/No:NOWater Service Provided by:If Yes, Provide Forest Practice Permit #:Sewer Service Provided by: SITE IMPROVEMENT BOND QUANTITY WORKSHEETPROJECT INFORMATIONCITY OF RENTONSOOS CREEK WATER & SEWER1 Select the current project status/phase from the following options: For Approval - Preliminary Data Enclosed, pending approval from the City; For Construction - Estimated Data Enclosed, Plans have been approved for contruction by the City; Project Closeout - Final Costs and Quantities Enclosed for Project Close-out Submittal253-332-5692Engineer Stamp Required (all cost estimates must have original wet stamp and signature)Clearing and GradingUtility ProvidersN/AProject Location and DescriptionProject Owner InformationCherie Lane Short PlatKent, WA 98030302305-9108Ram SinghLUA16-000964253-332-56928/31/2020Prepared by:FOR APPROVALProject Phase 1emecum@encompasses.netEdward Mecum, PE39374Encompass Engineering & Surveying165 NE Juniper St, Ste 201, Issaquah, 98027425-392-025034XX Talbot Road S10616 SE 268th StChany PreetSouth of Talbot Rd S/S 32nd St Intersection########10616 SE 268th StAbbreviated Legal Description: LOT 2 KC SHORT PLAT NO 1177127 REC # 7803311125 SD PLAT DAF-POR OF N 1/2 OF S 1/2 OF S 1/2 OF NE 1/4 OF SE 1/4 LY E OF KENT - RENTON RD TGW N 17 FT MEAS ALG E MGN OF SD RD OF W 170 FT MEAS ALG N LN OF S 1/2 OF S 1/2 OF S 1/2 OF NE 1/4 OF SE 1/4 LY ELY OF SD RDKent, WA 98030Page 2 of 14Ref 8-H Bond Quantity WorksheetSECTION I PROJECT INFORMATIONUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 8/26/2020 CED Permit #:########UnitReference #PriceUnitQuantity CostBackfill & compaction-embankmentESC-16.50$ CY Check dams, 4" minus rockESC-2SWDM 5.4.6.380.00$ Each Catch Basin ProtectionESC-335.50$ Each6213.00Crushed surfacing 1 1/4" minusESC-4WSDOT 9-03.9(3)95.00$ CY DitchingESC-59.00$ CY Excavation-bulkESC-62.00$ CY Fence, siltESC-7SWDM 5.4.3.11.50$ LF612918.00Fence, 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$ SY Interceptor Swale / DikeESC-121.00$ LF Jute 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$ SY Piping, temporary, CPP, 6"ESC-1712.00$ LFPiping, 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$ SY80320.00Rip 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$ Each Sediment 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$ LF Seeding, 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 CostPlasticMart.com5,000.00$ Each15,000.00 EROSION/SEDIMENT SUBTOTAL:15,451.00SALES TAX @ 10%1,545.10EROSION/SEDIMENT TOTAL:16,996.10(A)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR EROSION & SEDIMENT CONTROLDescription No.(A)5700 Gal Sediment TankWRITE-IN-ITEMS Page 3 of 14Ref 8-H Bond Quantity WorksheetSECTION II.a EROSION_CONTROLUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 8/26/2020 CED Permit #:########ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostGENERAL ITEMS Backfill & Compaction- embankmentGI-16.00$ CYBackfill & Compaction- trenchGI-29.00$ CYClear/Remove Brush, by hand (SY)GI-31.00$ SYBollards - fixedGI-4240.74$ EachBollards - removableGI-5452.34$ EachClearing/Grubbing/Tree RemovalGI-610,000.00$ Acre0.484,800.00Excavation - bulkGI-72.00$ CY22564,512.00Excavation - TrenchGI-85.00$ CY175.19875.93Fencing, cedar, 6' highGI-920.00$ LFFencing, chain link, 4'GI-1038.31$ LF52420,074.44Fencing, 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$ CYFill & compact - gravel baseGI-1427.00$ CYFill & 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$ SYMonuments, 3' LongGI-21250.00$ EachSensitive Areas SignGI-227.00$ Each214.00Sodding, 1" deep, sloped groundGI-238.00$ SYSurveying, line & gradeGI-24850.00$ Day21,700.00Surveying, lot location/linesGI-251,800.00$ AcreTopsoil Type A (imported)GI-2628.50$ CYTraffic control crew ( 2 flaggers )GI-27120.00$ HRTrail, 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$ SF95614,340.00SUBTOTAL THIS PAGE:46,316.37(B)(C)(D)(E)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR STREET AND SITE IMPROVEMENTSQuantity Remaining (Bond Reduction) (B)(C)Page 4 of 14Ref 8-H Bond Quantity WorksheetSECTION II.b TRANSPORTATIONUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 8/26/2020 CED Permit #:########ExistingFuture 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$ SYAC Grinding, 4' wide machine > 2000syRI-310.00$ SYAC Removal/DisposalRI-435.00$ SY15525.00Barricade, Type III ( Permanent )RI-556.00$ LFGuard RailRI-630.00$ LFCurb & Gutter, rolledRI-717.00$ LFCurb & Gutter, verticalRI-812.50$ LF1001,250.00Curb and Gutter, demolition and disposalRI-918.00$ LFCurb, extruded asphaltRI-105.50$ LFCurb, extruded concreteRI-117.00$ LFSawcut, asphalt, 3" depthRI-121.85$ LFSawcut, concrete, per 1" depthRI-133.00$ LF200600.00Sealant, asphaltRI-142.00$ LFShoulder, gravel, 4" thickRI-1515.00$ SYSidewalk, 4" thickRI-1638.00$ SY401,520.00Sidewalk, 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$ SYHMA Road, 2", 4" rock, First 2500 SYRI-2728.00$ SYHMA Road, 2", 4" rock, Qty. over 2500SYRI-2821.00$ SYHMA Road, 4", 6" rock, First 2500 SYRI-2945.00$ SY83737,665.00HMA 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$ SYGravel Road, 4" rock, Qty. over 2500 SYRI-3310.00$ SYThickened EdgeRI-348.60$ LF3733,207.80SUBTOTAL THIS PAGE:3,895.0040,872.80(B)(C)(D)(E)Page 5 of 14Ref 8-H Bond Quantity WorksheetSECTION II.b TRANSPORTATIONUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 8/26/2020 CED Permit #:########ExistingFuture 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-2Traffic SignalTR-3Traffic Signal ModificationTR-4SUBTOTAL TRAFFIC & LIGHTING:(B)(C)(D)(E)WRITE-IN-ITEMSSUBTOTAL WRITE-IN ITEMS:STREET AND SITE IMPROVEMENTS SUBTOTAL:3,895.0087,189.17SALES TAX @ 10%389.508,718.92STREET AND SITE IMPROVEMENTS TOTAL:4,284.5095,908.08(B)(C)(D)(E)Page 6 of 14Ref 8-H Bond Quantity WorksheetSECTION II.b TRANSPORTATIONUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 8/26/2020 CED Permit #:########ExistingFuture 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$ SY* (CBs include frame and lid)BeehiveD-290.00$ EachThrough-curb Inlet FrameworkD-3400.00$ EachCB Type ID-41,500.00$ Each23,000.0034,500.00CB Type ILD-51,750.00$ EachCB Type II, 48" diameterD-62,300.00$ Each for additional depth over 4' D-7480.00$ FTCB 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$ LF492.00Culvert, 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:3,000.004,592.00(B)(C)(D)(E)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESQuantity Remaining (Bond Reduction) (B)(C)Page 7 of 14Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 8/26/2020 CED Permit #:########ExistingFuture 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$ LFCulvert, Concrete, 15"D-4478.00$ LFCulvert, Concrete, 18"D-4548.00$ LF32315,504.00Culvert, 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:15,504.00(B)(C)(D)(E)Page 8 of 14Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 8/26/2020 CED Permit #:########ExistingFuture 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$ LF384,028.00Culvert, DI, 15"D-98129.00$ LFCulvert, DI, 18"D-99152.00$ LF243,648.00375,624.00Culvert, 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:3,648.009,652.00(B)(C)(D)(E)Page 9 of 14Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 8/26/2020 CED Permit #:########ExistingFuture 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$ HRPermeable PavementSD-14Permeable Concrete SidewalkSD-15Culvert, Box __ ft x __ ftSD-16SUBTOTAL SPECIALTY DRAINAGE ITEMS:(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-6Each Infiltration 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-15Each Bioretention FacilitySF-16Each SUBTOTAL STORMWATER FACILITIES:(B)(C)(D)(E)Page 10 of 14Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 8/26/2020 CED Permit #:########ExistingFuture 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)OldCastle BioPod Vault BPU-IB-48WI-17,000.00$ each17,000.00WI-2WI-3WI-4WI-5WI-6WI-7WI-8WI-9WI-10WI-11WI-12WI-13WI-14WI-15SUBTOTAL WRITE-IN ITEMS:7,000.00DRAINAGE AND STORMWATER FACILITIES SUBTOTAL:6,648.0036,748.00SALES TAX @ 10%664.803,674.80DRAINAGE AND STORMWATER FACILITIES TOTAL:7,312.8040,422.80(B) (C) (D) (E)Page 11 of 14Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 8/26/2020 CED Permit #:########ExistingFuture 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$ LF25615,360.00Ductile Iron Watermain, CL 52, 10 Inch DiameterW-570.00$ LFDuctile Iron Watermain, CL 52, 12 Inch DiameterW-680.00$ LFGate Valve, 4 inch DiameterW-7500.00$ EachGate Valve, 6 inch DiameterW-8700.00$ EachGate Valve, 8 Inch DiameterW-9800.00$ Each1800.001800.00Gate Valve, 10 Inch DiameterW-101,000.00$ EachGate Valve, 12 Inch DiameterW-111,200.00$ Each22,400.00Fire Hydrant AssemblyW-124,000.00$ Each14,000.00Permanent Blow-Off AssemblyW-131,800.00$ EachAir-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:7,200.0020,160.00SALES TAX @ 10%720.002,016.00WATER TOTAL:7,920.0022,176.00(B) (C) (D) (E)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR WATERQuantity Remaining (Bond Reduction) (B)(C)Page 12 of 14Ref 8-H Bond Quantity WorksheetSECTION II.d WATERUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 8/26/2020 CED Permit #:########ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostClean OutsSS-11,000.00$ EachGrease 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$ LFSewer Pipe, PVC, 8 inch DiameterSS-7105.00$ LFSewer 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$ EachManhole, 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:SALES TAX @ 10%SANITARY SEWER TOTAL:(B) (C) (D) (E)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR SANITARY SEWERQuantity Remaining (Bond Reduction) (B)(C)Page 13 of 14Ref 8-H Bond Quantity WorksheetSECTION II.e SANITARY SEWERUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 8/26/2020 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)12,204.50$ Future Public Improvements Subtotal(c)-$ Stormwater & Drainage Facilities (Public & Private) Subtotal(d)(d)47,735.60$ (e)(f)Site RestorationCivil Construction PermitMaintenance Bond11,988.02$ Bond Reduction2Construction Permit Bond Amount 3Minimum Bond Amount is $10,000.001 Estimate Only - May involve multiple and variable components, which will be established on an individual basis by Development Engineering.2 The City of Renton allows one request only for bond reduction prior to the maintenance period. Reduction of not more than 70% of the original bond amount, provided that the remaining 30% willcover all remaining items to be constructed. 3 Required Bond Amounts are subject to review and modification by Development Engineering.* Note: The word BOND as used in this document means any financial guarantee acceptable to the City of Renton.** Note: All prices include labor, equipment, materials, overhead and profit. 425-392-0250emecum@encompasses.netCherie Lane Short PlatLUA16-00096434XX Talbot Road S302305-9108FOR APPROVAL########165 NE Juniper St, Ste 201, Issaquah, 9802783,038.45$ P (a) x 100%SITE IMPROVEMENT BOND QUANTITY WORKSHEET BOND CALCULATIONS8/31/2020Edward Mecum, PE39374Encompass 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)16,996.10$ 12,204.50$ 66,042.35$ 16,996.10$ -$ 47,735.60$ -$ Page 14 of 14Ref 8-H Bond Quantity WorksheetSECTION III. BOND WORKSHEETUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 8/26/2020 Cherie Lane Short Plat Technical Information Report Appendix G Operation and Maintenance Manual 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 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 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 2017 City of Renton Surface Water Design Manual 12/12/2016 A-31 NO. 21 – PROPRIETARY FACILITY CARTRIDGE FILTER SYSTEMS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED In addition to the specific maintenance criteria provided below, all manufacturers’ requirements shall be followed. Facility Documentation Update facility inspection record after each inspection. Maintenance records are up to date. Provide certification of replaced filter media. Filter media is certified to meet manufacturer specifications. Site Trash and debris Any trash or debris which impairs the function of the facility. Trash and debris removed from facility. Contaminants and pollution Any evidence of contaminants or pollution such as oils, 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. Life cycle Once per year. Facility is re-inspected and any needed maintenance performed. Vault Treatment Area Sediment on vault floor Varies – Refer to manufacturer’s requirements. Vault is free of sediment. Sediment on top of cartridges Varies – Refer to manufacturer’s requirements. Vault is free of sediment. Multiple scum lines above top of cartridges Thick or multiple scum lines above top of cartridges. Probably due to plugged canisters or underdrain manifold. Cause of plugging corrected, canisters replaced if necessary. Vault Structure Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch and any evidence of soil particles entering the structure through the cracks, or qualified inspection personnel determines 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 person. Repair or replace baffles to specification. Filter Media Standing water in vault Varies – Refer to manufacturer’s requirements. No standing water in vault 24 hours after a rain event. Short circuiting Flows do not properly enter filter cartridges. Flows go through filter media. Underdrains and Clean-Outs Sediment and debris Underdrains or clean-outs partially plugged or filled with sediment and/or debris. Underdrains and clean-outs free of sediment and debris. 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. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-32 NO. 21 – PROPRIETARY FACILITY CARTRIDGE FILTER SYSTEMS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED 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 and cover 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 2017 City of Renton Surface Water Design Manual 12/12/2016 A-39 NO. 27 – GRAVEL FILLED DISPERSION 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 dispersion trench or preventing spreader function. Dispersion 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 dispersion trench is evident. No trash or debris that could get into the dispersion 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 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 to the trench. Broken or missing cleanout caps Cleanout caps are broken, missing, or buried. Cleanout caps are accessible and intact. Structure Flow not reaching trench Flows are not getting into the trench as designed. Water enters and exits trench as designed. Perforated pipe plugged Flow not able to enter or properly exit from perforated pipe. Water freely enters and exits perforated pipe. Flow not spreading evenly at outlet of trench Outlet flows channelizing or not spreading evenly from trench. Sheet flow occurs at the outlet of the trench. Cleanout/inspection access does not allow cleaning or inspection of perforated pipe 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 12/12/2016 2017 City of Renton Surface Water Design Manual A-40 NO. 28 – NATIVE VEGETATED SURFACE/NATIVE VEGETATED LANDSCAPE BMP 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 the native vegetated surface/native vegetated landscape site. Native vegetated surface site free of any trash or debris. Vegetation Insufficient vegetation Less than two species each of native trees, shrubs, and groundcover occur in the design area. A minimum of two species each of native trees, shrubs, and groundcover is established and healthy. Poor vegetation coverage Less than 90% if the required vegetated area has healthy growth. A minimum of 90% of the required vegetated area has healthy growth. Undesirable vegetation present Weeds, blackberry, and other undesirable plants are invading more than 10% of vegetated area. Less than 10% undesirable vegetation occurs in the required native vegetated surface area. Vegetated Area Soil compaction Soil in the native vegetation area compacted. Less than 8% of native vegetation area is compacted. Insufficient vegetation Less than 3.5 square feet of native vegetation area for every 1 square foot of impervious surface. A minimum of 3.5 square feet of native vegetation area for every 1 square foot of impervious surface. Excess slope Slope of native vegetation area greater than 15%. Slope of native growth area does not exceed 15%. NO. 29 – PERFORATED PIPE CONNECTIONS 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 into perforated pipe system or outfall of BMP is plugged or otherwise nonfunctioning. Outfall of BMP is receiving designed flows from perforated pipe connection. Inflow Inflow impeded Inflow into the perforated pipe is partially or fully blocked or altered to prevent flow from getting into the pipe. Inflow to the perforated pipe is unimpeded. Pipe Trench Area Surface compacted Ground surface over the perforated pipe trench is compacted or covered with impermeable material. Ground surface over the perforated pipe is not compacted and free of any impervious cover. Outflow Outflow impeded Outflow from the perforated pipe into the public drainage system is blocked. Outflow to the public drainage system is unimpeded. Outfall Area Erosion or landslides Existence of the perforated pipe is causing or exasperating erosion or landslides. Perforated pipe system is sealed off and an alternative BMP is implemented. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2017 City of Renton Surface Water Design Manual 12/12/2016 A-43 NO. 32 – RAINWATER HARVESTING BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Preventive Insufficient storage volume No rain water in storage unit at the beginning of the rain season. Maximum storage available at the beginning of the rain season (Oct. 1). Collection Area Trash and debris Trash of debris on collection area may plug filter system Collection area clear of trash and debris. Filter Restricted or plugged filter Filter is partially or fully plugged preventing water from getting in to the storage unit. Filter is allowing collection water into storage unit. NO. 33 – ROCK PAD BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Trash and debris accumulated on rock pad site. Rock pad site free of any trash or debris. Rock Pad Area Insufficient rock pad size Rock pad is not 2 feet by 3 feet by 6 inches thick or as designed. Rock pad is 2 feet by 3 feet by 6 inches thick or as designed. Vegetation growth Vegetation is seen growing in or through rock pad. No vegetation within rock pad area. Rock Exposed soil Soil can be seen through the rock pad. Full thickness of the rock pad is in place, no soil visible through rock pad. NO. 34 – SHEET FLOW BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Trash and debris accumulated on the sheet flow site. Sheet flow site free of any trash or debris. Sheet flow area Erosion Soil erosion occurring in sheet flow zone. Soil erosion is not occurring and rills and channels have been repaired. Concentrated flow Sheet flow is not occurring in the sheet flow zone. Sheet flow area is regraded to provide sheet flow. NO. 35 – SPLASH BLOCK BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Trash and debris accumulated on the splash block. Splash block site free of any trash or debris. Splash Block Dislodged splash block Splash block moved from outlet of downspout. Splash block correctly positioned to catch discharge from downspout. Channeling Water coming off the splash block causing erosion. No erosion occurs from the splash block. Downspout water misdirected Water coming from the downspout is not discharging to the dispersal area. Water is discharging normally to the dispersal area. 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. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-48 NO. 39 – RETAINED TREES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Tree Dead or declining Dead, damaged, or declining Tree replaced per planting plan or acceptable substitute NO. 40 – FILTERRA SYSTEM MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED In addition to the specific maintenance criteria provided below, all manufacturer’s requirements shall be followed. Facility – General Requirements Life cycle Once per year, except mulch and trash removal twice per year Facility is re-inspected and any needed maintenance performed 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 Excessive sediment or trash accumulation Accumulated sediments or trash impair free flow of water into system Inlet should be free of obstructions allowing free distributed flow of water into system Mulch Cover Trash and floatable debris accumulation Excessive trash and/or debris accumulation Minimal trash or other debris on mulch cover. Mulch cover raked level. “Ponding” of water on mulch cover “Ponding” in unit could be indicative of clogging due to excessive fine sediment accumulation or spill of petroleum oils Stormwater should drain freely and evenly through mulch cover Proprietary Filter Media/ Vegetation Substrate “Ponding” of water on mulch cover after mulch cover has been maintained Excessive fine sediment passes the mulch cover and clogs the filter media/vegetative substrate Stormwater should drain freely and evenly through mulch cover. Replace substrate and vegetation when needed Vegetation Plants not growing or in poor condition Soil/mulch too wet, evidence of spill, incorrect plant selection, pest infestation, and/or vandalism to plants Plants should be healthy and pest free Media/mulch too dry Irrigation is required Plants absent Plants absent Appropriate plants are present Excessive plant growth Excessive plant growth inhibits facility function or becomes a hazard for pedestrian and vehicular circulation and safety Pruning and/or thinning vegetation maintains proper plant density. Appropriate plants are present. Structure Structure has visible cracks Cracks wider than ½ inch Evidence of soil particles entering the structure through the cracks Structure is sealed and structurally sound Cherie Lane Short Plat Technical Information Report Appendix H Oldcastle BioPod Design Information 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