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F_Drainage Report_2017-07-28.pdf
Sonic Renton 749 Rainier Ave. S Technical Information Report Renton, Washington July 12, 2017 Prepared for Olympic Cascade Drive Ins, LLC 120 W Dayton Street, Suite D5 Edmonds, WA 98020 191 NE Tari Ln Stevenson, WA 98648 SONC-1501 FINAL LUA-16000229 PR-16000257 U-16006829 R-3929 IN COMPIANCE WITH CITY OF RENTON STANDARDS DEVELOPMENT ENGINEERING Ann Fowler 07/26/2017 SURFACE WATER UTILITY rstraka 07/26/2017 TABLE OF CONTENTS SECTION 1 PROJECT OVERVIEW 3 Project Data 3 Pre-developed Site Conditions 4 Post-developed Site Conditions 4 TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 5 SECTION 2 CONDITIONS & REQUIREMENTS SUMMARY 13 City of Renton Amendments to the 2009 King County Surface Water Design Manual Core Requirements 13 City of Renton Amendments to the 2009 King County Surface Water Design Manual Special Requirements: 14 SECTION 3 OFF-SITE ANALYSIS 16 Drainage System Description 16 Upstream 16 On-site 16 Downstream 16 Problem Descriptions 17 Mitigation of Existing or Potential Problems 17 SECTION 4 FLOW CONTROL & WATER QUALITY ANALYSIS AND DESIGN 18 Threshold Analysis 18 Flow Control BMPs 22 Water Quality 24 SECTION 5 CONVEYANCE SYSTEM ANALYSIS AND DESIGN 26 Conveyance Calculations 26 SECTION 6 SPECIAL REPORTS AND STUDIES 35 SECTION 7 OTHER PERMITS 36 SECTION 8 CSWPPP ANALYSIS AND DESIGN 37 Part A. ESC Plan Analysis and Design 37 Technical Information Report for Sonic Renton June 21, 2017 2 Part B. SWPPS Plan Design 38 SECTION 9 BOND QUANTITIES, FACILITY SUMMARIES 39 SECTION 10 OPERATIONS AND MAINTENANCE MANUAL 40 TABLE OF FIGURES Figure 1: Vicinity Map ................................................................................................................................................ 10 Figure 2: Existing Conditions ...................................................................................................................................... 11 Figure 3: Developed Conditions .................................................................................................................................. 12 Figure 4: Existing Impervious ..................................................................................................................................... 20 Figure 5: Developed Impervious ................................................................................................................................. 21 Figure 6: Permeable Pavement .................................................................................................................................... 23 Figure 7: Water Quality Basin ..................................................................................................................................... 25 Figure 8: Conveyance Basin ........................................................................................................................................ 28 Technical Information Report for Sonic Renton June 21, 2017 3 SECTION 1 PROJECT OVERVIEW Project Data Project: The proposal is a commercial development consisting of a fast-food restaurant with surface parking and landscaping. The restaurant will occupy a single-level building. Frontage improvements consist of replacement of sidewalk and street trees. Location: The property address is 735 Hardie Avenue. SW. The parcel is located at the east perimeter of the Walmart retail center near the intersection of Rainier Avenue S. and Hardie Avenue SW. Section 19, Township 23 North, Range 5 East, W.M. Site Area: The property area is 31,815 square feet (0.73 acres). Following dedication of 2 feet along it’s east edge the property area will become 31,487 square feet (0.72 acres) Site Soils: The soils report for the project (ZGA, January 25th, 2016) describes the soil profile as about 3 feet of silty gravelly sand (fill) over silt, clay and sand. Areas: Surface Cover Site Right-of-way Existing Developed Existing Developed Roof/Structure 0 sf 2,737 sf 0 sf 0 sf Parking/Driveway 17,548 sf 17,115 sf 0 sf 0 sf Sidewalk 591 sf 2,161 sf 768 sf 1,332 sf Landscape 13,348 sf 9,474 sf 3,496 sf 2,932 sf Total 31,487 sf 31,487 sf 4,264 sf 4,264 sf Total Impervious (new plus replaced): 18,139 sf 22,013 sf 768 sf 1,332 sf Technical Information Report for Sonic Renton June 21, 2017 4 Pre-developed Site Conditions The property is currently developed as a parking lot inside a larger retail center. Surface cover consists of asphalt pavement, concrete sidewalk and landscaping. Impervious coverage is 58 percent. The terrain is mildly sloped at grades generally less than 2 percent. Storm runoff on the property is contained onsite and collected into a single catchbasin. The site surface is dish-shaped with the catchbasin at the lowest point. Stormwater collected in the catchbasin is conveyed westward in a 12-inch diameter buried pipe that is part of the retail center’s private drainage network. A pipe also enters the onsite catchbasin carrying offsite drainage from an adjacent private driveway south of the site. Post-developed Site Conditions The development is the construction of a fast-food restaurant with parked car service, drive-through service, and indoor-outdoor seating. The improvements will include a single one-story building, paved drive aisles and parking, concrete sidewalks and landscaping. Frontage improvements consist of the replacement of some sidewalk in Hardie Avenue SW and addition of street trees. The final grades will be mildly sloping less than 3 percent. The impervious coverage will be 71 percent. The drainage system will consist of buried pipes, catchbasins and a water quality facility. Runoff from the roof will be collected and conveyed separately to the existing onsite catchbasin. Runoff from the remainder of the site will be collected into a Filterra treatment facility. The Filterra will be located at the low-point in the parking lot and will drain to a new catchbasin installed on an existing storm pipe. The existing storm pipe that crosses through the property will be maintained and reused to convey site discharge. There are no incoming pipes into the proposed Filterra vault. All drainage will enter the vault as surface flow through a side opening in the adjacent curb. The Filterra will be placed at the single low point in the parking lot; all surfaces slope down to this point. A valley gutter will collect surface water from the north part of the lot and direct this to the Filterra vault. Stormwater detention is not provided as the development qualifies for the City of Renton Amendments to the 2009 King County Surface Water Design Manual Exception #1 (page 1-34 of the manual). KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2009 Surface Water Design Manual 1/9/2009 1 Part 1 PROJECT OWNER AND PROJECT ENGINEER Part 2 PROJECT LOCATION AND DESCRIPTION Project Owner ________________________ Phone ______________________________ Address ____________________________ ____________________________________ Project Engineer ______________________ Company ___________________________ Phone ______________________________ Project Name _________________________ DDES Permit # ________________________ Location Township ______________ Range ________________ Section ________________ Site Address __________________________ _____________________________________ Part 3 TYPE OF PERMIT APPLICATION Part 4 OTHER REVIEWS AND PERMITS Landuse Services Subdivison / Short Subd. / UPD Building Services M/F / Commerical / 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 (circle): Date (include revision dates): Date of Final: Full / Targeted / Large Site ___________________ ___________________ ___________________ Type (circle one): Date (include revision dates): Date of Final: Full / Modified / Small Site __________________ __________________ __________________ Part 6 ADJUSTMENT APPROVALS Type (circle one): Standard / Complex / Preapplication / Experimental / Blanket Description: (include conditions in TIR Section 2) ____________________________________________________________________________________ ____________________________________________________________________________________ ____________________________________________________________________________________ Date of Approval: ______________________ Olympic Cascade Drive Ins, LLC (206) 372-8732 19689 7th Avenue NE, Suite 183 PMB 326 Pouslbo, WA 98370 Nick Bossoff PE Nick Bossoff Eng. (425) 881-5904 Renton Sonic LUA16-000229 23N 5E 19 735 Hardie Ave. SW x 12/29/16 12/29/16 None KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2009 Surface Water Design Manual 1/9/2009 2 Part 7 MONITORING REQUIREMENTS Monitoring Required: Yes / No Start Date: _______________________ Completion Date: _______________________ Describe: _________________________________ _________________________________________ _________________________________________ _________________________________________ _________________________________________ 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 Renton None Black River Peak flow rate, enhanced water quality Sandy fill over silt-clay/sand <2%Mild x KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2009 Surface Water Design Manual 1/9/2009 3 Part 11 DRAINAGE DESIGN LIMITATIONS REFERENCE Core 2 – Offsite Analysis_________________ Sensitive/Critical Areas___________________ SEPA________________________________ 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 (incl. facility summary sheet) Level: 1 / 2 / 3 or Exemption Number ____________ Small Site BMPs ___________________________________ Conveyance System Spill containment located at: _________________________ Erosion and Sediment Control ESC Site Supervisor: Contact Phone: After Hours Phone: Maintenance and Operation Responsibility: Private / Public If Private, Maintenance Log Required: Yes / No Financial Guarantees and Liability Provided: Yes / No Water Quality (include facility summary sheet) Type: Basic / Sens. Lake / Enhanced Basicm / 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: Major / Minor / Exemption / None 100-year Base Flood Elevation (or range): ______________ Datum: Flood Protection Facilities Describe: Source Control (comm./industrial landuse) Describe landuse: Describe any structural controls: x None Site 12/29/16 Exception #1 Filterra TBD 1 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2009 Surface Water Design Manual 1/9/2009 4 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 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 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 ________________ ________________ ________________ ________________ ________________ ________________ Biofiltration Wetpool Media Filtration Oil Control Spill Control Flow Control BMPs Other ________________ ________________ ________________ ________________ ________________ ________________ ________________ Filterra x x x x x x x x x x x x x x Filterra vault KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2009 Surface Water Design Manual 1/9/2009 5 Part 15 EASEMENTS/TRACTS Part 16 STRUCTURAL ANALYSIS Drainage Easement Covenant Native Growth Protection Covenant Tract Other Cast in Place Vault Retaining Wall Rockery > 4’ High Structural on Steep Slope Other Part 17 SIGNATURE OF PROFESSIONAL ENGINEER I, or a civil engineer under my supervision, have visited the site. Actual site conditions as observed were incorporated into this worksheet and the attached Technical Information Report. To the best of my knowledge the information provided here is accurate. Signed/Date x 12/29/16 King County Date: 2/8/2016 Notes: ±The information included on this map has been compiled by King County staff from a variety of sources and issubject to change without 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 intendedfor use as a survey product. King County shall not be liable for any general, special, indirect, incidental, or consequential damages including, but not limited to, lost revenues or lost profits resulting from the use or misuseof the information contained on this map. Any sale of this map or information on this map is prohibited except bywritten permission of King County. Vicinity Map SITE Technical Information Report for Sonic Renton June 21, 2017 13 SECTION 2 CONDITIONS & REQUIREMENTS SUMMARY Surface Water Design Manual Core and Special requirements are addressed in this section City of Renton Amendments to the 2009 King County Surface Water Design Manual Core Requirements: 1. Discharge at the Natural Location The existing destination of runoff from the site is through the private storm drain that flows from the onsite catchbasin to the west. The proposed site drainage system will discharge to the same private system preserving the existing flow direction. 2. Off-site Analysis An off-site analysis is included in Section 3 of this report. The analysis included an inspection of the downstream system and research. 3. Flow Control Flow control is not required as the project is below the flow rate threshold (Exception #1 on page 1-34 of the COR Amendments to the 2009 KCSWDM). See Section 4. Permeable paving has been selected to fulfill the BMP requirement. The small site and poor soils prevent the site from including dispersion and other infiltration BMPs. 4. Conveyance System Conveyance will be provided by buried pipes. 5. Erosion & Sediment Control Temporary erosion & sediment control (TESC) measures will be in place during construction. A TESC plan will be prepared as part of the permit drawings. All TESC measures proposed will conform to COR Amendments to the 2009 KCSWDM requirements (see Section 9 of this TIR). 6. Maintenance & Operations A maintenance and operations manual for the onsite storm system is provided in Section 10 of this TIR. The joint maintenance and operation of downstream facilities is covered in the maintenance agreement signed by the owner and Walmart-Renton. 7. Financial Guarantees & Liability The project owner will provide bonding as required by the City. Technical Information Report for Sonic Renton June 21, 2017 14 8. Water Quality The project is a commercial development that creates more than 5,000 square feet of PGIS, is a high-use site and is therefore required to provide enhanced water quality treatment and oil control. A Filterra water quality facility is proposed. City of Renton Amendments to the 2009 King County Surface Water Design Manual Special Requirements: 1. Other Adopted Area-specific Requirements There are no other adopted area-specific requirements for this site. 2. Flood Hazard Area Delineation This site does not lie within a 100-year floodplain. 3. Flood Protection Facilities There are no flood protection facilities located on or directly adjacent to this site. 4. Source Control The project is a fast-food restaurant. The typical areas of concern for this use are roof materials, high-use parking, cleaning of vent filters in the parking lot, dumpster exposure and landscaping. The roof materials for the project will be an inert material that does not contribute pollutants to runoff. Roof materials typically include painted metals and inert membranes. Pollutants from vehicles that enter the storm runoff will be treated in a Filterra treatment facility. Cleaning of vent filters in the parking lot such that grease enters the storm drain is not a practice allowed by the owners. The trash and recycling dumpsters will be weatherproof containers. The landscaping will not incorporate practices that are unusually polluting. Landscaping maintenance, pest treatment and fertilizing will be controlled by City, state and federal regulations. 5. Oil Control The site is a high-use site and is therefore required to provide oil control. A Filterra water quality facility is proposed. 6. Aquifer Protection Area Technical Information Report for Sonic Renton June 21, 2017 15 The project site is located outside Aquifer Protection Areas 1 and 2 and is therefore not subject to any of the protection requirements. Technical Information Report for Sonic Renton June 21, 2017 16 SECTION 3 OFF-SITE ANALYSIS A Level 1 analysis is provided ion this section. Drainage System Description Upstream Surface runoff does not flow into the site from offsite. Adjacent properties to the north and south have curbed pavement and drainage collection systems that contain runoff on those properties as does the rights-of-way to the east. The property to the west slopes down and away from the site. Drainage collected in a catchbasin at the curb of a private driveway south of the site enters and continues through the site in a 12-inch diameter buried pipe. The offsite catchbasin collects runoff from about 7,738 square feet of area that includes pavement, sidewalk and landscaping. On-site The existing site is an asphalt paved parking lot with perimeter and island landscaping. The site also includes a concrete sidewalk along its south boundary. The terrain is mildly sloped at grades generally less than 2 percent. Drainage on the property is contained onsite and collected into a single catchbasin. The site surface is dish-shaped with the catchbasin at the lowest point. Stormwater collected in the catchbasin is conveyed westward in a 12-inch diameter buried CPEP pipe. The pipe is part of a private system that extends through the Walmart site. The upstream end of the pipe system begins offsite at a catchbasin in a private driveway as mentioned above. The 12-inch diameter CPEP pipe enters the site about midway along its south boundary flowing in a northward direction. The pipe meets the onsite catchbasin at a point 83 feet north of the south site boundary. The catchbasin is drained by a 12-inch diameter CPEP pipe that flows west for 87 feet to cross the west site boundary. Downstream The pipe system that exits the site continues west and north through the Walmart parking lot, combining into the system that drains the retail center. The system passes through several catchbasins, changing from a 12-inch to an 18-inch dimeter pipe, before discharging to the head of a biofiltration swale at the northwest corner of the retail center. The biofiltration swale discharges to the 60-inch public storm main flowing west beneath SW 7th Street. The storm main eventually discharges to the Black River, a tributary of the Duwamish River. Technical Information Report for Sonic Renton June 21, 2017 17 Problem Descriptions No drainage problems were observed in the downstream system. The existing system is comprised of pipes, junction structures and a vegetated biofiltration swale that do not show any obvious signs of insufficient capacity or stability problems. Mitigation of Existing or Potential Problems No offsite mitigations are recommended. Onsite mitigation should include safe collection, conveyance and treatment of all runoff and discharge to the existing storm system. SITE Technical Information Report for Sonic Renton June 21, 2017 18 SECTION 4 FLOW CONTROL & WATER QUALITY ANALYSIS AND DESIGN Threshold Analysis Flow Control The project meets Exception #1 on page 1-34 of the City of Renton Amendments to the 2009 KCSWDM: “The facility requirement in Peak Rate Flow Control Standard Areas is waived for any threshold discharge area in which the target surfaces subject to this requirement will generate no more than a 0.1-cfs increase in the existing site conditions 100-year peak flow.” The 100-year flows from the existing and developed site computed by KCRTS are listed below. Existing 100-year flow: 0.286 cfs Developed 100-year flow: 0.314 cfs Difference: 0.028 cfs KCRTS output is included on the following page. Pervious areas are assumed to be till grass and the precipitation factor used for the SeaTac gage is 1.0. The soil type per the soils report is fill over silt/clay/sand and suggests a till-like hydrological response. Areas: Surface Cover Site ROW Total Existing Developed Existing Developed Existing Developed Pervious 13,348 sf 9,474 sf 3,496 sf 2,932 sf 16,844 sf (0.39ac) 12,406 sf (0.28ac) Impervious 18,139 sf 22,013 sf 768 sf 1,332 sf 18,907 sf (0.43ac) 23,345 sf (0.54ac) Total 31,487 sf 31,487 sf 4,264 sf 4,264 sf 35,751 sf (0.82ac) 35,751 sf (0.82ac) Technical Information Report for Sonic Renton June 21, 2017 19 Flow Frequency Analysis Time Series File:ex.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 0.139 5 2/09/01 2:00 0.286 1 100.00 0.990 0.110 8 1/05/02 16:00 0.168 2 25.00 0.960 0.168 2 2/27/03 7:00 0.166 3 10.00 0.900 0.114 7 8/26/04 2:00 0.147 4 5.00 0.800 0.139 6 10/28/04 16:00 0.139 5 3.00 0.667 0.147 4 1/18/06 16:00 0.139 6 2.00 0.500 0.166 3 10/26/06 0:00 0.114 7 1.30 0.231 0.286 1 1/09/08 6:00 0.110 8 1.10 0.091 Computed Peaks 0.247 50.00 0.980 Flow Frequency Analysis Time Series File:dv.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 0.156 6 2/09/01 2:00 0.314 1 100.00 0.990 0.128 8 1/05/02 16:00 0.203 2 25.00 0.960 0.188 3 2/27/03 7:00 0.188 3 10.00 0.900 0.140 7 8/26/04 2:00 0.168 4 5.00 0.800 0.168 4 10/28/04 16:00 0.165 5 3.00 0.667 0.165 5 1/18/06 16:00 0.156 6 2.00 0.500 0.203 2 10/26/06 0:00 0.140 7 1.30 0.231 0.314 1 1/09/08 6:00 0.128 8 1.10 0.091 Computed Peaks 0.277 50.00 0.980 Technical Information Report for Sonic Renton June 21, 2017 22 Flow Control BMPs Permeable pavement has been selected as the proposed BMP. Full dispersion is infeasible as the site is too small to accommodate the required flow path lengths and there is no native vegetation present to disperse runoff. The site is a “Large Lot High Impervious” site with impervious percentage of 70% (22,013sf/31,487sf). Per 5.2.1.3 of the SWDM, BMPs will be applied to a practical amount of impervious area; 10% of the lot size or 20% of the impervious area, whichever is less. 10% of lot = 10% of 31,487 sf = 3,149 sf 20% of impervious = 20% of 22,013 sf = 4,403 sf Permeable pavement is proposed for 3,160 sf slightly exceeding the requirement. Technical Information Report for Sonic Renton June 21, 2017 24 Water Quality The project is a commercial development that creates more than 5,000 square feet of PGIS, is a high-use site, and is therefore required to provide enhanced water quality treatment and oil control. A Filterra water quality facility is proposed for the project in accordance with the Blanket Adjustment Memorandum of June 26, 2014. The system will provide both enhanced water quality treatment and oil treatment, and is designed per conditions 4 and 6 of the Blanket Adjustment Memorandum. The Filterra system was designed using a filter hydraulic conductivity of 24.82 inches per hour to ensure both oil and enhanced treatment functions. The system was sized to treat 91% of runoff. The calculations were provided by Contech and are included in this report along with a letter. Blanket Adjustment The proposed Filterra system conforms to the conditions of the Blanket Adjustment Memorandum of June 26, 2014 (attached). A response to each condition is provided below. 1. The system is to be located on a private commercial property. The property is under one ownership and the owner will be responsible for maintenance. 2. The facility is not located inside a City right-of-way or easement. 3. The system has been designed for a hydraulic conductivity of 24.81 inches per hour which exceeds the requirement of this condition. 4. The Filterra system has been designed using a filter hydraulic conductivity of 24.81 inches per hour using the WWHM model. The system was sized to treat 91% of runoff. 5. The system has been designed for a hydraulic conductivity of 24.81 inches per hour which exceeds the requirement of this condition, and therefor provides Oil Control. 6. The system was designed per condition 4 and is therefore able to provide both Oil Control and Enhanced Water Quality Treatment. 7. Contech personnel have reviewed the grading and drainage plan and confirmed the facility size. A formal approval will be included in the final TIR. 8. The media will be provided or approved by Contech. 9. A maintenance contract will be set up with the Contech. An operation and maintenance manual is included in Section 10. 10. Inspection reports will be part of the maintenance contract with Contech. The reports will be provided to the City. 11. The permit and construction plans, and the TIR include the layout and design of the proposed Filterra system. 12. A Drainage Facility Covenant has been prepared and a copy included in Section 9 of this report. 13. Noted. Contech Engineered Solutions LLC 11815 NE Glenn Widing Dr. Portland, OR 97220 www.ContechES.com April 27, 2017 Nick Bossoff Nick Bossoff Engineering, Inc. 191 NE Tarl Lane Stevenson, WA 98648 Re: Filterra System Review – Renton Sonic Dear Nick: Contech Engineered Solutions, LLC has reviewed the plans prepared by Nick Bossoff Engineering, Inc. dated 12/28/2016 for the Renton Sonic project. Based on the information provided for review, it appears the Filterra system is designed to provide enhanced treatment for the basin and meets the Filterra General Use Level Designation (GULD) per the Technology Acceptance Protocol – Ecology (TAPE) program and that the following requirements are satisfied: 1. Treatment of 91% annual runoff volume appears to be provided as required by TAPE and allowed in the Filterra GULD. 2. Bypass appears to be provided through an approved mechanism: Internal bypass curb inlet configuration with terraflume tray and 8” bypass pipe. Additionally, the system appears to be specified to include all other components of the Filterra systems including impermeable walls, media at proper depth, mulch layer, and approved plants; the system appears to be constructible; and the location of the Filterra systems on the site appears to allow adequate maintenance access. As a result, the Filterra units are expected to operate in accordance with Contech’s design intent as well as the Filterra GULD. Please note that Contech has not reviewed the hydraulics of the collection system upstream or downstream of the Filterra systems for accuracy. We are pleased to work with you on this project and look forward to our continued interactions throughout the planning and installation process. Please let me know if we can be of additional assistance. Sincerely, Mike Gillette, E.I. Designer - Stormwater Products Contech Engineered Solutions 11815 NE Glenn Widing Dr. Portland, Oregon 97220 WWHM2012 PROJECT REPORT ___________________________________________________________________ Project Name: Sonic - Renton Site Name: Site Address: City : Report Date: 4/26/2017 Gage : Seatac Data Start : 1948/10/01 Data End : 2009/09/30 Precip Scale: 1.00 Version Date: 2016/02/25 Version : 4.2.12 ___________________________________________________________________ Low Flow Threshold for POC 1 : 50 Percent of the 2 Year ___________________________________________________________________ High Flow Threshold for POC 1: 50 year ___________________________________________________________________ PREDEVELOPED LAND USE MITIGATED LAND USE Name : Basin 1 Bypass: No GroundWater: No Pervious Land Use acre C, Lawn, Flat .19 Pervious Total 0.19 Impervious Land Use acre PARKING FLAT 0.41 Impervious Total 0.41 Basin Total 0.6 ___________________________________________________________________ Element Flows To: Surface Interflow Groundwater Filterra Filterra ___________________________________________________________________ Name : Filterra Bottom Length: 4.00 ft. Bottom Width: 12.00 ft. Depth: 0.75 ft. Side slope 1: 0 To 1 Side slope 2: 0 To 1 Side slope 3: 0 To 1 Side slope 4: 0 To 1 Filtration On Hydraulic conductivity: 24.82 Depth of filter medium: 1.8 Total Volume Infiltrated (ac-ft.): 70.812 Total Volume Through Riser (ac-ft.): 6.017 Total Volume Through Facility (ac-ft.): 76.829 Percent Infiltrated: 92.17 Total Precip Applied to Facility: 0 Total Evap From Facility: 0 Discharge Structure Riser Height: 0.7 ft. Riser Diameter: 100 in. Element Flows To: Outlet 1 Outlet 2 ___________________________________________________________________ Sand Filter Hydraulic Table Stage(feet) Area(ac.) Volume(ac-ft.) Discharge(cfs) Infilt(cfs) 0.0000 0.001 0.000 0.000 0.000 0.0083 0.001 0.000 0.000 0.027 0.0167 0.001 0.000 0.000 0.027 0.0250 0.001 0.000 0.000 0.028 0.0333 0.001 0.000 0.000 0.028 0.0417 0.001 0.000 0.000 0.028 0.0500 0.001 0.000 0.000 0.028 0.0583 0.001 0.000 0.000 0.028 0.0667 0.001 0.000 0.000 0.028 0.0750 0.001 0.000 0.000 0.028 0.0833 0.001 0.000 0.000 0.028 0.0917 0.001 0.000 0.000 0.029 0.1000 0.001 0.000 0.000 0.029 0.1083 0.001 0.000 0.000 0.029 0.1167 0.001 0.000 0.000 0.029 0.1250 0.001 0.000 0.000 0.029 0.1333 0.001 0.000 0.000 0.029 0.1417 0.001 0.000 0.000 0.029 0.1500 0.001 0.000 0.000 0.029 0.1583 0.001 0.000 0.000 0.030 0.1667 0.001 0.000 0.000 0.030 0.1750 0.001 0.000 0.000 0.030 0.1833 0.001 0.000 0.000 0.030 0.1917 0.001 0.000 0.000 0.030 0.2000 0.001 0.000 0.000 0.030 0.2083 0.001 0.000 0.000 0.030 0.2167 0.001 0.000 0.000 0.030 0.2250 0.001 0.000 0.000 0.031 0.2333 0.001 0.000 0.000 0.031 0.2417 0.001 0.000 0.000 0.031 0.2500 0.001 0.000 0.000 0.031 0.2583 0.001 0.000 0.000 0.031 0.2667 0.001 0.000 0.000 0.031 0.2750 0.001 0.000 0.000 0.031 0.2833 0.001 0.000 0.000 0.031 0.2917 0.001 0.000 0.000 0.032 0.3000 0.001 0.000 0.000 0.032 0.3083 0.001 0.000 0.000 0.032 0.3167 0.001 0.000 0.000 0.032 0.3250 0.001 0.000 0.000 0.032 0.3333 0.001 0.000 0.000 0.032 0.3417 0.001 0.000 0.000 0.032 0.3500 0.001 0.000 0.000 0.032 0.3583 0.001 0.000 0.000 0.033 0.3667 0.001 0.000 0.000 0.033 0.3750 0.001 0.000 0.000 0.033 0.3833 0.001 0.000 0.000 0.033 0.3917 0.001 0.000 0.000 0.033 0.4000 0.001 0.000 0.000 0.033 0.4083 0.001 0.000 0.000 0.033 0.4167 0.001 0.000 0.000 0.034 0.4250 0.001 0.000 0.000 0.034 0.4333 0.001 0.000 0.000 0.034 0.4417 0.001 0.000 0.000 0.034 0.4500 0.001 0.000 0.000 0.034 0.4583 0.001 0.000 0.000 0.034 0.4667 0.001 0.000 0.000 0.034 0.4750 0.001 0.000 0.000 0.034 0.4833 0.001 0.000 0.000 0.035 0.4917 0.001 0.000 0.000 0.035 0.5000 0.001 0.000 0.000 0.035 0.5083 0.001 0.000 0.000 0.035 0.5167 0.001 0.000 0.000 0.035 0.5250 0.001 0.000 0.000 0.035 0.5333 0.001 0.000 0.000 0.035 0.5417 0.001 0.000 0.000 0.035 0.5500 0.001 0.000 0.000 0.036 0.5583 0.001 0.000 0.000 0.036 0.5667 0.001 0.000 0.000 0.036 0.5750 0.001 0.000 0.000 0.036 0.5833 0.001 0.000 0.000 0.036 0.5917 0.001 0.000 0.000 0.036 0.6000 0.001 0.000 0.000 0.036 0.6083 0.001 0.000 0.000 0.036 0.6167 0.001 0.000 0.000 0.037 0.6250 0.001 0.000 0.000 0.037 0.6333 0.001 0.000 0.000 0.037 0.6417 0.001 0.000 0.000 0.037 0.6500 0.001 0.000 0.000 0.037 0.6583 0.001 0.000 0.000 0.037 0.6667 0.001 0.000 0.000 0.037 0.6750 0.001 0.000 0.000 0.037 0.6833 0.001 0.000 0.000 0.038 0.6917 0.001 0.000 0.000 0.038 0.7000 0.001 0.000 0.000 0.038 0.7083 0.001 0.000 0.067 0.038 0.7167 0.001 0.000 0.190 0.038 0.7250 0.001 0.000 0.349 0.038 0.7333 0.001 0.000 0.538 0.038 0.7417 0.001 0.000 0.752 0.038 0.7500 0.001 0.000 0.989 0.039 0.7583 0.001 0.000 1.246 0.039 ___________________________________________________________________ ___________________________________________________________________ ANALYSIS RESULTS POC #1 was not reported because POC must exist in both scenarios and both scenarios must have been run.Perlnd and Implnd Changes No changes have been made. ___________________________________________________________________ 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. 2005-2017; All Rights Reserved. Technical Information Report for Sonic Renton June 21, 2017 26 SECTION 5 CONVEYANCE SYSTEM ANALYSIS AND DESIGN Conveyance Calculations A uniform flow analysis is presented in this section for the site conveyance system. There are three drainage subbasins: Basin A is the area draining to the Filterra system; Basin B is the roof drainage; Basin C is offsite drainage that contributes to the pipe system that flows through the site. The 100-year rational method flow for each basin is computed as follows. 100-year/24-hour (P100) = 3.90 inches (COR Amendments to the 2009 KCSWDM) i100 = (2.61) Tc(-0.63) for Tc = minimum 6.3 minutes = (2.61) 6.3(-0.63) = 0.82 I100 = i100P100 = (0.82)(3.90) = 3.2 inches Q100 = CAI Where C = 0.9 for impervious and 0.25 for pervious areas For example, Basin A: Q100 = ((0.9)(0.42)+(0.25)(0.19))(3.2) = 1.36 cubic feet per second The basin areas and pipe capacities and calculated flow rates are tabulated below. Technical Information Report for Sonic Renton June 21, 2017 27 Areas: Basin Impervious Pervious 100-yr Flow Basin A 0.42 ac 0.19 ac 1.36 cfs Basin B 0.07 ac 0 ac 0.20 cfs Basin C 0.16 ac 0.02 ac 0.48 cfs Pipe Details: Pipe Diameter Slope Capacity 100-yr Flow SF – CB#2 8” 1.67% 1.56 cfs 1.36 cfs CO to CB#3 6” 2.00% 0.79 cfs 0.20 cfs CB#4 – CB#3 12” 0.23% 1.71 cfs 0.48 cfs CB#3 – CB#2 12” 0.52% 2.57 cfs 0.68 cfs CB#2 – CB#1 12” 0.52% 2.57 cfs 2.04 cfs The system therefore has adequate capacity to convey the expected 100-year flow rate. 3.90" MANNING'S EQUATION FOR PIPE FLOW Project: Renton Sonic Location: SF – CB#2 By: NB Date: 2/8/2016 Chk. By: Date:mdo version 12.8.00 INPUT D= 8 inches d= 8 inches Mannings Formula n= 0.013 mannings coeff 0.0 degrees Q=(1.486/n)ARh2/3S1/2 S= 0.0167 slope in/in R=A/P A=cross sectional area P=wetted perimeter V=(1.49/n)Rh2/3S1/2 S=slope of channel Q=V x A n=Manning's roughness coefficient Solution to Mannings Equation Area,ft2 Wetted Perimeter, ft Hydraulic Radius, ft velocity ft/s flow, cfs PVC 0.01 0.35 2.09 0.17 4.47 1.56 PE (<9"dia) 0.015 PE (>12"dia) 0.02 PE(9-12"dia) 0.017 CMP 0.025 ADS N12 0.012 Created by: Mike O'Shea HCMP 0.023 Conc 0.013 Manning's n-values d D Clear Data Entry Cells MANNING'S EQUATION FOR PIPE FLOW Project: Renton Sonic Location: Roof to CB#3 By: NB Date: 2/8/2016 Chk. By: Date:mdo version 12.8.00 INPUT D= 6 inches d= 6 inches Mannings Formula n= 0.013 mannings coeff 0.0 degrees Q=(1.486/n)ARh2/3S1/2 S= 0.02 slope in/in R=A/P A=cross sectional area P=wetted perimeter V=(1.49/n)Rh2/3S1/2 S=slope of channel Q=V x A n=Manning's roughness coefficient Solution to Mannings Equation Area,ft2 Wetted Perimeter, ft Hydraulic Radius, ft velocity ft/s flow, cfs PVC 0.01 0.20 1.57 0.13 4.04 0.79 PE (<9"dia) 0.015 PE (>12"dia) 0.02 PE(9-12"dia) 0.017 CMP 0.025 ADS N12 0.012 Created by: Mike O'Shea HCMP 0.023 Conc 0.013 Manning's n-values d D Clear Data Entry Cells MANNING'S EQUATION FOR PIPE FLOW Project: Renton Sonic Location: CB#2 – CB#1 By: NB Date: 2/8/2016 Chk. By: Date:mdo version 12.8.00 INPUT D= 12 inches d= 12 inches Mannings Formula n= 0.013 mannings coeff 0.0 degrees Q=(1.486/n)ARh2/3S1/2 S= 0.0052 slope in/in R=A/P A=cross sectional area P=wetted perimeter V=(1.49/n)Rh2/3S1/2 S=slope of channel Q=V x A n=Manning's roughness coefficient Solution to Mannings Equation Area,ft2 Wetted Perimeter, ft Hydraulic Radius, ft velocity ft/s flow, cfs PVC 0.01 0.79 3.14 0.25 3.27 2.57 PE (<9"dia) 0.015 PE (>12"dia) 0.02 PE(9-12"dia) 0.017 CMP 0.025 ADS N12 0.012 Created by: Mike O'Shea HCMP 0.023 Conc 0.013 Manning's n-values d D Clear Data Entry Cells MANNING'S EQUATION FOR PIPE FLOW Project: Renton Sonic Location: CB#3 – CB#2 By: NB Date: 2/8/2016 Chk. By: Date:mdo version 12.8.00 INPUT D= 12 inches d= 12 inches Mannings Formula n= 0.013 mannings coeff 0.0 degrees Q=(1.486/n)ARh2/3S1/2 S= 0.0052 slope in/in R=A/P A=cross sectional area P=wetted perimeter V=(1.49/n)Rh2/3S1/2 S=slope of channel Q=V x A n=Manning's roughness coefficient Solution to Mannings Equation Area,ft2 Wetted Perimeter, ft Hydraulic Radius, ft velocity ft/s flow, cfs PVC 0.01 0.79 3.14 0.25 3.27 2.57 PE (<9"dia) 0.015 PE (>12"dia) 0.02 PE(9-12"dia) 0.017 CMP 0.025 ADS N12 0.012 Created by: Mike O'Shea HCMP 0.023 Conc 0.013 Manning's n-values d D Clear Data Entry Cells MANNING'S EQUATION FOR PIPE FLOW Project: Renton Sonic Location: CB#4 – CB#3 By: NB Date: 2/8/2016 Chk. By: Date:mdo version 12.8.00 INPUT D= 12 inches d= 12 inches Mannings Formula n= 0.013 mannings coeff 0.0 degrees Q=(1.486/n)ARh2/3S1/2 S= 0.0023 slope in/in R=A/P A=cross sectional area P=wetted perimeter V=(1.49/n)Rh2/3S1/2 S=slope of channel Q=V x A n=Manning's roughness coefficient Solution to Mannings Equation Area,ft2 Wetted Perimeter, ft Hydraulic Radius, ft velocity ft/s flow, cfs PVC 0.01 0.79 3.14 0.25 2.18 1.71 PE (<9"dia) 0.015 PE (>12"dia) 0.02 PE(9-12"dia) 0.017 CMP 0.025 ADS N12 0.012 Created by: Mike O'Shea HCMP 0.023 Conc 0.013 Manning's n-values d D Clear Data Entry Cells Technical Information Report for Sonic Renton June 21, 2017 35 SECTION 6 SPECIAL REPORTS AND STUDIES A soils report was prepared by Zipper Geo and Associates (January 25th, 2016) and is included in the section. GEOTECHNICAL ENGINEERING REPORT PROPOSED SONIC DRIVE-IN 225 RAINIER AVENUE SOUTH RENTON, WASHINGTON Project No. 1559.01 January 25, 2016 Prepared for: Cascade Development Group Prepared by: Zipper Geo Associates, LLC Geotechnical and Environmental Consultants 19023 36th Avenue W., Suite D Lynnwood, WA 98036 ZGA Zipper Geo Associates, LLC Geotechnical and Environmental Consulting 19023 36th Avenue West, Suite D Lynnwood, WA 98036 (425) 582-9928 January 25, 2016 Project No. 1559.01 Cascade Development Group, LLC P.O. Box 4584 Rolling Bay, WA 98061 Attention: Mr. Don Morris Subject: Subsurface Exploration and Geotechnical Engineering Evaluation Proposed Sonic Drive-In Rainier Avenue South and Hardie Avenue SW Renton, Washington Dear Mr. Morris, In accordance with your request and authorization, Zipper Geo Associates, LLC (ZGA) has completed the final geotechnical engineering report for the above-referenced project. This report presents the findings of the subsurface exploration and geotechnical recommendations for the project. Our work was completed in general accordance with our Proposed Scope of Services and Cost Estimate (Proposal No. P15300) dated December 10, 2015. Written authorization to proceed was provided by Cascade Development Group on December 14, 2015. We appreciate the opportunity to be of service to you on this project. If you have any questions concerning this report, or if we may be of further service, please contact us. Sincerely, Zipper Geo Associates LLC Thomas A. Jones, P.E. Robert A. Ross, P.E. Managing Principal Principal TABLE OF CONTENTS INTRODUCTION .......................................................................................................................... 1 SITE DESCRIPTION..................................................................................................................... 1 PROJECT UNDERSTANDING ..................................................................................................... 1 SUBSURFACE CONDITIONS ...................................................................................................... 2 Published Geologic Mapping.................................................................................................. 2 Soil Conditions ....................................................................................................................... 2 Groundwater .......................................................................................................................... 2 CONCLUSIONS AND RECOMMENDATIONS .............................................................................. 3 General Considerations ................................................................................................................ 3 SEISMIC CONSIDERATIONS ...................................................................................................... 3 SITE PREPARATION ................................................................................................................... 5 STRUCTURAL FILL ...................................................................................................................... 8 UTILITY TRENCHING AND BACKFILLING ................................................................................ 10 TEMPORARY AND PERMANENT SLOPES .............................................................................. 11 BUILDING FOUNDATIONS ........................................................................................................ 12 Augercast Piles .................................................................................................................... 12 Ground Improvement ........................................................................................................... 13 Non-Building Shallow Foundations ...................................................................................... 15 SLAB-ON-GRADE CONCRETE FLOOR .................................................................................... 16 DRAINAGE CONSIDERATIONS ................................................................................................ 17 PAVEMENTS .............................................................................................................................. 17 Existing Pavements ............................................................................................................. 17 Asphalt Overlays .................................................................................................................. 17 New Asphalt Pavements ...................................................................................................... 18 Concrete Pavements ........................................................................................................... 19 CLOSURE .................................................................................................................................. 20 FIGURES Figure 1 – Site and Exploration Plan APPENDICES Appendix A – Subsurface Exploration Procedures and Boring Log Appendix B – Laboratory Testing Procedures and Results Cover Page Image Credit: Google Earth Page 1 GEOTECHNICAL ENGINEERING REPORT PROPOSED SONIC DRIVE-IN 225 RAINIER AVENUE SOUTH RENTON, WASHINGTON Project No. 1559.01 January 25, 2016 INTRODUCTION This report documents the subsurface conditions encountered at the project site and our geotechnical engineering recommendations relative to the proposed project. Supporting data including geotechnical exploration logs, field exploration procedures, results of laboratory testing and other supporting information are presented as appendices. Geotechnical evaluation of the site was completed on December 19, 2015. A single boring (B-1) was drilled to a depth of approximately 49 feet below existing grade. The approximate location of the boring is presented on Figure 1, the Site and Exploration Plan. A log of the boring is presented in Appendix A of this report. Laboratory test procedures and results are presented in Appendix B. SITE DESCRIPTION The project site is located on the east side of an existing Walmart development located at 743 Rainier Avenue in Renton, Washington at the intersection of Rainier Avenue and Hardie Avenue SW. The site is bordered to the west by the Walmart development, to the north by an asphalt covered parking lot, to the east by Rainier Avenue and Hardie Avenue SW, and to the south by an access driveway and a gas station beyond. Topographic relief across the site is estimated to be on the order of a couple feet. The site is bordered by the following: North: Asphalt covered parking area, South: Walmart entrance and gas station, East: Rainier Avenue and Hardie Avenue SW, West: Walmart development. PROJECT UNDERSTANDING The proposed project includes the construction of a one-story, approximately 2,700 square foot restaurant building. We understand the slab on grade finish floor elevation of the building will be 26.25 feet. Based on the proposed floor elevation, it appears that 1 to 2 feet of fill in the building pad may be necessary (after stripping) in order to establish the floor subgrade. We are not aware of any planned slopes that will be steeper than 3H:1V or the need for any free-standing retaining walls. A drive-thru lane, parking, and landscaping is also planned. Zipper Geo Associates, LLC Proposed Sonic Drive-in Renton, Washington ZGA Project No. 1559.01 January 25, 2016 Page 2 SUBSURFACE CONDITIONS Published Geologic Mapping The Geologic Map of the Renton Quadrangle, King County, Washington (1965) by the U.S. Geological Survey, indicates the surficial geologic conditions mapped at and around the site consist of Recent Alluvial Deposits. The alluvium is described as sand and gravel deposited by the Cedar River and associated thin beds of silt, clay and peat. According to the USDA Soil Conservation Service, Soil Survey for King County Area, Washington, 1973, as well as the USDA Natural Resource Conservation Service, Web Soil Survey for King County Area, Washington, (http://websoilsurvey.nrcs.usda.gov/app/HomePage.htm), the site is mapped as Urban land (Ur). Urban land is soil that has been modified by disturbance of the natural layers with additions of fill material several feet thick to accommodate development. Therefore, no soil characteristics are available and no USDA soil data is included in this report. Soil Conditions Soil descriptions presented in this report are based on the subsurface conditions encountered in the boring completed for this project. Variations in subsurface conditions may exist across the site and the nature and extent of variations may not become evident until construction. If variations then appear, it may be necessary to reevaluate the recommendations presented in this report. Specific conditions encountered at the boring location are presented on boring log B-1. Stratification boundaries on the logs represent the approximate location of changes in soil types; in situ, the transition between materials may be gradual. A detailed boring log is presented in Appendix A of this report. The subsurface conditions encountered in boring B-1 consisted of approximately 4 inches of landscape bark over loose, wet to saturated, silty gravelly sand that extended to a depth of approximately 3 feet below grade. This material was interpreted to be probable fill. Very soft to stiff silt with varying proportions of clay and sand was encountered below the fill and extended to a depth of approximately 36½ feet. The silt between 25 and 36 feet contained fine pieces of fibrous organics. Below the fine-grained soils loose grading to very dense, interbedded gravelly sand and sandy gravel was encountered to the full depth explored of 49 feet. Groundwater Groundwater was encountered in boring B-1 at the time of drilling at a depth of approximately 1 foot below grade. As part of a previous Phase II Environmental Site Assessment for the Walmart store, a groundwater monitor well was installed in a boring completed on the current project site (B-39) on October 7, 2009. On October 12, 2009, a water level reading was taken and reported to approximately 9 feet below grade. Additional well information was obtained from the Washington State Department of Ecology for the neighboring Mobil gas station (formerly USA Petro Mart) and Renton Honda sites. Groundwater depths of 8 to 10 feet were reported for those sites. The Zipper Geo Associates, LLC Proposed Sonic Drive-in Renton, Washington ZGA Project No. 1559.01 January 25, 2016 Page 3 observed groundwater level on December 19, 2015 may have been perched within the granular fill soils, although the moisture contents of all of the collected soil samples were relatively high. These water level observation provides an approximate indication of the groundwater conditions existing on the site at the time the exploration was completed. Fluctuations of the groundwater levels will likely occur due to seasonal variations in the amount of rainfall, runoff and other factors not evident at the time the explorations were performed. Therefore, groundwater levels during construction or at other times in the life of the structure may be higher than indicated on the logs. The possibility of groundwater level fluctuations and perched water should be considered when developing the design and construction plans for the project. CONCLUSIONS AND RECOMMENDATIONS General Considerations In our opinion, development as proposed is feasible from a geotechnical engineering standpoint based on the conditions encountered. Our analyses and related conclusions and recommendations are based on the subsurface evaluation and laboratory testing completed. Differing soil conditions than those observed in our boring may become evident during construction and the recommendation presented herein may need to be modified if the observed soil conditions vary from those reported. Our recommendations are also based on the assumption that earthwork for site grading, utilities, foundations, floor slabs, and pavements will be monitored by Zipper Geo Associates. A brief summary of unique geotechnical aspects of the project that may impact schedule and cost are as follows: Liquefaction: The site is underlain by loose to medium dense granular soils that are susceptible to liquefaction during a design earthquake. Our analyses indicate that post-liquefaction settlements on the order of 5 to 10 inches are possible. Due to the liquefaction potential, we recommend the proposed building be supported on augercast piles, stone columns or rammed aggregate piers. SEISMIC CONSIDERATIONS Seismic Setting: According to the United States Geological Survey Quaternary Fault and Fold Database for the United States (http://geohazards.usgs.gov/qfaults/map.php), the nearest mapped fault to the project site is the Seattle Fault Zone. The project site is approximately 3½ miles south of the southern extent of the fault zone. The fault zone is approximately 4 to 7 kilometers wide and is described as extending from the Cascade Mountain Range on the east to Hood Canal to the west. The zone consists of 3 or more south-dipping thrust faults. It has an average strike of N85⁰W and a dip direction to the south. Its slip rate is reported to be 0.2 to 1.0 mm/yr. Based on the information described above, we estimate that the risk associated with surface rupture at the site is low. Seismic Induced Liquefaction: Liquefaction is a phenomenon wherein saturated cohesionless soils build up excess pore water pressures during earthquake loading. Liquefaction typically occurs Zipper Geo Associates, LLC Proposed Sonic Drive-in Renton, Washington ZGA Project No. 1559.01 January 25, 2016 Page 4 in loose soils, but may occur in denser soils if the ground shaking is sufficiently strong. ZGA completed a liquefaction analysis in general accordance with Section 1803.5.12 of the 2012 IBC and Section 11.8.3 of ASCE 7-10. Specifically, our analysis used the following primary seismic ground motion parameters. • A Maximum Considered Earthquake Geometric Mean (MCEG) Peak Ground Acceleration of 0.59g, based on Figure 22-7 of ASCE 7-10. • A Modified Peak Ground Acceleration (PGAM) of 0.53g based on Site Class E, per Section 11.8.3 of ASCE 7-10 (Site Class modification to MCEG without regard to liquefaction in accordance with Sections 11.4.7 and 20.3.1 of ASCE 7-10). • A Geometric Mean Magnitude of 6.83 based on 2008 USGS National Seismic Hazard Mapping Project deaggregation data for a seismic event with a 2 percent probability of exceedance in 50 years (2,475 year return period). Our liquefaction analysis was completed using the computer program LiquefyPro Version 5.8. Our analysis was based on the subsurface conditions and blowcount data obtained from boring B-1, and laboratory test results. Our analysis indicates the potential for liquefaction in soil intervals between the groundwater table (1 foot) and a depth of approximately 40 feet below existing grade is high. We estimate that total liquefaction-induced settlements of approximately 5 to 10 inches and differential settlements of approximately 2.5 to 5 inches differential over 40 feet could be experienced at the ground surface during the design seismic event. A report, with maps, titled Liquefaction Susceptibility for the Des Moines and Renton 7.5-Minute Quadrangles, Washington, (Geologic Map GM-41), prepared by the Washington State Department of Natural Resources, delineates the site as being underlain by Category 1 soil deposits. Category 1 soil deposits are defined as having a high susceptibility to liquefaction. The report presents a written communication after the 1965, Richter magnitude 6.5, Seattle-Tacoma earthquake. Reportedly, a house about 1,500 feet east-northeast of the project site experienced settlement of about 2½ inches and an area approximately 2,500 feet east-northeast of the project site near the intersection of Burnett Street and 7th Avenue had dropped as much as 2 feet in some places. IBC Seismic Design Parameters: Based on the liquefaction potential of some of the soils underlying the proposed building, the IBC states: “Soils vulnerable to potential failure or collapse under seismic loading such as liquefiable soils” be classified in Site Class F. However, for structures with a fundamental period of less than 0.5 second, Section 20.3.1 of ASCE 7-05 allows the site coefficients Fa and Fv to be determined disregarding the potential for liquefaction. Therefore, the site conditions, based on blowcounts obtained during drilling, correspond to Site Class E. Values provided below are based upon data from USGS National Seismic Hazard Mapping Project. The following table summarizes our recommended seismic design criteria. Zipper Geo Associates, LLC Proposed Sonic Drive-in Renton, Washington ZGA Project No. 1559.01 January 25, 2016 Page 5 Seismic Design Criteria 2009 International Building Code Site Classification (IBC) Site Class E1 - Average soil profile within the top 100 feet consisting predominantly of soft clay and loose granular soils characterized by average Standard Penetration Test blowcounts of less than 15. Site Latitude/Longitude 47.4724º N/122.2183º W Spectral Short-Period Acceleration, Ss 1.438g (Site Class B) Spectral 1-Second Acceleration, S1 0.537g (Site Class B) Site Coefficient for a Short Period, Fa 0.9 Site Coefficient for a 1-Second Period, Fv 2.4 Spectral Acceleration for a 0.2-Second Period, SMs 1.295g (Site Class E) Spectral Acceleration for a 1-Second Period, SM1 1.289g (Site Class E) Design Short-Period Spectral Acceleration, SDS 0.863g (Site Class E) Design 1-Second Spectral Acceleration, SD1 0.860g (Site Class E) 1 Note: Based on borings completed and our familiarity with deeper geologic conditions in the project area. SITE PREPARATION Existing Utilities: All existing underground utilities and structures within the proposed building footprint should be relocated or abandoned. We recommend they be completely removed from within and 5 feet beyond the building pad. Utilities should be abandoned in accordance with all local, state and federal regulations. Localized excavations made for removal of structures and utilities backfilled with structural fill material placed and compacted in accordance with the Structural Fill section of this report. Utilities outside the building envelope could be abandoned in place, provided they are fully grouted with controlled density fill (CDF) and the trench backfill is density tested to verify that it meets the compaction levels specified in this report. Erosion Control Measures: Stripped surfaces and soil stockpiles are typically a source of runoff sediments. We recommend that silt fences, berms, and/or swales be installed around the downslope side of stripped areas and stockpiles in order to capture runoff water and sediment. If earthwork occurs during wet weather, we recommend that all stripped surfaces be covered with straw to reduce runoff erosion, whereas soil stockpiles should be protected with anchored plastic sheeting. We recommend that all temporary erosion and sediment control measures (TESC) be installed in accordance with project plans. Temporary Site Drainage: Stripping, excavation, grading, and subgrade preparation should be performed in a manner and sequence that will provide drainage at all times and provide proper control of erosion. If prolonged or substantial precipitation is anticipated, we recommend the open areas of the site be graded to prevent water from ponding in construction areas and/or flowing into excavations. Accumulated water should be pumped from temporary sumps in order to reduce potential damage or saturation of the subgrade soils. We recommend that sand bags or asphalt berms/curbs be used to divert parking lot runoff away from the building pad excavation. Equipment Zipper Geo Associates, LLC Proposed Sonic Drive-in Renton, Washington ZGA Project No. 1559.01 January 25, 2016 Page 6 access may be limited and the amount of soil rendered unfit for use as structural fill may be greatly increased if drainage efforts are not accomplished in a timely manner. Construction Dewatering: Based on the groundwater condition encountered at the time of drilling, dewatering may be necessary within the anticipated excavation depths. Given the granular nature of the material encountered within the upper approximate 5 feet, the rate and duration of flow to dewatering points could be relatively substantial. This will be dependent on the time of year, precipitation before and during construction, and the depth of the excavations. We recommend the contractor be responsible for developing and maintaining a dewatering system appropriate for the conditions at the time of construction. We further recommend that contractors be provided the opportunity to observe the groundwater conditions prior to bidding in order to budget for the appropriate level of dewatering. Clearing and Stripping: Site preparation will require removing surface vegetation and its associated root systems, topsoil, and other deleterious materials within planned building and pavement areas. Such materials are only anticipated within existing landscape areas and not beneath the pavements. Organic-rich materials generated from landscape areas should be considered unsuitable for reuse as structural fill. Actual removal depths should be determined by a qualified geotechnical engineer at the time of grading. Limited amounts of asphalt will need to be stripped from the building pad. We recommend these materials be removed from the site. Subgrade Preparation: After stripping and removing asphalt pavement, the exposed subgrade would likely consist of a variety of fill soils such as gravelly sand with silt, silty sand with gravel, or sandy silt. The exposed soils should be expected to be wet and very sensitive to disturbance and construction activities should be planned to reduce disturbance of the exposed soils. The method of stripping and filling will need to consider the moisture content of the existing soils at the time of earthwork relative to subgrade preparation, preservation, and placement of any new fill above these materials. Subgrade soils that become disturbed due to elevated moisture conditions should be over-excavated and replaced with compacted satisfactory structural fill. Wet season earthwork may require additional mitigative measures to protect the subgrade beyond that which would be expected during the drier summer months. It is our interpretation that the granular soils typically encountered within the upper 2 to 2½ feet in the building area is probable structural fill placed as a result of past development. Compaction and proof-rolling of the exposed subgrade will be difficult to impossible unless soil moisture is substantially lower at the time of construction. Soils that cannot be compacted and that are soft, yielding or otherwise uncompactable, should be over-excavated and replaced with structural fill. Alternatively, wet soils that cannot be dried, could be blended with cement. All replacement fill should be compacted in accordance with the Structural Fill section of this report. We recommend Zipper Geo Associates, LLC Proposed Sonic Drive-in Renton, Washington ZGA Project No. 1559.01 January 25, 2016 Page 7 that all subgrade preparation and compaction be observed by ZGA prior to the placement of additional structural fill. Wet Soil Conditions: In our opinion, earthwork should completed during periods of the year when the moisture content of the soils can be controlled by aeration and drying. If earthwork takes place during extended periods of wet weather, or if the soil moisture conditions are elevated more than about 2 percent above the optimum moisture content, the soils could become unstable, or uncompactable due to high moisture conditions. In this case, we recommend the soil be over- excavated to a sufficient depth in order to develop stable subgrade soils that can be compacted to the minimum recommended levels. The severity of construction problems will be dependent, in part, on the precautions taken by the contractor to protect the subgrade soils. Methods of stabilizing wet soils could include scarification, aeration and recompaction, removal of unstable materials and replacement with granular fill (with or without geotextiles) and stabilization with cement. The most suitable method of stabilization, if required, will be dependent upon factors such as schedule, weather, and the size of area to be stabilized and the nature of the instability. Performing site grading operations during the warmer and drier months would aid in reducing potential need for subgrade stabilization. Scarification and recompaction - It may be feasible to scarify, dry, and recompact the exposed soils. The success of this procedure would depend primarily on the in-situ soil moisture conditions at the time of earthwork and on favorable weather and sufficient time to dry the soils. Even with adequate time and weather, stable subgrades may not be achievable if the thickness of the soft soil is greater than about 1 to 1½ feet. Crushed rock mat- The use of crushed gravel and quarry spalls could be considered to improve subgrade stability. The use of high modulus geotextiles (such as Mirafi 600X or Tensar TX140 geogrid) are not recommended due to the need for pile foundations or soil improvement. The maximum particle size of granular material should not exceed 2 inches. Over-excavations should be backfilled with structural fill material placed and compacted in accordance with the Structural Fill section of this report. Subgrade preparation and selection, placement, and compaction of structural fill should be performed under engineering controlled conditions in accordance with the project specifications. Cement stabilization - Improvement of subgrades with Portland cement could be considered for unstable soils. Cement modification should be performed by a pre-qualified contractor having experience with successfully stabilizing subgrades in the project area on similar sized projects with similar soil conditions. The hazards of cement blowing across the site or onto adjacent property should also be considered. The use of cement will increase the strength and durability of the soils, and make wet soils easier to compact. If cement amendment of the native soils is a possibility, we recommend that a soil-cement mix design be completed prior to Zipper Geo Associates, LLC Proposed Sonic Drive-in Renton, Washington ZGA Project No. 1559.01 January 25, 2016 Page 8 construction at a range of moisture contents so that adjustments in the cement ratio can be made at the time of construction. Due to the potential for increased corrosion potential under the building pad due to the increase in pH from the addition of cement, we do not recommend chemical treatment of the building pad soils. The building pad should be surfaced with “select” naturally-occurring granular material or free-draining crushed aggregate and crowned to promote drainage towards perimeter collection points. Select soils are specified in the Structural Fill section of this report. Subgrade Protection: If it becomes necessary to protect the subgrade during wet weather, we recommend that dedicated haul roads or lay-down areas be constructed with a minimum of 12 inches of 2- to 4-inch quarry spalls, free-draining permeable ballast, or crushed recycled concrete of equivalent gradation. Permeable ballast is defined in Section 9-03.9(2) of the 2014 Washington State Department of Transportation (WSDOT) Standard Specifications for Road Bridge and Municipal Construction (Publication M 41-10). The level of subgrade protection should be determined by the contractor at the time of construction and will be a function of the type and magnitude of traffic over the work areas and the effectiveness of controlling runoff and draining areas where runoff or groundwater collects. Freezing Conditions: If earthwork takes place during freezing conditions, all exposed subgrades should be allowed to thaw and then be recompacted prior to placing subsequent lifts of structural fill. Alternatively, the frozen material could be stripped from the subgrade to expose unfrozen soil prior to placing subsequent lifts of fill or foundation components. The frozen soil should not be reused as structural fill until allowed to thaw and adjusted to the proper moisture content, which may not be possible during winter months. STRUCTURAL FILL Structural fill includes any material placed below foundations, floor slab, appurtenances and pavement sections, within utility trenches, and behind retaining walls. Prior to the placement of structural fill, all surfaces to receive fill should be prepared as previously recommended in the Site Preparation section of this report. Laboratory Testing: Representative samples of on-site and imported soils to be used as structural fill should be submitted for laboratory testing at least 4 days in advance of its intended use. Imported Fill Properties: We recommend that imported soils used for structural fill consist of granular material that complies with WSDOT Standard Specification 9-03.14(1), Gravel Borrow. We also recommend that the material have less than 3 percent organics and be free of vegetation, debris, roots and sticks larger than ½ inch in diameter. Re-Use of Site Soils as Structural Fill: The suitability of soil for use as structural fill will depend on the time of year, the moisture content of the soil, and the fines content (that portion passing the Zipper Geo Associates, LLC Proposed Sonic Drive-in Renton, Washington ZGA Project No. 1559.01 January 25, 2016 Page 9 U.S. No. 200 sieve) of the soil. As the amount of fines increases, the soil becomes increasingly sensitive to small changes in moisture content. Soils containing more than about 5 percent fines (such as most of the native on-site soils) cannot be consistently compacted to the appropriate levels when the moisture content is more than approximately 2 percent above or below the optimum moisture content (per ASTM D1557). Optimum moisture content is that moisture content which results in the greatest compacted dry density with a specified compactive effort. Based on the groundwater conditions and soil moisture levels encountered, it is our opinion that the existing near-surface soils encountered on site are not suitable for reuse as structural fill. We recommend that all fine-grained silts encountered at the site only be used for non-structural applications such as landscaping. Organic-rich soil derived from earthwork activities should only be utilized in landscape areas or exported from the site. Imported Select Structural Fill for Grading: Imported structural fill may be required due to weather or other reasons. The appropriate type of imported structural fill will depend on weather conditions. During extended periods of dry weather, we recommend imported fill meet the recommended criteria presented above for satisfactory fill. During wet weather, higher-quality “select” structural fill might be required. In this case, we recommend that imported structural fill meet the requirements for Gravel Borrow as specified in Section 9-03.14(1) of the 2014 WSDOT Standard Specifications with the modification that the percent passing the U.S. No. 200 sieve be limited to 5 percent. Materials with higher silt and clay content that meets WSDOT Standard Specification 9-03.14(3), Common Borrow could be used but this type of material has a greater potential to retain soil moisture and a greater potential to wick soil moisture up to the bottom of the floor slab. Pavement Subgrades: Any structural fill used within one foot of pavement subgrade should have a minimum CBR value of 20 when compacted to a minimum of 95 percent of the modified Proctor maximum dry density. A CBR value of 20 is representative of locally available soils that typically have a non-plastic fines content of less than 25 percent. Fill Placement and Compaction Criteria: Each lift of fill should be compacted using compaction equipment suitable for the soil type and lift thickness. However, we recommend that the maximum lift thickness be 10 inches. Each lift of fill should be compacted to the minimum levels recommended in the following table based on the maximum laboratory dry density as determined by the ASTM D1557 Modified Proctor Test. Structural fill for roadways and utility trenches in municipal rights-of-way should be placed and compacted in accordance with the jurisdiction codes and standards. The moisture content of the fill at the time of placement should be within plus or minus 2 percent of optimum moisture content for compaction of granular soils. We recommend that ZGA be present during grading so that an adequate number of density tests may be conducted as structural fill placement occurs. In this way, the adequacy of the earthwork may be evaluated as it proceeds. Our recommendations for soil compaction are summarized in the following table. Zipper Geo Associates, LLC Proposed Sonic Drive-in Renton, Washington ZGA Project No. 1559.01 January 25, 2016 Page 10 RECOMMENDED SOIL COMPACTION LEVELS Location Minimum Percent Compaction Modified Proctor All fill below building floor slabs, foundations and appurtenances 95 Upper 2 feet of fill below pavements 95 Pavement fill below two feet 92 Retaining wall backfill less than 2 feet from wall 90 Retaining wall backfill more than 2 feet from wall 92 Upper two feet of utility trench backfill 95 Utility trenches below two feet 92 Landscape Areas 90 UTILITY TRENCHING AND BACKFILLING Trenching: We recommend that utility trenching conform to all applicable federal, state, and local regulations, such as OSHA and WISHA, for open excavations. Some excavation sidewall stability problems should be expected where soils are wet or they extend into groundwater. Flatter temporary slopes, temporary bracing or trench box shoring will be necessary to support utility trench sidewalls. Trench Dewatering: Depending on the time of year, excavations for utilities could possibly extend below the groundwater table. Groundwater flow in the granular soils should be expected to be moderate to heavy. If dewatering becomes necessary, it should be designed, operated and maintained by the contractor based on the conditions encountered. Depending on the time of year, the presence of groundwater and elevation of the groundwater table could be as high as that encountered in the boring. Utility Subgrade Preparation: We recommend that all utility subgrades be firm and unyielding and free of all soils that are loose, disturbed, or pumping. Such soils should be removed and replaced. All structural fill used to replace over-excavated soils should be compacted as recommended in the Structural Fill section of this report. If utility foundation soils are soft, we recommend that they be over-excavated a minimum of 12 inches and replaced with 2- to 4-inch quarry spalls. Structures such as manholes and catch basins which extend into soft soils should be underlain by at least 12 inches of crushed gravel fill compacted to at least 90 percent of the modified Proctor maximum dry density and be firm and unyielding. This granular material could consist of crushed rock, riprap, or coarse crushed concrete. Alternatively, riprap could be used until above the water table. It may be necessary to place a geotextile fabric such as Mirafi 600x or approved equivalent over the native subgrade soils if they are too soft, to provide a separation between the bedding and subgrade soils. Zipper Geo Associates, LLC Proposed Sonic Drive-in Renton, Washington ZGA Project No. 1559.01 January 25, 2016 Page 11 Bedding, Haunching and Initial Backfill: We recommend that pipe bedding, haunching and initial backfill consist of Gravel Backfill for Pipe Zone Bedding as specified in Section 9-03.12(3) of the WSDOT Standard Specifications. We recommend that a minimum of 4 inches of bedding material be placed above and below all utilities or in general accordance with the utility manufacturer’s recommendations and local ordinances. All trenches should be wide enough to allow for compaction around the haunches of the pipe, or material such as pea gravel should be used below the spring line of the pipes to eliminate the need for mechanical compaction in this portion of the trenches. Trench Backfill: Materials, placement and compaction of utility trench backfill should be in accordance with the recommendations presented in the Structural Fill section of this report. In our opinion, the initial lift thickness should not exceed one foot unless recommended by the manufacturer to protect utilities from damage by compacting equipment. Light, hand operated compaction equipment may be utilized directly above utilities if damage resulting from heavier compaction equipment is of concern. Compaction of the on-site soils will not likely be possible due to elevated moisture conditions. We recommend that trench backfill conform to WSDOT Standard Specification 9-03.14(1), Gravel Borrow, with less than 5 percent passing the U.S. No. 200 sieve. TEMPORARY AND PERMANENT SLOPES Temporary excavation slope stability is a function of many factors, including: The presence and abundance of groundwater; The type and density of the various soil strata; The depth of cut; Surcharge loadings adjacent to the excavation; and The length of time the excavation remains open. As the cut is deepened, or as the length of time an excavation is open, the likelihood of bank failure increases; therefore, maintenance of safe slopes and worker safety should remain the responsibility of the contractor, who is present at the site, able to observe changes in the soil conditions, and monitor the performance of the excavation. Temporary Cuts: It is exceedingly difficult under the variable circumstances to pre-establish a safe and “maintenance-free” temporary cut slope angle. Therefore, it should be the responsibility of the contractor to maintain safe temporary slope configurations since the contractor is continuously at the job site, able to observe the nature and condition of the cut slopes, and able to monitor the subsurface materials and groundwater conditions encountered. We recommend the contractor make a determination of excavation side slopes based on classification of soils encountered at the time of excavation. Temporary cuts may need to be constructed at flatter angles based upon the soil moisture and groundwater conditions at the time of construction. Adjustments to the slope angles should be determined by the contractor at that time. Unsupported vertical slopes or cuts deeper than 4 feet are not recommended if worker access is necessary. The cuts should be adequately sloped, shored, or supported to prevent injury to personnel from local Zipper Geo Associates, LLC Proposed Sonic Drive-in Renton, Washington ZGA Project No. 1559.01 January 25, 2016 Page 12 sloughing and spalling. Excavations should conform to applicable Federal, State, and Local regulations. Permanent Slopes: Slope stability evaluations were not performed for this project due to our understanding of the anticipated grading on this site. We recommend that cut and fill slopes constructed with native soils be sloped at 3H:1V or flatter. Steeper fill slopes on the order of 2H:1V could possibly be constructed with native soils if they are thoroughly mixed with cement or granular material is used. For slopes exposed to periodic saturation and rapid drawdown, such as stormwater detention ponds, we recommend that the interior slopes be constructed at a maximum 5H:1V angle. BUILDING FOUNDATIONS Foundations: Based on the results of our liquefaction analysis, we recommend that the proposed building be supported on a system of augercast piles, stone columns, or rammed aggregate piers. Conventional shallow foundations and slab-on-grade floors could be used in conjunction with the stone columns and aggregate piers. Augercast Piles: An augercast pile is formed by drilling to an appropriate pre-determined depth with a continuous-flight, hollow-stem auger. Cement grout is then pumped down the stem of the auger under high pressure as the auger is withdrawn. The final result is a cast-in-place pile. Reinforcing can be lowered into the unset concrete column to provide lateral and uplift resistance. Depending on the soil conditions, the diameter of the pile may vary and is generally greater than the nominal diameter of the drilled hole. Based on our experience at the neighboring Walmart site, we anticipate that grout volumes could average 1.3 to 1.6 times the theoretical volume of the drilled holes. We recommend the contractor be required to maintain at least 10 feet of horizontal separation between freshly grouted piles to reduce the risk of blowouts between piles. Piles can be drilled within 10 feet of each other after one has set for at least 24 hours. Augercast piles gain their vertical compressive capacity from side friction between the pile and the soils and from end bearing. Uplift pile capacity will develop as a result of side friction between the pile and the soil plus the weight of the pile. Due to the depth of potentially liquefiable soils, the piles will develop their capacities in their uplift and compressive capacities below the maximum predicted depth of liquefaction. Embedment Depths: In order to develop the recommended uplift compressive capacities, the piles must extend a minimum of 5 feet into the bearing layer. This corresponds to a pile length of 45 feet. The minimum pile length should be no less than 45 feet in order to have a minimum of 5 feet embedment into the bearing layer. We have provided pile capacities for 45- and 50-foot long piles in the following table. Pile Diameters: Given the relatively light structural loads, we anticipate that piles diameters of 16 or 18 inches will be adequate. Zipper Geo Associates, LLC Proposed Sonic Drive-in Renton, Washington ZGA Project No. 1559.01 January 25, 2016 Page 13 Compressive and Uplift Capacities: We recommend the following allowable compressive and uplift capacities. The recommended allowable uplift capacities include the weight of the piles. These take into account the liquefaction condition. The vertical pile capacities are based on the assumption that piles are located at least 3 pile diameters apart. If piles are located closer together, a reduced pile capacity should be used to account for pile group effects. We can provide pile group capacities upon request. ALLOWABLE PILE CAPACITIES Pile Diameter (in.) Pile Length (ft.) Compressive Capacity (tons) Uplift Capacity (tons)* Allowable Lateral Capacity, Fixed-head (kips) 16 45 24 9 8 18 45 30 11 9.5 16 50 29 13 8 18 50 36 15 9.5 * Includes the weight of the pile Lateral Capacities: Recommended allowable lateral capacities were developed using an assumed modulus of horizontal subgrade reaction of 2 pci in the loose, near-surface soils and limiting lateral deflection to ½ inch. The stiffness factor for fixed-head, 16- and 18-inch diameter augercast piles was calculated to be 87 and 96 inches, respectively. For grade beams, we recommend using an allowable passive resistance of 275 pounds per cubic foot for that portion of the beam that is more than 12 inches below surrounding finish grade. This incorporates a factor of safety of 1.5. The recommended passive pressure is based on the assumption that compacted structural fill will be placed on each side of the grade beam and will be compacted to a minimum of 95 percent of the modified Proctor maximum dry density. Pea gravel or washed rock should not be considered acceptable as a substitute for compacted fill. According to ACI 543R-12, Guide to Design, Manufacture, and Installation of Concrete Piles, soils with an undrained shear strength of more than 100 psf will usually provide sufficient support to prevent the embedded length of most concrete-pile cross sections from buckling under axial load. Our analysis indicates that, based on the soil conditions encountered in our boring, the residual shear strength during liquefaction exceeds 100 psf. Foundation Settlement: Provided that piles are constructed as recommended, we estimate that total foundation settlement will be approximately ¾ inch and differential settlement will be approximately ½ inch over 40 feet, respectively. Ground Improvement: As an alternative to augercast pile foundation support, ground improvement could be considered. Ground improvement can generally be separated into two categories; densification and reinforcement. Based on the thickness of unsuitable soils encountered (approximately 40 feet), we recommend that vibro-replacement stone columns or rammed aggregate piers (RAPs) be used to both densify potentially liquefiable soils and reinforce Zipper Geo Associates, LLC Proposed Sonic Drive-in Renton, Washington ZGA Project No. 1559.01 January 25, 2016 Page 14 soft, fine-grained soils in order to meet performance requirements. Using ground improvement stone columns/RAPs would allow the building to be supported on conventional shallow foundations. Additionally, the floor slab could be supported on-grade although the thickness and reinforcing requirements could be greater than for a conventional slab-on-grade floor. Stone column/RAP construction involves the partial replacement of unsuitable soils with a column of compacted crushed gravel. Stone columns/RAPs are constructed using a vibrating probe that penetrates the ground either under its own weight or from the pressure provided by a mandrel. Once the probe reaches the design depth, crushed gravel is fed to the tip of the probe and the gravel column is constructed from the bottom up. The gravel column is constructed in lifts as gravel is densified using the vibrating probe. Stone columns/RAPS are generally about 18 to 24 inches in diameter. Ground improvement design is typically completed by a specialty contractor on a design-build basis to meet performance criteria (allowable total and differential settlements, bearing capacity, liquefaction mitigation, etc.) established by the owner or structural engineer. The contractor would use the data from the boring log and lab testing in this report as the basis for the specific design, or acquire additional data if they deem necessary. The contractor also develops specifications for construction of the aggregate piers, the diameter and spacing, products to be used, as well as tolerance and acceptance criteria. We recommend the project team consult with local ground improvement contractors (such as Geopier, Hayward Baker, Condon Johnson, and DBM) to evaluate the feasibility of the ground improvement option and its associated cost. For design of ground improvement for the project, we recommend the project team and ground improvement contractors consider the following: Performance Criteria: We recommend the project team provide performance criteria to the ground improvement contractors including allowable static and seismic total and differential foundation settlements and foundation loads. For example, static total and differential settlements could be limited to 1 inch and ¾ inch, respectively. Total seismic settlement could be limited to a maximum of 2 to 3 inches and 1 to 2 inches for differential seismic settlement. Foundation Design: Bearing surfaces should be specified to provide an allowable bearing capacity of 2,500 psf for structural design of the footings. The recommended allowable bearing pressure assumes any unsuitable fill or soft soils, if encountered, will be over-excavated and replaced with structural fill. The net allowable bearing pressure be increased by one-third to resist transient, dynamic loads such as wind or seismic forces. We recommend that spread and continuous footings have minimum dimensions of 24 inches and 18 inches, respectively. Exterior footings should be embedded a minimum of 18 inches below finished grade for frost protection. We recommend using an allowable passive pressure of 175 psf per foot of embedment, neglecting the upper 12 inches of embedment and an allowable coefficient of base friction 0.3. Zipper Geo Associates, LLC Proposed Sonic Drive-in Renton, Washington ZGA Project No. 1559.01 January 25, 2016 Page 15 Geotechnical Information: Provide ground improvement contractors a copy of this report. Ground improvement contractors should be provided an opportunity to acquire additional geotechnical data or request additional geotechnical data to satisfy their understanding of subsurface soil and groundwater conditions at the site from which their design and cost will be based. Existing Site Conditions: Ground improvement contractors should review and understand existing site conditions that may impact their work. They should also review the presence of underground utilities and above-ground structures that could be impacted due to vibrations during the construction of stone columns and aggregate piers. Verification Testing: The selected ground improvement contractor should be required to complete some form of post-installation verification testing (such as load tests) to verify their design and design assumptions. Additional design considerations, such as thickness of the aggregate base course underneath slabs to provide more uniform support over the aggregate piers, will also need to be considered by the architect, floor designer, and/or structural engineer. Geotechnical Review: We recommend that ZGA be retained to assist the design-build contractor in the preparation of suitable improvement plans and specifications for this project, as well as to review the plans, calculations and specifications once they have been prepared. We recommend that a qualified geotechnical engineer from ZGA provide construction observation and testing services during construction of the aggregate columns. After construction of the aggregate columns, we recommend that the specialty contractor’s assumptions and design be confirmed by post-installation cone penetrometer test (CPT) probes. The post-construction explorations should be reviewed to confirm that the acceptance criteria have been achieved, and the factors of safety against liquefaction have been increased to meet project tolerances. The contractor should be prepared to install additional piers as necessary to achieve the design requirements. Non-Building Shallow Foundations: Shallow foundations may be used to support non-building structures such as trash enclosures, canopies, and poles. We recommend that all shallow foundations be supported on a 2-foot thick prism of structural fill. The fill should also extend a minimum of 2 feet laterally beyond each side of the foundation. We recommend using an allowable bearing capacity of 1,200 psf provided total and differential settlements on the order of one inch can be tolerated. Conventional shallow foundations can derive passive resistance from that portion of the footing embedded at least 12 inches below the surrounding finish grade. We recommend using an allowable passive resistance of 175 pcf equivalent fluid pressure. We also recommend utilizing an allowable base friction coefficient of 0.3 and a unit weight of 130 pcf for structural fill placed above the footing. Shallow foundations constructed in this manner should be expected to settle on the order of 5 to 10 inches after a design earthquake due to post-liquefaction consolidation of the soils. Poles will likely be out of plumb after such an event. In order to reduce the potential for Zipper Geo Associates, LLC Proposed Sonic Drive-in Renton, Washington ZGA Project No. 1559.01 January 25, 2016 Page 16 seismic settlement and rotation of cantilever poles, the structures could be supported on aggregate pier/stone column-densified soil or be structurally supported on augercast piles. The allowable bearing capacity can be increased to those recommended for building support, depending on the selected method of support. STRUCTURAL CONCRETE FLOOR If augercast piles are used for building support, we recommend that the floor be designed as a structural slab. SLAB-ON-GRADE CONCRETE FLOOR The site is generally underlain by very soft to medium stiff silt and loose silty sand. Based on the conditions encountered, the need for structural fill in the building pad to establish subgrade elevation and the anticipated floor load of about 200 psf, our analyses indicates that floor settlements could exceed the typical maximum allowable settlement for floor slabs. Additionally, the settlement potential during a design seismic event could be on the order of 5 to 10 inches. Therefore, we recommend that a slab-on-grade floor only be used if the liquefaction induced settlement is mitigated to acceptable limits using stone columns or rammed aggregate piers. Subgrade Preparation: Subgrades for on-grade slabs should be prepared in accordance with the Site Preparation and Structural Fill sections of this report. Slab Subbase: We recommend that slab-on-grade floors be separated from the tops of the stone columns/RAPS by a minimum of one foot of structural fill. Slab Base: To provide a uniform slab bearing surface, as well as serving as a capillary break, we recommend the on-grade slabs be underlain by a minimum 6-inch thick layer of compacted crushed rock meet the requirements of WSDOT Standard Specification Section 9-03.9(3), Crushed Surfacing Top Course, with the modification of a maximum of 7 percent passing the U.S. No. 200 sieve. If a vapor barrier is used beneath the slab, we recommend that a thin lift of sand be spread over the crushed aggregate in order to reduce the risk of puncturing the sheet plastic. Vapor Barrier: Given the very shallow depth that groundwater was encountered, we anticipate that moisture will develop beneath the slab. Therefore, we recommend that a 10- to 15-mil moisture barrier be installed beneath all interior slabs. We recommend using a puncture-resistant product such as Stego Wrap or an approved equivalent that is classified as a Class A vapor retarder in accordance with ASTM E1745. Puncturing the vapor barrier should be avoided; construction traffic should not be allowed to drive over any vapor barrier material. The slab designer should and contractor should refer to ACI 302 for procedures and cautions regarding the use and placement of a vapor retarder. Zipper Geo Associates, LLC Proposed Sonic Drive-in Renton, Washington ZGA Project No. 1559.01 January 25, 2016 Page 17 DRAINAGE CONSIDERATIONS Surface Drainage: We recommend that final site grades in landscaped areas be sloped at a minimum of 3 percent for a minimum distance of 10 feet around the building to carry surface water away from buildings and other drainage-sensitive areas. We recommend that site grades be designed such that concentrated runoff on to landscaped surfaces be avoided. Any surface runoff directed towards landscaped slopes should be collected at the top of the slope and routed to the bottom of the slope and discharged in a manner that prevents erosion. In paved areas, we recommend that a minimum gradient of one percent be provided away from the building. Footing Drains: We recommend a permanent subsurface drainage system be installed around the proposed building and along the base of all retaining walls. We recommend that the drains consist of a 4-inch diameter, Schedule 40, perforated PVC drain pipe placed at the base of the heel of shallow foundations and/or near the base of grade beams. The pipe should be surrounded by a minimum of 4 inches of clean free-draining material that cannot migrate through the pipe perforations. We recommend placing a non-woven geotextile such as Mirafi 140N or equivalent between the free-draining pipe backfill and the surrounding fill and native materials. Footing drains should be routed to a suitable discharge structure. Roof runoff should be collected independently in non-perforated, solid pipes and also routed to a suitable discharge system. Subsurface Slab Drainage: Based on the finish floor elevation of 26.25 feet, sub-slab drainage is not considered to be necessary on this project. Sub-slab drainage should be reconsidered if the finish floor elevation is lowered. PAVEMENTS Existing Pavements: Based on previous borings completed through the existing pavement, it appears that the asphalt varies in thickness from about 2 to 2½ inches and the crushed gravel base course varies from about 3 to 3½ inches. Asphalt Overlays: Based on our visual reconnaissance of the existing pavement, it appears that it is in fair to good condition. Existing Asphalt Preparation: If an overlay will be placed, we recommend the entire existing pavement surface be thoroughly cleaned and the cracks pressure washed to remove debris. After drying, the cracks should be sealed with an emulsified or cut-back asphalt. In areas where the existing pavement is relatively intact we recommend the linear cracks be covered with minimum 1- foot wide strips of paving fabric to reduce the risk of reflective cracking up into the new asphalt. The fabric should be installed per the manufacturer’s guidelines. Additional surface preparations, such as tack coating the existing asphalt, should be completed in general accordance with applicable sections of Standard Specification 5-04.3 of the 2014 WSDOT Manual. Zipper Geo Associates, LLC Proposed Sonic Drive-in Renton, Washington ZGA Project No. 1559.01 January 25, 2016 Page 18 Overlay Thicknesses: We recommend the following minimum asphalt overlay sections: Standard-duty over existing standard-duty: 1½ inches, Heavy-duty over existing standard-duty: 2 inches If the recommended overlays are too thick to tie into existing grades, we recommend removing the existing pavement sections and replacing with new sections as recommended in the following New Pavement Sections portion of this report. New Asphalt Pavements: It should be realized that asphaltic pavements are not maintenance- free. The following pavement sections represent our minimum recommendations for an average level of performance during a 20-year design life; therefore, an average level of maintenance will likely be required. A 20-year pavement life typically assumes that an overlay will be placed after about 12 years. Thicker asphalt, base, and subbase courses would offer better long-term performance, but would cost more initially. Conversely, thinner courses would be more susceptible to “alligator” cracking and other failure modes. As such, pavement design can be considered a compromise between a high initial cost and low maintenance costs versus a low initial cost and higher maintenance costs. Soil Design Values: Given the moisture content of the shallow soil samples, it appears that compaction of the pavement subgrade soils will be difficult to impossible. We recommend the subbase material have a minimum CBR value of 40 when compacted to 95 percent of the modified Proctor maximum dry density. Generally a material that meets the gradation criteria for Gravel Borrow (WSDOT 9-03.14(1)). Asphalt Pavement Sections: For standard-duty pavements (parking lot areas), we recommend a 3 inches of asphalt concrete over 4 inches of crushed rock base course over 5 inches of subbase. For heavy-duty pavements (main access roads, truck delivery routes, etc.), we recommend 3½ inches of asphalt concrete over 5 inches of crushed rock base course over 6 inches of subbase. For all new pavement sections, we recommend placing Tensar BX 1100 or approved equivalent below the pit-run subbase. Materials and Construction: We recommend the following regarding asphalt pavement materials and pavement construction. Subgrade Preparation: Upper 12 inches of pavement subgrade should be prepared in accordance with the recommendations presented in the Subgrade Preparation section of this report. Based on the soil moisture conditions determined, it may be difficult to compact subgrade soils except during the drier summer months. Structural Fill: All fill soils used on this project within pavement areas should have a minimum CBR value of 20 when compacted to 95 percent of the modified Proctor maximum dry density. Zipper Geo Associates, LLC Proposed Sonic Drive-in Renton, Washington ZGA Project No. 1559.01 January 25, 2016 Page 19 Asphalt Concrete: We recommend that the asphalt concrete conform to Section 9-02.1(4) for PG 64-22 Performance Grade Asphalt Cement as presented in the WSDOT Standard Specifications. We also recommend that the gradation of the asphalt aggregate conform to the aggregate gradation control points for ½-inch mix as presented in Section 9-03.8(6), HMA Proportions of Materials. Base Course: We recommend that the crushed aggregate base course conform to Section 9-03.9(3), Crushed Surfacing Base Course, as presented in the 2014 WSDOT Standard Specifications. Subbase: We recommend the subbase consist of pit-run sand and gravel that has a minimum CBR value of 40 when compacted to a minimum of 95 percent of the modified Proctor maximum dry density. We recommend the material conform to Section 9-03.14(1), Gravel Borrow. Compaction: We recommend that all subbase and base materials be compacted to at least 95 percent of the maximum dry density determined in accordance with ASTM: D 1557. We also recommend the subgrade and base course be proof rolled with a loaded dump truck or other construction equipment weighing at least 20 tons. We recommend that asphalt be compacted to a minimum of 92 percent and a maximum of 96 percent of the theoretical maximum density. Concrete Pavements: Concrete for pavement should be produced and placed in general conformance with Section 5-05, Cement Concrete Pavement, as presented in the 2014 WSDOT Standard Specifications. Concrete pavement design recommendations are based on an assumed modulus of rupture of 580 psi and a minimum compressive strength of 4,000 psi for the concrete. We recommend the concrete have a minimum of 3 percent and a maximum of 7 percent air entrainment. Concrete Pavement Sections: For light duty pavements, we recommend 5 inches of concrete over 4 inches of crushed aggregate base over 5 inches of subbase. For heavy duty pavements, we recommend 6 inches of concrete over 4 inches of crushed aggregate base over 5 inches of subbase. Concrete Pavement Joints and Reinforcing: It is our opinion that concrete pavements should be lightly reinforced and have relatively closely spaced control joints on the order of 10 to 12 feet. We recommend using 6x6-W2.0xW2.0 welded wire in order to provide interlock across cracks that could develop in the pavement. Concrete pavements should be protected from construction traffic until a compressive strength of 3,000 psi has been achieved. Zipper Geo Associates, LLC Proposed Sonic Drive-in Renton, Washington ZGA Project No. 1559.01 January 25, 2016 Page 20 CLOSURE This report has been prepared for the exclusive use of Cascade Development Group and their respective successors, assigns, affiliates, and subsidiaries for this specific project. The analysis and recommendations presented in this report are based on the explorations and laboratory testing completed for this study. The number, location, and depth of the explorations were completed within the constraints of budget and site access so as to yield the information to formulate our recommendations. Project plans were in the preliminary stage at the time this report was prepared. We therefore recommend we be provided an opportunity to review the final plans and specifications when they become available in order to assess that the recommendations and design considerations presented in this report have been properly interpreted and implemented into the project design. The performance of earthwork, structural fill, foundations, and pavements depend greatly on proper site preparation and construction procedures. We recommend that ZGA be retained to provide geotechnical inspection services during the earthwork-related construction phases of the project to determine that the work being completed generally complies with the project plans and specifications. If variations in subsurface conditions are observed at that time, we can provide additional geotechnical recommendations to the contractor and design team in a timely manner as the project construction progresses. B-1B-15(AGRA E&E, 1995)B-39(ZZA, 2009)B-44(ZZA, 2009)FIGUREJob No.Zipper Geo Associates, LLC19023 36th Ave. W.,Suite DLynnwood, WA, 98036SHT. of11SITE AND EXPLORATION PLAN1559.01DATE: JANUARY 20161PROPOSED SONIC DRIVE-IN225 RAINER AVENUE SOUTHRENTON, WASHINGTONLEGENDB-1BORING NUMBER ANDAPPROXIMATE LOCATIONBASE DRAWING PROVIDED BY PB ARCHITECTS, 12/8/2015.BORING BY OTHERS ANDAPPROXIMATE LOCATIONB-1APPROXIMATE SCALE IN FEET0202010 APPENDIX A FIELD EXPLORATION PROCEDURES AND BORING LOG FIELD EXPLORATION PROCEDURES AND LOGS Our field exploration program for this project included the completion of one boring on December 19, 2015. The approximate location of the exploration is presented on Figure 1, the Site and Exploration Plan. The following sections describe our procedures associated with the exploration. A descriptive log of the exploration is enclosed in this appendix. Soil Boring Procedures Our boring was advanced using a truck-mounted drill rig operated by Environmental Drilling, an independent drilling firm working under subcontract to ZGA. The boring was completed utilizing hollow-stem auger methods. A geotechnical engineer from our firm continuously observed the boring, logged the subsurface conditions encountered, and obtained representative soil samples. All samples were stored in moisture-tight containers and transported to our laboratory for further visual classification and possible testing. Throughout the drilling operation, soil samples were obtained at 2.5- to 5-foot depth intervals by means of the Standard Penetration Test Method. This testing and sampling procedure consists of using an auto-hammer to drive a standard 2-inch outside diameter steel split spoon sampler 18 inches into the soil with a 140-pound hammer free falling 30 inches. The number of blows required to drive the sampler through each 6-inch interval is recorded, and the total number of blows struck during the final 12 inches is recorded as the Standard Penetration Resistance, or “blow count” (N value). If a total of 50 blows are struck within any 6-inch interval, the driving is stopped and the blow count is recorded as 50 blows for the actual penetration distance. The resulting Standard Penetration Resistance values indicate the relative density of granular soils and the relative consistency of cohesive soils. The enclosed boring log describes the vertical sequence of soils and materials encountered in each boring, based primarily upon our field classifications and supported by our subsequent laboratory examination and testing. Where a soil contact was observed to be gradational, our logs indicate the average contact depth. Where a soil type changed between sample intervals, we inferred the contact depth. Our log also graphically indicate the blow count, sample type, sample number, and approximate depth of each soil sample obtained from the boring, as well as any laboratory tests performed on these soil samples. Where groundwater was encountered in the borehole, the approximate groundwater depth, and date of observation, is depicted on the log. The groundwater depth was determined by observing the water level in a hand-dug hole before drilling began. The soil descriptions presented on the boring log in this appendix are based upon the drilling action, observation of the samples secured, laboratory test results, and field logs. The various types of soils are indicated as well as the depth where the soils or characteristics of the soils changed. It should be noted that these changes may have been gradual, and if the changes occurred between sample intervals, they were inferred. Drilling Company:Bore Hole Dia.: Top Elevation:Drilling Method:Hammer Type: Drill Rig:Logged by: Standard Penetration Test Hammer Weight and Drop: SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm) 2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content 3-inch I.D. Shelby tube sample Bentonite Liquid Limit Grout/Concrete Screened Casing TESTING KEY Blank Casing GSA = Grain Size Analysis 200W = 200 Wash Analysis Date:Project No.: Consol. = Consolidation Test Att. = Atterberg Limits Boring Location:Sample Number SAMPLES Recovery (inches)Depth (ft)SOIL DESCRIPTION Date Drilled: The stratification lines represent the approximate boundaries between soil types. The transition may be gradual. Refer to report text and appendices for additional information.Ground WaterPENETRATION RESISTANCE (blows/foot) B-1 B-1 1559.01Blow CountsProposed Sonic 225 Rainier Avenue S. Zipper Geo Associates 19023 36th Ave. W, Suite D Lynnwood, WA Renton, WA Page 1 of 2 BORING LOG:TestingPlastic Limit Groundwater level at time of drilling (ATD) or on date of measurement. Natural Water Content 12/19/2015 0 20 40 60 18'' 18'' 18'' 15'' 18 15'' 18'' S-1 S-2 S-3 S-4 S-5 S-6 S-7 0 5 10 15 20 25 See Figure 1, Site and Exploration Plan - 12/19/2015 Environmental Hollow Stem Auger Truck 8" Auto 11/2/128 2 5 2 10 12 6 Att. GSA GSA TAJ 12/19/15Approx. 4 inches landscape bark Medium stiff, wet to saturated, brown, sandy SILT with trace clay and gravel Very soft, wet, green-gray, SILT with trace to some clay and sand Medium stiff, wet, green-gray, clayey SILT Very soft, wet, gray-green, sandy SILT with trace to some clay, trace gravel Stiff, wet to saturated, gray-green, sandy SILT with trace gravel interbedded with med. dense, wet to saturated, green- gray, silty SAND with trace clay Medium stiff, wet, green-gray, clayey SILT, with trace to some sand Stiff, wet to saturated, green-gray, sandy SILT with trace gravel interbedded with loose, wet to saturated, green-gray, silty SAND with trace clay Loose, saturated, brown, silty gravelly SAND with pieces of clay (Fill) Drilling Company:Bore Hole Dia.: Top Elevation:Drilling Method:Hammer Type: Drill Rig:Logged by: Standard Penetration Test Hammer Weight and Drop: SAMPLE LEGEND GROUNDWATER LEGEND % Fines (<0.075 mm) 2-inch O.D. split spoon sample Clean Sand % Water (Moisture) Content 3-inch I.D. Shelby tube sample Bentonite Liquid Limit Grout/Concrete Screened Casing TESTING KEY Blank Casing GSA = Grain Size Analysis 200W = 200 Wash Analysis Date:Project No.: Consol. = Consolidation Test Att. = Atterberg Limits Boring Location: B-1 Date Drilled:Depth (ft)SOIL DESCRIPTION Sample Number SAMPLES RecoveryGround WaterPENETRATION RESISTANCE (blows/foot)Blow CountsTesting225 Rainier Avenue S. The stratification lines represent the approximate boundaries between soil types. The transition may be gradual. Refer to report text and appendices for additional information. Plastic Limit Natural Water Content Proposed Sonic Groundwater level at time of drilling (ATD) or on date of measurement. Renton, WA 1559.01 Zipper Geo Associates 19023 36th Ave. W, Suite D Lynnwood, WA BORING LOG:B-1 Page 2 of 2 12/19/2015 18" 18" 18" 8" 18" S-8 S-9 S-10 S-11 S-12 0 20 40 60 25 30 35 40 45 50 See Figure 1, Site and Exploration Plan - 12/19/2015 Environmental Hollow Stem Auger Truck 8" Auto 11/2/126 14 6 47 61 TAJ Medium stiff, wet, brown, clayey SILT with trace fine fibrous organics Stiff, wet, brown, clayey SILT with trace sand and fine fibrous organics Loose, saturated, gray, gravelly SAND with trace silt Dense, saturated, gray sandy GRAVEL/gravelly SAND Very dense, saturated, gray sandy GRAVEL/gravelly SAND Boring completed at approximately 49 feet. Groundwater encountered at approximately 7 inches. APPENDIX B LABORATORY TESTING PROCEDURES AND RESULTS LABORATORY TESTING PROCEDURES A series of laboratory tests were performed during the course of this study to evaluate the index and geotechnical engineering properties of the subsurface soils. Descriptions of the types of tests performed are given below. Visual Classification Samples recovered from the exploration locations were visually classified in the field during the exploration program. Representative portions of the samples were carefully packaged in moisture tight containers and transported to our laboratory where the field classifications were verified or modified as required. Visual classification was generally done in accordance with the Unified Soil Classification system. Visual soil classification includes evaluation of color, relative moisture content, soil type based upon grain size, and accessory soil types included in the sample. Soil classifications are presented on the exploration logs in Appendix A. Moisture Content Determinations Moisture content determinations were performed on representative samples obtained from the exploration in order to aid in identification and correlation of soil types. The determinations were made in general accordance with the test procedures described in ASTM D2216. The results are shown on the exploration logs in Appendix A. Grain Size Analysis A grain size analysis determines the range in diameter of soil particles included in a particular sample. Grain size analyses were performed on representative samples in general accordance with ASTM D422. The results of the grain size determinations for the samples were used in classification of the soils, and are presented in this appendix. Atterberg Limits Atterberg limits are used primarily for classification and indexing of cohesive soils. The liquid and plastic limits are two of the five Atterberg limits and are defined as the moisture content of a cohesive soil at arbitrarily established limits for liquid and plastic behavior, respectively. Liquid and plastic limits were established for selected samples in general accordance with ASTM: D- 4318. The results of the Atterberg limits are presented on a plasticity chart in this appendix where the plasticity index (liquid limit minus plastic limit) is related to the liquid limit. Received Liquid Plastic Plasticity Symbol Boring Sample M.C. (%)Limit Limit Index B-1 S-3 47 45 31 13 Remarks: PLASTICITY CHART ASTM D 4318 Low Plasticity SILT Comments USCS ML Description 0 10 20 30 40 50 60 0 10 20 30 40 50 60 70 80 90 100Plasticity Index %Liquid Limit % ML U-line A-line Inorganic clays of high plasticity CH Micaceous or diatomaceous fine sandy and silty soils; elastic silts; organic silts, clays, and silty clays OH or MH Low plastic inorganic clays; sandy and silty clays Medium plastic inorganic clays 7 4 Inorganic and organic silts and silty clays of low plasticity; rock flour; silty or clayey fine sands ML or OLCL CL-ML Silty clays; clayey silts and sands Zipper Geo Associates, LLC Geotechnical and Environmental Consultants PROJECT NO:PROJECT NAME: Renton SonicDATE OF TESTING: 1559.01 12/22/2015 0 10 20 30 40 50 60 70 80 90 100 0.0010.0100.1001.00010.000100.0001000.000PERCENT FINER BY WEIGHTPARTICLE SIZE IN MILLIMETERS GRAIN SIZE ANALYSIS Comments: 36"12"6"3"1 1/2"3/4"3/8"4 10 20 40 60 140 200 Coarse Medium Fine Silt ClayFineCoarse COBBLESBOULDERS GRAVEL SAND FINE GRAINED SIZE OF OPENING IN INCHES U.S. STANDARD SIEVE SIZE HYDROMETER Project No.:Project Name: Renton SonicDate of Testing: Exploration Sample Depth (feet)Moisture (%)Fines (%)Description B-1 10 -11.5 ft.32.7 Sandy SILT with trace gravelS-4 55.2 1559.01 12/19/2015 ASTM D 422Test Results Summary Zipper Geo Associates, LLC Geotechnical and Environmental Consultants 0 10 20 30 40 50 60 70 80 90 100 0.0010.0100.1001.00010.000100.0001000.000PERCENT FINER BY WEIGHTPARTICLE SIZE IN MILLIMETERS GRAIN SIZE ANALYSIS Comments: 36"12"6"3"1 1/2"3/4"3/8"4 10 20 40 60 140 200 Coarse Medium Fine Silt ClayFineCoarse COBBLESBOULDERS GRAVEL SAND FINE GRAINED SIZE OF OPENING IN INCHES U.S. STANDARD SIEVE SIZE HYDROMETER Project No.:Project Name: Renton SonicDate of Testing: Exploration Sample Depth (feet)Moisture (%)Fines (%)Description B-1 17.5-19 33.0 Sandy SILT with trace gravelS-6 55.8 1559.01 12/23/2015 ASTM D 422Test Results Summary Zipper Geo Associates, LLC Geotechnical and Environmental Consultants Technical Information Report for Sonic Renton June 21, 2017 36 SECTION 7 OTHER PERMITS A right-of-way permit will be required for construction in right-of-way. A NPDES permit will not be required from the state Department of Ecology as the site is less than one acre. A building permit will be required for the building construction. Technical Information Report for Sonic Renton June 21, 2017 37 SECTION 8 CSWPPP ANALYSIS AND DESIGN Part A. ESC Plan Analysis and Design A Temporary Erosion and Sedimentation Control (TESC) plan has been prepared as part of the permit and construction drawings. The site is relatively flat and is not particularly susceptible to erosion. The soils report by Zipper Geo and Associates (Jan. 25, 2016) does not recommend extraordinary measures and speaks only of covering practices and water collection. The TESC BMPs will include: Clearing Limits. Clearly defined limits will limit disturbed area and hence limit the source of sediment. The clearing limit is delineated by the silt fence. Catchbasin Inserts. These will be placed inside existing catch basins to filter out waterborne sediments that may leave the site. Silt Barrier Fence. Placed at the down-slope limits of construction the silt fence will provide adequate silt retention for the disturbed areas. Construction Entrance. A rock construction entrance will be provided both at the site entry and exit points. Covering Practices. This will limit the area available to erode. Straw mulch or plastic sheeting will be placed over exposed soil that remains unworked for more than seven days in the dry season or two days in the wet season. Anchored plastic sheeting is recommended for soil stockpiles. Revegetation. Disturbed areas that are not covered with impervious surface will be landscaped towards the end of construction to provide permanent stabilization. Sediment Removal. The project will incorporate a portable sediment tank system (Baker Tank) that will treat runoff prior to discharge. Runoff from the project site will be collected and pumped to the Baker Tank where particles will settle out. The discharge from the tank will be by gravity flow to the existing storm system. The maximum pump rate into the tank, and size of the tank system, is based on the 2-year runoff flow rate from the site. The 2-year flow (see Section 4) for the full developed site is 0.156 cfs. In the absence of local design criteria the system is designed using the City of Seattle method. Technical Information Report for Sonic Renton June 21, 2017 38 The 2-year inflow to the Baker Tank is: = (0.156 cfs)(448) = 69.9 gpm A 70 gpm maximum pump rate is specified on the plans: Cubic feet storage = Pump Discharge in gallons per minute (gpm) x 16. = (70 gpm)(16) = 1,120 cubic feet = (1,120)(7.48) gallons = 8,378 gallons A 10,000 gallon tank system is specified on the plans Part B. SWPPS Plan Design Potential sources of pollution for this project are: • Storage and Handling of Liquids • Storage and Stockpiling of Construction Materials and Wastes • Fueling • Maintenance, Repairs, and Storage of Vehicles and Equipment • Concrete Saw Cutting, Slurry, and Washwater Disposal Mitigations in note form have been added to the TESC plan. Technical Information Report for Sonic Renton June 21, 2017 39 SECTION 9 BOND QUANTITIES, FACILITY SUMMARIES A Stormwater Facility Summary Sheet is included in this section. Bond Quantities and the Declaration of Covenant for inspection and maintenance are also included. KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 2009 Surface Water Design Manual 1/9/20091 STORMWATER FACILITY SUMMARY SHEET DDES Permit Number__________________ (provide one Stormwater Facility Summary Sheet per Natural Discharge Location) Overview: Project Name _______________________________________________________Date___________________ Downstream Drainage Basins Major Basin Name _____________________________ Immediate Basin Name __________________________ Flow Control: Flow Control Facility Name/Number ________________________________ Facility Location________________________________________________________________________ ___ If none, Flow control provided in regional/shared facility (give location)___________________________________ No flow control required_____________ Exemption number _______________________________ General Facility Information: Type/Number of detention facilities: Type/Number of infiltration facilities: ______ ponds ______ ponds ______ vaults ______ tanks ______ tanks ______ trenches Control Structure Location _____________________________________________________________________ Type of Control Structure ______________________________ Number of Orifices/Restrictions _____________ Size of Orifice/Restriction: No. 1 ________________ No. 2 ________________ No. 3 ________________ No. 4 ________________ Flow Control Performance Standard _________________________________ 0 (Exempt) #1 page 1-39 of the KCSWDM Sonic Renton 2/8/2016 Duwamish River 735 Hardie Ave. SW Under covered parking area near NW building corner Basic Black River KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 2009 Surface Water Design Manual 1/9/2009 2 Live Storage Volume __________________ Depth _______________ Volume Factor of Safety ________________ Number of Acres Served ____________________ Number of Lots ____________________ Dam Safety Regulations (Washington State Department of Ecology) Reservoir Volume above natural grade ________________ Depth of Reservoir above natural grade _______________ Facility Summary Sheet Sketch All detention, infiltration and water quality facilities must include a detailed sketch. (11"x17" reduced size plan sheets may be used) KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 2009 Surface Water Design Manual 1/9/20093 Water Quality: Type/Number of water quality facilities/BMPs: ______ biofiltration swale ______ sand filter (basic or large) (regular/wet/ or continuous inflow) ______ sand filter, linear (basic or large) ______ combined detention/wetpond ______ sand filter vault (basic or large) (wetpond portion basic or large) sand bed depth______ (inches) ______ combined detention/wetvault ______ stormwater wetland ______ filter strip ______ storm filter ______ flow dispersion ______ wetpond (basic or large) ______ farm management plan ______ wetvault ______ landscape management plan ______ Is facility Lined? ______ oil/water separator If so, what marker is used above (baffle or coalescing plate) Liner?____________________ ______ catch basin inserts: Manufacturer____________________________________________ ______ pre-settling pond ______ pre-settling structure: Manufacturer__________________________________________ ______ high flow bypass structure (e.g., flow-splitter catch basin) ______ source controls _________________________________________________________ Design Information Water Quality design flow ______________________________ Water Quality treated volume (sandfilter) ___________________ Water Quality storage volume (wetpool) ___________________ Facility Summary Sheet Sketch __X_____ Filterra System Contech x Internal 91% of all runoff 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: Abbreviated Legal Description:A PORTION OF LOT 3 CITY OF RENTON LOT LINE ADJUSTMENT NO LUA 15‐000237735 Hardie Ave. SW120 W Dayton Street, Suite D5 Hardie Ave. SW and Rainier Ave. SU16006829(425) 582‐96737/12/2017Prepared by:FOR APPROVALProject Phase 1nick@nbengineering.comNick Bossoff29631Nick Bossoff Engineering191 NE Tari Lane, Stevenson WA 98648(425) 881‐5904SITE IMPROVEMENT BOND QUANTITY WORKSHEETPROJECT INFORMATIONCITY OF RENTONCITY OF RENTON1 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 SubmittalEngineer Stamp Required (all cost estimates must have original wet stamp and signature)Clearing and Grading Utility ProvidersN/AProject Location and Description Project Owner InformationRenton SonicEdmonds, WA 980201923059104Olympic Cascade Drive Ins LLC16‐000229Page 1 of 1Ref 8‐H Bond Quantity WorksheetSECTION I PROJECT INFORMATIONUnit Prices Updated: 06/14/2016Version: 06/14/2016Printed 7/12/2017 CED Permit #:U16006829UnitReference # Price Unit Quantity CostBackfill & compaction‐embankmentESC‐16.50$ CYCheck dams, 4" minus rockESC‐2SWDM 5.4.6.380.00$ EachCatch Basin ProtectionESC‐335.50$ Each 3106.50Crushed surfacing 1 1/4" minusESC‐4WSDOT 9‐03.9(3)95.00$ CYDitchingESC‐59.00$ CYExcavation‐bulkESC‐62.00$ CYFence, siltESC‐7SWDM 5.4.3.11.50$ LF 661991.50Fence, Temporary (NGPE)ESC‐81.50$ LFGeotextile FabricESC‐92.50$ SYHay Bale Silt TrapESC‐100.50$ Each 2512.50HydroseedingESC‐11SWDM 5.4.2.40.80$ SYInterceptor Swale / DikeESC‐121.00$ LFJute MeshESC‐13SWDM 5.4.2.23.50$ SYLevel SpreaderESC‐141.75$ LFMulch, by hand, straw, 3" deepESC‐15SWDM 5.4.2.12.50$ SY 326815.00Mulch, by machine, straw, 2" deepESC‐16SWDM 5.4.2.12.00$ SYPiping, temporary, CPP, 6"ESC‐1712.00$ LFPiping, temporary, CPP, 8"ESC‐1814.00$ LFPiping, temporary, CPP, 12"ESC‐1918.00$ LFPlastic covering, 6mm thick, sandbaggedESC‐20SWDM 5.4.2.34.00$ SYRip Rap, machine placed; slopesESC‐21WSDOT 9‐13.1(2)45.00$ CYRock Construction Entrance, 50'x15'x1'ESC‐22SWDM 5.4.4.11,800.00$ EachRock Construction Entrance, 100'x15'x1'ESC‐23SWDM 5.4.4.13,200.00$ Each 13,200.00Sediment pond riser assemblyESC‐24SWDM 5.4.5.22,200.00$ EachSediment trap, 5' high berm ESC‐25SWDM 5.4.5.119.00$ LFSed. trap, 5' high, riprapped spillway berm section ESC‐26SWDM 5.4.5.170.00$ LFSeeding, by handESC‐27SWDM 5.4.2.41.00$ SYSodding, 1" deep, level groundESC‐28SWDM 5.4.2.58.00$ SYSodding, 1" deep, sloped groundESC‐29SWDM 5.4.2.510.00$ SYTESC SupervisorESC‐30110.00$ HR 323,520.00Water truck, dust controlESC‐31SWDM 5.4.7140.00$ HRUnitReference # Price Unit Quantity CostEROSION/SEDIMENT SUBTOTAL: 8,645.50SALES TAX @ 9.5% 821.32EROSION/SEDIMENT TOTAL: 9,466.82(A)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR EROSION & SEDIMENT CONTROLDescription No.(A)WRITE‐IN‐ITEMS Page 1 of 1Ref 8‐H Bond Quantity WorksheetSECTION II.a EROSION_CONTROLUnit Prices Updated: 06/14/2016Version: 06/14/2016Printed 7/12/2017 CED Permit #:U16006829Existing Future Public PrivateRight‐of‐Way Improvements Improvements(D) (E)Description No. Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Quant. CostGENERAL ITEMS Backfill & Compaction‐ embankment GI‐1 6.00$ CY 90540.00Backfill & Compaction‐ trench GI‐2 9.00$ CY 19171.0089801.00Clear/Remove Brush, by hand (SY) GI‐3 1.00$ SYBollards ‐ fixed GI‐4 240.74$ EachBollards ‐ removable GI‐5 452.34$ EachClearing/Grubbing/Tree Removal GI‐6 10,000.00$ Acre 0.07700.00Excavation ‐ bulk GI‐7 2.00$ CY 2448.00288576.00Excavation ‐ Trench GI‐8 5.00$ CY 1995.0091455.00Fencing, cedar, 6' high GI‐9 20.00$ LFFencing, chain link, 4' GI‐10 38.31$ LFFencing, chain link, vinyl coated, 6' high GI‐11 20.00$ LFFencing, chain link, gate, vinyl coated, 20' GI‐12 1,400.00$ EachFill & compact ‐ common barrow GI‐13 25.00$ CY 2857,125.00Fill & compact ‐ gravel base GI‐14 27.00$ CYFill & compact ‐ screened topsoil GI‐15 39.00$ CYGabion, 12" deep, stone filled mesh GI‐16 65.00$ SYGabion, 18" deep, stone filled mesh GI‐17 90.00$ SYGabion, 36" deep, stone filled mesh GI‐18 150.00$ SYGrading, fine, by hand GI‐19 2.50$ SYGrading, fine, with grader GI‐20 2.00$ SYMonuments, 3' Long GI‐21 250.00$ EachSensitive Areas Sign GI‐22 7.00$ EachSodding, 1" deep, sloped ground GI‐23 8.00$ SYSurveying, line & grade GI‐24 850.00$ Day 1850.0054,250.00Surveying, lot location/lines GI‐25 1,800.00$ Acre 0.721,296.00Topsoil Type A (imported) GI‐26 28.50$ CY 12342.00361,026.00Traffic control crew ( 2 flaggers ) GI‐27 120.00$ HR 8960.00242,880.00Trail, 4" chipped wood GI‐28 8.00$ SYTrail, 4" crushed cinder GI‐29 9.00$ SYTrail, 4" top course GI‐30 12.00$ SYConduit, 2" GI‐31 5.00$ LF 2801,400.00Wall, retaining, concrete GI‐32 55.00$ SFWall, rockery GI‐33 15.00$ SFSUBTOTAL THIS PAGE:2,466.00 21,049.00(B)(C)(D)(E)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR STREET AND SITE IMPROVEMENTSQuantity Remaining (Bond Reduction) (B) (C)Page 1 of 3Ref 8‐H Bond Quantity WorksheetSECTION II.b TRANSPORTATIONUnit Prices Updated: 06/14/2016Version: 06/14/2016Printed 7/12/2017 CED Permit #:U16006829Existing Future Public PrivateRight‐of‐Way Improvements Improvements(D) (E)Description No. Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Quant. CostSITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR STREET AND SITE IMPROVEMENTSQuantity Remaining (Bond Reduction) (B) (C)ROAD IMPROVEMENT/PAVEMENT/SURFACINGAC Grinding, 4' wide machine < 1000sy RI‐1 30.00$ SY 17510.00AC Grinding, 4' wide machine 1000‐2000sy RI‐2 16.00$ SYAC Grinding, 4' wide machine > 2000sy RI‐3 10.00$ SYAC Removal/Disposal RI‐4 35.00$ SY 12420.00179962,965.00Barricade, Type III ( Permanent ) RI‐5 56.00$ LFGuard Rail RI‐6 30.00$ LFCurb & Gutter, rolled RI‐7 17.00$ LFCurb & Gutter, vertical RI‐8 12.50$ LF 562.50106113,262.50Curb and Gutter, demolition and disposal RI‐9 18.00$ LF 590.0070712,726.00Curb, extruded asphalt RI‐10 5.50$ LFCurb, extruded concrete RI‐11 7.00$ LFSawcut, asphalt, 3" depth RI‐12 1.85$ LF 4786.95139257.15Sawcut, concrete, per 1" depth RI‐13 3.00$ LFSealant, asphalt RI‐14 2.00$ LF 4794.00139278.00Shoulder, gravel, 4" thick RI‐15 15.00$ SYSidewalk, 4" thick RI‐16 38.00$ SY 1485,624.00742,812.00Sidewalk, 4" thick, demolition and disposal RI‐17 32.00$ SY 943,008.0012384.00Sidewalk, 5" thick RI‐18 41.00$ SYSidewalk, 5" thick, demolition and disposal RI‐19 40.00$ SYSign, Handicap RI‐20 85.00$ Each 185.00Striping, per stall RI‐21 7.00$ Each 24168.00Striping, thermoplastic, ( for crosswalk ) RI‐22 3.00$ SF 4151,245.00Striping, 4" reflectorized line RI‐23 0.50$ LFAdditional 2.5" Crushed Surfacing RI‐24 3.60$ SYHMA 1/2" Overlay 1.5" RI‐25 14.00$ SYHMA 1/2" Overlay 2" RI‐26 18.00$ SYHMA Road, 2", 4" rock, First 2500 SY RI‐27 28.00$ SYHMA Road, 2", 4" rock, Qty. over 2500SY RI‐28 21.00$ SYHMA Road, 4", 6" rock, First 2500 SY RI‐29 45.00$ SY 156870,560.00HMA Road, 4", 6" rock, Qty. over 2500 SY RI‐30 37.00$ SYHMA Road, 4", 4.5" ATB RI‐31 38.00$ SYGravel Road, 4" rock, First 2500 SY RI‐32 15.00$ SYGravel Road, 4" rock, Qty. over 2500 SY RI‐33 10.00$ SYThickened Edge RI‐34 8.60$ LF 217.20SUBTOTAL THIS PAGE:9,912.65 164,742.65(B)(C)(D)(E)Page 2 of 3Ref 8‐H Bond Quantity WorksheetSECTION II.b TRANSPORTATIONUnit Prices Updated: 06/14/2016Version: 06/14/2016Printed 7/12/2017 CED Permit #:U16006829Existing Future Public PrivateRight‐of‐Way Improvements Improvements(D) (E)Description No. Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Quant. CostSITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR STREET AND SITE IMPROVEMENTSQuantity Remaining (Bond Reduction) (B) (C)PARKING LOT SURFACING No.2" AC, 2" top course rock & 4" borrow PL‐1 21.00$ SY2" AC, 1.5" top course & 2.5" base course PL‐2 28.00$ SY4" select borrow PL‐3 5.00$ SY1.5" top course rock & 2.5" base course PL‐4 14.00$ SYSUBTOTAL PARKING LOT SURFACING:(B)(C)(D)(E)LANDSCAPING & VEGETATION No.Street Trees LA‐1 750.00$ 43,000.00Median Landscaping LA‐2Right‐of‐Way Landscaping LA‐3Wetland Landscaping LA‐4SUBTOTAL LANDSCAPING & VEGETATION:3,000.00(B)(C)(D)(E)TRAFFIC & LIGHTING No.Signs TR‐1Street Light System ( # of Poles) TR‐2Traffic Signal TR‐3Traffic Signal Modification TR‐4SUBTOTAL TRAFFIC & LIGHTING:(B)(C)(D)(E)WRITE‐IN‐ITEMSSUBTOTAL WRITE‐IN ITEMS:STREET AND SITE IMPROVEMENTS SUBTOTAL: 15,378.65 185,791.65SALES TAX @ 9.5% 1,460.97 17,650.21STREET AND SITE IMPROVEMENTS TOTAL: 16,839.62 203,441.86(B)(C)(D)(E)Page 3 of 3Ref 8‐H Bond Quantity WorksheetSECTION II.b TRANSPORTATIONUnit Prices Updated: 06/14/2016Version: 06/14/2016Printed 7/12/2017 CED Permit #:U16006829Existing Future Public PrivateRight‐of‐Way Improvements Improvements(D) (E)Description No. Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Quant. 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/D D‐1 26.00$ SY* (CBs include frame and lid)Beehive D‐2 90.00$ EachThrough‐curb Inlet Framework D‐3 400.00$ EachCB Type I D‐4 1,500.00$ Each 11,500.00CB Type IL D‐5 1,750.00$ EachCB Type II, 48" diameter D‐6 2,300.00$ Each for additional depth over 4' D‐7 480.00$ FTCB Type II, 54" diameter D‐8 2,500.00$ Each for additional depth over 4' D‐9 495.00$ FTCB Type II, 60" diameter D‐10 2,800.00$ Each for additional depth over 4' D‐11 600.00$ FTCB Type II, 72" diameter D‐12 6,000.00$ Each for additional depth over 4' D‐13 850.00$ FTCB Type II, 96" diameter D‐14 14,000.00$ Each for additional depth over 4' D‐15 925.00$ FTTrash Rack, 12" D‐16 350.00$ EachTrash Rack, 15" D‐17 410.00$ EachTrash Rack, 18" D‐18 480.00$ EachTrash Rack, 21" D‐19 550.00$ EachCleanout, PVC, 4" D‐20 150.00$ Each 2300.00Cleanout, PVC, 6" D‐21 170.00$ Each 1170.00Cleanout, PVC, 8" D‐22 200.00$ EachCulvert, PVC, 4" (Not allowed in ROW)D‐23 10.00$ LF 2002,000.00Culvert, PVC, 6" (Not allowed in ROW)D‐24 13.00$ LF 71923.00Culvert, PVC, 8" (Not allowed in ROW)D‐25 15.00$ LF 9135.00Culvert, PVC, 12" (Not allowed in ROW)D‐26 23.00$ LFCulvert, PVC, 15" (Not allowed in ROW)D‐27 35.00$ LFCulvert, PVC, 18" (Not allowed in ROW)D‐28 41.00$ LFCulvert, PVC, 24" (Not allowed in ROW)D‐29 56.00$ LFCulvert, PVC, 30" (Not allowed in ROW)D‐30 78.00$ LFCulvert, PVC, 36" (Not allowed in ROW)D‐31 130.00$ LFCulvert, CMP, 8" D‐32 19.00$ LFCulvert, CMP, 12" D‐33 29.00$ LFSUBTOTAL THIS PAGE:5,028.00(B) (C) (D) (E)Quantity Remaining (Bond Reduction) (B) (C)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESPage 1 of 5Ref 8‐H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 06/14/2016Printed 7/12/2017 CED Permit #:U16006829Existing Future Public PrivateRight‐of‐Way Improvements Improvements(D) (E)Description No. Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Quant. CostQuantity Remaining (Bond Reduction) (B) (C)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESDRAINAGE (Continued)Culvert, CMP, 15" D‐34 35.00$ LFCulvert, CMP, 18" D‐35 41.00$ LFCulvert, CMP, 24" D‐36 56.00$ LFCulvert, CMP, 30" D‐37 78.00$ LFCulvert, CMP, 36" D‐38 130.00$ LFCulvert, CMP, 48" D‐39 190.00$ LFCulvert, CMP, 60" D‐40 270.00$ LFCulvert, CMP, 72" D‐41 350.00$ LFCulvert, Concrete, 8" D‐42 42.00$ LFCulvert, Concrete, 12" D‐43 48.00$ LFCulvert, Concrete, 15" D‐44 78.00$ LFCulvert, Concrete, 18" D‐45 48.00$ LFCulvert, Concrete, 24" D‐46 78.00$ LFCulvert, Concrete, 30" D‐47 125.00$ LFCulvert, Concrete, 36" D‐48 150.00$ LFCulvert, Concrete, 42" D‐49 175.00$ LFCulvert, Concrete, 48" D‐50 205.00$ LFCulvert, CPE, 6" (Not allowed in ROW)D‐51 14.00$ LFCulvert, CPE, 8" (Not allowed in ROW)D‐52 16.00$ LFCulvert, CPE, 12" (Not allowed in ROW)D‐53 24.00$ LFCulvert, CPE, 15" (Not allowed in ROW)D‐54 35.00$ LFCulvert, CPE, 18" (Not allowed in ROW)D‐55 41.00$ LFCulvert, CPE, 24" (Not allowed in ROW)D‐56 56.00$ LFCulvert, CPE, 30" (Not allowed in ROW)D‐57 78.00$ LFCulvert, CPE, 36" (Not allowed in ROW)D‐58 130.00$ LFCulvert, LCPE, 6" D‐59 60.00$ LFCulvert, LCPE, 8" D‐60 72.00$ LFCulvert, LCPE, 12" D‐61 84.00$ LFCulvert, LCPE, 15" D‐62 96.00$ LFCulvert, LCPE, 18" D‐63 108.00$ LFCulvert, LCPE, 24" D‐64 120.00$ LFCulvert, LCPE, 30" D‐65 132.00$ LFCulvert, LCPE, 36" D‐66 144.00$ LFCulvert, LCPE, 48" D‐67 156.00$ LFCulvert, LCPE, 54" D‐68 168.00$ LFSUBTOTAL THIS PAGE:(B) (C) (D) (E)Page 2 of 5Ref 8‐H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 06/14/2016Printed 7/12/2017 CED Permit #:U16006829Existing Future Public PrivateRight‐of‐Way Improvements Improvements(D) (E)Description No. Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Quant. CostQuantity Remaining (Bond Reduction) (B) (C)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESDRAINAGE (Continued)Culvert, LCPE, 60" D‐69 180.00$ LFCulvert, LCPE, 72" D‐70 192.00$ LFCulvert, HDPE, 6" D‐71 42.00$ LFCulvert, HDPE, 8" D‐72 42.00$ LFCulvert, HDPE, 12" D‐73 74.00$ LFCulvert, HDPE, 15" D‐74 106.00$ LFCulvert, HDPE, 18" D‐75 138.00$ LFCulvert, HDPE, 24" D‐76 221.00$ LFCulvert, HDPE, 30" D‐77 276.00$ LFCulvert, HDPE, 36" D‐78 331.00$ LFCulvert, HDPE, 48" D‐79 386.00$ LFCulvert, HDPE, 54" D‐80 441.00$ LFCulvert, HDPE, 60" D‐81 496.00$ LFCulvert, HDPE, 72" D‐82 551.00$ LFPipe, Polypropylene, 6" D‐83 84.00$ LFPipe, Polypropylene, 8" D‐84 89.00$ LFPipe, Polypropylene, 12" D‐85 95.00$ LFPipe, Polypropylene, 15" D‐86 100.00$ LFPipe, Polypropylene, 18" D‐87 106.00$ LFPipe, Polypropylene, 24" D‐88 111.00$ LFPipe, Polypropylene, 30" D‐89 119.00$ LFPipe, Polypropylene, 36" D‐90 154.00$ LFPipe, Polypropylene, 48" D‐91 226.00$ LFPipe, Polypropylene, 54" D‐92 332.00$ LFPipe, Polypropylene, 60" D‐93 439.00$ LFPipe, Polypropylene, 72" D‐94 545.00$ LFCulvert, DI, 6" D‐95 61.00$ LFCulvert, DI, 8" D‐96 84.00$ LFCulvert, DI, 12" D‐97 106.00$ LFCulvert, DI, 15" D‐98 129.00$ LFCulvert, DI, 18" D‐99 152.00$ LFCulvert, DI, 24" D‐100 175.00$ LFCulvert, DI, 30" D‐101 198.00$ LFCulvert, DI, 36" D‐102 220.00$ LFCulvert, DI, 48" D‐103 243.00$ LFCulvert, DI, 54" D‐104 266.00$ LFCulvert, DI, 60" D‐105 289.00$ LFCulvert, DI, 72" D‐106 311.00$ LFSUBTOTAL THIS PAGE:(B) (C) (D) (E)Page 3 of 5Ref 8‐H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 06/14/2016Printed 7/12/2017 CED Permit #:U16006829Existing Future Public PrivateRight‐of‐Way Improvements Improvements(D) (E)Description No. Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Quant. CostQuantity Remaining (Bond Reduction) (B) (C)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESSpecialty Drainage ItemsDitching SD‐1 9.50$ CYFlow Dispersal Trench (1,436 base+) SD‐3 28.00$ LF French Drain (3' depth) SD‐4 26.00$ LFGeotextile, laid in trench, polypropylene SD‐5 3.00$ SYMid‐tank Access Riser, 48" dia, 6' deep SD‐6 2,000.00$ EachPond Overflow Spillway SD‐7 16.00$ SYRestrictor/Oil Separator, 12" SD‐8 1,150.00$ EachRestrictor/Oil Separator, 15" SD‐9 1,350.00$ EachRestrictor/Oil Separator, 18" SD‐10 1,700.00$ EachRiprap, placed SD‐11 42.00$ CYTank End Reducer (36" diameter) SD‐12 1,200.00$ EachInfiltration pond testing SD‐13 125.00$ HRPermeable Pavement SD‐14 60.00$ SY 18611,160.00Permeable Concrete Sidewalk SD‐15 65.00$ SY 16510,725.00Culvert, Box __ ft x __ ft SD‐16SUBTOTAL SPECIALTY DRAINAGE ITEMS:21,885.00(B) (C) (D) (E)STORMWATER FACILITIES (Include Flow Control and Water Quality Facility Summary Sheet and Sketch)Detention Pond SF‐1 Each Detention Tank SF‐2 Each Detention Vault SF‐3 Each Infiltration Pond SF‐4 Each Infiltration Tank SF‐5 Each Infiltration Vault SF‐6 Each Infiltration Trenches SF‐7 Each Basic Biofiltration Swale SF‐8 Each Wet Biofiltration Swale SF‐9 Each Wetpond SF‐10 Each Wetvault SF‐11 Each Sand Filter SF‐12 Each Sand Filter Vault SF‐13 Each Linear Sand Filter SF‐14 Each StormFilter SF‐15 Each Rain Garden SF‐16 Each SUBTOTAL STORMWATER FACILITIES:(B) (C) (D) (E)Page 4 of 5Ref 8‐H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 06/14/2016Printed 7/12/2017 CED Permit #:U16006829Existing Future Public PrivateRight‐of‐Way Improvements Improvements(D) (E)Description No. Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Quant. CostQuantity Remaining (Bond Reduction) (B) (C)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESWRITE‐IN‐ITEMSFilterra Vault WI‐1 45,480.00$ 145,480.00WI‐2WI‐3WI‐4WI‐5WI‐6WI‐7WI‐8WI‐9WI‐10WI‐11WI‐12WI‐13WI‐14WI‐15SUBTOTAL WRITE‐IN ITEMS:45,480.00DRAINAGE AND STORMWATER FACILITIES SUBTOTAL: 72,393.00SALES TAX @ 9.5% 6,877.34DRAINAGE AND STORMWATER FACILITIES TOTAL: 79,270.34(B) (C) (D) (E)Page 5 of 5Ref 8‐H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 06/14/2016Printed 7/12/2017 CED Permit #:U16006829Existing Future Public PrivateRight‐of‐Way Improvements Improvements(D) (E)Description No. Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Quant. CostConnection to Existing Watermain W‐1 2,000.00$ EachDuctile Iron Watermain, CL 52, 4 Inch Diameter W‐2 50.00$ LFDuctile Iron Watermain, CL 52, 6 Inch Diameter W‐3 56.00$ LFDuctile Iron Watermain, CL 52, 8 Inch Diameter W‐4 60.00$ LFDuctile Iron Watermain, CL 52, 10 Inch Diameter W‐5 70.00$ LFDuctile Iron Watermain, CL 52, 12 Inch Diameter W‐6 80.00$ LFGate Valve, 4 inch Diameter W‐7 500.00$ EachGate Valve, 6 inch Diameter W‐8 700.00$ EachGate Valve, 8 Inch Diameter W‐9 800.00$ EachGate Valve, 10 Inch Diameter W‐10 1,000.00$ EachGate Valve, 12 Inch Diameter W‐11 1,200.00$ EachFire Hydrant Assembly W‐12 4,000.00$ EachPermanent Blow‐Off Assembly W‐13 1,800.00$ EachAir‐Vac Assembly, 2‐Inch Diameter W‐14 2,000.00$ EachAir‐Vac Assembly, 1‐Inch Diameter W‐15 1,500.00$ EachCompound Meter Assembly 3‐inch Diameter W‐16 8,000.00$ EachCompound Meter Assembly 4‐inch Diameter W‐17 9,000.00$ EachCompound Meter Assembly 6‐inch Diameter W‐18 10,000.00$ EachPressure Reducing Valve Station 8‐inch to 10‐inch W‐19 20,000.00$ EachWATER SUBTOTAL:SALES TAX @ 9.5%WATER TOTAL:(B) (C) (D) (E)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR WATERQuantity Remaining (Bond Reduction) (B) (C)Page 1 of 1Ref 8‐H Bond Quantity WorksheetSECTION II.d WATERUnit Prices Updated: 06/14/2016Version: 06/14/2016Printed 7/12/2017 CED Permit #:U16006829Existing Future Public PrivateRight‐of‐Way Improvements Improvements(D) (E)Description No. Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Quant. CostClean Outs SS‐1 1,000.00$ Each 33,000.00Grease Interceptor, 500 gallon SS‐2 8,000.00$ EachGrease Interceptor, 1000 gallon SS‐3 10,000.00$ EachGrease Interceptor, 1500 gallon SS‐4 15,000.00$ Each 115,000.00Side Sewer Pipe, PVC. 4 Inch Diameter SS‐5 80.00$ LF 725,760.00Side Sewer Pipe, PVC. 6 Inch Diameter SS‐6 95.00$ LF 171,615.00Sewer Pipe, PVC, 8 inch Diameter SS‐7 105.00$ LFSewer Pipe, PVC, 12 Inch Diameter SS‐8 120.00$ LFSewer Pipe, DI, 8 inch Diameter SS‐9 115.00$ LFSewer Pipe, DI, 12 Inch Diameter SS‐10 130.00$ LFManhole, 48 Inch Diameter SS‐11 6,000.00$ EachManhole, 54 Inch Diameter SS‐13 6,500.00$ EachManhole, 60 Inch Diameter SS‐15 7,500.00$ EachManhole, 72 Inch Diameter SS‐17 8,500.00$ EachManhole, 96 Inch Diameter SS‐19 14,000.00$ EachPipe, C‐900, 12 Inch Diameter SS‐21 180.00$ LFOutside Drop SS‐24 1,500.00$ LSInside Drop SS‐25 1,000.00$ LSSewer Pipe, PVC, ____ Inch Diameter SS‐26Lift Station (Entire System) SS‐27 LSSANITARY SEWER SUBTOTAL:25,375.00SALES TAX @ 9.5% 2,410.63SANITARY SEWER TOTAL: 27,785.63(B) (C) (D) (E)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR SANITARY SEWERQuantity Remaining (Bond Reduction) (B) (C)Page 1 of 1Ref 8‐H Bond Quantity WorksheetSECTION II.e SANITARY SEWERUnit Prices Updated: 06/14/2016Version: 06/14/2016Printed 7/12/2017 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) (a)9,466.82$ Existing Right‐of‐Way Improvements Subtotal (b) (b)16,839.62$ Future Public Improvements Subtotal (c) (c)‐$ Stormwater & Drainage Facilities Subtotal (d) (d)79,270.34$ Bond Reduction (Quantity Remaining)2(e) (e)‐$ Site RestorationCivil Construction PermitMaintenance Bond19,221.99$ Bond Reduction2Construction Permit Bond Amount 3Minimum Bond Amount is $10,000.001 Estimate Only ‐ May involve multiple and variable components, which will be established on an individual basis by Development Engineering.2 The City of Renton allows one request only for bond reduction prior to the maintenance period. Reduction of not more than 70% of the original bond amount, provided that the remaining 30% willcover all remaining items to be constructed. 3 Required Bond Amounts are subject to review and modification by Development Engineering.* Note: The word BOND as used in this document means any financial guarantee acceptable to the City of Renton.** Note: All prices include labor, equipment, materials, overhead and profit. R((b)+(c)+(d)) x 150%EST1((b) + (c) + (d)) x 20%‐$ MAINTENANCE BOND */**(after final acceptance of construction)9,466.82$ 16,839.62$ 144,164.94$ 14,200.23$ ‐$ ‐$ 79,270.34$ S(e) x 150%SITE IMPROVEMENT BOND QUANTITY WORKSHEET BOND CALCULATIONS7/12/2017Nick Bossoff29631Nick Bossoff EngineeringT(P +R ‐ S)Prepared by:Project InformationCONSTRUCTION BOND AMOUNT */**(prior to permit issuance)(425) 881‐5904nick@nbengineering.comRenton Sonic16‐000229735 Hardie Ave. SW1923059104FOR APPROVALU16006829191 NE Tari Lane, Stevenson WA 98648158,365.17$ P (a) x 150%Page 1 of 1Ref 8‐H Bond Quantity WorksheetSECTION III. BOND WORKSHEETUnit Prices Updated: 06/14/2016Version: 06/14/2016Printed 7/12/2017 Return Address: City Clerk’s Office City of Renton 1055 S Grady Way Renton, WA 98057 DECLARATION OF COVENANT FOR INSPECTION AND MAINTENANCE OF STORMWATER FACILITIES AND BMPS Grantor: Grantee: City of Renton Legal Description: Assessor's Tax Parcel ID#: IN CONSIDERATION of the approved City of Renton ___________________________ permit for application file No. LUA/SWP_______________________ relating to the real property ("Property") described above, the Grantor(s), the owner(s) in fee of that Property, hereby covenants(covenant) with the City of Renton, a political subdivision of the state of Washington, that he/she(they) will observe, consent to, and abide by the conditions and obligations set forth and described in Paragraphs 1 through 10 below with regard to the Property, and hereby grants(grant) an easement as described in Paragraphs 2 and 3. Grantor(s) hereby grants(grant), covenants(covenant), and agrees(agree) as follows: 1. The Grantor(s) or his/her(their) successors in interest and assigns ("Owners of the described property") shall at their own cost, operate, maintain, and keep in good repair, the Property's stormwater facilities and/or best management practices ("BMPs") constructed as required in the approved construction plans and specifications __________ on file with the City of Renton and submitted to the City of Renton for the review and approval of permit(s) _____________________________. The property's stormwater facilities and/or best management practices ("BMPs") are shown and/or listed on Exhibit A. The property’s stormwater facilities and/or BMPs shall be maintained in compliance with the operation and maintenance schedule included and attached herein as Exhibit B. Stormwater facilities include pipes, swales, tanks, vaults, ponds, and other engineered structures designed to manage and/or treat stormwater on the Property. Stormwater BMPs include dispersion and infiltration devices, native vegetated areas, permeable pavements, vegetated roofs, rainwater harvesting systems, reduced impervious surface coverage, and other measures designed to reduce the amount of stormwater runoff on the Property. 2. City of Renton shall have the right to ingress and egress over those portions of the Property necessary to perform inspections of the stormwater facilities and BMPs and conduct maintenance activities specified in this Declaration of Covenant and in accordance with RMC 4-6-030. 3. If City of Renton determines that maintenance or repair work is required to be done to any of the stormwater facilities or BMPs, City of Renton shall give notice of the specific maintenance and/or repair work required pursuant to RMC 4-6-030. The City shall also set a reasonable time in which such Page 1 of 3 Form Approved by City Attorney 10/2013 Bonnell Family LLC 1923059104 LUA16-000229 Construction See Exhibit C Sonic Renton U16006829 work is to be completed by the Owners. If the above required maintenance or repair is not completed within the time set by the City, the City may perform the required maintenance or repair, and hereby is given access to the Property, subject to the exclusion in Paragraph 2 above, for such purposes. Written notice will be sent to the Owners stating the City’s intention to perform such work. This work will not commence until at least seven (7) days after such notice is mailed. If, within the sole discretion of the City, there exists an imminent or present danger, the seven (7) day notice period will be waived and maintenance and/or repair work will begin immediately. 4. If at any time the City of Renton reasonably determines that a stormwater facility or BMP on the Property creates any of the hazardous conditions listed in RMC 4-4-060 G or relevant municipal successor's codes as applicable and herein incorporated by reference, the City may take measures specified therein. 5.The Owners shall assume all responsibility for the cost of any maintenance or repair work completed by the City as described in Paragraph 3 or any measures taken by the City to address hazardous conditions as described in Paragraph 4. Such responsibility shall include reimbursement to the City within thirty (30) days of the receipt of the invoice for any such work performed. Overdue payments will require payment of interest at the current legal rate as liquidated damages. If legal action ensues, the prevailing party is entitled to recover reasonable litigation costs and attorney’s fees. 6. The Owners are hereby required to obtain written approval from City of Renton prior to filling, piping, cutting, or removing vegetation (except in routine landscape maintenance) in open vegetated stormwater facilities (such as swales, channels, ditches, ponds, etc.), or performing any alterations or modifications to the stormwater facilities and BMPs referenced in this Declaration of Covenant. 7. Any notice or consent required to be given or otherwise provided for by the provisions of this Agreement shall be effective upon personal delivery, or three (3) days after mailing by Certified Mail, return receipt requested. 8.With regard to the matters addressed herein, this agreement constitutes the entire agreement between the parties, and supersedes all prior discussions, negotiations, and all agreements whatsoever whether oral or written. 9. This Declaration of Covenant is intended to protect the value and desirability of the real property described above, and shall inure to the benefit of all the citizens of the City of Renton and its successors and assigns. This Declaration of Covenant shall run with the land and be binding upon Grantor(s), and Grantor's(s') successors in interest, and assigns. 10. This Declaration of Covenant may be terminated by execution of a written agreement by the Owners and the City that is recorded by King County in its real property records. IN WITNESS WHEREOF, this Declaration of Covenant for the Inspection and Maintenance of Stormwater Facilities and BMPs is executed this _____ day of ____________________, 20_____. GRANTOR, owner of the Property GRANTOR, owner of the Property Page 2 of 3 Form Approved by City Attorney 10/2013 STATE OF WASHINGTON ) COUNTY OF KING )ss. On this day personally appeared before me: , to me known to be the individual(s) described in and who executed the within and foregoing instrument and acknowledged that they signed the same as their free and voluntary act and deed, for the uses and purposes therein stated. Given under my hand and official seal this _____ day of ____________________, 20_____. Printed name Notary Public in and for the State of Washington, residing at My appointment expires Page 3 of 3 Form Approved by City Attorney 10/2013 EXHIBIT B Operation and Maintenance Manual NO. 5 - CATCH BASINS Maintenance Component Defect Conditions When Maintenance is Needed Results Expected When Maintenance is performed General Trash & Debris (Includes Sediment) Trash or debris of more than 1/2 cubic foot which is located immediately in front of the catch basin opening or is blocking capacity of the basin by more than 10% No Trash or debris located immediately in front of catch basin opening. Trash or debris (in the 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. Trash or debris in any inlet or outlet pipe blocking more than 1/3 of its height. Inlet and outlet pipes free of trash or debris. Dead animals or vegetation that could generate odors that could cause complaints or dangerous gases (e.g., methane). No dead animals or vegetation present within the catch basin. Deposits of garbage exceeding 1 cubic foot in volume No condition present which would attract or support the breeding of insects or rodents. Structure Damage to Frame and/or Top Slab Corner of frame extends more than 3/4 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 1/4 inch (intent is to make sure all material is running into basin). Top slab is free of holes and cracks. Frame not sitting flush on top slab, i.e., separation of more than 3/4 inch of the frame from the top slab. Frame is sitting flush on top slab. Cracks in Basin Walls/ Bottom Cracks wider than 1/2 inch and longer than 3 feet, any evidence of soil particles entering catch basin through cracks, or maintenance person judges that structure is unsound. Basin replaced or repaired to design standards. Cracks wider than 1/2 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. Sediment/ Misalignment Basin has settled more than 1 inch or has rotated more than 2 inches out of alignment. Basin replaced or repaired to design standards. NO. 5 - CATCH BASINS (CONTINUED) Maintenanc e Component Defect Conditions When Maintenance is Needed Results Expected When Maintenance is performed Fire Hazard Presence of chemicals such as natural gas, oil and gasoline. No flammable chemicals present. Vegetation Vegetation growing across and blocking more than 10% of the basin opening. No vegetation blocking opening to basin. Vegetation growing in inlet/outlet pipe joints that is more than six inches tall and less than six inches apart. No vegetation or root growth present. Pollution Nonflammable chemicals of more than 1/2 cubic foot per three feet of basin length. No pollution present other than surface film. Catch Basin Cover Cover Not in Place Cover is missing or only partially in place. Any open catch basin requires maintenance. Catch basin cover is closed Locking Mechanism Not Working Mechanism cannot be opened by on maintenance person with proper tools. Bolts into frame have less than 1/2 inch of thread. Mechanism opens with proper tools. Cover Difficult to Remove One maintenance person cannot remove lid after applying 80 lbs. of lift; intent is keep cover from sealing off access to maintenance. Cover can be removed by one maintenance person. Ladder Ladder Rungs Unsafe Ladder is unsafe due to missing rungs, misalignment, rust, cracks, or sharp edges. Ladder meets design standards and allows maintenance person safe access. Metal Grates (If Applicable) 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. Damaged or Missing. Grate missing or broken member(s) of the grate. Grate is in place and meets design standards. NO. 10 - CONVEYANCE SYSTEMS (PIPES & DITCHES) Maintenance Component Defect Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Pipes Sediment & Debris Accumulated sediment that exceeds 20% of the diameter of the pipe. Pipe cleaned of all sediment and debris. Vegetation Vegetation that reduces free movement of water through pipes. All vegetation removed so water flows freely through pipes. Damaged Protective coating is damaged; rust is causing more than 50% deterioration to any part of pipe. Pipe repaired or replaced. Any dent that decreases the cross section area of pipe by more than 20%. Pipe repaired or replaced. Open Ditches Trash & Debris Trash and debris exceeds 1 cubic foot per 1,000 square feet of ditch and slopes. Trash and debris cleared from ditches. Sediment Accumulated sediment that exceeds 20 % of the design depth. Ditch cleaned/ flushed of all sediment and debris so that it matches design. Vegetation Vegetation that reduces free movement of water through ditches. Water flows freely through ditches. Erosion Damage to Slopes See “Ponds” Standard No. 1 See “Ponds” Standard No. 1 Rock Lining Out of Place or Missing (If Applicable). Maintenance person can see native soil beneath the rock lining. Replace rocks to design standards. Catch Basins See “Catch Basins: Standard No. 5 See “Catch Basins” Standard No. 5 Debris Barriers (e.g., Trash Rack) See “Debris Barriers” Standard No.6 See “Debris Barriers” Standard No. 6 Permeable Asphalt and Concrete Inspect project upon completion to correct accumulation of fine material. Conduct periodic visual inspections to determine if surfaces are clogged with vegetation or fine soils. Clogged surfaces should be corrected immediately. Surfaces should be swept with a high-efficiency or vacuum sweeper twice per year; preferably, once in the autumn after leaf fall, and again in early spring. As long as annual infiltration rate testing demonstrates that a rate of 10 inches per hour or greater is being maintained through the pervious surface, the sweeping frequency can be reduced to once per year. EXHIBIT C LEGAL DESCRIPTION THAT PORTION OF LOT 3 OF CITY OF RENTON LOT LINE ADJUSTMENT LUA 15-000237 AS RECORDED UNDER REC. NO.20151006900005, LYING IN THE NORTHEAST QUARTER OF THE NORTHWEST QUARTER OF SECTION 19, TOWNSHIP 23 NORTH, RANGE 5 EAST, W.M., MORE PARTICULARLY DESCRIBED AS FOLLOWS: COMMENCING AT THE SOUTHEAST CORNER OF LOT 1 OF SAID LOT LINE ADJUSTMENT ADJOINING HARDIE AVENUE SW; THENCE NORTH 01º23'12" EAST, ALONG THE WEST MARGIN OF HARDIE AVENUE SOUTHWEST A DISTANCE OF 38.56 FEET TO THE TRUE POINT OF BEGINNING; THENCE CONTINUING NORTH 1°23'12" EAST ALONG THE WEST MARGIN OF HARDIE AVENUE SOUTHWEST A DISTANCE OF 207.42 FEET; THENCE NORTH 88°45'24" WEST A DISTANCE OF 144.58 FEET TO THE WEST LINE OF SAID LOT 3; THENCE SOUTH 1°14'36" WEST A DISTANCE OF 18.31 FEET; THENCE SOUTH 1°13'55" WEST A DISTANCE OF 153.38 FEET; THENCE SOUTH 11°26'39" WEST A DISTANCE OF 35.05 FEET; TO A POINT OF CURVATURE OF A CURVE TO THE LEFT WHOSE RADIUS IS 14.56 FEET, THENCE ALONG SAID CURVE THROUGH A CENTRAL ANGLE OF 102°51'32" AN ARC LENGTH OF 26.14 FEET; THENCE SOUTH 88°33'44" EAST A DISTANCE OF 98.48 FEET; THENCE SOUTH 88°44'59" EAST A DISTANCE OF 3.58 FEET; THENCE NORTH 1°15'01" EAST A DISTANCE OF 16.43 FEET; THENCE SOUTH 88°44'59" EAST A DISTANCE OF 33.41 FEET TO THE TRUE POINT OF BEGINNING; EXCEPT THE SOUTH 20.00 FEET OF THE EAST 15.00 FEET ADJOINING HARDIE AVENUE SW. SITUATE IN THE CITY OF RENTON, COUNTY OF KING, STATE OF WASHINGTON. CONTAINING 31,602 SQUARE FEET, OR 0.73 ACRES, MORE OR LESS. Technical Information Report for Sonic Renton June 21, 2017 40 SECTION 10 OPERATIONS AND MAINTENANCE MANUAL The storm drainage system will be privately maintained. A suggested maintenance schedule for the facilities is listed below. NO. 5 - CATCH BASINS Maintenance Component Defect Conditions When Maintenance is Needed Results Expected When Maintenance is performed General Trash & Debris (Includes Sediment) Trash or debris of more than 1/2 cubic foot which is located immediately in front of the catch basin opening or is blocking capacity of the basin by more than 10% No Trash or debris located immediately in front of catch basin opening. Trash or debris (in the 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. Trash or debris in any inlet or outlet pipe blocking more than 1/3 of its height. Inlet and outlet pipes free of trash or debris. Dead animals or vegetation that could generate odors that could cause complaints or dangerous gases (e.g., methane). No dead animals or vegetation present within the catch basin. Deposits of garbage exceeding 1 cubic foot in volume No condition present which would attract or support the breeding of insects or rodents. Structure Damage to Frame and/or Top Slab Corner of frame extends more than 3/4 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 1/4 inch (intent is to make sure all material is running into basin). Top slab is free of holes and cracks. Frame not sitting flush on top slab, i.e., separation of more than 3/4 inch of the frame from the top slab. Frame is sitting flush on top slab. Cracks in Basin Walls/ Bottom Cracks wider than 1/2 inch and longer than 3 feet, any evidence of soil particles entering catch basin through cracks, or maintenance person judges that structure is unsound. Basin replaced or repaired to design standards. Cracks wider than 1/2 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. Sediment/ Misalignment Basin has settled more than 1 inch or has rotated more than 2 inches out of alignment. Basin replaced or repaired to design standards. Technical Information Report for Sonic Renton June 21, 2017 41 NO. 5 - CATCH BASINS (CONTINUED) Maintenance Component Defect Conditions When Maintenance is Needed Results Expected When Maintenance is performed Fire Hazard Presence of chemicals such as natural gas, oil and gasoline. No flammable chemicals present. Vegetation Vegetation growing across and blocking more than 10% of the basin opening. No vegetation blocking opening to basin. Vegetation growing in inlet/outlet pipe joints that is more than six inches tall and less than six inches apart. No vegetation or root growth present. Pollution Nonflammable chemicals of more than 1/2 cubic foot per three feet of basin length. No pollution present other than surface film. Catch Basin Cover Cover Not in Place Cover is missing or only partially in place. Any open catch basin requires maintenance. Catch basin cover is closed Locking Mechanism Not Working Mechanism cannot be opened by on maintenance person with proper tools. Bolts into frame have less than 1/2 inch of thread. Mechanism opens with proper tools. Cover Difficult to Remove One maintenance person cannot remove lid after applying 80 lbs. of lift; intent is keep cover from sealing off access to maintenance. Cover can be removed by one maintenance person. Ladder Ladder Rungs Unsafe Ladder is unsafe due to missing rungs, misalignment, rust, cracks, or sharp edges. Ladder meets design standards and allows maintenance person safe access. Metal Grates (If Applicable) 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. Damaged or Missing. Grate missing or broken member(s) of the grate.Grate is in place and meets design standards. Technical Information Report for Sonic Renton June 21, 2017 42 NO. 10 - CONVEYANCE SYSTEMS (PIPES & DITCHES) Maintenance Component Defect Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Pipes Sediment & Debris Accumulated sediment that exceeds 20% of the diameter of the pipe. Pipe cleaned of all sediment and debris. Vegetation Vegetation that reduces free movement of water through pipes. All vegetation removed so water flows freely through pipes. Damaged Protective coating is damaged; rust is causing more than 50% deterioration to any part of pipe. Pipe repaired or replaced. Any dent that decreases the cross section area of pipe by more than 20%. Pipe repaired or replaced. Open Ditches Trash & Debris Trash and debris exceeds 1 cubic foot per 1,000 square feet of ditch and slopes. Trash and debris cleared from ditches. Sediment Accumulated sediment that exceeds 20 % of the design depth. Ditch cleaned/ flushed of all sediment and debris so that it matches design. Vegetation Vegetation that reduces free movement of water through ditches. Water flows freely through ditches. Erosion Damage to Slopes See “Ponds” Standard No. 1 See “Ponds” Standard No. 1 Rock Lining Out of Place or Missing (If Applicable). Maintenance person can see native soil beneath the rock lining. Replace rocks to design standards. Catch Basins See “Catch Basins: Standard No. 5 See “Catch Basins” Standard No. 5 Debris Barriers (e.g., Trash Rack) See “Debris Barriers” Standard No.6 See “Debris Barriers” Standard No. 6 Operation & Maintenance (OM) Manual v01 ® Bioretention Systems ENGINEERED SOLUTIONS www.ContechES.com/filterra | 800-338-1122 Table of Contents Overview • Filterra® General Description • Filterra® Schematic • Basic Operations • Design Maintenance • Maintenance Overview »Why Maintain? »When to Maintain? • Exclusion of Services • Maintenance Visit Summary • Maintenance Tools, Safety Equipment and Supplies • Maintenance Visit Procedure • Maintenance Checklist ® Bioretention Systems ENGINEERED SOLUTIONS www.ContechES.com/filterra | 800-338-1122 General Description The following general specifications describe the general operations and maintenance requirements for the Contech Engineered Solutions LLC stormwater bioretention filtration system, the Filterra®. The system utilizes physical, chemical and biological mechanisms of a soil, plant and microbe complex to remove pollutants typically found in urban stormwater runoff. The treatment system is a fully equipped, pre-constructed drop-in place unit designed for applications in the urban landscape to treat contaminated runoff. Stormwater flows through a specially designed filter media mixture contained in a landscaped concrete container. The mixture immobilizes pollutants which are then decomposed, volatilized and incorporated into the biomass of the Filterra® system’s micro/macro fauna and flora. Stormwater runoff flows through the media and into an underdrain system at the bottom of the container, where the treated water is discharged. Higher flows bypass the Filterra® to a downstream inlet or outfall. Maintenance is a simple, inexpensive and safe operation that does not require confined space access, pumping or vacuum equipment or specialized tools. Properly trained landscape personnel can effectively maintain Filterra® Stormwater systems by following instructions in this manual. www.ContechES.com/filterra | 800-338-1122 Basic Operations Filterra® is a bioretention system in a concrete box. Contaminated stormwater runoff enters the filter box through the curb inlet spreading over the 3-inch layer of mulch on the surface of the filter media. As the water passes through the mulch layer, most of the larger sediment particles and heavy metals are removed through sedimentation and chemical reactions with the organic material in the mulch. Water passes through the soil media where the finer particles are removed and other chemical reactions take place to immobilize and capture pollutants in the soil media. The cleansed water passes into an underdrain and flows to a pipe system or other appropriate discharge point. Once the pollutants are in the soil, the bacteria begin to break down and metabolize the materials and the plants begin to uptake and metabolize the pollutants. Some pollutants such as heavy metals, which are chemically bound to organic particles in the mulch, are released over time as the organic matter decomposes to release the metals to the feeder roots of the plants and the cells of the bacteria in the soil where they remain and are recycled. Other pollutants such as phosphorus are chemically bound to the soil particles and released slowly back to the plants and bacteria and used in their metabolic processes. Nitrogen goes through a very complex variety of biochemical processes where it can ultimately end up in the plant/bacteria biomass, turned to nitrogen gas or dissolves back into the water column as nitrates depending on soil temperature, pH and the availability of oxygen. The pollutants ultimately are retained in the mulch, soil and biomass with some passing out of the system into the air or back into the water. Design and Installation Each project presents different scopes for the use of Filterra® systems. To ensure the safe and specified function of the stormwater BMP, Contech reviews each application before supply. Information and help may be provided to the design engineer during the planning process. Correct Filterra® box sizing (by rainfall region) is essential to predict pollutant removal rates for a given area. The engineer shall submit calculations for approval by the local jurisdiction. The contractor is responsible for the correct installation of Filterra units as shown in approved plans. A comprehensive installation manual is available at www.conteches.com. Maintenance Why Maintain? All stormwater treatment systems require maintenance for effective operation. This necessity is often incorporated in your property’s permitting process as a legally binding BMP maintenance agreement. • Avoid legal challenges from your jurisdiction’s maintenance enforcement program. • Prolong the expected lifespan of your Filterra media. • Avoid more costly media replacement. • Help reduce pollutant loads leaving your property. Simple maintenance of the Filterra® is required to continue effective pollutant removal from stormwater runoff before discharge into downstream waters. This procedure will also extend the longevity of the living biofilter system. The unit will recycle and accumulate pollutants within the biomass, but is also subjected to other materials entering the throat. This may include trash, silt and leaves etc. which will be contained within the void below the top grate and above the mulch layer. Too much silt may inhibit the Filterra’s® flow rate, which is the reason for site stabilization before activation. Regular replacement of the mulch stops accumulation of such sediment. When to Maintain? Contech includes a 1-year maintenance plan with each system purchase. Annual included maintenance consists of a maximum of two (2) scheduled visits. Additional maintenance may be necessary depending on sediment and trash loading (by Owner or at additional cost). The start of the maintenance plan begins when the system is activated for full operation. Full operation is defined as the unit installed, curb and gutter and transitions in place and activation (by Supplier) when mulch and plant are added and temporary throat protection removed. Activation cannot be carried out until the site is fully stabilized (full landscaping, grass cover, final paving and street sweeping completed). Maintenance visits are scheduled seasonally; the spring visit aims to clean up after winter loads including salts and sands while the fall visit helps the system by removing excessive leaf litter. It has been found that in regions which receive between 30-50 inches of annual rainfall, (2) two visits are generally required; regions with less rainfall often only require (1) one visit per annum. Varying land uses can affect maintenance frequency; e.g. some fast food restaurants require more frequent trash removal. Contributing drainage areas which are subject to new development wherein the recommended erosion and sediment control measures have not been implemented may require additional maintenance visits. Some sites may be subjected to extreme sediment or trash loads, requiring more frequent maintenance visits. This is the reason for detailed notes of maintenance actions per unit, helping the Supplier and Owner predict future maintenance frequencies, reflecting individual site conditions. Owners must promptly notify the (maintenance) Supplier of any damage to the plant(s), which constitute(s) an integral part of the bioretention technology. Owners should also advise other landscape or maintenance contractors to leave all maintenance to the Supplier (i.e. no pruning or fertilizing). www.ContechES.com/filterra | 800-338-1122 Exclusion of Services It is the responsibility of the owner to provide adequate irrigation when necessary to the plant of the Filterra® system. Clean up due to major contamination such as oils, chemicals, toxic spills, etc. will result in additional costs and are not covered under the Supplier maintenance contract. Should a major contamination event occur the Owner must block off the outlet pipe of the Filterra® (where the cleaned runoff drains to, such as drop inlet) and block off the throat of the Filterra®. The Supplier should be informed immediately. Maintenance Visit Summary Each maintenance visit consists of the following simple tasks (detailed instructions below). 1. Inspection of Filterra® and surrounding area 2. Removal of tree grate and erosion control stones 3. Removal of debris, trash and mulch 4. Mulch replacement 5. Plant health evaluation and pruning or replacement as necessary 6. Clean area around Filterra® 7. Complete paperwork Maintenance Tools, Safety Equipment and Supplies Ideal tools include: camera, bucket, shovel, broom, pruners, hoe/rake, and tape measure. Appropriate Personal Protective Equipment (PPE) should be used in accordance with local or company procedures. This may include impervious gloves where the type of trash is unknown, high visibility clothing and barricades when working in close proximity to traffic and also safety hats and shoes. A T-Bar or crowbar should be used for moving the tree grates (up to 170 lbs ea.). Most visits require minor trash removal and a full replacement of mulch. See below for actual number of bagged mulch that is required in each unit size. Mulch should be a double shredded, hardwood variety; do not use colored or dyed mulch. Some visits may require additional Filterra® engineered soil media available from the Supplier. Box Length Box Width Filter Surface Area (ft²) Volume at 3” (ft³) # of 2 ft³ Mulch Bags 4 4 16 4 2 6 4 24 6 3 8 4 32 8 4 6 6 36 9 5 8 6 48 12 6 10 6 60 15 8 12 6 72 18 9 13 7 91 23 12 www.ContechES.com/filterra | 800-338-1122 Maintenance Visit Procedure Keep sufficient documentation of maintenance actions to predict location specific maintenance frequencies and needs. An example Maintenance Report is included in this manual. 1. Inspection of Filterra® and surrounding area • Record individual unit before maintenance with photograph (numbered). Record on Maintenance Report (see example in this document) the following: 2. Removal of tree grate and erosion control stones • Remove cast iron grates for access into Filterra® box. • Dig out silt (if any) and mulch and remove trash & foreign items. 3. Removal of debris, trash and mulch • After removal of mulch and debris, measure distance from the top of the Filterra® engineered media soil to the bottom of the top slab. If this distance is greater than 12”, add Filterra® media (not top soil or other) to recharge to a 9” distance Record on Maintenance Report the following: Standing Water yes | no Damage to Box Structure yes | no Damage to Grate yes | no Is Bypass Clear yes | no If yes answered to any of these observations, record with close-up photograph (numbered). Record on Maintenance Report the following: Silt/Clay yes | no Cups/ Bags yes | no Leaves yes | no # of Buckets Removed ________ Record on Maintenance Report the following: Distance of Bottom of Top Slab (inches) ________ # of Buckets of Media Added ________ www.ContechES.com/filterra | 800-338-1122 4. Mulch replacement • Please see mulch specifications. • Add double shredded mulch evenly across the entire unit to a depth of 3”. • Ensure correct repositioning of erosion control stones by the Filterra® inlet to allow for entry of trash during a storm event. • Replace Filterra® grates correctly using appropriate lifting or moving tools, taking care not to damage the plant. 5. Plant health evaluation and pruning or replacement as necessary • Examine the plant’s health and replace if dead. • Prune as necessary to encourage growth in the correct directions 6. Clean area around Filterra® • Clean area around unit and remove all refuse to be disposed of appropriately. 7. Complete paperwork • Deliver Maintenance Report and photographs to appropriate location (normally Contech during maintenance contract period). • Some jurisdictions may require submission of maintenance reports in accordance with approvals. It is the responsibility of the Owner to comply with local regulations. Record on Maintenance Report the following: Height above Grate ________________(ft) Width at Widest Point ________________(ft) Health alive | dead Damage to Plant yes | no Plant Replaced yes | no www.ContechES.com/filterra | 800-338-1122 Maintenance Checklist Drainage System Failure Problem Conditions to Check Condition that Should Exist Actions Inlet Excessive sediment or trash accumulation. Accumulated sediments or trash impair free flow of water into Filterra. Inlet should be free of obstructions allowing free distributed flow of water into Filterra. Sediments and/or trash should be removed. Mulch Cover Trash and floatable debris accumulation. Excessive trash and/or debris accumulation. Minimal trash or other debris on mulch cover. Trash and debris should be removed and mulch cover raked level. Ensure bark nugget mulch is not used. Mulch Cover “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. Recommend contact manufacturer and replace mulch as a minimum. Vegetation Plants not growing or in poor condition. Soil/mulch too wet, evidence of spill. Incorrect plant selection. Pest infestation. Vandalism to plants. Plants should be healthy and pest free. Contact manufacturer for advice. Vegetation Plant growth excessive. Plants should be appropriate to the species and location of Filterra. Trim/prune plants in accordance with typical landscaping and safety needs. Structure Structure has visible cracks. Cracks wider than 1/2 inch or evidence of soil particles entering the structure through the cracks. Vault should be repaired. Maintenance is ideally to be performed twice annually. ENGINEERED SOLUTIONS © 2015 Contech Engineered Solutions LLC Revised 6/22/2015