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HomeMy WebLinkAboutTIR-4362TECHNICAL INFORMATION REPORT FOR Kite Realty Group at 17803 & 17805 108TH AVE SE Renton, WA 98055 April 14, 2025 PREPARED FOR: Kite Realty Group 17803 & 17805 108TH AVE SE RENTON, WA, 98055 PREPARED BY: KIMLEY-HORN 1201 3RD AVE, SUITE 2800 SEATTLE, WA 98101 OFFICE: (206) 607-2600 KHA PROJECT #: 090191000 ©Kimley-Horn and Associates, Inc., 2025 DEVELOPMENT ENGINEERING HHuynh 07/22/2025 Surface Water Enginering jfarah 07/23/2025 (This sheet was intentionally left blank) Disclosure Statement: This document, together with the concepts and designs presented herein, as an instrument of service, is intended only for the specific purpose and client for which it was prepared. Reuse of and improper reliance on this document without written authorization and adaptation by Kimley-Horn and Associates, Inc. shall be without liability to Kimley-Horn and Associates, Inc. PREPARED BY: KIMLEY-HORN AND ASSOCIATES, INC. 1201 THIRD AVENUE, SUITE 2800 SEATTLE, WA 98101 Chris Miller, PE (WA) 03/06/2025 Taylor Bellefeuille 2024/03/182024/04/14 17803 & 17805 108th Ave SE – Kite Realty Group Kimley-Horn and Associates, Inc. Renton, WA Preliminary Stormwater Report April 11, 2025 Page 1 Table of Contents TECHNICAL INFORMATION REPORT WORKSHEET ............................................................................ 3 SECTION A – PROJECT OVERVIEW ..................................................................................................... 4 A.1 SITE LOCATION .................................................................................................................... 4 A.2 EXISTING SITE CONDITIONS ............................................................................................... 4 A.3 EXISTING ON-SITE STORMWATER SYSTEMS .................................................................... 4 A.4 ADJACENT PROPERTIES ..................................................................................................... 4 A.5 PROJECT IMPACT ON ADJACENT AREAS .......................................................................... 4 A.6 PROPOSED SITE CONDITIONS ............................................................................................ 5 SECTION B – CORE REQUIREMENTS .................................................................................................. 5 B.1 APPLICABLE CORE REQUIREMENTS ......................................................................................... 5 TABLE 1 – LAND DISTURBING ACTIVITY ....................................................................................... 5 CR#1: DISCHARGE AT THE NATURAL LOCATION ........................................................................ 5 CR#2: OFFSITE ANALYSIS ............................................................................................................. 6 CR#3: FLOW CONTROL FACILITIES .............................................................................................. 6 CR#4: CONVEYANCE SYSTEM ...................................................................................................... 6 CR#5: CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN (CSWPPP) ............... 6 CR#6: MAINTENANCE AND OPERATIONS..................................................................................... 6 CR#7: FINANCIAL GUARANTEES AND LIABILITY .......................................................................... 6 CR#8: WATER QUALITY FACILITIES .............................................................................................. 6 CR#9: ON-SITE BMPS ..................................................................................................................... 7 B.2 APPLICABLE SPECIAL REQUIREMENTS .................................................................................... 8 SR#1: OTHER ADOPTED AREA-SPECIFIC REQUIREMENTS........................................................ 8 SR#2: FLOOD HAZARD AREA DELINEATION ................................................................................ 8 SR#3: FLOOD PROTECTION FACILITIES ....................................................................................... 9 SR#4: SOURCE CONTROLS ........................................................................................................... 9 SR#5: OIL CONTROL ...................................................................................................................... 9 SR#6: AQUIFER PROTECTION AREA ............................................................................................ 9 SECTION C – PRELIMINARY SOILS EVALUATION ............................................................................... 9 SECTION D – CONVEYANCE SYSTEM (CR#4) ..................................................................................... 9 SECTION E – OTHER PERMITS ............................................................................................................ 9 SECTION F – APPENDICES ................................................................................................................... 9 APPENDIX A: MAPS ........................................................................................................................... 9 1.VICINITY MAP ...................................................................................................................... 10 17803 & 17805 108th Ave SE – Kite Realty Group Kimley-Horn and Associates, Inc. Renton, WA Preliminary Stormwater Report April 11, 2025 Page 2 2. FLOOD INSURANCE RATE MAP ......................................................................................... 11 3. PRE-DEVELOPMENT DRAINAGE AREA MAP .................................................................... 12 4. POST-DEVELOPMENT DRAINAGE AREA MAP .................................................................. 13 5. PROPOSED DRAINAGE PLAN ............................................................................................ 14 6. AQUIFER PROTECTION AREA MAP ................................................................................... 15 APPENDIX B: ADDITIONAL PLANS AND REPORTS ........................................................................ 16 1. GEOTECHNICAL ENGINEERING REPORT ......................................................................... 16 2. NRCS WEB SOIL SURVEY .................................................................................................. 17 3. SWPPP ................................................................................................................................ 18 4. MAINTENANCE AND OPERATIONS MANUAL .................................................................... 19 5. BOND QUANTITY WORKSHEET ......................................................................................... 20 17803 & 17805 108th Ave SE – Kite Realty Group Kimley-Horn and Associates, Inc. Renton, WA Preliminary Stormwater Report April 11, 2025 Page 3 TECHNICAL INFORMATION REPORT WORKSHEET CITY OF RENTON SURFACE WATER DESIGN MANUAL 2017 City of Renton Surface Water Design Manual 12/12/2016 8-A-1 REFERENCE 8-A TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 1 PROJECT OWNER AND PROJECT ENGINEER Part 2 PROJECT LOCATION AND DESCRIPTION Project Owner _Tony Halsey_ Phone _317-713-5653_ Address _30 S Meridian St, Suite 110_ _Indianapolis, IN 46204_ Project Engineer _Taylor Bellefeuille_ Company _Kimley-Horn_ Phone _317-713-5653_ Project Name _Chipotle 108th Ave SE_ CED Permit # ________________________ Location Township _23_______________ Range ___05_______________ Section __32_______________ Site Address _17803 & 17805 108th Ave SE_ _Renton, WA 98055_ Part 3 TYPE OF PERMIT APPLICATION Part 4 OTHER REVIEWS AND PERMITS  Land Use (e.g., Subdivision / Short Subd.)  Building (e.g., M/F / Commercial / SFR)  Grading  Right-of-Way Use  Other _______________________  DFW HPA  COE 404  DOE Dam Safety  FEMA Floodplain  COE Wetlands  Other ________  Shoreline Management  Structural Rockery/Vault/_____  ESA Section 7 Part 5 PLAN AND REPORT INFORMATION Technical Information Report Site Improvement Plan (Engr. Plans) Type of Drainage Review (check one): Date (include revision dates): Date of Final: ____________________________________ __________________ Plan Type (check one): Date (include revision dates): Date of Final:  Full  Modified  Simplified ____________________________________ __________________  Full  Targeted  Simplified  Large Project  Directed _________________ REFERENCE 8: PLAN REVIEW FORMS AND WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 12/12/2016 2017 City of Renton Surface Water Design Manual 8-A-2 Part 6 SWDM ADJUSTMENT APPROVALS Type (circle one): Standard / Blanket Description: (include conditions in TIR Section 2) ____________________________________________________________________________________ ____________________________________________________________________________________ ____________________________________________________________________________________ Approved Adjustment No. ______________________ Date of Approval: _______________________ Part 7 MONITORING REQUIREMENTS Monitoring Required: Yes / No Start Date: _______________________ Completion Date: _______________________ Describe: _________________________________ _________________________________________ _________________________________________ Re: SWDM Adjustment No. ________________ Part 8 SITE COMMUNITY AND DRAINAGE BASIN Community Plan: _Benson_ Special District Overlays: _N/A_ Drainage Basin: _Panther Creek_ Stormwater Requirements: _N/A_ Part 9 ONSITE AND ADJACENT SENSITIVE AREAS  River/Stream ________________________  Lake ______________________________  Wetlands ____________________________  Closed Depression ____________________  Floodplain ___________________________  Other _None_  Steep Slope __________________________  Erosion Hazard _______________________  Landslide Hazard ______________________  Coal Mine Hazard ______________________  Seismic Hazard _______________________  Habitat Protection ______________________  _____________________________________ REFERENCE 8-A: TECHNICAL INFORMATION REPORT (TIR) WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2017 City of Renton Surface Water Design Manual 12/12/2016 Ref 8-A-3 Part 10 SOILS Soil Type _Alderwood Gravelly Sandy Loam_ Slopes _8-15%_ Erosion Potential _Very low infiltration rate_ _(Ksat = 0.00% - 0.06%)_  High Groundwater Table (within 5 feet)  Other ________________________________  Sole Source Aquifer  Seeps/Springs  Additional Sheets Attached Part 11 DRAINAGE DESIGN LIMITATIONS REFERENCE  Core 2 – Offsite Analysis_________________  Sensitive/Critical Areas__________________  SEPA________________________________  LID Infeasibility________________________  Other________________________________  _Not Applicable_ 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) Site property area highlighted in Appendix A Core Requirements (all 8 apply): Discharge at Natural Location Number of Natural Discharge Locations: 1 Offsite Analysis Level: 1 / 2 / 3 dated:__N/A_____________ Flow Control (include facility summary sheet) Standard: __N/A (Basic Exemption per Sec. 1.2.3 of the SWDM)_ or Exemption Number: ____________ On-site BMPs: _Native Soil Retention_____________ Conveyance System Spill containment located at: ___N/A_______________________ Erosion and Sediment Control / Construction Stormwater Pollution Prevention CSWPP/CESCL/ESC Site Supervisor: __tbd________________ Contact Phone: _________________________ After Hours Phone: _________________________ REFERENCE 8: PLAN REVIEW FORMS AND WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 12/12/2016 2017 City of Renton Surface Water Design Manual 8-A-4 Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet per Threshold Discharge Area) Maintenance and Operation Responsibility (circle one): Private / Public If Private, Maintenance Log Required: Yes / No Financial Guarantees and Liability Provided: Yes / No Water Quality (include facility summary sheet) Type (circle one): Basic / Sens. Lake / Enhanced Basic / Bog or Exemption No. ___N/A_________________ Special Requirements (as applicable): Area Specific Drainage Requirements Type: SDO / MDP / BP / Shared Fac. / None Name: ________________________ Floodplain/Floodway Delineation Type (circle one): Major / Minor / Exemption / None 100-year Base Flood Elevation (or range): _______________ Datum: Flood Protection Facilities Describe: N/A Source Control (commercial / industrial land use) Describe land use: N/A Describe any structural controls: N/A Oil Control High-Use Site: Yes / No Treatment BMP: __N/A____________________________ Maintenance Agreement: Yes / No with whom? __N/A________________________________ Other Drainage Structures Describe: REFERENCE 8-A: TECHNICAL INFORMATION REPORT (TIR) WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2017 City of Renton Surface Water Design Manual 12/12/2016 Ref 8-A-5 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  Control Pollutants  Protect Existing and Proposed BMPs/Facilities  Maintain Protective BMPs / Manage Project MINIMUM ESC REQUIREMENTS AFTER CONSTRUCTION  Stabilize exposed surfaces  Remove and restore Temporary ESC Facilities  Clean and remove all silt and debris, ensure operation of Permanent BMPs/Facilities, restore operation of BMPs/Facilities as necessary  Flag limits of sensitive areas 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  On-site BMPs  Other ________________ ________________ ________________ ________________ ________________ _Catch Basins_  Vegetated Flowpath  Wetpool  Filtration  Oil Control  Spill Control  On-site BMPs  Other ________________ ________________ ________________ ________________ ________________ ________________ _Not Applicable____ Part 15 EASEMENTS/TRACTS Part 16 STRUCTURAL ANALYSIS  Drainage Easement  Covenant  Native Growth Protection Covenant  Tract  Other _Not Applicable_  Cast in Place Vault  Retaining Wall  Rockery > 4′ High  Structural on Steep Slope  Other _Not Applicable_ REFERENCE 8: PLAN REVIEW FORMS AND WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 12/12/2016 2017 City of Renton Surface Water Design Manual 8-A-6 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 2025/04/14 17803 & 17805 108th Ave SE – Kite Realty Group Kimley-Horn and Associates, Inc. Renton, WA Preliminary Stormwater Report April 11, 2025 Page 4 SECTION A – PROJECT OVERVIEW A.1 SITE LOCATION The 0.85-acre site (on a 3.62-acre parcel) is located along 108th Ave SE between SE Carr Rd and SE 180th St in the City of Renton, King County, Washington. Legal description for property was obtained from king county accessors database. No easements, restrictions, or reservations of record which would be disclosed by title report are shown. The legal description of the site is as follows: Lot Y of King County boundary line adjustment No. L07L0040, according to that boundary line adjustment recorded August 22, 2007 under recording No. 20070822900006, in King County, Washington. A.2 EXISTING SITE CONDITIONS The site contains an existing building of approximately 3,000 square feet. The site is bounded by 108th Avenue to the east, a parking lot to the west, a parking lot entryway to the north, and an adjacent retail development to the south. The entryway separates the north parcel, an onsite landscape buffer runs along the ROW to the east, and a landscape buffer also separates the adjacent parcel to the south. However, the existing site is relatively flat, decreasing in elevation from east to west. The landscape buffers along the north, east, and southern frontages are relatively steep. The portion of the site proposed to be improved contains existing asphalt pavement across the site with some existing concrete beneath an existing drive through structure. The rest of the remaining site is landscaping with a rock wall supporting the existing landscaping along the northern and southern sides of the site, and the existing site is approximately 80% impervious. Refer to Appendix A for the Pre-Development Drainage Area Map for additional information. A.3 EXISTING ON-SITE STORMWATER SYSTEMS There are existing drainage structures on-site that convey stormwater runoff to the public storm main in 105th Place SE. Stormwater runoff is collected by these existing structures and carried off-site. Drainage from the roof is not visibly tightlined to the existing stormwater infrastructure and the survey didn’t capture any roof leaders. Thus, it is assumed that the runoff captured from the roof splashes at grade. Refer to the Pre-Development Drainage Area Map in Appendix A for additional information. A.4 ADJACENT PROPERTIES The site is lower than the property to the south. However, grading on the parcel to the south keeps runoff away from subject property by conveying flow into their developed storm infrastructure, minimizing impacts to our drainage calculations. The drainage patterns and directions will be maintained in the post- development condition. Refer to the Drainage Area Maps in Appendix A for additional information. A.5 PROJECT IMPACT ON ADJACENT AREAS The stormwater design intent of the project is to produce minimal impact on the adjacent properties and public drainage system. The project does not proposing any new stormwater infrastructure, so any additional impacts on adjacent areas will be minimal as the scope of work is limited. The project results in a net increase in pervious cover and as such will have a positive impact on the existing drainage system. 17803 & 17805 108th Ave SE – Kite Realty Group Kimley-Horn and Associates, Inc. Renton, WA Preliminary Stormwater Report April 11, 2025 Page 5 A.6 PROPOSED SITE CONDITIONS The project will redevelop a small site retail development, renovating the existing building and drive through structures onsite. There will also be additional frontage improvements along 108th St SE to modify the existing sidewalk with additional proposed landscaping and demolition of existing utility infrastructure as needed with the proper replacement in-kind. Site stormwater runoff will be captured on- site by the existing catch basins and will be conveyed to the public storm main in 105th Place SE. The proposed project will disturb approximately 0.15 acres, and the developed site is approximately 75% impervious. See Table 1 – Land Disturbing Activity below for additional information. One at grade curb ramp is proposed to be installed northwest of the existing building, a service ramp is proposed to be installed southeast of the existing building, and the pavement material will be replaced in-kind. This project results in less than 5000 sqft of new plus replaced hard surface area and as such is flow control exempt. Refer to Appendix A for the Post-Development Drainage Area Map for additional information. SECTION B – CORE REQUIREMENTS B.1 APPLICABLE CORE REQUIREMENTS As the site has an existing impervious surface coverage of more than 35%, the proposed project is considered a redevelopment project. The project is not a single-family project, will create more than 2,000 square feet of hard surfaces, and will disturb more than 7,000 square feet of land. Therefore, the project is subject to Full Drainage Review per page 1-14 of the 2022 City of Renton Surface Water Design Manual (SWDM)and must apply some of Core Requirements (CRs) #1 through #9 and Special Requirements (SRs) #1 through #5. See below for list of the Core and Special Requirements and the applicability of each to the project. See Table 1 below for a summary of Land Disturbing Activity for the project. TABLE 1 – LAND DISTURBING ACTIVITY EXISTING IMPERVIOUS SURFACE 0.66 AC EXISTING PERVIOUS SURFACE 0.19 AC PROPOSED IMPERVIOUS SURFACE 0.65 AC PROPOSED PERVIOUS SURFACE 0.20 AC NEW + REPLACED IMPERVIOUS SURFACE 0.11 AC TOTAL LAND DISTURBANCE 0.15 AC UNDISTURBED AREA 0.70 AC CR#1: DISCHARGE AT THE NATURAL LOCATION The project is required to adhere to CR#1, which states that, “All storm water runoff and surface water from a project must be discharged at the natural location so as not to be diverted onto or away from downstream properties. The manner in which stormwater runoff and surface water are discharged from the project site must not create a significant adverse impact to downhill properties or drainage facilities.” The existing site drainage patterns will be maintained to collect stormwater runoff in the post-developed condition. No adverse impacts to downstream drainage facilities are anticipated. 17803 & 17805 108th Ave SE – Kite Realty Group Kimley-Horn and Associates, Inc. Renton, WA Preliminary Stormwater Report April 11, 2025 Page 6 CR#2: OFFSITE ANALYSIS All proposed projects must adhere to CR#2, which states that “projects must submit an offsite analysis report that assesses potential offsite drainage and water quality impacts associated with development of the project site, and that proposes appropriate mitigation of those impacts.” This project is proposing no modifications to the stormwater system. There are no proposed increases in flows and existing drainage patterns have been matched. There are no downstream flow complications that the applicant is aware of. As such, a downstream analysis has not been provided for this project. CR#3: FLOW CONTROL FACILITIES As the project proposes less than 5,000 square feet of new plus replaced impervious surface, the project is not required to adhere to CR#3. For reference, CR#3 states that, “All proposed projects, including redevelopment projects, must provide on-site flow control facilities to mitigate the impacts of storm and surface water runoff.” CR#4: CONVEYANCE SYSTEM The project is not required to adhere to CR#4 as the proposed improvements are maintaining the existing flow characteristics on site. For reference, CR#4 states that, “All engineered conveyance system elements for proposed projects must be analyzed, designed, and constructed to provide a minimum level of protection against overtopping, flooding, erosion, and structural failure.” Please refer to the Proposed Drainage Area Map located in Appendix A for more information. CR#5: CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN (CSWPPP) The project shall comply with CR#5. Temporary erosion control plans have been developed for this project site complying with City of Renton and Washington State Department of Ecology requirements. A Construction Stormwater Pollution Prevention Plan (CSWPPP) has been included with the Final Stormwater Report. CR#6: MAINTENANCE AND OPERATIONS The project is required to adhere to CR#6, which states, “maintenance and operation of all drainage facilities is the responsibility of the applicant or property owner, except those facilities for which the City assumes maintenance and operation,” An operations and maintenance manual has been included in the Final Stormwater Report. See Appendix B.4. CR#7: FINANCIAL GUARANTEES AND LIABILITY The project is required to adhere to CR#7, which states, “In accordance with Renton Municipal Code (RMC) 4-6-030, Community and Economic Development (CED) shall require all persons constructing any surface water facilities (including flow control/water quality facilities, conveyance systems, erosion control, and road drainage), to post with the City of Renton a bond, assignment of funds or certified check”. This project does not propose any flow control water quality nor conveyance systems. It does propose erosion control and a such will adhere to CR#7. See Appendix B.5. CR#8: WATER QUALITY FACILITIES As a redevelopment project that proposes less than 5,000 square feet of new and replaced impervious surface as well as less than ¾ acre of new pollution generating pervious surfaces, the project is not required to adhere to CR#8. For reference, CR#8 states that “All proposed projects, including redevelopment projects, must provide water quality (WQ) facilities to treat the runoff from those new and replaced pollution-generating impervious surfaces and new pollution-generating pervious surfaces targeted for treatment.” 17803 & 17805 108th Ave SE – Kite Realty Group Kimley-Horn and Associates, Inc. Renton, WA Preliminary Stormwater Report April 11, 2025 Page 7 CR#9: ON-SITE BMPS The project proposes more than 2,000 square feet of new and replaced impervious surface and more than 7,000 square feet of land disturbing activity will occur, therefore this project must abide by CR#9. For reference, CR#9 states that “All proposed projects, including redevelopment projects, must provide on- site BMPs to mitigate the impacts of storm and surface water runoff generated by new impervious surface, new pervious surface, existing impervious surfaces, and replaced impervious surface targeted for mitigation.” As the proposed project site is larger than 22,000 square feet, per Section 1.2.9.2.2 of the SWDM the project must apply on-site BMPs as specified in the requirements of that section and outlined below: C.2.1 – FULL DISPERSION: Full Dispersion is infeasible on our site given that the improvements on the eastern frontage above the proposed retaining wall will result in slopes greater than 15%, fulfilling the infeasibility criteria listed for this section in the SWDM. C2.2 – FULL INFILTRATION: Full infiltration is infeasible as per the NRCS web soil survey and supporting information from the geotechnical report, the infiltration rate is low on site. This doesn’t fulfill the requirement to “fully and reliably infiltrate runoff into the ground” as specified in this section. C2.3 – LIMITED INFILTRATION: Limited Infiltration is infeasible as well given the soil makeup referenced in the NRCS web soil survey and the geotechnical report as both sources indicate low infiltration rates for the native soil on site. C2.4 – BASIC DISPERSION: Basic Dispersion is infeasible as our site is unable to properly incorporate a vegetated flow path given the minimal site improvements and space available on site for such a path. C2.5 – FARMLAND DISPERSION: This BMP does not apply to the City of Renton, and thus our site is exempt from needing to apply this BMP. C2.6 – BIORETENTION: Bioretention is infeasible on our site due to the infeasibility criterion #5 which states that bioretention is deemed impractical “where there is a lack of usable space for bioretention facilities at re-development sites, or where there is insufficient space within the existing public right-of-way on public road projects”. Given the limited scope and space available on the site, this project falls into this criterion and is thus exempt. C2.7 – PERMEABLE PAVEMENT: Permeable Pavement is infeasible to incorporate on site given the fact that installation of such pavement would occur “within 50 feet from the top of slopes that are greater than 20%”. Given that the proposed 17803 & 17805 108th Ave SE – Kite Realty Group Kimley-Horn and Associates, Inc. Renton, WA Preliminary Stormwater Report April 11, 2025 Page 8 slopes on the eastern frontage have slopes in exceedance of 20%, this project fulfills criterion 12, exempting the project from the usage of permeable pavement. C2.8 – RAINWATER HARVESTING: Rainwater Harvesting does not apply to this project as there are no changes to the existing storm infrastructure on site. C2.9 – Reduced Impervious Surface Credit: The Reduced Impervious Credit is not applicable to this project. C2.10 – NATIVE GROWTH RETENTION CREDIT: The Native Growth Retention Credit is not applicable to this project given the proposed improvements. C2.11 – PERFORATED PIPE CONNECTION: Perforated Pipe Connections are infeasible because the soil on site has a low infiltration rate. C2.12 – RAIN GARDENS: Rain Gardens are infeasible on site citing the same criterion listed in section C2.6 mentioned earlier. The City of Renton SWDM dictates that Rain Gardens apply to these same infeasibility criteria. C2.13 – SOIL AMENDMENT: Native soil retention and reuse will be used on site to the maximum extent feasible. C2.14 – TREE RETENTION CREDIT: Existing trees on site will be protected in place and retained to the maximum extent feasible. There are no existing trees within the project limits of disturbance that are proposed to be removed. C2.15 – VEGETATED ROOFS: Vegetated Roofs do not apply to our project as the existing building has minimal renovations to the existing structure, preserving the existing runoff characteristics. B.2 APPLICABLE SPECIAL REQUIREMENTS SR#1: OTHER ADOPTED AREA-SPECIFIC REQUIREMENTS Copies of all adopted basin plans, Salmon Conservation Plans (SCPs), Hazard Mitigation Plans, and Lake Management Plans have been obtained from the City of Renton. None of the exhibits obtained dictate any specific requirements for the site and the site is thus exempt from further hazard area mitigation. SR#2: FLOOD HAZARD AREA DELINEATION The proposed project is not within or adjacent to a flood hazard area, so SR#2 is not applicable to the project. See Appendix A for the project site Flood Map. 17803 & 17805 108th Ave SE – Kite Realty Group Kimley-Horn and Associates, Inc. Renton, WA Preliminary Stormwater Report April 11, 2025 Page 9 SR#3: FLOOD PROTECTION FACILITIES The proposed project is not a flood protection facility and doesn’t require additional flood mitigation. Thus, SR#3 is not applicable to this site. SR#4: SOURCE CONTROLS The project is not a high use site nor a commercial building and does not require a commercial site development permit and is thus exempt from SR#4. For reference, SR#4 states that “When applicable per the Stormwater Pollution Prevention Manual, structural source control measures, such as car wash pads or dumpster area roofing, shall be applied to the entire site containing the proposed project, not just the project site.” Additionally, the project will generate 102 new daily trips but is under the high use threshold (100 trips/1000 square feet of building area) as we have 3,000 square feet of building area which rounds out to 34 daily trips/1000 square feet of building area. This site is not considered a high use site. SR#5: OIL CONTROL The project is not considered a high use site. Thus, the project is not required to adhere to SR#5. For reference, SR#5 states that “Projects proposing to develop or redevelop a high-use site must provide oil controls in addition to any other water quality controls required by this manual.” This project is not a high use site, so SR#5 is not applicable. SR#6: AQUIFER PROTECTION AREA The project site is not within an Aquifer Protection Area (APA), so SR#6 is not applicable to the project. Refer to Appendix A for the APA Map. SECTION C – PRELIMINARY SOILS EVALUATION A soil survey retrieved from the NRCS Web Soil Survey has been included with this report in addition to a geotechnical report as well. Generally, the soils on site consist of a singular layer of Alderwood gravelly sandy loam with slopes ranging from 8 to 15 percent according to the NRCS survey. Conversely, the geotechnical report soil borings indicate a large presence of Vashon till which is described as “an unsorted deposit (diamict) of clay, silt, sand and gravel that has been glacially transported and deposited. However, in both cases, the soil infiltration rate is low, making infiltration infeasible as described earlier. It is also good to note that there was relatively high drainage seepage present in the soil boring labeled “#3”, so it is important to be weary of this item. Refer to Appendix C for both reports. SECTION D – CONVEYANCE SYSTEM (CR#4) Per Section 1.2.4.2 of the SWDM, existing stormwater pipe systems must be analyzed and shown to have sufficient capacity to convey and contain (at minimum) the 25-year peak flow assuming developed conditions for onsite tributary areas and existing conditions for any offsite tributary areas. This project is not required to abide by this standard given that the proposed improvements or modifications to the existing stormwater system are maintain existing on-site flow characteristics as aforementioned. SECTION E – OTHER PERMITS Construction of this project and its stormwater facilities will require the following additional permits: Construction Stormwater General Permit – Washington Department of Ecology Status: Not yet submitted SECTION F – APPENDICES APPENDIX A: MAPS 17803 & 17805 108th Ave SE – Kite Realty Group Kimley-Horn and Associates, Inc. Renton, WA Preliminary Stormwater Report April 11, 2025 Page 10 SECTION F – APPENDICES APPENDIX A: MAPS 1. VICINITY MAP IN COMPLIANCE WITH CITY OF RENTON STANDARDS PROJECT SITE NORTH 10 8 T H A V E S E VICINITY MAP OF SITE 17803 & 17805 108th Ave SE – Kite Realty Group Kimley-Horn and Associates, Inc. Renton, WA Preliminary Stormwater Report April 11, 2025 Page 11 2. FLOOD INSURANCE RATE MAP SITE LOCATION 17803 & 17805 108th Ave SE – Kite Realty Group Kimley-Horn and Associates, Inc. Renton, WA Preliminary Stormwater Report April 11, 2025 Page 12 3. PRE-DEVELOPMENT DRAINAGE AREA MAP IN COMPLIANCE WITH CITY OF RENTON STANDARDS NORTH PR E L I M I N A R Y - N O T F O R C O N S T R U C T I O N 17803 & 17805 108th Ave SE – Kite Realty Group Kimley-Horn and Associates, Inc. Renton, WA Preliminary Stormwater Report April 11, 2025 Page 13 4. POST-DEVELOPMENT DRAINAGE AREA MAP IN COMPLIANCE WITH CITY OF RENTON STANDARDS NORTH PR E L I M I N A R Y - N O T F O R C O N S T R U C T I O N 17803 & 17805 108th Ave SE – Kite Realty Group Kimley-Horn and Associates, Inc. Renton, WA Preliminary Stormwater Report April 11, 2025 Page 14 5. PROPOSED DRAINAGE PLAN 399.32 ± ME 399.33 SW 399.57 ± ME 399.57 SW 399.40 SW 399.45 SW 390.13 P 390.15 P 390.49 P 390.45 P 391.35 ± ME391.27 ± ME 389.42 ± ME 389.84 ± ME 389.66 ± ME 389.94 ± ME389.98 ± ME 389.96 ± ME 389.84 ± ME 389.77 ± ME 389.52 ± ME 389.11 ± ME 389.00 ± ME 389.51 ± ME 389.10 ± ME 389.42 ± ME 384.97 ± ME 384.84 ± ME 386.76 ± ME 386.73 ± ME 385.57 ± ME 388.05 ± ME 389.77 TC 389.27 BC 389.69 TC 389.19 BC 389.74 TC 389.24 BC 390.46 TC 389.96 BC 390.32 TC 389.82 BC 390.36 SW 390.32 SW 386.96 TC 386.46 BC385.71 TC 385.21 BC 387.08 TC 386.58 BC 390.27 TC 389.77 BC390.02 TC 389.52 BC 390.79 ± ME 390.72 ± ME 388.89 ± ME 388.24 ± ME 388.07 ± ME 388.15 ± ME 388.51 ± ME 389.40 ± ME 388.74 SW 388.71 SW 388.92 TC 388.42 BC 388.69 ± ME 388.65 ± ME 388.46 ± ME 390.36 TC 389.86 BC 391.05 TC 390.55 BC 389.07 TC 388.57 BC388.59 ± ME 390.33 TC 389.83 BC 385.58 TC 385.08 BC 386.93 TC 386.43 BC 385.59 TC 385.09 BC 389.59 TC 389.09 BC 390.44 TC 389.94 BC 388.94 TC 388.44 BC 388.75 TC 388.25 BC 390.39 TC 389.89 BC 390.89 TC 390.39 BC 390.48 TC 389.98 BC 390.27 TC 389.77 BC 389.68 TC 389.18 BC 389.63 TC 389.13 BC 399.53 ± ME 399.29 ± ME 388.29 ± ME 388.64 TC 388.14 BC 390.22 TC 389.72 BC SEE ADA DETAIL 390.16 TC 389.66 BC 392.54 TW 389.22 BW PRIVATE ROAD BEND RIM: 389.53 SS CLEANOUT 2 RIM: 389.93 SS CLEANOUT 1 RIM: 390.16 390.27 FFE 10 8 T H A V E S E (EX.) CB RIM: 389.19 RAISE CB TO GRADE INV (EX): 385.22 INV: 385.32 SEE ENTRY DETAIL 389.71 TC 389.21 BC CB-01 RIM: 388.12 (EX) INV: 386.41 (EX) INV: 385.62 (EX) INV: 385.09 (EX) INV: 384.89 INV: 378.40 389.67 ± ME 388.70 ± ME WYE RIM: 389.63 FFE: 390.27 390.52 BW 390.00 BW 392.50 TW 389.73 BW 392.38 TW 392.72 TW 399.36 SW 392.51 TW390.70 BW 396.70 TW 393.29 BW 396.70 TW 393.20 BW 399.70 ± ME 392.72 TW 391.88 BW 391.51 ± ME CONNECT TO ROCKERY WALL DRAIN INV: 386.00 30 LF OF 6" PVC CB-O2 RIM: 396.84 INV: 378.05 (EX) INV: 377.95 35 LF OF 12" PVC PIPE ENCASEMENT PER COR STD PLAN 412 389.40 ± ME 389.31 ± ME 389.98 ± ME 389.88 ± ME 389.19 ± ME 389.08 ± ME 389.70 ± ME 389.61 ± ME 389.46 ± ME 389.45 ± ME 389.49 ± ME 389.60 ± ME 390.27 FFE390.18 TC 389.68 BC 390.20 TC 389.70 BC 390.21 TC 389.71 BC 390.23 SW 390.23 SW 389.76 SW 390.27 TC 389.77 BC 389.40 ± ME 389.46 ± ME 388.37 ± ME 388.41 ± ME 388.47 ± ME 389.41 TC 388.91 BC 389.23 TC 388.73 BC 388.41 ± ME 389.50 P 389.74 P 390.27 FFE 389.71 TC 389.21 BC 388.93 LP 389.50 P 389.29 SW 389.64 SW 390.01 SW 389.87 SW FFE: 390.27 388.95 P 389.55 TC 389.05 BC 390.05 TC 389.55 BC 390.24 TC 389.74 BC IN COMPLIANCE WITH CITY OF RENTON STANDARDS GRADING & DRAINAGE NOTES 1.ADA ACCESSIBLE SPACES ARE DESIGNED TO HAVE A MAXIMUM SLOPE OF 2.0% IN ANY DIRECTION. 2.THE PROPOSED ACCESSIBLE PATH SIDEWALKS AROUND THE BUILDING AND ALONG THE PROPERTY FRONTAGES SHALL HAVE A MAXIMUM 2% CROSS SLOPE AND 5% LONGITUDINAL SLOPE. 3.CONTRACTOR TO VERIFY DEPTH OF EXISTING UNDERGROUND UTILITIES PRIOR TO PLACEMENT OF ANY PAVEMENT AND NOTIFY KIMLEY-HORN IF ANY CONFLICTS EXIST. 4.TOP OF CURB SHALL BE 6" ABOVE PAVEMENT ELEVATION UNLESS OTHERWISE SPECIFIED. PROPERTY LINE EXISTING CONTOUR PROPOSED MAJOR CONTOUR PROPOSED MINOR CONTOUR PROPOSED SPOT ELEVATION GRADING LEGEND XXX.XX GR A D I N G A N D D R A I N A G E P L A N NORTH C5.0 6/5/25 7 GRADING AND DRAINAGE PLAN CHIPOTLE 108TH AVE SE ADA DETAILED GRADING NORTH NORTH ENTRY DETAILED GRADING SPOT ELEVATION LEGEND TC TOP OF CURB HP HIGH POINT ME MATCH EXISTING P TOP OF PAVING BW BOTTOM OF WALL BC BOTTOM OF CURB LP LOW POINT SW SIDEWALK TW TOP OF WALL 15 17803 & 17805 108th Ave SE – Kite Realty Group Kimley-Horn and Associates, Inc. Renton, WA Preliminary Stormwater Report April 11, 2025 Page 15 6. AQUIFER PROTECTION AREA MAP SITE LOCATION 17803 & 17805 108th Ave SE – Kite Realty Group Kimley-Horn and Associates, Inc. Renton, WA Preliminary Stormwater Report April 11, 2025 Page 16 APPENDIX B: ADDITIONAL PLANS AND REPORTS 1. GEOTECHNICAL ENGINEERING REPORT ________________________________________________ 3213 Eastlake Avenue East, Suite B Seattle, WA 98102 (206) 262-0370 | pangeoinc.com Geotechnical & Earthquake Engineering Consultants January 13, 2025 Project No. 24-497 Tony Halsey, P.E. Kite Realty Group 30 South Meridian Street, Suite 1100 Indianapolis, IN 46204 Subject: Limited Geotechnical Report Proposed Retaining Wall 17803 108th Avenue SE, Renton, WA 98055 Dear Tony: As requested, PanGEO, Inc. completed a geotechnical study to support the design and permitting of the proposed retaining wall at the above-referenced site in Renton, Washington. Our service scope included reviewing readily available geologic and geotechnical data in the vicinity of the project, conducting a reconnaissance of the site, performing limited subsurface investigations, and formulating the conclusions and recommendations presented in this report. Our work was completed in accordance with our proposal for geotechnical engineering services, dated December 20, 2024, and the professional services agreement with you, dated 1/3/2025. SITE & PROJECT DESCRIPTION The subject site is located at 17803 108th Avenue SE, in Renton, Washington, as shown on the attached Figure 1, Vicinity Map. The site is bounded by 108th Avenue SE/Benson Road South to the east, and by commercial properties to the north, west and south, anchored by the Fred Meyer retail store to the west. The project site is currently developed with a one-level at-grade structure that was formerly a Bank of America branch. The structure is surrounded with asphalt parking areas and driveways. The majority of the site is relatively flat, with the exception of the eastern margin of the site that slopes up from the parking lot at an angle of about 2H:1V to the sidewalk of 108th Avenue SE, with a vertical relief of about 12 feet. Limited Geotechnical Report – Proposed Retaining Wall 17803 108th Avenue SE, Renton, WA January 13, 2025 24-497_17803 108th ave se_renton_r_wall.docx 2 PanGEO, Inc. The specific focus of our current study is the slope on the eastern portion of the site. As part of the proposed re-development of the property, we understand that the City of Renton is requiring street improvements along the frontage of the subject property, which includes the addition of a planter strip and widened sidewalk which will extend over the existing slope on the east side of the subject site. As such, a new retaining wall will need to be incorporated into the project to support the new sidewalk, and/or retain the fill soils placed to support the new sidewalk. Plates 1 and 2 below depict current site conditions. Plate 1. Looking north-northeast at the slope on the east side of the property where the proposed retaining wall will be constructed. A portion of the existing bank drive-through structure can be seen on the left side of the photo. Limited Geotechnical Report – Proposed Retaining Wall 17803 108th Avenue SE, Renton, WA January 13, 2025 24-497_17803 108th ave se_renton_r_wall.docx 3 PanGEO, Inc. Plate 2. Looking south along the western sidewalk of 108th Avenue SE. The proposed retaining wall will be located near the toe of the slope shown on the right side of the photo. The conclusions and recommendations outlined in this report are based on our understanding of the proposed project, which is in turn based on the project information provided to us. If the above project description is substantially different from the proposed improvements, or if the project scope changes, PanGEO should be consulted to review the recommendations contained in this study and make modifications, if needed. SUBSURFACE EXPLORATIONS Our subsurface exploration program included advancing four (4) hand borings (PG-1 to PG-4) on December 30, 2024, to explore near-surface soil conditions at the location of the proposed retaining wall and backslope. The boring locations are shown on Figure 2, Site and Exploration Plan, and were measured in the field from existing site features. Limited Geotechnical Report – Proposed Retaining Wall 17803 108th Avenue SE, Renton, WA January 13, 2025 24-497_17803 108th ave se_renton_r_wall.docx 4 PanGEO, Inc. The hand borings were advanced utilizing a post-hole digger and a 4-inch diameter hand auger to depths of up to 4½-feet below the existing ground surface. An engineer from PanGEO performed the explorations and logged the subsurface conditions encountered in the test holes. The relative density of granular soils and the relative consistency of cohesive soils were generally estimated based on the excavation resistance encountered throughout the depth of the exploration, and on the penetration resistance of the soil from a ½-inch diameter steel hand probe. After each test hole was completed, it was backfilled with excavated spoils, and the surface tamped firm. The summary hand boring logs are included in Appendix A at the end of this report. The soil samples were described using the system outlined in Appendix A, Figure A-1. GEOLOGY General geologic information for the project area was obtained by reviewing the Geologic Map of the Renton Quadrangle, King County, Washington (Mullineaux, 1965) and the Geologic Map of the Tacoma 1:100,000-scale Quadrangle, Washington (Schuster et al, 2015). Based on our review, the geologic unit in the vicinity of the site consists of Vashon till – Geologic Map Unit Qgt. Vashon till is described as consisting of an unsorted deposit (diamict) of clay, silt, sand and gravel that has been glacially transported and deposited. This soil has been directly deposited by a glacier and overridden by several thousand feet of glacial ice and is typically dense to very dense. Plate 3 on the following page depicts and excerpt from the geologic map by Schuster et at, 2015. SUBSURFACE CONDITIONS SOIL CONDITIONS Based on the conditions encountered in our test borings, the area of the proposed retaining wall is generally underlain by a relatively thin layer of undocumented fill over medium dense to dense silty and with some gravel, which we interpreted to be the mapped glacial till. A summary of the soil units encountered in the explorations is provided below, and details of the soil conditions encountered in each of the test borings can be found in Appendix A. Limited Geotechnical Report – Proposed Retaining Wall 17803 108th Avenue SE, Renton, WA January 13, 2025 24-497_17803 108th ave se_renton_r_wall.docx 5 PanGEO, Inc. Topsoil: All of the test borings encountered from about 6 to 8 inches of loose, dark brown, silty sand and sandy silt with prevalent organics which we interpreted to be topsoil. Fill: Below the organic-rich topsoil, all of the test borings encountered a relatively thin layer of fill, except boring PG-2, where no fill was encountered. The fill typically consisted of loose to medium dense, silty sand and sandy silt with trace to some gravel and scattered organic matter. In general, near the toe of the slope, the fill extended to about 2½ feet below the ground surface, while near the middle of the slope, at the location of PG-3, about two feet of fill was encountered. Plate 3 – Geology map of the area. The site is located in an area mapped as glacial till (map unit Qgt). (Schuster et al, 2015) SITE Limited Geotechnical Report – Proposed Retaining Wall 17803 108th Avenue SE, Renton, WA January 13, 2025 24-497_17803 108th ave se_renton_r_wall.docx 6 PanGEO, Inc. Drainage Gravel - At the toe of the slope, PG-1 encountered washed drainage rock at a depth from about 1 to 2½ feet below the ground surface. We infer that a drain line may have been installed at the toe of the slope to intercept groundwater seeping from the slope cut to transport the water to a suitable drainage outlet. Glacial Till: Below the topsoil in PG-2, and below the fill in all other borings, we generally encountered a medium dense to dense, silty sand with some gravel that we interpreted to be the mapped glacial till. Due to the medium dense to dense nature of this deposit, and evidence of iron-oxide staining, we inferred that the top of the glacial till deposit encountered in the test borings was weathered, and that the underlying un-weathered soils would become dense to very dense, which his typical of glacial till deposits. Our subsurface descriptions are based on the conditions encountered at the time of our exploration. Soil conditions between our exploration locations may vary from those encountered. The nature and extent of variations between our exploratory locations may not become evident until construction. If variations do appear, PanGEO should be requested to reevaluate the recommendations in this report and to modify or verify them in writing prior to proceeding with earthwork and construction. GROUNDWATER CONDITIONS At the toe of the slope, the test borings encountered groundwater seepage as shallow as 1-foot below the ground surface (see Hand Boring Log – PG-3). All borings encountered soils with iron- oxide stains, which is an indication of groundwater fluctuations within the soil layer. We interpret that the groundwater seepage encountered in PG-3, and the cause of the iron oxide staining in the other borings, is perched water that forms on top of the underlying dense glacial till during wet times of the year. We anticipate that stormwater infiltrates into the ground above the slope, becomes perched on the low permeability till, and then flows downslope to the west, following the contact of the glacial till. We anticipate that a significant amount of groundwater was accumulating at the toe of the slope during original grading of the property, which is the likely reason a drainage measure was installed at the toe of the slope to intercept and collect the groundwater seepage. It may be noted that glacial till deposits also typically contain pockets of clean sand and gravel that can also contain groundwater, which may contribute to seepage once they are excavated into. Limited Geotechnical Report – Proposed Retaining Wall 17803 108th Avenue SE, Renton, WA January 13, 2025 24-497_17803 108th ave se_renton_r_wall.docx 7 PanGEO, Inc. Groundwater levels will change depending on the season, amount of rainfall, surface water runoff, and other factors. Generally, the water level is higher and seepage rates are greater in the wetter, winter months (typically October through May). GEOTECHNICAL RECOMMENDATIONS RETAINING WALL DESIGN Due to the depth of competent bearing soils near the mid-height of the slope (about 4½ feet), in our opinion it will be more cost effective to locate the proposed retaining wall along the toe of the slope, instead of mid-height. Based on the results of our subsurface exploration program and our site reconnaissance, in our opinion a cast-in-place concrete wall located at the toe of the existing slope represents a feasible wall type at the subject site. To limit the wall height, in our opinion, a backslope no steeper than 2H:1V may be constructed behind the wall to support the new frontage improvements. We recommend that the wall be designed to stick up a minimum of 1-foot above the ground surface to account for any erosion that could occur on the backslope behind the wall. Retaining walls should be properly designed to resist the pressure exerted by the soils behind the wall, including a backslope. Proper drainage provisions should also be provided behind the walls to intercept and remove any groundwater from behind the wall. In this particular case, as described above, groundwater seepage is anticipated behind the proposed wall, and therefore adequate drainage provisions are critical, and should not be omitted during the design or construction of the wall. Our geotechnical recommendations for the design and construction of the proposed retaining wall are presented below. Footing Depth and Allowable Bearing Pressure We recommend that the wall footing bears on the undisturbed, medium dense to dense native soils which we estimate is present about 2½ feet below the toe of the slope. As such, the footing will need to be embedded about 2½ feet below the existing pavement elevation, or the soils below the footing should be over-excavated to about 2½ feet below the pavement elevation, and backfilled with properly compacted structural fill or lean-mix concrete (1.5 sack mix, minimum) up to the design footing elevation. We recommend a minimum foundation embedment of 18 inches below final exterior grade. The footings may be designed for a maximum allowable bearing pressure of Limited Geotechnical Report – Proposed Retaining Wall 17803 108th Avenue SE, Renton, WA January 13, 2025 24-497_17803 108th ave se_renton_r_wall.docx 8 PanGEO, Inc. 3,000 psf. For allowable stress design, the recommended allowable bearing pressure may be increased by 1/3 for transient conditions such as wind and seismic loadings. Lateral Earth Pressures Considering the maximum backslope of 2H:1V, the wall should be designed for an earth pressure based upon an equivalent fluid weight of 53 pcf for a wall that is allowed to yield (active condition), and 35 pcf for a wall with a level backslope. For the seismic condition and a 2H:1V wall backslope, we recommend a uniform lateral earth pressure of 15H psf (where H is the height of the below grade portion of the wall) be added to the static pressure for sizing the walls for the ultimate condition. If the wall backfill will be level, we recommend a uniform lateral earth pressure of 10H psf be added for the seismic condition. The recommended lateral pressures assume that adequate wall drainage will be incorporated into the design and construction of the walls to prevent the development of hydrostatic pressure. Lateral Resistance Lateral forces may be resisted by the combination of passive earth pressures acting against the embedded portions of the foundations and by friction acting on the base of the foundations. Passive resistance values may be determined using an equivalent fluid weight of 300 pounds per cubic foot (pcf), which assumes level ground conditions in front of the wall. This value includes a geotechnical factor of safety of at least 1.5 assuming that properly compacted structural fill will be placed adjacent to the sides of the footings. A coefficient of friction of 0.45 may be used to determine the frictional resistance at the base of the footings. This coefficient includes a geotechnical factor of safety of approximately 1.5. Wall Drainage Provisions for permanent control of subsurface water should be incorporated into the design and construction of the new walls, as groundwater seepage is expected behind the proposed wall. For walls constructed with conventional free-draining backfill, a footing drain consisting of a 4-inch diameter perforated pipe embedded in at least 12 inches of washed gravel wrapped with a geotextile fabric should be placed at the base of the new wall footing. We recommend a minimum 12-inch-wide chimney of free draining gravel be placed behind the wall. In addition, prefabricated drainage mats, such as Mirafi 6000 or equivalent, may be installed behind the walls to promote Limited Geotechnical Report – Proposed Retaining Wall 17803 108th Avenue SE, Renton, WA January 13, 2025 24-497_17803 108th ave se_renton_r_wall.docx 9 PanGEO, Inc. wall drainage. The drain can likely be connected to the same outlet as an existing drain we anticipate is located along the toe of the slope. Wall Backfill Wall backfill should consist of free draining granular soils. Imported wall backfill may consist of granular soils such as Gravel Borrow (Section 9.03.14 (1) of the 2024 WSDOT Standard Specifications) or approved equivalent. Wall backfill should be moisture conditioned to within about 3 percent of optimum moisture content, placed in loose, horizontal lifts less than 8 inches in thickness, and systematically compacted to a dense and relatively unyielding condition and to at least 95 percent of the maximum dry density, as determined using test method ASTM D 1557 (Modified Proctor). Within 5 feet of the wall, the backfill should be compacted to 90 percent of the maximum dry density. Wall Foundation Performance Total and differential settlements are anticipated to be within tolerable limits for footings designed and constructed as discussed above. Footing settlement under static loading conditions is estimated to be less than approximately 3/4 inch, and differential settlement along the wall should be less than about ½-inch. Global Stability Provided that the proposed retaining wall is founded on spread footings bearing below the fill soils on medium dense to very dense native soils at the toe of the slope, and the recommendations provided in this report are adhered to in the design and construction of the walls, the retaining walls will meet current code requirements for global stability. PERMANENT SLOPES Provided that the proposed retaining wall is backfilled with free-draining imported gravel borrow (Section 9.03.14 (1) of the 2024 WSDOT Standard Specifications) or approved equivalent, and the fill is adequately compacted as described above for wall backfill, we recommend permanent fill slopes be constructed no steeper than 2H:1V (Horizontal:Vertical). All existing topsoil should be removed from the slope before backfilling, and any existing loose/soft fill soils should be re- Limited Geotechnical Report – Proposed Retaining Wall 17803 108th Avenue SE, Renton, WA January 13, 2025 24-497_17803 108th ave se_renton_r_wall.docx 10 PanGEO, Inc. compacted to a firm condition, or removed, prior to placement on compaction of the granular wall backfill. RETAINING WALL CONSTRUCTION CONSIDERATIONS We offer the following geotechnical considerations related to construction aspects of the proposed cast-in-place retaining wall. Footing Construction Considerations All footing subgrades should be carefully prepared. Any loose soil should be removed from the footing excavations or re-compacted. Footing subgrades should be observed by PanGEO to confirm that the exposed footing subgrade is consistent with the expected conditions and adequate to support the design bearing pressure. As noted above, at the toe of the slope drainage gravel may be encountered during the excavation for the retaining wall footing. We recommend that the drainage gravel be removed below the proposed footing to expose the medium dense to very dense native soils. Footing Subgrade Protection The contractor should be aware that the site soils are sensitive to moisture, and may become disturbed and soft when exposed to inclement weather conditions. If the footing subgrades are exposed to water, it may be necessary to place 3 to 4 inches of clean crushed rock on the prepared footing subgrade, or lean-mix concrete (1.5 sack, minimum), to protect it against moisture and disturbance. Temporary Excavations In general, maximum temporary excavation cuts are expected to be about 12 feet tall. Temporary excavations greater than 4 feet deep should be properly sloped or shored. All temporary excavations should be performed in accordance with Part N of WAC (Washington Administrative Code) 296-155. The contractor is responsible for maintaining safe excavation slopes and/or shoring. For planning purposes, the temporary excavations may be sloped to as steep as 1H:1V (Horizontal:Vertical). The temporary cut slopes should be re-evaluated by a representative of PanGEO during construction based on actual observed soil conditions. Limited Geotechnical Report – Proposed Retaining Wall 17803 108th Avenue SE, Renton, WA January 13, 2025 24-497_17803 108th ave se_renton_r_wall.docx 11 PanGEO, Inc. During periods of precipitation, the temporary cuts should be protected with plastic sheeting. If areas of seepage are encountered during construction, the slopes may need to be flattened or armored with quarry spalls to reduce the potential of face instability. We recommend that traffic, construction equipment, building materials and excavated soil should not be allowed within a distance equal to one-half the slope height from the top of any excavation, or 3-foot minimum. The setback distance of heavy point loads, such as crane or pump truck outriggers, should be evaluated on a case-by-case basis. Temporary Groundwater Control The contractor should be aware that groundwater seepage is expected in the excavation for the wall foundation, especially during wet times of the year. We anticipate that sumps and pumps will be adequate to dewater the wall footing excavation. STRUCTURAL FILL AND COMPACTION Stuctural fill will be needed next to the wall footing, and may be needed below wall footings if over-excavation of unsuitable soils occurs. Structural fill, should be free of organic and inorganic debris, be near the optimum moisture content and be capable of being compacted to the recommendations provided below. The site soils are relatively fine grained and, in our opinion will not be suitable for re-use as structural fill and an imported structural fill will be needed. Fill for use during wet weather should consist of a well graded soil free of organic material with less than 5 percent fines (silt and clay sized particles passing the U.S. 200 sieve). Structural fill should be moisture conditioned to within about 3 percent of optimum moisture content, placed in loose, horizontal lifts less than 8 inches in thickness, and compacted to at least 95 percent maximum density, determined using ASTM D1557 (Modified Proctor). The procedure to achieve proper density of a compacted fill depends on the size and type of compacting equipment, the number of passes, thickness of the lifts being compacted, and certain soil properties. If the excavation to be backfilled is constricted and limits the use of heavy equipment, smaller equipment can be used, but the lift thickness will need to be reduced to achieve the required relative compaction. Generally, loosely compacted soils are a result of poor construction technique or improper moisture content. Soils with high fines contents are particularly susceptible to becoming too wet Limited Geotechnical Report – Proposed Retaining Wall 17803 108th Avenue SE, Renton, WA January 13, 2025 24-497_17803 108th ave se_renton_r_wall.docx 12 PanGEO, Inc. and coarse-grained materials easily become too dry, for proper compaction. Silty or clayey soils with a moisture content too high for adequate compaction should be dried as necessary, or moisture conditioned by mixing with drier materials, or other methods. PERMANENT DRAINAGE CONSIDERATIONS Permanent control of surface water should be incorporated in the final grading design. Adequate surface gradients and drainage systems should be incorporated into the design such that surface runoff is directed away from the wall. Under no circumstances should collected surface water be allowed to discharge behind retaining walls. TEMPORARY & PERMANENT EROSION CONTROL CONSIDERATIONS Surface runoff can be controlled during construction by careful grading practices. This may include the construction of shallow, upgrade perimeter ditches or low earthen or asphalt berms to collect runoff and prevent water from entering the excavation. All collected water should be directed to a positive and permanent discharge system such as a storm sewer. It should be noted that the site soils are prone to surficial erosion. Special care should be taken to avoid surface water on open cut excavations, and exposed slopes should be protected with plastic sheeting. Permanent erosion control measures such as covering exposed ground surfaces with topsoil or mulch, and installing landscaping, should be performed as soon as possible after construction to limit the time the exposed surfaces are susceptible to erosion. LIMITATIONS We have prepared this report for use by Kite Realty Group and the project team. Recommendations contained in this report are based on a review of existing data, a site reconnaissance, the results of our limited subsurface exploration program, and our understanding of the project. The study was performed using a mutually agreed-upon scope of work. Variations in soil conditions may exist between the observed soil type and the actual conditions underlying the site. The nature and extent of soil variations may not be evident until construction occurs. If any soil conditions are encountered at the site that are different from those described in this report, we should be notified immediately to review the applicability of our recommendations. Additionally, we should also be notified to review the applicability of our recommendations if there are any changes in the project scope. Limited Geotechnical Report – Proposed Retaining Wall 17803 108th Avenue SE, Renton, WA January 13, 2025 24-497_17803 108th ave se_renton_r_wall.docx 13 PanGEO, Inc. The scope of our work does not include services related to construction safety precautions. Our recommendations are not intended to direct the contractors’ methods, techniques, sequences or procedures, except as specifically described in our report for consideration in design. Additionally, the scope of our work specifically excludes the assessment of environmental characteristics, particularly those involving hazardous substances. We are not mold consultants nor are our recommendations to be interpreted as being preventative of mold development. A mold specialist should be consulted for all mold-related issues. This report may be used only by the client and for the purposes stated, within a reasonable time from its issuance. Land use, site conditions (both off and on-site), or other factors including advances in our understanding of applied science, may change over time and could materially affect our findings. Therefore, this report should not be relied upon after 24 months from its issuance. PanGEO should be notified if the project is delayed by more than 24 months from the date of this report so that we may review the applicability of our conclusions considering the time lapse. It is the client’s responsibility to see that all parties to this project, including the designer, contractor, subcontractors, etc., are made aware of this report in its entirety. The use of information contained in this report for bidding purposes should be done at the contractor’s option and risk. Any party other than the client who wishes to use this report shall notify PanGEO of such intended use and for permission to copy this report. Based on the intended use of the report, PanGEO may require that additional work be performed and that an updated report be reissued. Noncompliance with any of these requirements will release PanGEO from any liability resulting from the use this report. Within the limitation of scope, schedule and budget, PanGEO engages in the practice of geotechnical engineering and endeavors to perform its services in accordance with generally accepted professional principles and practices at the time the Report or its contents were prepared. No warranty, express or implied, is made. Limited Geotechnical Report – Proposed Retaining Wall 17803 108th Avenue SE, Renton, WA January 13, 2025 24-497_17803 108th ave se_renton_r_wall.docx 14 PanGEO, Inc. We appreciate the opportunity to be of service to you on this project. Please feel free to contact our office with any questions you have regarding our study, this report, or any geotechnical engineering related project issues. Sincerely, PanGEO, Inc. Jon C. Rehkopf, P.E. Principal Geotechnical Engineer jrehkopf@pangeoinc.com ATTACHMENTS Figures Figure 1 – Vicinity Map Figure 2 – Site and Exploration Plan Appendix A Figure A-1 – Terms and Symbols for Boring and Test Pit Logs Figures A-2 through A-5 – Subsurface Exploration Logs PG-1 through PG-4 Limited Geotechnical Report – Proposed Retaining Wall 17803 108th Avenue SE, Renton, WA January 13, 2025 24-497_17803 108th ave se_renton_r_wall.docx PanGEO, Inc. REFERENCES Mullineaux, D.R., 1965, Geologic Map of the Renton Quadrangle, King County, Washington – U.S. Geological Survey Geologic, Quadrangle Map GQ-405, scale 1:24,000. Schuster, J.E., Cabibbo, A.A., Schilter, J.F., and Hubert I.J., 2015, Geologic Map of the Tacoma 1:100,000-scale Quadrangle, Washington – Washington Division of Geology and Earth Resources, Map Series 2015-03, scale 1:100,000. WSDOT, 2024, Standard Specifications for Road, Bridge and Municipal Construction, M 41-10. Washington Administrative Code (WAC), 2013, Chapter 296-155 - Safety Standards for Construction Work, Part N - Excavation, Trenching, and Shoring, Olympia, Washington. 24-497 Proposed Retaining Wall 17803 108th Avenue SE Renton, Washington 1 VICINITY MAP Figure No.Project No. Fig 1 - V i c i n i t y M a p . g p j 1 / 1 3 / 2 5 ( 1 0 : 3 1 : 4 4 ) Base Map Credit: King County iMAP. Project Site NOT TO SCALE Project Vicinity Project No.Figure No. SITE AND EXPLORATION PLAN 24-497 2 Fig 2 - S i t e a n d E x p l o r a t i o n P l a n . g p j 1 / 1 3 / 2 5 ( 1 1 : 0 9 : 3 2 ) J C R 0 20 40 1 inch ~ 40 feet Note: Base map modified from site survey prepared by SAM, dated 5/8/2024. 10 8 t h A V E S E Proposed Retaining Wall 17803 108th Avenue SE Renton, Washington PG-1 PG-2 PG-3 PG-4 LEGEND Approximate Location of Subsurface Explorations (PanGEO, 2024) Approximate Location of Proposed Retaining Wall Limits of Subject Site Limited Geotechnical Report – Proposed Retaining Wall 17803 108th Avenue SE, Renton, WA January 13, 2025 24-497_17803 108th ave se_renton_r_wall.docx PanGEO, Inc. APPENDIX A SUBSURFACE EXPLORATION LOGS MOISTURE CONTENT 2-inch OD Split Spoon, SPT (140-lb. hammer, 30" drop) 3.25-inch OD Spilt Spoon (300-lb hammer, 30" drop) Non-standard penetration test (see boring log for details) Thin wall (Shelby) tube Grab Rock core Vane Shear Dusty, dry to the touch Damp but no visible water Visible free water Terms and Symbols for Boring and Test Pit Logs Density SILT / CLAY GRAVEL (<5% fines) GRAVEL (>12% fines) SAND (<5% fines) SAND (>12% fines) Liquid Limit < 50 Liquid Limit > 50 Breaks along defined planes Fracture planes that are polished or glossy Angular soil lumps that resist breakdown Soil that is broken and mixed Less than one per foot More than one per foot Angle between bedding plane and a planenormaltocoreaxis Very Loose Loose Med. Dense Dense Very Dense SPT N-values Approx. Undrained Shear Strength (psf) <4 4 to 10 10 to 30 30 to 50 >50 <2 2 to 4 4 to 8 8 to 15 15 to 30 >30 SPT N-values Units of material distinguished by color and/orcomposition frommaterial unitsabove andbelow Layers of soil typically 0.05 to 1mm thick, max. 1 cm Layer of soil that pinches out laterally Alternating layers of differing soil material Erratic, discontinuous deposit of limited extent Soil with uniform color and composition throughout Approx. Relative Density (%) Gravel Layered: Laminated: Lens: Interlayered: Pocket: Homogeneous: Highly Organic Soils #4 to #10 sieve (4.5 to 2.0 mm) #10 to #40 sieve (2.0 to 0.42 mm) #40 to #200 sieve (0.42 to 0.074 mm) 0.074 to 0.002 mm <0.002 mm UNIFIED SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONS GROUP DESCRIPTIONS Notes: MONITORING WELL <15 15 - 35 35 - 65 65 - 85 85 - 100 GW GP GM GC SW SP SM SC ML CL OL MH CH OH PT TEST SYMBOLS 50%or more passing #200 sieve Groundwater Level at time of drilling (ATD)Static Groundwater Level Cement / Concrete Seal Bentonite grout / seal Silica sand backfill Slotted tip Slough <250 250 - 500 500 - 1000 1000 - 2000 2000 - 4000 >4000 RELATIVE DENSITY / CONSISTENCY Fissured: Slickensided: Blocky: Disrupted: Scattered: Numerous: BCN: COMPONENT DEFINITIONS Dry Moist Wet 1. Soil exploration logs contain material descriptions based on visual observation and field tests using a systemmodified from the Uniform Soil Classification System (USCS). Where necessary laboratory tests have beenconducted (as noted in the "Other Tests" column), unit descriptions may include a classification. Please refer to thediscussions in the report text for a more complete description of the subsurface conditions. 2. The graphic symbols given above are not inclusive of all symbols that may appear on the borehole logs.Other symbols may be used where field observations indicated mixed soil constituents or dual constituent materials. COMPONENT SIZE / SIEVE RANGE COMPONENT SIZE / SIEVE RANGE SYMBOLS Sample/In Situ test types and intervals Silt and Clay Consistency SAND / GRAVEL Very Soft Soft Med. Stiff Stiff Very Stiff Hard Phone: 206.262.0370 Bottom of BoringBoulder: Cobbles: Gravel Coarse Gravel: Fine Gravel: Sand Coarse Sand: Medium Sand: Fine Sand: Silt Clay > 12 inches 3 to 12 inches 3 to 3/4 inches 3/4 inches to #4 sieve Atterberg Limit Test Compaction Tests Consolidation Dry Density Direct Shear Fines Content Grain Size Permeability Pocket Penetrometer R-value Specific Gravity Torvane Triaxial Compression Unconfined Compression Sand 50% or more of the coarsefraction passing the #4 sieve.Use dual symbols (eg. SP-SM)for 5% to 12% fines. for In Situ and Laboratory Testslisted in "Other Tests" column. 50% or more of the coarsefraction retained on the #4sieve. Use dual symbols (eg.GP-GM) for 5% to 12% fines. DESCRIPTIONS OF SOIL STRUCTURES Well-graded GRAVEL Poorly-graded GRAVEL Silty GRAVEL Clayey GRAVEL Well-graded SAND Poorly-graded SAND Silty SAND Clayey SAND SILT Lean CLAY Organic SILT or CLAY Elastic SILT Fat CLAY Organic SILT or CLAY PEAT ATT Comp Con DD DS %F GS Perm PP R SG TV TXC UCC Figure A-1 Project No: 24-497 Project Name: Proposed Retaining Wall Project Loca�on: 17803 108th Ave SE, Renton, Washington Date Excavated: 12/30/2024 24-497 hand boring logs.docx Figure A-2 PanGEO, Inc. Hand Boring Log: PG-1 Approximate ground surface eleva�on: ~390 feet (NAVD 88) Approximate Loca�on: 26 feet north of southern rockery, about 1’ east of curb at toe of slope Depth (feet) Material Descrip�on 0 – ½ Loose, moist, dark brown, silty SAND and sandy SILT with some gravel and prevalent organics. [Topsoil] ½ – 1 Loose to medium dense, moist, tan with iron oxide staining, silty SAND with some gravel and trace organics. [Fill] 1 – 2 ½ Washed 7/8-inch diameter rounded drain rock [Fill from apparent drainage system] 2½ Medium dense to dense, silty SAND with some gravel [Glacial Till (Qvt)] - Soil descrip�on based on probing with a ½-inch diameter soil probe through the washed rock. Probe penetra�ons were observed to be less than 2 to 3 inches into the underlying na�ve soil. Photo shows drain rock at ~1 foot below ground surface at bottom of hole. -PG-1 was terminated approximately 2½ feet below ground surface due to caving drain rock. -Light groundwater seepage was observed about 2’ below ground surface. Project No: 24-497 Project Name: Proposed Retaining Wall Project Loca�on: 17803 108th Ave SE, Renton, Washington Date Excavated: 12/30/2024 24-497 hand boring logs.docx Figure A-3 PanGEO, Inc. Hand Boring Log: PG-2 Approximate ground surface eleva�on: ~392 feet (NAVD 88) Approximate Loca�on: 28 feet north of southern rockery, about 4’ east of curb at toe of slope Depth (feet) Material Descrip�on 0 – ½ Loose, moist, dark brown, silty SAND and sandy SILT with some gravel and prevalent organics. [Topsoil] ½ - 2 Medium dense to dense, moist, tan with some iron-oxide stains, silty SAND with some gravel [Glacial Till (Qvt)] - Soil probe penetra�on less than 1” into dense silty SAND Photo shows soil sample at ~2 feet below ground surface. -PG-2 was terminated approximately 2 feet below ground surface due to refusal on dense gravelly soils. -No groundwater seepage was observed in test hole. Project No: 24-497 Project Name: Proposed Retaining Wall Project Loca�on: 17803 108th Ave SE, Renton, Washington Date Excavated: 12/30/2024 24-497 hand boring logs.docx Figure A-4 PanGEO, Inc. Hand Boring Log: PG-3 Approximate ground surface eleva�on: ~391 feet (NAVD 88) Approximate Loca�on: 20 feet north of former bank sign, about 3’ east of curb at toe of slope Depth (feet) Material Descrip�on 0 – ½ Loose, moist, dark brown, silty SAND and sandy SILT with some gravel and prevalent organics. [Topsoil] ½ – 2½ Loose to medium dense, moist to wet, tan with iron oxide staining, silty SAND with some gravel and trace organics. [Fill] - Groundwater seepage at 1 foot below ground surface - Some washed rock observed - maybe near drainage line 2½ Medium dense to dense, tan with iron oxide staining, moist to wet, silty SAND with some gravel [Glacial Till (Qvt)] - Soil probe penetra�ons of less than 1 inch @ 2½ feet below ground surface. Photo shows seepage filling hole to about 1 foot below ground surface. -PG-3 was terminated approximately 2½ feet below ground surface due to dense soils and groundwater seepage causing caving of hole. -Heavy groundwater seepage was observed about 1’ below ground surface. Project No: 24-497 Project Name: Proposed Retaining Wall Project Loca�on: 17803 108th Ave SE, Renton, Washington Date Excavated: 12/30/2024 24-497 hand boring logs.docx Figure A-5 PanGEO, Inc. Logged by HKR & JCR Hand Boring Log: PG-4 Approximate ground surface eleva�on: ~395 feet (NAVD 88) Approximate Loca�on: 12 feet south of former bank sign, ~12’ east of curb at toe of slope Depth (feet) Material Descrip�on 0 – 2/3 Loose, moist, dark brown, silty SAND and sandy SILT with some gravel and prevalent organics. [Topsoil] 2/3 – 2 Loose to medium dense, moist, medium to dark brown, sandy SILT with trace gravel and trace to some organics. [Fill] 2 - 4½ Medium dense to dense, moist, tan with heavy iron-oxide stains, silty SAND with some gravel [Glacial Till (Qvt)] - Soil probe penetra�ons about 2” @ 2 feet depth - Gravel content increases around a depth of about 4 feet - Soil probe penetra�on less than 1” @ 4½ feet depth Photo shows soil sample at ~2½ feet below ground surface. -PG-4 was terminated approximately 4½ feet below ground surface due to refusal on dense gravelly soils. -No groundwater seepage was observed in test hole. 17803 & 17805 108th Ave SE – Kite Realty Group Kimley-Horn and Associates, Inc. Renton, WA Preliminary Stormwater Report April 11, 2025 Page 17 2. NRCS WEB SOIL SURVEY United States Department of Agriculture A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for King County Area, Washington Natural Resources Conservation Service December 30, 2024 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/ portal/nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid=nrcs142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require 2 alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface....................................................................................................................2 How Soil Surveys Are Made..................................................................................5 Soil Map..................................................................................................................8 Soil Map (Kite Realty Group Renton)...................................................................9 Legend................................................................................................................10 Map Unit Legend (Kite Realty Group Renton)....................................................11 Map Unit Descriptions (Kite Realty Group Renton)............................................11 King County Area, Washington.......................................................................13 AgC—Alderwood gravelly sandy loam, 8 to 15 percent slopes...................13 References............................................................................................................15 4 How Soil Surveys Are Made Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil 5 scientists classified and named the soils in the survey area, they compared the individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil-landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil-landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field-observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and Custom Soil Resource Report 6 identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. Custom Soil Resource Report 7 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 8 9 Custom Soil Resource Report Soil Map (Kite Realty Group Renton) 52 5 4 6 9 0 52 5 4 7 0 0 52 5 4 7 1 0 52 5 4 7 2 0 52 5 4 7 3 0 52 5 4 7 4 0 52 5 4 7 5 0 52 5 4 6 9 0 52 5 4 7 0 0 52 5 4 7 1 0 52 5 4 7 2 0 52 5 4 7 3 0 52 5 4 7 4 0 52 5 4 7 5 0 560450 560460 560470 560480 560490 560500 560510 560520 560530 560540 560550 560560 560450 560460 560470 560480 560490 560500 560510 560520 560530 560540 560550 560560 47° 26' 36'' N 12 2 ° 1 1 ' 5 3 ' ' W 47° 26' 36'' N 12 2 ° 1 1 ' 4 8 ' ' W 47° 26' 34'' N 12 2 ° 1 1 ' 5 3 ' ' W 47° 26' 34'' N 12 2 ° 1 1 ' 4 8 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 10N WGS84 0 25 50 100 150 Feet 0 5 10 20 30 Meters Map Scale: 1:531 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: King County Area, Washington Survey Area Data: Version 20, Aug 27, 2024 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jul 31, 2022—Aug 8, 2022 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 10 Map Unit Legend (Kite Realty Group Renton) Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI AgC Alderwood gravelly sandy loam, 8 to 15 percent slopes 1.1 100.0% Totals for Area of Interest 1.1 100.0% Map Unit Descriptions (Kite Realty Group Renton) The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The Custom Soil Resource Report 11 delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha-Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. Custom Soil Resource Report 12 King County Area, Washington AgC—Alderwood gravelly sandy loam, 8 to 15 percent slopes Map Unit Setting National map unit symbol: 2t626 Elevation: 50 to 800 feet Mean annual precipitation: 20 to 60 inches Mean annual air temperature: 46 to 52 degrees F Frost-free period: 160 to 240 days Farmland classification: Prime farmland if irrigated Map Unit Composition Alderwood and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Alderwood Setting Landform:Hills, ridges Landform position (two-dimensional):Shoulder Landform position (three-dimensional):Nose slope, talf Down-slope shape:Convex, linear Across-slope shape:Convex Parent material:Glacial drift and/or glacial outwash over dense glaciomarine deposits Typical profile A - 0 to 7 inches: gravelly sandy loam Bw1 - 7 to 21 inches: very gravelly sandy loam Bw2 - 21 to 30 inches: very gravelly sandy loam Bg - 30 to 35 inches: very gravelly sandy loam 2Cd1 - 35 to 43 inches: very gravelly sandy loam 2Cd2 - 43 to 59 inches: very gravelly sandy loam Properties and qualities Slope:8 to 15 percent Depth to restrictive feature:20 to 39 inches to densic material Drainage class:Moderately well drained Capacity of the most limiting layer to transmit water (Ksat):Very low to moderately low (0.00 to 0.06 in/hr) Depth to water table:About 18 to 37 inches Frequency of flooding:None Frequency of ponding:None Available water supply, 0 to 60 inches: Very low (about 2.7 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 4s Hydrologic Soil Group: B Ecological site: F002XA004WA - Puget Lowlands Forest Forage suitability group: Limited Depth Soils (G002XN302WA), Limited Depth Soils (G002XS301WA), Limited Depth Soils (G002XF303WA) Custom Soil Resource Report 13 Other vegetative classification: Limited Depth Soils (G002XN302WA), Limited Depth Soils (G002XS301WA), Limited Depth Soils (G002XF303WA) Hydric soil rating: No Minor Components Indianola Percent of map unit:5 percent Landform:Terraces, kames, eskers Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Hydric soil rating: No Everett Percent of map unit:5 percent Landform:Kames, moraines, eskers Landform position (two-dimensional):Shoulder, footslope Landform position (three-dimensional):Base slope, crest Down-slope shape:Convex Across-slope shape:Convex Hydric soil rating: No Shalcar Percent of map unit:3 percent Landform:Depressions Landform position (three-dimensional):Dip Down-slope shape:Concave Across-slope shape:Concave Hydric soil rating: Yes Norma Percent of map unit:2 percent Landform:Drainageways, depressions Landform position (three-dimensional):Dip Down-slope shape:Linear, concave Across-slope shape:Concave Hydric soil rating: Yes Custom Soil Resource Report 14 References American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs142p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ home/?cid=nrcs142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 15 United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/soils/scientists/?cid=nrcs142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/? cid=nrcs142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf Custom Soil Resource Report 16 17803 & 17805 108th Ave SE – Kite Realty Group Kimley-Horn and Associates, Inc. Renton, WA Preliminary Stormwater Report April 11, 2025 Page 18 3. SWPPP Construction Stormwater General Permit (CSWGP) Stormwater Pollution Prevention Plan (SWPPP) for Chipotle 108th Ave SE Prepared for: Washington Department of Ecology Permittee / Owner Developer Operator / Contractor Tony Halsey Kite Realty Group TBD 17803 108th Ave SE, Renton, WA, 98055 Certified Erosion and Sediment Control Lead (CESCL) Name Organization Contact Phone Number TBD TBD TBD SWPPP Prepared By Name Organization Contact Phone Number Matteo Schulz Kimley-Horn 253-300-1814 SWPPP Preparation Date 03/28/2025 Project Construction Dates Activity / Phase Start Date End Date Demolition MM / DD / YYYY MM / DD / YYYY Construction MM / DD / YYYY MM / DD / YYYY List of Acronyms and Abbreviations Acronym / Abbreviation Explanation 303(d) Section of the Clean Water Act pertaining to Impaired Waterbodies BFO Bellingham Field Office of the Department of Ecology BMP(s) Best Management Practice(s) CESCL Certified Erosion and Sediment Control Lead CO2 Carbon Dioxide CRO Central Regional Office of the Department of Ecology CSWGP Construction Stormwater General Permit CWA Clean Water Act DMR Discharge Monitoring Report DO Dissolved Oxygen Ecology Washington State Department of Ecology EPA United States Environmental Protection Agency ERO Eastern Regional Office of the Department of Ecology ERTS Environmental Report Tracking System ESC Erosion and Sediment Control GULD General Use Level Designation NPDES National Pollutant Discharge Elimination System NTU Nephelometric Turbidity Units NWRO Northwest Regional Office of the Department of Ecology pH Power of Hydrogen RCW Revised Code of Washington SPCC Spill Prevention, Control, and Countermeasure su Standard Units SWMMEW Stormwater Management Manual for Eastern Washington SWMMWW Stormwater Management Manual for Western Washington SWPPP Stormwater Pollution Prevention Plan TESC Temporary Erosion and Sediment Control SWRO Southwest Regional Office of the Department of Ecology TMDL Total Maximum Daily Load VFO Vancouver Field Office of the Department of Ecology WAC Washington Administrative Code WSDOT Washington Department of Transportation WWHM Western Washington Hydrology Model Project Information (1.0) Project/Site Name: Chipotle 108th Ave SE Street/Location: 17803 108th Ave SE City: Renton State: WA Zip code: 98055 Subdivision: N/A Receiving waterbody: Panther Creek Existing Conditions (1.1) Total acreage (including support activities such as off-site equipment staging yards, material storage areas, borrow areas). Total acreage: 0.85 Disturbed acreage: 0.15 Existing structures: Municipal Utilities including storm and sewer systems, parking lot, building structure to be renovated, and foliage Landscape topography: Developed Parking lot with sloped hills along adjacent properties and along the ROW Drainage patterns: Proposed redevelopment to maintain existing on-site municipal storm system and won’t alter existing drainage patterns Existing Vegetation: A variety of grasses, shrubs, and trees surrounding the developed concrete and asphalt on site Critical Areas: N/A List of known impairments for 303(d) listed or Total Maximum Daily Load (TMDL) for the receiving waterbody: No known impairments Table 1 includes a list of suspected and/or known contaminants associated with the construction activity. Table 1 – Summary of Site Pollutant Constituents Constituent (Pollutant) Location Depth Concentration Waste streams generated form concrete grinding and sawing On-site N/A N/A Exposed aggregate processes On-site N/A N/A Concrete pumping and mixer washout waters On-site N/A N/A Proposed Construction Activities (1.2) Description of site development: Commercial Description of construction activities: Demolition of on site concrete and asphalt, replacement of asphalt and concrete, and installation of additional pervious cover Description of site drainage including flow from and onto adjacent properties. Must be consistent with Site Map in Appendix A: Site drainage will not be altered. Given the net increase of pervious cover on site, there will be no alterations to the existing on site municipal storm system. Description of final stabilization: Paving and landscaping Contaminated Site Information: Proposed activities regarding contaminated soils or groundwater: Authorized sanitary sewer discharge Construction Stormwater Best Management Practices (BMPs) (2.0) The 13 Elements (2.1) Element 1: Preserve Vegetation / Mark Clearing Limits (2.1.1) List and describe BMPs: Soil Amendment and Tree Retention Credit Installation Schedules: Native soil retention and reuse will be used throughout the construction process. Existing Trees within the project limits of disturbance will be protected in place and retained the maximum extent feasible. Please refer to landscape plans for additional information. Inspection and Maintenance plan: TBD Responsible Staff: TBD Element 2: Establish Construction Access (2.1.2) List and describe BMPs: Construction Entrance per City of Renton Standards (see plansheet C7.1) Installation Schedules: Please see plansheet C7.1 for additional information. Inspection and Maintenance plan: TBD Responsible Staff: TBD Element 3: Control Flow Rates (2.1.3) Will you construct stormwater retention and/or detention facilities? Yes No Will you use permanent infiltration ponds or other low impact development (example: rain gardens, bio-retention, porous pavement) to control flow during construction? Yes No List and describe BMPs: Please refer to CR#9 of the TIR for information on BMP exemption. Installation Schedules: N/A Inspection and Maintenance plan: N/A Responsible Staff: N/A Element 4: Install Sediment Controls (2.1.4) List and describe BMPs: Catch Basin Inserts will be used. Please refer to detail sheet C7.1 for additional information (Std. Plan – 216.30) Installation Schedules: Please refer to detail sheet C7.1 for additional information (Std. Plan – 216.30) Inspection and Maintenance plan: TBD Responsible Staff: TBD Element 5: Stabilize Soils (2.1.5) West of the Cascade Mountains Crest Season Dates Number of Days Soils Can be Left Exposed During the Dry Season May 1 – September 30 7 days During the Wet Season October 1 – April 30 2 days Soils must be stabilized at the end of the shift before a holiday or weekend if needed based on the weather forecast. Anticipated project dates: Start date: TBD End date: TBD Will you construct during the wet season? Yes No List and describe BMPs: Please refer to landscape plans and the geotechnical report for additional information. Installation Schedules: Please refer to landscape plans and the geotechnical report for additional information. Inspection and Maintenance plan: TBD Responsible Staff: TBD Element 6: Protect Slopes (2.1.6) Will steep slopes be present at the site during construction? Yes No List and describe BMPs: Please refer to the geotechnical report included in Appendix A detailing the exemption of BMPs given existing on site soil conditions and the retaining wall present on site. Installation Schedules: N/A Inspection and Maintenance plan: N/A Responsible Staff: N/A Element 7: Protect Drain Inlets (2.1.7) List and describe BMPs: Catch Basin Inserts will be used. Please refer to detail sheet C7.1 for additional information (Std. Plan – 216.30) Installation Schedules: Please refer to detail sheet C7.1 for additional information (Std. Plan – 216.30). Inspection and Maintenance plan: TBD Responsible Staff: TBD Element 8: Stabilize Channels and Outlets (2.1.8) List and describe BMPs: Site erosion is not proposed to be conveyed in channels, discharged to a stream, or discharged to a natural drainage point and is thus exempt from Element 8 requirements. Installation Schedules: N/A Inspection and Maintenance plan: N/A Responsible Staff: N/A Element 9: Control Pollutants (2.1.9) The following pollutants are anticipated to be present on-site: Table 2 – Pollutants Pollutant (and source, if applicable) Waste streams generated from concrete grinding and sawing Exposed aggregate processes Concrete pumping and mixer washout waters List and describe BMPs: On site drainage facilities will maintain water quality standards in the developed condition to match that of the existing condition, thus exempting this project from additional stormwater pollutant control. Installation Schedules: N/A Inspection and Maintenance plan: N/A Responsible Staff: N/A Will maintenance, fueling, and/or repair of heavy equipment and vehicles occur on-site? Yes No List and describe BMPs: N/A Installation Schedules: N/A Inspection and Maintenance plan: N/A Responsible Staff: N/A Will wheel wash or tire bath system BMPs be used during construction? Yes No List and describe BMPs: N/A Installation Schedules: N/A Inspection and Maintenance plan: N/A Responsible Staff: N/A Will pH-modifying sources be present on-site? Yes No If yes, check the source(s). Table 3 – pH-Modifying Sources None Bulk cement Cement kiln dust Fly ash Other cementitious materials New concrete washing or curing waters Waste streams generated from concrete grinding and sawing Exposed aggregate processes Dewatering concrete vaults Concrete pumping and mixer washout waters Recycled concrete Other (i.e. calcium lignosulfate) [please describe] List and describe BMPs: Catch Basin Inserts will be used. Please refer to detail sheet C7.1 for additional information (Std. Plan – 216.30) Installation Schedules: Please refer to detail sheet C7.1 for additional information (Std. Plan – 216.30) Inspection and Maintenance plan: TBD Responsible Staff: TBD Element 10: Control Dewatering (2.1.10) Dewatering will not be required on site. Please refer to CR#9 of the TIR for additional information. List and describe BMPs: N/A Installation Schedules: N/A Inspection and Maintenance plan: N/A Responsible Staff: N/A Element 11: Maintain BMPs (2.1.11) All temporary and permanent Erosion and Sediment Control (ESC) BMPs shall be maintained and repaired as needed to ensure continued performance of their intended function. Maintenance and repair shall be conducted in accordance with each particular BMP specification (see Volume II of the SWMMWW or Chapter 7 of the SWMMEW). Visual monitoring of all BMPs installed at the site will be conducted at least once every calendar week and within 24 hours of any stormwater or non-stormwater discharge from the site. If the site becomes inactive and is temporarily stabilized, the inspection frequency may be reduced to once every calendar month. All temporary ESC BMPs shall be removed within 30 days after final site stabilization is achieved or after the temporary BMPs are no longer needed. Trapped sediment shall be stabilized on-site or removed. Disturbed soil resulting from removal of either BMPs or vegetation shall be permanently stabilized. Additionally, protection must be provided for all BMPs installed for the permanent control of stormwater from sediment and compaction. BMPs that are to remain in place following completion of construction shall be examined and restored to full operating condition. If sediment enters these BMPs during construction, the sediment shall be removed and the facility shall be returned to conditions specified in the construction documents. Element 12: Manage the Project (2.1.12) The project will be managed based on the following principles: • Projects will be phased to the maximum extent practicable and seasonal work limitations will be taken into account. • Inspection and monitoring: o Inspection, maintenance and repair of all BMPs will occur as needed to ensure performance of their intended function. o Site inspections and monitoring will be conducted in accordance with Special Condition S4 of the CSWGP. Sampling locations are indicated on the Site Map. Sampling station(s) are located in accordance with applicable requirements of the CSWGP. • Maintain an updated SWPPP. o The SWPPP will be updated, maintained, and implemented in accordance with Special Conditions S3, S4, and S9 of the CSWGP. As site work progresses the SWPPP will be modified routinely to reflect changing site conditions. The SWPPP will be reviewed monthly to ensure the content is current. Table 5 – Management Design the project to fit the existing topography, soils, and drainage patterns Emphasize erosion control rather than sediment control Minimize the extent and duration of the area exposed Keep runoff velocities low Retain sediment on-site Thoroughly monitor site and maintain all ESC measures Schedule major earthwork during the dry season Other (please describe) Element 13: Protect Low Impact Development (LID) BMPs (2.1.13) There are no bioretention or rain gardens present on site in the existing conditions and given that existing flow conditions will be preserved, element 13 does not apply to this project. The net increase of pervious area in the developed condition will provide additional infiltration and mitigates additional stormwater impacts. Please refer to the TIR for additional information on the infeasibility of rain gardens, infiltration, and permeable pavent. Pollution Prevention Team (3.0) Table 7 – Team Information Title Name(s) Phone Number Certified Erosion and Sediment Control Lead (CESCL) TBD TBD Resident Engineer TBD TBD Emergency Ecology Contact TBD TBD Emergency Permittee/ Owner Contact TBD TBD Non-Emergency Owner Contact TBD TBD Monitoring Personnel TBD TBD Ecology Regional Office Northwest 206-594-0000 Monitoring and Sampling Requirements (4.0) Monitoring includes visual inspection, sampling for water quality parameters of concern, and documentation of the inspection and sampling findings in a site log book. A site log book will be maintained for all on-site construction activities and will include: • A record of the implementation of the SWPPP and other permit requirements • Site inspections • Stormwater sampling data File a blank form under Appendix D. The site log book must be maintained on-site within reasonable access to the site and be made available upon request to Ecology or the local jurisdiction. The receiving waterbody, Panther Creek, is not impaired. All stormwater and dewatering dischas rges from the site are subject to an effluent limit of 8.5 su for pH and/or 25 NTU for turbidity. Site Inspection (4.1) Site inspections will be conducted at least once every calendar week and within 24 hours following any discharge from the site. For sites that are temporarily stabilized and inactive, the required frequency is reduced to once per calendar month. The discharge point(s) are indicated on the Site Map (see Appendix A) and in accordance with the applicable requirements of the CSWGP. Stormwater Quality Sampling (4.2) Turbidity Sampling (4.2.1) Turbidity sampling is not required for this site given that the existing stormwater network will not be altered. Please note that the net pervious area will also increase, aiding in infiltration across the site. Please refer to the TIR for additional information. pH Sampling (4.2.2) No pH sampling is required for this site given that the existing stormwater network will not be altered. Please note that the net pervious area will also increase, aiding in infiltration across the site. Please refer to the TIR for additional information. Discharges to 303(d) or Total Maximum Daily Load (TMDL) Waterbodies (5.0) 303(d) Listed Waterbodies (5.1) Is the receiving water 303(d) (Category 5) listed for turbidity, fine sediment, phosphorus, or pH? Yes No List the impairment(s): No impairments. The receiving waterbody, Panther Creek, is not impaired. All stormwater and dewatering discharges from the site are subject to an effluent limit of 8.5 su for pH and/or 25 NTU for turbidity. List and describe BMPs: N/A TMDL Waterbodies (5.2) Waste Load Allocation for CWSGP discharges: The site is exempt from sampling turbidity given the limited scope of development, maintenance of existing on-site flow control facilities, and net positive of pervious area proposed in the developed condition. List and describe BMPs: Catch Basin Inserts will be used. Please refer to detail sheet C7.1 for additional information (Std. Plan – 216.30) The Construction Stormwater General Permit Proposed New Discharge to an Impaired Water Body form is included in Appendix F. Reporting and Record Keeping (6.0) Record Keeping (6.1) Site Log Book (6.1.1) A site log book will be maintained for all on-site construction activities and will include: • A record of the implementation of the SWPPP and other permit requirements • Site inspections • Sample logs Records Retention (6.1.2) Records will be retained during the life of the project and for a minimum of three (3) years following the termination of permit coverage in accordance with Special Condition S5.C of the CSWGP. Permit documentation to be retained on-site: • CSWGP • Permit Coverage Letter • SWPPP • Site Log Book Permit documentation will be provided within 14 days of receipt of a written request from Ecology. A copy of the SWPPP or access to the SWPPP will be provided to the public when requested in writing in accordance with Special Condition S5.G.2.b of the CSWGP. Updating the SWPPP (6.1.3) The SWPPP will be modified if: • Found ineffective in eliminating or significantly minimizing pollutants in stormwater discharges from the site. • There is a change in design, construction, operation, or maintenance at the construction site that has, or could have, a significant effect on the discharge of pollutants to waters of the State. The SWPPP will be modified within seven (7) days if inspection(s) or investigation(s) determine additional or modified BMPs are necessary for compliance. An updated timeline for BMP implementation will be prepared. Reporting (6.2) Discharge Monitoring Reports (6.2.1) Cumulative soil disturbance is less than one (1) acre; therefore, Discharge Monitoring Reports (DMRs) will not be submitted to Ecology because water quality sampling is not being conducted at the site. DMRs will be reported online through Ecology’s WQWebDMR System. Notification of Noncompliance (6.2.2) If any of the terms and conditions of the permit is not met, and the resulting noncompliance may cause a threat to human health or the environment, the following actions will be taken: 1. Ecology will be notified within 24-hours of the failure to comply by calling the applicable Regional office ERTS phone number (Regional office numbers listed below). 2. Immediate action will be taken to prevent the discharge/pollution or otherwise stop or correct the noncompliance. If applicable, sampling and analysis of any noncompliance will be repeated immediately and the results submitted to Ecology within five (5) days of becoming aware of the violation. 3. A detailed written report describing the noncompliance will be submitted to Ecology within five (5) days, unless requested earlier by Ecology. Anytime turbidity sampling indicates turbidity is 250 NTUs or greater, or water transparency is 6 cm or less, the Ecology Regional office will be notified by phone within 24 hours of analysis as required by Special Condition S5.A of the CSWGP. • Central Region at (509) 575-2490 for Benton, Chelan, Douglas, Kittitas, Klickitat, Okanogan, or Yakima County • Eastern Region at (509) 329-3400 for Adams, Asotin, Columbia, Ferry, Franklin, Garfield, Grant, Lincoln, Pend Oreille, Spokane, Stevens, Walla Walla, or Whitman County • Northwest Region at (425) 649-7000 for Island, King, Kitsap, San Juan, Skagit, Snohomish, or Whatcom County • Southwest Region at (360) 407-6300 for Clallam, Clark, Cowlitz, Grays Harbor, Jefferson, Lewis, Mason, Pacific, Pierce, Skamania, Thurston, or Wahkiakum Include the following information: 1. Your name and / Phone number 2. Permit number 3. City / County of project 4. Sample results 5. Date / Time of call 6. Date / Time of sample 7. Project name In accordance with Special Condition S4.D.5.b of the CSWGP, the Ecology Regional office will be notified if chemical treatment other than CO2 sparging is planned for adjustment of high pH water. Appendix/Glossary A. Site Map IN COMPLIANCE WITH CITY OF RENTON STANDARDS PROJECT SITE NORTH 10 8 T H A V E S E VICINITY MAP OF SITE B. BMP Detail IN COMPLIANCE WITH CITY OF RENTON STANDARDS DE T A I L S H E E T 1 C7.0 4/7/25 ----12 DETAIL SHEET 1 CHIPOTLE 108TH AVE SE C. Correspondence D. Site Inspection Form E. Construction Stormwater General Permit (CSWGP) F. 303(d) List Waterbodies / TMDL Waterbodies Information G. Contaminated Site Information H. Engineering Calculations 17803 & 17805 108th Ave SE – Kite Realty Group Kimley-Horn and Associates, Inc. Renton, WA Preliminary Stormwater Report April 11, 2025 Page 19 4. MAINTENANCE AND OPERATIONS MANUAL CITY OF RENTON SURFACE WATER DESIGN MANUAL 2022 City of Renton Surface Water Design Manual 6/22/2022 A-1 APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS This appendix contains the maintenance requirements for the following typical stormwater flow control and water quality facilities and on-site BMPs (ctrl/click the title to follow the link): No. 1 – Detention Ponds No. 2 – Infiltration Facilities No. 3 – Detention Tanks and Vaults No. 4 – Control Structure/Flow Restrictor No. 5 – Catch Basins and Manholes No. 6 – Conveyance Pipes and Ditches No. 7 – Debris Barriers (e.g., trash racks) No. 8 – Energy Dissipaters No. 9 – Fencing No. 10 – Gates/Bollards/Access Barriers No. 11 – Grounds (landscaping) No. 12 – Access Roads No. 13 – Basic Bioswale (grass) No. 14 – Wet Bioswale No. 15 – Filter Strip No. 16 – Wetpond No. 17 – Wetvault No. 18 – Stormwater Wetland No. 19 – Sand Filter Pond No. 20 – Sand Filter Vault No. 21 – Proprietary Facility Cartridge Filter Systems No. 22 – Baffle Oil/Water Separator No. 23 – Coalescing Plate Oil/Water Separator APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-2 No. 24 – Catch Basin Insert (not allowed in the city for oil control) No. 25 – Drywell BMP No. 26 – Gravel Filled Infiltration Trench BMP No. 27 – Gravel Filled Dispersion Trench BMP No. 28 – Native Vegetated Surface/Native Vegetated Landscape BMP No. 29 – Perforated Pipe Connections BMP No. 30 – Permeable Pavement BMP No. 31 – Bioretention BMP No. 32 – RainWater Harvesting BMP No. 33 – Rock Pad BMP No. 34 – Sheet Flow BMP No. 35 – Splash Block BMP No. 36 – Vegetated Roof BMP No. 37 – Rain Garden BMP No. 38 – Soil Amendment BMP No. 39 – Retained Trees No. 40 – Filterra System No. 41 – Compost Amended Vegetated Filter Strip (CAVFS) No. 42 – Media Filter Drain (MFD) No. 43 – Compost-Amended Biofiltration Swale APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-3 NO. 1 – DETENTION PONDS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash and debris which exceed 1 cubic foot per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Trash and debris cleared from site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive growth of grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Top or Side Slopes of Dam, Berm or Embankment Rodent holes Any evidence of rodent holes if facility is acting as a dam or berm, or any evidence of water piping through dam or berm via rodent holes. Rodents removed or destroyed and dam or berm repaired. Tree growth Tree growth threatens integrity of slopes, does not allow maintenance access, or interferes with maintenance activity. If trees are not a threat or not interfering with access or maintenance, they do not need to be removed. Trees do not hinder facility performance or maintenance activities. Erosion Eroded damage over 2 inches deep where cause of damage is still present or where there is potential for continued erosion. Any erosion observed on a compacted slope. Slopes stabilized using appropriate erosion control measures. If erosion is occurring on compacted slope, a licensed civil engineer should be consulted to resolve source of erosion. Settlement Any part of a dam, berm or embankment that has settled 4 inches lower than the design elevation. Top or side slope restored to design dimensions. If settlement is significant, a licensed civil engineer should be consulted to determine the cause of the settlement. Storage Area Sediment accumulation Accumulated sediment that exceeds 10% of the designed pond depth. Sediment cleaned out to designed pond shape and depth; pond reseeded if necessary to control erosion. Liner damaged (If applicable) Liner is visible or pond does not hold water as designed. Liner repaired or replaced. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Emergency Overflow/Spillway Tree growth Tree growth impedes flow or threatens stability of spillway. Trees removed. Rock missing Only one layer of rock exists above native soil in area five square feet or larger or any exposure of native soil on the spillway. Spillway restored to design standards. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-4 NO. 2 – INFILTRATION FACILITIES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash and debris which exceed 1 cubic foot per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Trash and debris cleared from site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive growth of grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Infiltration Pond, Top or Side Slopes of Dam, Berm or Embankment Rodent holes Any evidence of rodent holes if facility is acting as a dam or berm, or any evidence of water piping through dam or berm via rodent holes. Rodents removed or destroyed and dam or berm repaired. Tree growth Tree growth threatens integrity of dams, berms or slopes, does not allow maintenance access, or interferes with maintenance activity. If trees are not a threat to dam, berm, or embankment integrity or not interfering with access or maintenance, they do not need to be removed. Trees do not hinder facility performance or maintenance activities. Erosion Eroded damage over 2 inches deep where cause of damage is still present or where there is potential for continued erosion. Any erosion observed on a compacted slope. Slopes stabilized using appropriate erosion control measures. If erosion is occurring on compacted slope, a licensed civil engineer should be consulted to resolve source of erosion. Settlement Any part of a dam, berm or embankment that has settled 4 inches lower than the design elevation. Top or side slope restored to design dimensions. If settlement is significant, a licensed civil engineer should be consulted to determine the cause of the settlement. Infiltration Pond, Tank, Vault, Trench, or Small Basin Storage Area Sediment accumulation If two inches or more sediment is present or a percolation test indicates facility is working at or less than 90% of design. Facility infiltrates as designed. Liner damaged (If applicable) Liner is visible or pond does not hold water as designed. Liner repaired or replaced. Infiltration Tank Structure Plugged air vent Any blockage of the vent. Tank or vault freely vents. Tank bent out of shape Any part of tank/pipe is bent out of shape more than 10% of its design shape. Tank repaired or replaced to design. Gaps between sections, damaged joints or cracks or tears in wall A gap wider than ½-inch at the joint of any tank sections or any evidence of soil particles entering the tank at a joint or through a wall. No water or soil entering tank through joints or walls. Infiltration Vault Structure Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch, any evidence of soil entering the structure through cracks or qualified inspection personnel determines that the vault is not structurally sound. Vault is sealed and structurally sound. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-5 NO. 2 – INFILTRATION FACILITIES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Inlet/Outlet Pipes Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Access Manhole Cover/lid not in place Cover/lid is missing or only partially in place. Any open manhole requires immediate maintenance. Manhole access covered. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. Large access doors/plate Damaged or difficult to open Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can be opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat; covers access opening completely. Lifting rings missing, rusted Lifting rings not capable of lifting weight of door or plate. Lifting rings sufficient to lift or remove door or plate. Infiltration Pond, Tank, Vault, Trench, or Small Basin Filter Bags Plugged filter bag (if applicable) Filter bag more than 1/2 full. Replace filter bag or redesign system. Infiltration Pond, Tank, Vault, Trench, or Small Basin Pre- settling Ponds and Vaults Sediment accumulation 6" or more of sediment has accumulated. Pre-settling occurs as designed Infiltration Pond, Rock Filter Plugged rock filter High water level on upstream side of filter remains for extended period of time or little or no water flows through filter during heavy rain storms. Rock filter replaced evaluate need for filter and remove if not necessary. Infiltration Pond Emergency Overflow Spillway Rock missing Only one layer of rock exists above native soil in area five square feet or larger, or any exposure of native soil at the top of out flow path of spillway. Rip-rap on inside slopes need not be replaced. Spillway restored to design standards. Tree growth Tree growth impedes flow or threatens stability of spillway. Trees removed. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-6 NO. 3 – DETENTION TANKS AND VAULTS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash and debris which exceed 1 cubic foot per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Trash and debris cleared from site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive growth of grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Tank or Vault Storage Area Trash and debris Any trash and debris accumulated in vault or tank (includes floatables and non- floatables). No trash or debris in vault. Sediment accumulation Accumulated sediment depth exceeds 10% of the diameter of the storage area for ½ length of storage vault or any point depth exceeds 15% of diameter. Example: 72-inch storage tank would require cleaning when sediment reaches depth of 7 inches for more than ½ length of tank. All sediment removed from storage area. Tank Structure Plugged air vent Any blockage of the vent. Tank or vault freely vents. Tank bent out of shape Any part of tank/pipe is bent out of shape more than 10% of its design shape. Tank repaired or replaced to design. Gaps between sections, damaged joints or cracks or tears in wall A gap wider than ½-inch at the joint of any tank sections or any evidence of soil particles entering the tank at a joint or through a wall. No water or soil entering tank through joints or walls. Vault Structure Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch, any evidence of soil entering the structure through cracks or qualified inspection personnel determines that the vault is not structurally sound. Vault is sealed and structurally sound. Inlet/Outlet Pipes Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipes Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Access Manhole Cover/lid not in place Cover/lid is missing or only partially in place. Any open manhole requires immediate maintenance. Manhole access covered. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-7 NO. 3 – DETENTION TANKS AND VAULTS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Access Manhole (cont.) Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. Large access doors/plate Damaged or difficult to open Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can be opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat; covers access opening completely. Lifting rings missing, rusted Lifting rings not capable of lifting weight of door or plate. Lifting rings sufficient to lift or remove door or plate. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-8 NO. 4 – CONTROL STRUCTURE/FLOW RESTRICTOR MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Structure Trash and debris Trash or debris of more than ½ cubic foot which is located immediately in front of the structure opening or is blocking capacity of the structure by more than 10%. No Trash or debris blocking or potentially blocking entrance to structure. Trash or debris in the structure 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 structure. Deposits of garbage exceeding 1 cubic foot in volume. No condition present which would attract or support the breeding of insects or rodents. Sediment accumulation Sediment exceeds 60% of the depth from the bottom of the structure to the invert of the lowest pipe into or out of the structure or the bottom of the FROP-T section or is within 6 inches of the invert of the lowest pipe into or out of the structure or the bottom of the FROP-T section. Sump of structure contains no sediment. Damage to frame and/or top slab Corner of frame extends more than ¾ inch past curb face into the street (If applicable). Frame is even with curb. Top slab has holes larger than 2 square inches or cracks wider than ¼ inch. Top slab is free of holes and cracks. Frame not sitting flush on top slab, i.e., separation of more than ¾ inch of the frame from the top slab. Frame is sitting flush on top slab. Cracks in walls or bottom Cracks wider than ½ inch and longer than 3 feet, any evidence of soil particles entering structure through cracks, or maintenance person judges that structure is unsound. Structure is sealed and structurally sound. Cracks wider than ½ inch and longer than 1 foot at the joint of any inlet/outlet pipe or any evidence of soil particles entering structure through cracks. No cracks more than 1/4 inch wide at the joint of inlet/outlet pipe. Settlement/ misalignment Structure has settled more than 1 inch or has rotated more than 2 inches out of alignment. Basin replaced or repaired to design standards. Damaged pipe joints Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering the structure at the joint of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of inlet/outlet pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Ladder rungs missing or unsafe Ladder is unsafe due to missing rungs, misalignment, rust, cracks, or sharp edges. Ladder meets design standards and allows maintenance person safe access. FROP-T Section Damaged FROP-T T section is not securely attached to structure wall and outlet pipe structure should support at least 1,000 lbs of up or down pressure. T section securely attached to wall and outlet pipe. Structure is not in upright position (allow up to 10% from plumb). Structure in correct position. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-9 NO. 4 – CONTROL STRUCTURE/FLOW RESTRICTOR MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED FROP-T Section (cont.) Damaged FROP-T (cont.) Connections to outlet pipe are not watertight or show signs of deteriorated grout. Connections to outlet pipe are water tight; structure repaired or replaced and works as designed. Any holes—other than designed holes—in the structure. Structure has no holes other than designed holes. Cleanout Gate Damaged or missing cleanout gate Cleanout gate is missing. Replace cleanout gate. Cleanout gate is not watertight. Gate is watertight and works as designed. Gate cannot be moved up and down by one maintenance person. Gate moves up and down easily and is watertight. Chain/rod leading to gate is missing or damaged. Chain is in place and works as designed. Orifice Plate Damaged or missing orifice plate Control device is not working properly due to missing, out of place, or bent orifice plate. Plate is in place and works as designed. Obstructions to orifice plate Any trash, debris, sediment, or vegetation blocking the plate. Plate is free of all obstructions and works as designed. Overflow Pipe Obstructions to overflow pipe Any trash or debris blocking (or having the potential of blocking) the overflow pipe. Pipe is free of all obstructions and works as designed. Deformed or damaged lip of overflow pipe Lip of overflow pipe is bent or deformed. Overflow pipe does not allow overflow at an elevation lower than design Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Metal Grates (If applicable) Unsafe grate opening Grate with opening wider than 7/8 inch. Grate opening meets design standards. Trash and debris Trash and debris that is blocking more than 20% of grate surface. Grate free of trash and debris. Damaged or missing grate Grate missing or broken member(s) of the grate. Grate is in place and meets design standards. Manhole Cover/Lid Cover/lid not in place Cover/lid is missing or only partially in place. Any open structure requires urgent maintenance. Cover/lid protects opening to structure. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs. of lift. Cover/lid can be removed and reinstalled by one maintenance person. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-10 NO. 5 – CATCH BASINS AND MANHOLES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Structure Sediment accumulation Sediment exceeds 60% of the depth from the bottom of the catch basin to the invert of the lowest pipe into or out of the catch basin or is within 6 inches of the invert of the lowest pipe into or out of the catch basin. Sump of catch basin contains no sediment. Trash and debris Trash or debris of more than ½ cubic foot which is located immediately in front of the catch basin opening or is blocking capacity of the catch basin by more than 10%. No Trash or debris blocking or potentially blocking entrance to catch basin. Trash or debris in the catch basin that exceeds 1/3 the depth from the bottom of basin to invert the lowest pipe into or out of the basin. No trash or debris in the catch basin. Dead animals or vegetation that could generate odors that could cause complaints or dangerous gases (e.g., methane). No dead animals or vegetation present within catch basin. Deposits of garbage exceeding 1 cubic foot in volume. No condition present which would attract or support the breeding of insects or rodents. Damage to frame and/or top slab Corner of frame extends more than ¾ inch past curb face into the street (If applicable). Frame is even with curb. Top slab has holes larger than 2 square inches or cracks wider than ¼ inch. Top slab is free of holes and cracks. Frame not sitting flush on top slab, i.e., separation of more than ¾ inch of the frame from the top slab. Frame is sitting flush on top slab. Cracks in walls or bottom Cracks wider than ½ inch and longer than 3 feet, any evidence of soil particles entering catch basin through cracks, or maintenance person judges that catch basin is unsound. Catch basin is sealed and is structurally sound. Cracks wider than ½ inch and longer than 1 foot at the joint of any inlet/outlet pipe or any evidence of soil particles entering catch basin through cracks. No cracks more than 1/4 inch wide at the joint of inlet/outlet pipe. Settlement/ misalignment Catch basin has settled more than 1 inch or has rotated more than 2 inches out of alignment. Basin replaced or repaired to design standards. Damaged pipe joints Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering the catch basin at the joint of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of inlet/outlet pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-11 NO. 5 – CATCH BASINS AND MANHOLES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Inlet/Outlet Pipe (cont.) Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Metal Grates (Catch Basins) Unsafe grate opening Grate with opening wider than 7/8 inch. Grate opening meets design standards. Trash and debris Trash and debris that is blocking more than 20% of grate surface. Grate free of trash and debris. Damaged or missing grate Grate missing or broken member(s) of the grate. Any open structure requires urgent maintenance. Grate is in place and meets design standards. Manhole Cover/Lid Cover/lid not in place Cover/lid is missing or only partially in place. Any open structure requires urgent maintenance. Cover/lid protects opening to structure. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs. of lift. Cover/lid can be removed and reinstalled by one maintenance person. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-12 NO. 6 – CONVEYANCE PIPES AND DITCHES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Pipes Sediment & debris accumulation Accumulated sediment or debris that exceeds 20% of the diameter of the pipe. Water flows freely through pipes. Vegetation/root growth in pipe Vegetation/roots that reduce free movement of water through pipes. Water flows freely through pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Damage to protective coating or corrosion Protective coating is damaged; rust or corrosion is weakening the structural integrity of any part of pipe. Pipe repaired or replaced. Damaged pipes Any dent that decreases the cross section area of pipe by more than 20% or is determined to have weakened structural integrity of the pipe. Pipe repaired or replaced. Ditches Trash and debris Trash and debris exceeds 1 cubic foot per 1,000 square feet of ditch and slopes. Trash and debris cleared from ditches. Sediment accumulation Accumulated sediment that exceeds 20% of the design depth. Ditch cleaned/flushed of all sediment and debris so that it matches design. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive vegetation growth Vegetation that reduces free movement of water through ditches. Water flows freely through ditches. Erosion damage to slopes Any erosion observed on a ditch slope. Slopes are not eroding. Rock lining out of place or missing (If applicable) One layer or less of rock exists above native soil area 5 square feet or more, any exposed native soil. Replace rocks to design standards. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-13 NO. 7 – DEBRIS BARRIERS (E.G., TRASH RACKS) MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED. Site Trash and debris Trash or debris plugging more than 20% of the area of the barrier. Barrier clear to receive capacity flow. Sediment accumulation Sediment accumulation of greater than 20% of the area of the barrier Barrier clear to receive capacity flow. Structure Cracked, broken, or loose pipe or structure Structure which bars attached to is damaged – pipe is loose or cracked or concrete structure is cracked, broken, or loose. Structure barrier attached to is sound. Bars Incorrect bar spacing Bar spacing exceeds 6 inches. Bars have at most 6 inches spacing. Damaged or missing bars Bars are bent out of shape more than 3 inches. Bars in place with no bends more than ¾ inch. Bars are missing or entire barrier missing. Bars in place according to design. Bars are loose and rust is causing 50% deterioration to any part of barrier. Repair or replace barrier to design standards. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-14 NO. 8 – ENERGY DISSIPATERS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED. Site Trash and debris Trash and/or debris accumulation. Dissipater clear of trash and/or debris. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Rock Pad Missing or moved rock Only one layer of rock exists above native soil in area five square feet or larger or any exposure of native soil. Rock pad prevents erosion. Dispersion Trench Pipe plugged with sediment Accumulated sediment that exceeds 20% of the design depth. Pipe cleaned/flushed so that it matches design. Not discharging water properly Visual evidence of water discharging at concentrated points along trench (normal condition is a “sheet flow” of water along trench). Water discharges from feature by sheet flow. Perforations plugged Over 1/4 of perforations in pipe are plugged with debris or sediment. Perforations freely discharge flow. Water flows out top of “distributor” catch basin. Water flows out of distributor catch basin during any storm less than the design storm. No flow discharges from distributor catch basin. Receiving area over- saturated Water in receiving area is causing or has potential of causing landslide problems. No danger of landslides. Gabions Damaged mesh Mesh of gabion broken, twisted or deformed so structure is weakened or rock may fall out. Mesh is intact, no rock missing. Corroded mesh Gabion mesh shows corrosion through more than ¼ of its gage. All gabion mesh capable of containing rock and retaining designed form. Collapsed or deformed baskets Gabion basket shape deformed due to any cause. All gabion baskets intact, structure stands as designed. Missing rock Any rock missing that could cause gabion to loose structural integrity. No rock missing. Manhole/Chamber Worn or damaged post, baffles or side of chamber Structure dissipating flow deteriorates to ½ or original size or any concentrated worn spot exceeding one square foot which would make structure unsound. Structure is in no danger of failing. Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch or any evidence of soil entering the structure through cracks, or maintenance inspection personnel determines that the structure is not structurally sound. Manhole/chamber is sealed and structurally sound. Damaged pipe joints Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering the structure at the joint of the inlet/outlet pipes. No soil or water enters and no water discharges at the joint of inlet/outlet pipes. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-15 NO. 9 – FENCING MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Erosion or holes under fence Erosion or holes more than 4 inches high and 12-18 inches wide permitting access through an opening under a fence. No access under the fence. Wood Posts, Boards and Cross Members Missing or damaged parts Missing or broken boards, post out of plumb by more than 6 inches or cross members broken No gaps on fence due to missing or broken boards, post plumb to within 1½ inches, cross members sound. Weakened by rotting or insects Any part showing structural deterioration due to rotting or insect damage All parts of fence are structurally sound. Damaged or failed post foundation Concrete or metal attachments deteriorated or unable to support posts. Post foundation capable of supporting posts even in strong wind. Metal Posts, Rails and Fabric Damaged parts Post out of plumb more than 6 inches. Post plumb to within 1½ inches. Top rails bent more than 6 inches. Top rail free of bends greater than 1 inch. Any part of fence (including post, top rails, and fabric) more than 1 foot out of design alignment. Fence is aligned and meets design standards. Missing or loose tension wire. Tension wire in place and holding fabric. Deteriorated paint or protective coating Part or parts that have a rusting or scaling condition that has affected structural adequacy. Structurally adequate posts or parts with a uniform protective coating. Openings in fabric Openings in fabric are such that an 8-inch diameter ball could fit through. Fabric mesh openings within 50% of grid size. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-16 NO. 10 – GATES/BOLLARDS/ACCESS BARRIERS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Chain Link Fencing Gate Damaged or missing members Missing gate. Gates in place. Broken or missing hinges such that gate cannot be easily opened and closed by a maintenance person. Hinges intact and lubed. Gate is working freely. Gate is out of plumb more than 6 inches and more than 1 foot out of design alignment. Gate is aligned and vertical. Missing stretcher bar, stretcher bands, and ties. Stretcher bar, bands, and ties in place. Locking mechanism does not lock gate Locking device missing, non-functioning or does not link to all parts. Locking mechanism prevents opening of gate. Openings in fabric Openings in fabric are such that an 8-inch diameter ball could fit through. Fabric mesh openings within 50% of grid size. Bar Gate Damaged or missing cross bar Cross bar does not swing open or closed, is missing or is bent to where it does not prevent vehicle access. Cross bar swings fully open and closed and prevents vehicle access. Locking mechanism does not lock gate Locking device missing, non-functioning or does not link to all parts. Locking mechanism prevents opening of gate. Support post damaged Support post does not hold cross bar up. Cross bar held up preventing vehicle access into facility. Bollards Damaged or missing bollards Bollard broken, missing, does not fit into support hole or hinge broken or missing. No access for motorized vehicles to get into facility. Bollards do not lock Locking assembly or lock missing or cannot be attached to lock bollard in place. No access for motorized vehicles to get into facility. Boulders Dislodged boulders Boulders not located to prevent motorized vehicle access. No access for motorized vehicles to get into facility. Evidence of vehicles circumventing boulders Motorized vehicles going around or between boulders. No access for motorized vehicles to get into facility. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-17 NO. 11 – GROUNDS (LANDSCAPING) MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash and debris which exceed 1 cubic foot per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Trash and debris cleared from site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive growth of grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Trees and Shrubs Hazard tree identified Any tree or limb of a tree identified as having a potential to fall and cause property damage or threaten human life. A hazard tree identified by a qualified arborist must be removed as soon as possible. No hazard trees in facility. Damaged tree or shrub identified Limbs or parts of trees or shrubs that are split or broken which affect more than 25% of the total foliage of the tree or shrub. Trees and shrubs with less than 5% of total foliage with split or broken limbs. Trees or shrubs that have been blown down or knocked over. No blown down vegetation or knocked over vegetation. Trees or shrubs free of injury. Trees or shrubs which are not adequately supported or are leaning over, causing exposure of the roots. Tree or shrub in place and adequately supported; dead or diseased trees removed. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-18 NO. 12 – ACCESS ROADS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Trash and debris exceeds 1 cubic foot per 1,000 square feet (i.e., trash and debris would fill up one standards size garbage can). Roadway drivable by maintenance vehicles. Debris which could damage vehicle tires or prohibit use of road. Roadway drivable by maintenance vehicles. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Blocked roadway Any obstruction which reduces clearance above road surface to less than 14 feet. Roadway overhead clear to 14 feet high. Any obstruction restricting the access to a 10- to 12 foot width for a distance of more than 12 feet or any point restricting access to less than a 10 foot width. At least 12-foot of width on access road. Road Surface Erosion, settlement, potholes, soft spots, ruts Any surface defect which hinders or prevents maintenance access. Road drivable by maintenance vehicles. Vegetation on road surface Trees or other vegetation prevent access to facility by maintenance vehicles. Maintenance vehicles can access facility. Shoulders and Ditches Erosion Erosion within 1 foot of the roadway more than 8 inches wide and 6 inches deep. Shoulder free of erosion and matching the surrounding road. Weeds and brush Weeds and brush exceed 18 inches in height or hinder maintenance access. Weeds and brush cut to 2 inches in height or cleared in such a way as to allow maintenance access. Modular Grid Pavement Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Damaged or missing blocks/grids Access surface compacted because of broken on missing modular block. Access road surface restored so road infiltrates. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-19 NO. 13 – BASIC BIOSWALE (GRASS) MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash and/or debris accumulated on the bioswale site. No trash or debris on the bioswale site. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Swale Section Sediment accumulation Sediment depth exceeds 2 inches in 10% of the swale treatment area. No sediment deposits in grass treatment area of the bioswale. Sediment inhibits grass growth over 10% of swale length. Grass growth not inhibited by sediment. Sediment inhibits even spreading of flow. Flow spreads evenly through swale Erosion/scouring Eroded or scoured swale bottom due to channelization or high flows. No eroded or scoured areas in bioswale. Cause of erosion or scour addressed. Poor vegetation coverage Grass is sparse or bare or eroded patches occur in more than 10% of the swale bottom. Swale has no bare spots and grass is thick and healthy. Excessive vegetation growth Grass excessively tall (greater than 10 inches), grass is thin or nuisance weeds and other vegetation have taken over. Grass is between 3 and 4 inches tall, thick and healthy. No nuisance vegetation present. Excessive shade Grass growth is poor because sunlight does not reach swale. Healthy grass growth or swale converted to a wet bioswale. Constant baseflow Continuous flow through the swale, even when it has been dry for weeks or an eroded, muddy channel has formed in the swale bottom. Baseflow removed from swale by a low- flow pea-gravel drain or bypassed around the swale. Standing water Water pools in the swale between storms or does not drain freely. Swale freely drains and there is no standing water in swale between storms. Channelization Flow concentrates and erodes channel through swale. No flow channels in swale. Flow Spreader Concentrated flow Flow from spreader not uniformly distributed across entire swale width. Flows are spread evenly over entire swale width. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-20 NO. 14 – WET BIOSWALE MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash and/or debris accumulated at the site. No trash or debris at the site. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Swale Section Sediment accumulation Sediment depth exceeds 2 inches in 10% of the swale treatment area. No sediment deposits in treatment area. Erosion/scouring Eroded or scoured swale bottom due to channelization or high flows. No eroded or scoured areas in bioswale. Cause of erosion or scour addressed. Water not retained in swale during wet season Water not retained to a depth of about 4 inches during the wet season. Water depth of 4 inches throughout swale for most of wet season. Poor vegetation coverage and/or nuisance vegetation present Vegetation sparse, does not provide adequate filtration or crowded out by very dense clumps of cattail or nuisance vegetation. Wetland vegetation fully covers bottom of swale and no cattails or nuisance vegetation present. Insufficient water to maintain vegetation growth Wetland vegetation dies due to lack of water. Wetland vegetation remains healthy (may require converting to grass lined bioswale) Flow Spreader Concentrated flow Flow from spreader not uniformly distributed across entire swale width. Flows are spread evenly over entire swale width. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-21 NO. 15 – FILTER STRIP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash and debris accumulated on the filter strip site. Filter strip site free of any trash or debris Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Grass Strip Sediment accumulation Sediment accumulation on grass exceeds 2 inches depth. No sediment deposits in treatment area. Erosion/scouring Eroded or scoured swale bottom due to channelization or high flows. No eroded or scoured areas in bioswale. Cause of erosion or scour addressed. Excessive vegetation growth Grass excessively tall (greater than 10 inches), grass is thin or nuisance weeds and other vegetation have taken over. Grass is between 3 and 4 inches tall, thick and healthy. No nuisance vegetation present. Poor vegetation coverage and/or nuisance vegetation present Grass has died out, become excessively tall (greater than 10 inches) or nuisance vegetation is taking over. Grass is healthy, less than 9 inches high and no nuisance vegetation present. Flow Spreader Concentrated flow Flow from spreader not uniformly distributed across entire swale width. Flows are spread evenly over entire swale width. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-22 NO. 16 – WETPOND MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash and debris accumulated on the wetpond site. Wetpond site free of any trash or debris. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive growth of grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Side Slopes of Dam, Berm, internal berm or Embankment Rodent holes Any evidence of rodent holes if facility is acting as a dam or berm, or any evidence of water piping through dam or berm via rodent holes. Rodents removed or destroyed and dam or berm repaired. Tree growth Tree growth threatens integrity of dams, berms or slopes, does not allow maintenance access, or interferes with maintenance activity. If trees are not a threat to dam, berm or embankment integrity, are not interfering with access or maintenance or leaves do not cause a plugging problem they do not need to be removed. Trees do not hinder facility performance or maintenance activities. Erosion Eroded damage over 2 inches deep where cause of damage is still present or where there is potential for continued erosion. Any erosion observed on a compacted slope. Slopes stabilized using appropriate erosion control measures. If erosion is occurring on compacted slope, a licensed civil engineer should be consulted to resolve source of erosion. Top or Side Slopes of Dam, Berm, internal berm or Embankment Settlement Any part of a dam, berm or embankment that has settled 4 inches lower than the design elevation. Top or side slope restored to design dimensions. If settlement is significant, a licensed civil engineer should be consulted to determine the cause of the settlement. Irregular surface on internal berm Top of berm not uniform and level. Top of berm graded to design elevation. Pond Areas Sediment accumulation (except first wetpool cell) Accumulated sediment that exceeds 10% of the designed pond depth. Sediment cleaned out to designed pond shape and depth. Sediment accumulation (first wetpool cell) Sediment accumulations in pond bottom that exceeds the depth of sediment storage (1 foot) plus 6 inches. Sediment storage contains no sediment. Liner damaged (If applicable) Liner is visible or pond does not hold water as designed. Liner repaired or replaced. Low water level (all wetpool cells) Cell level(s) drops more than 12 inches in any 7-day period. Cell level(s) drops less than 12 inches in any 7-day period. Algae mats (first wetpool cell) Algae mats develop over more than 10% of the water surface should be removed. Algae mats removed (usually in the late summer before Fall rains, especially in Sensitive Lake Protection Areas.) APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-23 NO. 16 – WETPOND MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Pond Areas (cont.) Sparse or dying design planting and poor vegetation survival Sparse or dying design planting, or when design plantings are not thriving across 80% or more of the design vegetated areas within the pond; invasive vegetation (e.g., cattails) Design plantings and vegetation are thriving and appropriately spaced across 80% or more of the design vegetated areas within the pond; invasives removed including root clumps Gravity Drain Inoperable valve Valve will not open and close. Valve opens and closes normally. Valve won’t seal Valve does not seal completely. Valve completely seals closed. Emergency Overflow Spillway Tree growth Tree growth impedes flow or threatens stability of spillway. Trees removed. Rock missing Only one layer of rock exists above native soil in area five square feet or larger, or any exposure of native soil at the top of out flow path of spillway. Rip-rap on inside slopes need not be replaced. Spillway restored to design standards. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-24 NO. 17 – WETVAULT MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Trash and debris accumulated on facility site. Trash and debris removed from facility site. Treatment Area Trash and debris Any trash and debris accumulated in vault (includes floatables and non-floatables). No trash or debris in vault. Sediment accumulation Sediment accumulation in vault bottom exceeds the depth of the sediment zone plus 6 inches. No sediment in vault. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Vault Structure Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch, any evidence of soil entering the structure through cracks, vault does not retain water or qualified inspection personnel determines that the vault is not structurally sound. Vault is sealed and structurally sound. Baffles damaged Baffles corroding, cracking, warping and/or showing signs of failure or baffle cannot be removed. Repair or replace baffles or walls to specifications. Ventilation area blocked/plugged Ventilation area blocked or plugged. No reduction of ventilation area exists. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Gravity Drain Inoperable valve Valve will not open and close. Valve opens and closes normally. Valve won’t seal Valve does not seal completely. Valve completely seals closed. Access Manhole Access cover/lid damaged or difficult to open Access cover/lid cannot be easily opened by one person. Corrosion/deformation of cover/lid. Access cover/lid can be opened by one person. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Access doors/plate has gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat; covers access opening completely. Lifting rings missing, rusted Lifting rings not capable of lifting weight of door or plate. Lifting rings sufficient to lift or remove door or plate. Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-25 NO. 18 – STORMWATER WETLAND MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Trash and debris accumulated on facility site. Trash and debris removed from facility site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive growth or grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Side Slopes of Dam, Berm, Internal Berm or Embankment Rodent holes Any evidence of rodent holes if facility is acting as a dam or berm, or any evidence of water piping through dam or berm via rodent holes. Rodents removed or destroyed and dam or berm repaired. Tree growth Tree growth threatens integrity of dams, berms or slopes, does not allow maintenance access, or interferes with maintenance activity. If trees are not a threat to dam, berm, or embankment integrity or not interfering with access or maintenance, they do not need to be removed. Trees do not hinder facility performance or maintenance activities. Erosion Eroded damage over 2 inches deep where cause of damage is still present or where there is potential for continued erosion. Any erosion observed on a compacted slope. Slopes stabilized using appropriate erosion control measures. If erosion is occurring on compacted slope, a licensed civil engineer should be consulted to resolve source of erosion. Top or Side Slopes of Dam, Berm, Internal Berm or Embankment Settlement Any part of a dam, berm or embankment that has settled 4 inches lower than the design elevation. Top or side slope restored to design dimensions. If settlement is significant, a licensed civil engineer should be consulted to determine the cause of the settlement. Irregular surface on internal berm Top of berm not uniform and level. Top of berm graded flat to design elevation. Pond Areas Sediment accumulation (first cell/forebay) Sediment accumulations in pond bottom that exceeds the depth of sediment storage (1 foot) plus 6 inches. Sediment storage contains no sediment. Sediment accumulation (wetland cell) Accumulated sediment that exceeds 10% of the designed pond depth. Sediment cleaned out to designed pond shape and depth. Liner damaged (If applicable) Liner is visible or pond does not hold water as designed. Liner repaired or replaced. Low water level (first cell/forebay) Cell level drops more than 12 inches in any 7-day period. Cell level drops no more than 12 inches in any 7-day period. Low water level (wetland cell) Cell does not retain water for at least 10 months of the year or wetland plants are not surviving. Water retained at least 10 months of the year or wetland plants are surviving. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-26 NO. 18 – STORMWATER WETLAND MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Pond Areas (cont.) Algae mats (first cell/forebay) Algae mats develop over more than 10% of the water surface should be removed. Algae mats removed (usually in the late summer before Fall rains, especially in Sensitive Lake Protection Areas.) Vegetation Vegetation dead, dying, or overgrown (cattails) or not meeting original planting specifications across more than 20% of the entire design vegetated area within the pond. Plants in wetland cell surviving across 80% or more of the entire design vegetated area within the pond and not interfering with wetland function. Gravity Drain Inoperable valve Valve will not open and close. Valve opens and closes normally. Valve won’t seal Valve does not seal completely. Valve completely seals closed. Emergency Overflow Spillway Tree growth Tree growth impedes flow or threatens stability of spillway. Trees removed. Rock missing Only one layer of rock exists above native soil in area five square feet or larger, or any exposure of native soil at the top of outflow path of spillway. Rip-rap on inside slopes need not be replaced. Spillway restored to design standards. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-27 NO. 19 – SAND FILTER POND MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Trash and debris accumulated on facility site. Trash and debris removed from facility site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive growth of grass/groundcover (not in the treatment area) Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Pre-Treatment (if applicable) Sediment accumulation Sediment accumulations in pond bottom that exceeds the depth of sediment storage (1 foot) plus 6 inches. Sediment storage contains no sediment. Liner damaged (If applicable) Liner is visible or pond does not hold water as designed. Liner repaired or replaced. Low water level Cell empty, doesn't hold water. Water retained in first cell for most of the year. Algae mats Algae mats develop over more than 10% of the water surface should be removed. Algae mats removed (usually in the late summer before Fall rains, especially in Sensitive Lake Protection Areas.) Pond Area Sediment accumulation Sediment or crust depth exceeds ½-inch over 10 % of surface area of sand filter. No sediment or crust deposit on sand filter that would impede permeability of the filter section. Excessive grass growth (if applicable) Grass becomes excessively tall (greater than 6 inches) or when nuisance weeds and other vegetation start to take over or thatch build up occurs. Mow vegetation and/or remove nuisance vegetation. Side Slopes of Pond Rodent holes Any evidence of rodent holes if facility is acting as a dam or berm, or any evidence of water piping through dam or berm via rodent holes. Rodents removed or destroyed and dam or berm repaired. Tree growth Tree growth threatens integrity of dams, berms or slopes, does not allow maintenance access, or interferes with maintenance activity. If trees are not a threat to dam, berm, or embankment integrity or not interfering with access or maintenance, they do not need to be removed. Trees do not hinder facility performance or maintenance activities. Erosion Eroded damage over 2 inches deep where cause of damage is still present or where there is potential for continued erosion. Any erosion observed on a compacted slope. Slopes stabilized using appropriate erosion control measures. If erosion is occurring on compacted slope, a licensed civil engineer should be consulted to resolve source of erosion. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-28 NO. 19 – SAND FILTER POND MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Sand Filter Media Plugged media Drawdown of water through the sand filter media, takes longer than 24 hours, and/or flow through the overflow pipes occurs frequently. A sieve analysis of >4% -100 or >2% -200 requires replacing sand filter media. Sand filter media surface is aerated or the surface is scraped and replaced, and drawdown rate is normal. Prolonged flows Sand is saturated for prolonged periods of time (several weeks) and does not dry out between storms due to continuous base flow or prolonged flows from detention facilities. Excess flows bypassed or confined to small portion of filter media surface. Short circuiting Flows become concentrated over one section of the sand filter rather than dispersed or drawdown rate of pool exceeds 12 inches per hour. Flow and percolation of water through the sand filter is uniform and dispersed across the entire filter area and drawdown rate is normal. Insufficient media thickness Sand thickness is less than 18 inches. Rebuild sand thickness to a minimum of 18 inches. Underdrains and Clean-Outs Sediment and debris Underdrains or clean-outs partially plugged or filled with sediment and/or debris. Junction box/cleanout wyes not watertight. Underdrains and clean-outs free of sediment and debris and are watertight. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Rock Pad Missing rock or out of place Only one layer of rock exists above native soil in area five square feet or larger, or any exposure of native soil. Rock pad restored to design standards. Flow Spreader Concentrated flow Flow from spreader not uniformly distributed across sand filter. Flows spread evenly over sand filter. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-29 NO. 20 – SAND FILTER VAULT MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Trash and debris accumulated on facility site. Trash and debris removed from facility site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive growth of grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Pre-Treatment Chamber Sediment accumulation Sediment accumulation exceeds the depth of the sediment zone plus 6 inches. Sediment storage contains no sediment. Sand Filter Media Sediment accumulation Sediment depth exceeds ½-inch on sand filter media. Sand filter freely drains at normal rate. Trash and debris Trash and debris accumulated in vault (floatables and non-floatables). No trash or debris in vault. Plugged media Drawdown of water through the sand filter media, takes longer than 24 hours, and/or flow through the overflow pipes occurs frequently. A sieve analysis of >4% -100 or >2% -200 requires replacing sand filter media. Sand filter media drawdown rate is normal. Short circuiting Seepage or flow occurs along the vault walls and corners. Sand eroding near inflow area. Cleanout wyes are not watertight. Sand filter media section re-laid and compacted along perimeter of vault to form a semi-seal. Erosion protection added to dissipate force of incoming flow and curtail erosion. Vault Structure Damaged to walls, frame, bottom and/or top slab. Cracks wider than ½-inch, any evidence of soil entering the structure through cracks or qualified inspection personnel determines that the vault is not structurally sound. Vault replaced or repaired to provide complete sealing of the structure. Ventilation area blocked/plugged Ventilation area blocked or plugged. No reduction of ventilation area exists. Underdrains and Cleanouts Sediment and debris Underdrains or clean-outs partially plugged, filled with sediment and/or debris or not watertight. Underdrains and clean-outs free of sediment and debris and sealed. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-30 NO. 20 – SAND FILTER VAULT MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Access Manhole Cover/lid not in place Cover/lid is missing or only partially in place. Any open manhole requires immediate maintenance. Manhole access covered. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. Large Access Doors/Plate Damaged or difficult to open access doors/plate Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can be opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat; covers access opening completely. Lifting rings missing, rusted Lifting rings not capable of lifting weight of door or plate. Lifting rings sufficient to lift or remove door or plate. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-31 NO. 21 – PROPRIETARY FACILITY CARTRIDGE FILTER SYSTEMS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED In addition to the specific maintenance criteria provided below, all manufacturers’ requirements shall be followed. Facility Documentation Update facility inspection record after each inspection. Maintenance records are up to date. Provide certification of replaced filter media. Filter media is certified to meet manufacturer specifications. Site Trash and debris Any trash or debris which impairs the function of the facility. Trash and debris removed from facility. Contaminants and pollution Any evidence of contaminants or pollution such as oils, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Life cycle Once per year. Facility is re-inspected and any needed maintenance performed. Vault Treatment Area Sediment on vault floor Varies – Refer to manufacturer’s requirements. Vault is free of sediment. Sediment on top of cartridges Varies – Refer to manufacturer’s requirements. Vault is free of sediment. Multiple scum lines above top of cartridges Thick or multiple scum lines above top of cartridges. Probably due to plugged canisters or underdrain manifold. Cause of plugging corrected, canisters replaced if necessary. Vault Structure Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch and any evidence of soil particles entering the structure through the cracks, or qualified inspection personnel determines the vault is not structurally sound. Vault replaced or repaired to design specifications. Baffles damaged Baffles corroding, cracking warping, and/or showing signs of failure as determined by maintenance/inspection person. Repair or replace baffles to specification. Filter Media Standing water in vault Varies – Refer to manufacturer’s requirements. No standing water in vault 24 hours after a rain event. Short circuiting Flows do not properly enter filter cartridges. Flows go through filter media. Underdrains and Clean-Outs Sediment and debris Underdrains or clean-outs partially plugged or filled with sediment and/or debris. Underdrains and clean-outs free of sediment and debris. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-32 NO. 21 – PROPRIETARY FACILITY CARTRIDGE FILTER SYSTEMS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Access Manhole Cover/lid not in place Cover/lid is missing or only partially in place. Any open manhole requires immediate maintenance. Manhole access covered. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. Large Access Doors/Plate Damaged or difficult to open Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can be opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat and cover access opening completely. Lifting Rings missing, rusted Lifting rings not capable of lifting weight of door or plate. Lifting rings sufficient to lift or remove door or plate. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-33 NO. 22 – BAFFLE OIL/WATER SEPARATOR MAINTENANCE COMPONENT DEFECT CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash or debris which impairs the function of the facility. Trash and debris removed from facility. Contaminants and pollution Floating oil in excess of 1 inch in first chamber, any oil in other chambers or other contaminants of any type in any chamber. No contaminants present other than a surface oil film. Vault Treatment Area Sediment accumulation Sediment accumulates exceeds 6 inches in the vault. No sediment in the vault. Discharge water not clear Inspection of discharge water shows obvious signs of poor water quality- effluent discharge from vault shows thick visible sheen. Effluent discharge is clear. Trash or debris accumulation Any trash and debris accumulation in vault (floatables and non-floatables). Vault is clear of trash and debris. Oil accumulation Oil accumulations that exceed 1 inch, at the surface of the water in the oil/water separator chamber. No visible oil depth on water. Vault Structure Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch or evidence of soil particles entering the structure through the cracks, or maintenance/inspection personnel determines that the vault is not structurally sound. Vault replaced or repaired to design specifications. Baffles damaged Baffles corroding, cracking, warping and/or showing signs of failure as determined by maintenance inspection personnel. Repair or replace baffles to specifications. Gravity Drain Inoperable valve Valve will not open and close. Valve opens and closes normally. Valve won’t seal Valve does not seal completely. Valve completely seals closed. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Access Manhole Cover/lid not in place Cover/lid is missing or only partially in place. Any open manhole requires immediate maintenance. Manhole access covered. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-34 NO. 22 – BAFFLE OIL/WATER SEPARATOR MAINTENANCE COMPONENT DEFECT CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Large Access Doors/Plate Damaged or difficult to open Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can be opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat and cover access opening completely. Lifting rings missing, rusted Lifting rings not capable of lifting weight of door or cover/lid. Lifting rings sufficient to lift or remove cover/lid. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-35 NO. 23 – COALESCING PLATE OIL/WATER SEPARATOR MAINTENANCE COMPONENT DEFECT CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash or debris which impairs the function of the facility. Trash and debris removed from facility. Contaminants and pollution Floating oil in excess of 1 inch in first chamber, any oil in other chambers or other contaminants of any type in any chamber. No contaminants present other than a surface oil film. Vault Treatment Area Sediment accumulation in the forebay Sediment accumulation of 6 inches or greater in the forebay. No sediment in the forebay. Discharge water not clear Inspection of discharge water shows obvious signs of poor water quality – effluent discharge from vault shows thick visible sheen. Repair function of plates so effluent is clear. Trash or debris accumulation Trash and debris accumulation in vault (floatables and non-floatables). Trash and debris removed from vault. Oil accumulation Oil accumulation that exceeds 1 inch at the water surface in the in the coalescing plate chamber. No visible oil depth on water and coalescing plates clear of oil. Coalescing Plates Damaged Plate media broken, deformed, cracked and/or showing signs of failure. Replace that portion of media pack or entire plate pack depending on severity of failure. Sediment accumulation Any sediment accumulation which interferes with the operation of the coalescing plates. No sediment accumulation interfering with the coalescing plates. Vault Structure Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch and any evidence of soil particles entering the structure through the cracks, or maintenance inspection personnel determines that the vault is not structurally sound. Vault replaced or repaired to design specifications. Baffles damaged Baffles corroding, cracking, warping and/or showing signs of failure as determined by maintenance/inspection person. Repair or replace baffles to specifications. Ventilation Pipes Plugged ventilation pipes Any obstruction to the ventilation pipes. Ventilation pipes are clear. Shutoff Valve Damaged or inoperable shutoff valve Shutoff valve cannot be opened or closed. Shutoff valve operates normally. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Access Manhole Cover/lid not in place Cover/lid is missing or only partially in place. Any open manhole requires immediate maintenance. Manhole access covered. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-36 NO. 23 – COALESCING PLATE OIL/WATER SEPARATOR MAINTENANCE COMPONENT DEFECT CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Access Manhole (cont.) Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. Large access doors/plate Damaged or difficult to open Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can be opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat and cover access opening completely. Lifting rings missing, rusted Lifting rings not capable of lifting weight of door or plate. Lifting rings sufficient to lift or remove door or plate. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-37 NO. 24 – CATCH BASIN INSERT (NOT ALLOWED IN THE CITY FOR OIL CONTROL) APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-38 NO. 25 – DRYWELL BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Preventive Plugging, obstructions Any cause limiting flow into drywell. Drywell able to receive full flow prior to and during wet season. Site Trash and debris Trash or debris that could end up in the drywell is evident. No trash or debris that could get into the drywell can be found. Pipes Plugged inlet The entrance to the pipe is restricted due to sediment, trash, or debris. The entrance to the pipe is not restricted. Vegetation/root growth in pipes Vegetation/roots that reduce free movement of water through pipes. Water flows freely through pipes. Plugged pipe Sediment or other material prevents free flow of water through the pipe. Water flows freely through pipes. Broken pipe or joint leaks Damage to the pipe or pipe joints allowing water to seep out. Pipe does not allow water to exit other than at the outlet. Structure Basin leaks Holes or breaks in the basin allow water to leave the basin at locations other than per design. Basin is sealed and allows water to exit only where designed. Filter Media Plugged filter media Filter media plugged. Flow through filter media is normal. NO. 26 – GRAVEL FILLED INFILTRATION TRENCH BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Preventive Blocking, obstructions Debris or trash limiting flow to infiltration trench. Infiltration trench able to receive full flow prior to and during wet season. Site Trash and debris Trash or debris that could end up in the infiltration trench is evident. No trash or debris that could get into the infiltration trench can be found. Pipes Plugged inlet The entrance to the pipe is restricted due to sediment, trash, or debris. The entrance to the pipe is not restricted. Vegetation/root growth in pipes Vegetation/roots that reduce free movement of water through pipes. Water flows freely through pipes. Plugged pipes Sediment or other material prevents free flow of water through the pipe. Water flows freely through pipes. Broken pipe or joint leaks Damage to the pipe or pipe joints allowing water to seep out. Pipe does not allow water to exit other than at the outlet to the trench. Structure Flow not reaching trench Flows are not getting into the trench as designed. Water enters and exits trench as designed. Cleanout/inspection access does not allow cleaning or inspection of trench The cleanout/inspection access is not available. Cleanout/inspection access is available. Filter Media Plugged filter media Filter media plugged. Flow through filter media is normal. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-39 NO. 27 – GRAVEL FILLED DISPERSION TRENCH BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Preventive Blocking, obstructions Debris or trash limiting flow to dispersion trench or preventing spreader function. Dispersion trench able to receive full flow prior to and during wet season. Site Trash and debris Trash or debris that could end up in the dispersion trench is evident. No trash or debris that could get into the dispersion trench can be found. Pipes Plugged inlet The entrance to the pipe is restricted due to sediment, trash, or debris. The entrance to the pipe is not restricted. Vegetation/root growth in pipes Vegetation/roots that reduce free movement of water through pipes. Water flows freely through pipes. Plugged pipe Sediment or other material prevents free flow of water through the pipe. Water flows freely through pipes. Broken pipe or joint leaks. Damage to the pipe or pipe joints allowing water to seep out. Pipe does not allow water to exit other than at the outlet to the trench. Broken or missing cleanout caps Cleanout caps are broken, missing, or buried. Cleanout caps are accessible and intact. Structure Flow not reaching trench Flows are not getting into the trench as designed. Water enters and exits trench as designed. Perforated pipe plugged Flow not able to enter or properly exit from perforated pipe. Water freely enters and exits perforated pipe. Flow not spreading evenly at outlet of trench Outlet flows channelizing or not spreading evenly from trench. Sheet flow occurs at the outlet of the trench. Cleanout/inspection access does not allow cleaning or inspection of perforated pipe The cleanout/inspection access is not available. Cleanout/inspection access is available. Filter Media Plugged filter media Filter media plugged. Flow through filter media is normal. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-40 NO. 28 – NATIVE VEGETATED SURFACE/NATIVE VEGETATED LANDSCAPE BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Trash and debris accumulated on the native vegetated surface/native vegetated landscape site. Native vegetated surface site free of any trash or debris. Vegetation Insufficient vegetation Less than two species each of native trees, shrubs, and groundcover occur in the design area. A minimum of two species each of native trees, shrubs, and groundcover is established and healthy. Poor vegetation coverage Less than 90% if the required vegetated area has healthy growth. A minimum of 90% of the required vegetated area has healthy growth. Undesirable vegetation present Weeds, blackberry, and other undesirable plants are invading more than 10% of vegetated area. Less than 10% undesirable vegetation occurs in the required native vegetated surface area. Vegetated Area Soil compaction Soil in the native vegetation area compacted. Less than 8% of native vegetation area is compacted. Insufficient vegetation Less than 3.5 square feet of native vegetation area for every 1 square foot of impervious surface. A minimum of 3.5 square feet of native vegetation area for every 1 square foot of impervious surface. Excess slope Slope of native vegetation area greater than 15%. Slope of native growth area does not exceed 15%. NO. 29 – PERFORATED PIPE CONNECTIONS BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Preventive Blocking, obstructions Debris or trash limiting flow into perforated pipe system or outfall of BMP is plugged or otherwise nonfunctioning. Outfall of BMP is receiving designed flows from perforated pipe connection. Inflow Inflow impeded Inflow into the perforated pipe is partially or fully blocked or altered to prevent flow from getting into the pipe. Inflow to the perforated pipe is unimpeded. Pipe Trench Area Surface compacted Ground surface over the perforated pipe trench is compacted or covered with impermeable material. Ground surface over the perforated pipe is not compacted and free of any impervious cover. Outflow Outflow impeded Outflow from the perforated pipe into the public drainage system is blocked. Outflow to the public drainage system is unimpeded. Outfall Area Erosion or landslides Existence of the perforated pipe is causing or exasperating erosion or landslides. Perforated pipe system is sealed off and an alternative BMP is implemented. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-41 NO. 30 – PERMEABLE PAVEMENT BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Preventive Surface cleaning/ vegetation control Media surface vacuumed or pressure washed annually, vegetation controlled to design maximum. Weed growth suggesting sediment accumulation. No dirt, sediment, or debris clogging porous media, or vegetation limiting infiltration. Porous Concrete, Porous Asphaltic Concrete, and Permeable Pavers Trash and debris Trash and debris on the pavement interfering with infiltration; leaf drop in fall season. No trash or debris interfering with infiltration. Sediment accumulation Sediment accumulation on the pavement interfering with infiltration; runoff from adjacent areas depositing sediment/debris on pavement. Pavement infiltrates as designed; adjacent areas stabilized. Insufficient infiltration rate Pavement does not infiltrate at a rate of 10 inches per hour. Pavement infiltrates at a rate greater than 10 inches per hour. Excessive ponding Standing water for a long period of time on the surface of the pavement. Standing water infiltrates at the desired rate. Broken or cracked pavement Pavement is broken or cracked. No broken pavement or cracks on the surface of the pavement. Settlement Uneven pavement surface indicating settlement of the subsurface layer. Pavement surface is uniformly level. Moss growth Moss growing on pavement interfering with infiltration. No moss interferes with infiltration. Inflow restricted Inflow to the pavement is diverted, restricted, or depositing sediment and debris on the pavement. Inflow to pavement is unobstructed and not bringing sediment or debris to the pavement. Underdrain not freely flowing Underdrain is not flowing when pavement has been infiltrating water. Underdrain flows freely when water is present. Overflow not controlling excess water Overflow not controlling excess water to desired location; native soil is exposed or other signs of erosion damage are present. Overflow permits excess water to leave the site at the desired location; Overflow is stabilized and appropriately armored. Permeable Pavers Broken or missing pavers Broken or missing paving blocks on surface of pavement. No missing or broken paving blocks interfering with infiltration. Uneven surface Uneven surface due to settlement or scour of fill in the interstices of the paving blocks. Pavement surface is uniformly level. Compaction Poor infiltration due to soil compaction between paving blocks. No soil compaction in the interstices of the paver blocks limiting infiltration. Poor vegetation growth (if applicable) Grass in the interstices of the paving blocks is dead. Healthy grass is growing in the interstices of the paver blocks. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-42 NO. 31 – BIORETENTION BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Preventive Vegetation Vegetation to be watered and pruned as needed and mulch applied to a minimum of 2 inches to maintain healthy growth. Healthy vegetation growth with full coverage as designed. Bioretention Area Trash and debris Trash and debris in the bioretention area; leaf drop in the fall season. No trash or debris In the bioretention area. Sediment accumulation Sediment accumulation in the bioretention area interfering with infiltration. Water in the bioretention infiltrates as designed. Excessive ponding Standing water in the bioretention area for more than two days. Standing water infiltrates at the desired rate. Inflow restricted Inflow not getting into bioretention; debris/sediment blockage at inlet features; native soil is exposed or other signs of erosion damage is present. Unobstructed and properly routed inflow into bioretention area; inlet is stabilized and appropriately armored. Overflow not controlling excess water Overflow water not controlled by outlet features; native soil is exposed or other signs of erosion damage is present. Outlet features control overflow; overflow is stabilized and appropriately armored. Underdrain not freely flowing Underdrain is not flowing when bioretention area has been infiltrating water. Underdrain flows freely when water is present. Vegetation Poor vegetation coverage Plants not thriving across at least 80% of the entire design vegetated area within the BMP; overly dense vegetation requiring pruning. Healthy water tolerant plants in bioretention area, plants thriving across at least 80% of the entire design vegetated area within the facility. Insufficient vegetation Plants not water tolerant species. Plants are water tolerant. Weeds present Weeds growing in bioretention area. No weeds in bioretention area. Watering not occurring Planting schedule requires frequent watering (approx. weekly Year 1, bimonthly Years 2 and 3) for new facilities, and as needed for established plantings or dry periods Plants are established and thriving Pest control Signs of pests, such as wilting or chewed leaves or bark, spotting or other indicators; extended ponding period encouraging mosquitoes Plant community is pest-free when following an approved Integrated Pest Management plan; bioretention functioning normally and ponding controlled as needed for pest control Containment Berm and Earthen Slopes Erosion Erosion occurring at earthen slopes or containment berm side slope. Erosion on the containment berm and side slopes has been repaired and the cause of the erosion corrected. Voids created by nuisance animals (e.g., rodents) or tree roots Voids affecting berm integrity or creating leaky pond condition Voids have been repaired; facility is free of nuisance animals following an approved Integrated Pest Management plan. Settlement Any part of the containment berm top has less than 6 inches of freeboard from the maximum pond level to the top of the berm. A minimum of 6 inches freeboard from the maximum pond level to the top of the berm. Amended Soil Poor soil nutrients Soil not providing plant nutrients. Soil providing plant nutrients. Bare spots Bare spots on soil in bioretention area. No bare spots, bioretention area covered with vegetation or mulch mixed into the underlying soil. Compaction Poor infiltration due to soil compaction in the bioretention area. No soil compaction in the bioretention area. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-43 NO. 32 – RAINWATER HARVESTING BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Preventive Insufficient storage volume No rain water in storage unit at the beginning of the rain season. Maximum storage available at the beginning of the rain season (Oct. 1). Collection Area Trash and debris Trash of debris on collection area may plug filter system Collection area clear of trash and debris. Filter Restricted or plugged filter Filter is partially or fully plugged preventing water from getting in to the storage unit. Filter is allowing collection water into storage unit. NO. 33 – ROCK PAD BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Trash and debris accumulated on rock pad site. Rock pad site free of any trash or debris. Rock Pad Area Insufficient rock pad size Rock pad is not 2 feet by 3 feet by 6 inches thick or as designed. Rock pad is 2 feet by 3 feet by 6 inches thick or as designed. Vegetation growth Vegetation is seen growing in or through rock pad. No vegetation within rock pad area. Rock Exposed soil Soil can be seen through the rock pad. Full thickness of the rock pad is in place, no soil visible through rock pad. NO. 34 – SHEET FLOW BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Trash and debris accumulated on the sheet flow site. Sheet flow site free of any trash or debris. Sheet flow area Erosion Soil erosion occurring in sheet flow zone. Soil erosion is not occurring and rills and channels have been repaired. Concentrated flow Sheet flow is not occurring in the sheet flow zone. Sheet flow area is regraded to provide sheet flow. NO. 35 – SPLASH BLOCK BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Trash and debris accumulated on the splash block. Splash block site free of any trash or debris. Splash Block Dislodged splash block Splash block moved from outlet of downspout. Splash block correctly positioned to catch discharge from downspout. Channeling Water coming off the splash block causing erosion. No erosion occurs from the splash block. Downspout water misdirected Water coming from the downspout is not discharging to the dispersal area. Water is discharging normally to the dispersal area. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-44 NO. 36 – VEGETATED ROOF BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Preventive Vegetation Vegetation to be watered and pruned as needed to maintain healthy growth. Healthy vegetation growth with full coverage as designed. Site Trash and debris Trash and debris has accumulated on the vegetated roof. Vegetated roof free of any trash or debris. Waterproof Membrane Leaking waterproof membrane Waterproof membrane breached. Waterproof membrane has no tears or holes allowing water through it. Drainage Layer Drainage pathway plugged/obstructed Drainage layer flow plugged or obstructed. Drainage layer passing water with no obstruction. Drainage Overflow obstructed Drainage of overflow is obstructed. Overflow has no obstruction. Growth Media Compaction Soil in the growth media area compacted. No part of the growth media is compacted. Erosion Growth media washed out. Growth media is not being washed away. Insufficient nutrients Plants are not thriving. Growth media has proper nutrients to support plant growth. Vegetation Insufficient vegetation Vegetation species not succulents, grass, herbs, and/or wildflowers adapted to harsh conditions. Correct species of vegetation is used. Poor vegetation coverage Healthy vegetation covers less than 90% of vegetation area. Healthy vegetation covers more than 90% of vegetation area. Undesirable vegetation Weeds and other undesirable plants are invading more than 10% of vegetated area. No undesirable vegetation occurs in the vegetated area. No herbicides or pesticides used to control undesirable vegetation. Poor vegetation growth Special vegetation not thriving. Special vegetation is kept healthy and inspected on frequent schedule. Border Zone Access restricted Border zone limited by vegetation overgrowth or other means. Border zone is kept open so vegetated area is accessible. Gravel Stop Overflow uncontained Gravel stop does not contain overflow or divert it to a designed outlet. Overflow water is only exits from the designed outlet. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-45 NO. 37 – RAIN GARDEN BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Facility – General Requirements Mosquitoes Standing water remains for more than 3 days after the end of a storm Rain garden drains freely. Standing water in rain garden does not persist for more than 3 days after a storm event. Cause of the standing water addressed (see “Ponded water”). Trash and debris Trash and debris present No trash or debris present Earthen Side Slopes and Berms Erosion Persistent soil erosion on slopes No eroded or scoured areas. Cause of erosion or scour addressed. Rockery Sidewalls Unstable rockery Rockery side walls are insecure Stable rockery sidewalls (may require consultation with licensed engineer, particularly for walls 4 feet or greater in height) Rain Garden Bottom Area Sediment accumulation Visible sediment deposition in the rain garden that reduces drawdown time of water in the rain garden No sediment accumulation in rain garden. Source of sediment addressed. Debris accumulation Accumulated leaves in facility No leaves clogging outlet structure or impeding water flow. Mulch Lack of mulch Bare spots (without mulch cover) are present or mulch depth less than 2 inches Facility has a minimum 2- to 3-inch layer of an appropriate type of mulch. Mulch kept away from woody stems. Splash Block Inlet Water not properly directed to rain garden Water is being directed towards building structure Blocks are reconfigured to direct water to rain garden and away from structure. Pipe Inlet/Outlet Erosion Rock or cobble removed or missing and concentrated flows contacting soil No eroded or scoured areas. Cause of erosion or scour addressed. Cover of rock or cobbles protects the ground where concentrated water flows into the rain garden. Accumulated debris Accumulated leaves, sediment, debris or vegetation at curb cuts, inlet or outlet pipe Blockage cleared Damaged pipe Pipe is damaged Pipe repaired/replaced Clogged pipe Pipe is clogged Pipe clear of roots and debris Blocked access Maintain access for inspections Vegetation cleared or transplanted within 1 foot of inlets and outlets Ponded Water Ponded water Excessive ponding water: Ponded water remains in the rain garden more than 48 hours after the end of a storm Rain garden drains freely. Standing water in rain garden does not persist for more than 48 hours after a storm event. Leaf litter/debris/sediment removed. Overflow Blocked overflow Capacity reduced by sediment or debris No sediment or debris in overflow. Vegetation Blocked site distances and sidewalks Vegetation inhibits sight distances and sidewalks Sidewalks and sight distances along roadways and sidewalks are kept clear. Blocked pipes Vegetation is crowding inlets and outlets Inlets and outlets in rain garden clear of vegetation. Unhealthy vegetation Yellowing: possible Nitrogen (N) deficiency Poor growth: possible Phosphorous (P) deficiency Poor flowering, spotting or curled leaves, or weak roots or stems: possible Potassium (K) deficiency Plants are healthy and appropriate for site conditions. Weeds Presence of weeds Weeds removed (manual methods preferred) and mulch applied. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-46 NO. 37 – RAIN GARDEN BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Summer Watering (years 1–3) Plant establishment Tree, shrubs and groundcovers in first 3 years of establishment period Plants are watered during plant establishment period (years 1–3). Summer Watering (after establishment) Drought conditions Vegetation requires supplemental water Plants are watered during drought conditions or more often if necessary during post-establishment period (after 2 years). APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-47 NO. 38 – SOIL AMENDMENT BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Soil Media Unhealthy vegetation Vegetation not fully covering ground surface or vegetation health is poor. Yellowing: possible Nitrogen (N) deficiency. Poor growth: possible Phosphorous (P) deficiency. Poor flowering, spotting or curled leaves, or weak roots or stems: possible Potassium (K) deficiency. Plants are healthy and appropriate for site conditions Inadequate soil nutrients and structure In the fall, return leaf fall and shredded woody materials from the landscape to the site when possible Soil providing plant nutrients and structure Excessive vegetation growth Grass becomes excessively tall (greater than 10 inches); nuisance weeds and other vegetation start to take over. Healthy turf- “grasscycle” (mulch-mow or leave the clippings) to build turf health Weeds Preventive maintenance Avoid use of pesticides (bug and weed killers), like “weed & feed,” which damage the soil Fertilizer needed Where fertilization is needed (mainly turf and annual flower beds), a moderate fertilization program should be used which relies on compost, natural fertilizers or slow-release synthetic balanced fertilizers Integrated Pest Management (IPM) protocols for fertilization followed Bare spots Bare spots on soil No bare spots, area covered with vegetation or mulch mixed into the underlying soil. Compaction Poor infiltration due to soil compaction  To remediate compaction, aerate soil, till to at least 8-inch depth, or further amend soil with compost and re-till  If areas are turf, aerate compacted areas and top dress them with 1/4 to 1/2 inch of compost to renovate them  If drainage is still slow, consider investigating alternative causes (e.g., high wet season groundwater levels, low permeability soils)  Also consider site use and protection from compacting activities No soil compaction Poor infiltration Soils become waterlogged, do not appear to be infiltrating. Facility infiltrating properly Erosion/Scouring Erosion Areas of potential erosion are visible Causes of erosion (e.g., concentrate flow entering area, channelization of runoff) identified and damaged area stabilized (regrade, rock, vegetation, erosion control matting).For deep channels or cuts (over 3 inches in ponding depth), temporary erosion control measures in place until permanent repairs can be made Grass/Vegetation Unhealthy vegetation Less than 75% of planted vegetation is healthy with a generally good appearance. Healthy vegetation. Unhealthy plants removed/replaced. Appropriate vegetation planted in terms of exposure, soil and soil moisture. Noxious Weeds Noxious weeds Listed noxious vegetation is present (refer to current County noxious weed list). No noxious weeds present. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-48 NO. 39 – RETAINED TREES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Tree Dead or declining Dead, damaged, or declining Tree replaced per planting plan or acceptable substitute NO. 40 – FILTERRA SYSTEM MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED In addition to the specific maintenance criteria provided below, all manufacturer’s requirements shall be followed. Facility – General Requirements Life cycle Once per year, except mulch and trash removal twice per year Facility is re-inspected and any needed maintenance performed Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries, or paint Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Inlet Excessive sediment or trash accumulation Accumulated sediments or trash impair free flow of water into system Inlet should be free of obstructions allowing free distributed flow of water into system Mulch Cover Trash and floatable debris accumulation Excessive trash and/or debris accumulation Minimal trash or other debris on mulch cover. Mulch cover raked level. “Ponding” of water on mulch cover “Ponding” in unit could be indicative of clogging due to excessive fine sediment accumulation or spill of petroleum oils Stormwater should drain freely and evenly through mulch cover Proprietary Filter Media/ Vegetation Substrate “Ponding” of water on mulch cover after mulch cover has been maintained Excessive fine sediment passes the mulch cover and clogs the filter media/vegetative substrate Stormwater should drain freely and evenly through mulch cover. Replace substrate and vegetation when needed Vegetation Plants not growing or in poor condition Soil/mulch too wet, evidence of spill, incorrect plant selection, pest infestation, and/or vandalism to plants Plants should be healthy and pest free Media/mulch too dry Irrigation is required Plants absent Plants absent Appropriate plants are present Excessive plant growth Excessive plant growth inhibits facility function or becomes a hazard for pedestrian and vehicular circulation and safety Pruning and/or thinning vegetation maintains proper plant density. Appropriate plants are present. Structure Structure has visible cracks Cracks wider than ½ inch Evidence of soil particles entering the structure through the cracks Structure is sealed and structurally sound APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-49 NO. 41 – COMPOST AMENDED VEGETATED FILTER STRIP (CAVFS) MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED General Sediment accumulation on grass Sediment depth exceeds 2 inches. Remove sediment deposits. Relevel so slope is even and flows pass evenly through strip. Excessive vegetation growth Grass becomes excessively tall (greater than 10 inches); nuisance weeds and other vegetation start to take over. Mow grass and control nuisance vegetation so that flow is not impeded. Grass should be mowed to a height of 6 inches. Trash and debris Trash and debris have accumulated on the vegetated filter strip. Remove trash and debris from filter. Erosion/scouring Areas have eroded or scoured due to flow channelization or high flows. For ruts or bare areas less than 12 inches wide, repair the damaged area by filling with a 50/50 mixture of crushed gravel and compost. The grass will creep in over the rock in time. If bare areas are large, generally greater than 12 inches wide, the vegetated filter strip should be regraded and reseeded. For smaller bare areas, overseed when bare spots are evident. Flow spreader uneven or clogged Flow spreader is uneven or clogged so that flows are not uniformly distributed over entire filter width. Level the spreader and clean so that flows are spread evenly over entire filter width APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-50 NO. 42 – MEDIA FILTER DRAIN (MFD) MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED General Sediment accumulation on grass filter strip Sediment depth exceeds 2 inches or creates uneven grading that interferes with sheet flow. Remove sediment deposits on grass treatment area of the embankment. When finished, embankment should be level from side to side and drain freely toward the toe of the embankment slope. There should be no areas of standing water once inflow has ceased. No-vegetation zone/flow spreader is uneven or clogged Flow spreader is uneven or clogged so that flows are not uniformly distributed over entire embankment width. Level the spreader and clean to spread flows evenly over entire embankment width. Poor vegetation coverage Grass is sparse or bare, or eroded patches are observed in more than 10% of the grass strip surface area. Determine why grass growth is poor and correct the offending condition. Reseed into loosened, fertile soil or compost; or, replant with plugs of grass from the upper slope. Excessive vegetation growth Grass becomes excessively tall (greater than 10 inches); nuisance weeds and other vegetation start to take over. Mow vegetation or remove nuisance vegetation to not impede flow. Mow grass to a height of 6 inches. Media filter drain mix needs replacement Water is seen on the surface of the media filter drain mix long after the storms have ceased. Typically, the 6-month, 24-hour precipitation event should drain within 48 hours. More common storms should drain within 24 hours. Maintenance also needed on a 10-year cycle and during a preservation project. Excavate and replace all of the media filter drain mix contained within the media filter drain. Excessive shading Grass growth is poor because sunlight does not reach embankment. If possible, trim back overhanging limbs and remove brushy vegetation on adjacent slopes. Trash and debris Trash and debris have accumulated on embankment. Remove trash and debris from embankment. Flooding of media filter drain When media filter drain is inundated by flood water Evaluate media filter drain material for acceptable infiltration rate and replace if media filter drain does not meet long-term infiltration rate standards. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-51 NO. 43 – COMPOST-AMENDED BIOFILTRATION SWALE MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash and/or debris accumulated on the bioswale site. No trash or debris on the bioswale site. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Swale Section Sediment accumulation Sediment depth exceeds 2 inches in 10% of the swale treatment area. No sediment deposits in grass treatment area of the bioswale. Sediment inhibits grass growth over 10% of swale length. Grass growth not inhibited by sediment. Sediment inhibits even spreading of flow. Flow spreads evenly through swale Erosion/scouring Eroded or scoured swale bottom due to channelization or high flows. No eroded or scoured areas in bioswale. Cause of erosion or scour addressed. Poor vegetation coverage Grass is sparse or bare or eroded patches occur in more than 10% of the swale bottom. Swale has no bare spots and grass is thick and healthy. Excessive vegetation growth Grass excessively tall (greater than 10 inches), grass is thin or nuisance weeds and other vegetation have taken over. Grass is between 3 and 4 inches tall, thick and healthy. No nuisance vegetation present. Excessive shade Grass growth is poor because sunlight does not reach swale. Healthy grass growth or swale converted to a wet bioswale. Constant baseflow Continuous flow through the swale, even when it has been dry for weeks or an eroded, muddy channel has formed in the swale bottom. Baseflow removed from swale by a low- flow pea-gravel drain or bypassed around the swale. Standing water Water pools in the swale between storms or does not drain freely. Swale freely drains and there is no standing water in swale between storms. Channelization Flow concentrates and erodes channel through swale. No flow channels in swale. Insufficient compost depth Depth of compost is less than 3 inches. Compost depth is 3 inches. Flow Spreader Concentrated flow Flow from spreader not uniformly distributed across entire swale width. Flows are spread evenly over entire swale width. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2021 Surface Water Design Manual – Appendix A 7/23/2021 A-5 NO. 3 – DETENTION TANKS AND VAULTS Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Site Trash and debris Any trash and debris which exceed 1 cubic foot per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Trash and debris cleared from site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to County personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where County personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Tank or Vault Storage Area Trash and debris Any trash and debris accumulated in vault or tank (includes floatables and non-floatables). No trash or debris in vault. Sediment accumulation Accumulated sediment depth exceeds 10% of the diameter of the storage area for ½ length of storage vault or any point depth exceeds 15% of diameter. Example: 72-inch storage tank would require cleaning when sediment reaches depth of 7 inches for more than ½ length of tank. All sediment removed from storage area. Tank Structure Plugged air vent Any blockage of the vent. Tank or vault freely vents. Tank bent out of shape Any part of tank/pipe is bent out of shape more than 10% of its design shape. Tank repaired or replaced to design. Gaps between sections, damaged joints or cracks or tears in wall A gap wider than ½-inch at the joint of any tank sections or any evidence of soil particles entering the tank at a joint or through a wall. No water or soil entering tank through joints or walls. Vault Structure Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch, any evidence of soil entering the structure through cracks or qualified inspection personnel determines that the vault is not structurally sound. Vault is sealed and structurally sound. Inlet/Outlet Pipes Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 7/23/2021 2021 Surface Water Design Manual – Appendix A A-6 NO. 3 – DETENTION TANKS AND VAULTS Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Access Manhole Cover/lid not in place Cover/lid is missing or only partially in place. Any open manhole requires immediate maintenance. Manhole access covered. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. Large access doors/plate Damaged or difficult to open Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat; covers access opening completely. Lifting Rings missing, rusted Lifting rings not capable of lifting weight of door or plate. Lifting rings sufficient to lift or remove door or plate. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2021 Surface Water Design Manual – Appendix A 7/23/2021 A-7 NO. 4 – CONTROL STRUCTURE/FLOW RESTRICTOR Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Structure Trash and debris Trash or debris of more than ½ cubic foot which is located immediately in front of the structure opening or is blocking capacity of the structure by more than 10%. No Trash or debris blocking or potentially blocking entrance to structure. Trash or debris in the structure 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 structure. Deposits of garbage exceeding 1 cubic foot in volume. No condition present which would attract or support the breeding of insects or rodents. Sediment Sediment exceeds 60% of the depth from the bottom of the structure to the invert of the lowest pipe into or out of the structure or the bottom of the FROP-T section or is within 6 inches of the invert of the lowest pipe into or out of the structure or the bottom of the FROP-T section. Sump of structure contains no sediment. Damage to frame and/or top slab Corner of frame extends more than ¾ inch past curb face into the street (If applicable). Frame is even with curb. Top slab has holes larger than 2 square inches or cracks wider than ¼ inch. Top slab is free of holes and cracks. Frame not sitting flush on top slab, i.e., separation of more than ¾ inch of the frame from the top slab. Frame is sitting flush on top slab. Cracks in walls or bottom Cracks wider than ½ inch and longer than 3 feet, any evidence of soil particles entering structure through cracks, or maintenance person judges that structure is unsound. Structure is sealed and structurally sound. Cracks wider than ½ inch and longer than 1 foot at the joint of any inlet/outlet pipe or any evidence of soil particles entering structure through cracks. No cracks more than 1/4 inch wide at the joint of inlet/outlet pipe. Settlement/ misalignment Structure has settled more than 1 inch or has rotated more than 2 inches out of alignment. Basin replaced or repaired to design standards. Damaged pipe joints Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering the structure at the joint of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of inlet/outlet pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Ladder rungs missing or unsafe Ladder is unsafe due to missing rungs, misalignment, rust, cracks, or sharp edges. Ladder meets design standards and allows maintenance person safe access. FROP-T Section Damage T section is not securely attached to structure wall and outlet pipe structure should support at least 1,000 lbs of up or down pressure. T section securely attached to wall and outlet pipe. Structure is not in upright position (allow up to 10% from plumb). Structure in correct position. Connections to outlet pipe are not watertight or show signs of deteriorated grout. Connections to outlet pipe are water tight; structure repaired or replaced and works as designed. Any holes—other than designed holes—in the structure. Structure has no holes other than designed holes. Cleanout Gate Damaged or missing Cleanout gate is missing. Replace cleanout gate. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 7/23/2021 2021 Surface Water Design Manual – Appendix A A-8 NO. 4 – CONTROL STRUCTURE/FLOW RESTRICTOR Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Cleanout gate is not watertight. Gate is watertight and works as designed. Gate cannot be moved up and down by one maintenance person. Gate moves up and down easily and is watertight. Chain/rod leading to gate is missing or damaged. Chain is in place and works as designed. Orifice Plate Damaged or missing Control device is not working properly due to missing, out of place, or bent orifice plate. Plate is in place and works as designed. Obstructions Any trash, debris, sediment, or vegetation blocking the plate. Plate is free of all obstructions and works as designed. Overflow Pipe Obstructions Any trash or debris blocking (or having the potential of blocking) the overflow pipe. Pipe is free of all obstructions and works as designed. Deformed or damaged lip Lip of overflow pipe is bent or deformed. Overflow pipe does not allow overflow at an elevation lower than design Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Metal Grates (If Applicable) Unsafe grate opening Grate with opening wider than 7/8 inch. Grate opening meets design standards. Trash and debris Trash and debris that is blocking more than 20% of grate surface. Grate free of trash and debris. Damaged or missing Grate missing or broken member(s) of the grate. Grate is in place and meets design standards. Manhole Cover/Lid Cover/lid not in place Cover/lid is missing or only partially in place. Any open structure requires urgent maintenance. Cover/lid protects opening to structure. Locking mechanism Not Working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to Remove One maintenance person cannot remove cover/lid after applying 80 lbs. of lift. Cover/lid can be removed and reinstalled by one maintenance person. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2021 Surface Water Design Manual – Appendix A 7/23/2021 A-9 NO. 5 – CATCH BASINS AND MANHOLES Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Structure Sediment Sediment exceeds 60% of the depth from the bottom of the catch basin to the invert of the lowest pipe into or out of the catch basin or is within 6 inches of the invert of the lowest pipe into or out of the catch basin. Sump of catch basin contains no sediment. Trash and debris Trash or debris of more than ½ cubic foot which is located immediately in front of the catch basin opening or is blocking capacity of the catch basin by more than 10%. No Trash or debris blocking or potentially blocking entrance to catch basin. Trash or debris in the catch basin that exceeds 1/3 the depth from the bottom of basin to invert the lowest pipe into or out of the basin. No trash or debris in the catch basin. Dead animals or vegetation that could generate odors that could cause complaints or dangerous gases (e.g., methane). No dead animals or vegetation present within catch basin. Deposits of garbage exceeding 1 cubic foot in volume. No condition present which would attract or support the breeding of insects or rodents. Damage to frame and/or top slab Corner of frame extends more than ¾ inch past curb face into the street (If applicable). Frame is even with curb. Top slab has holes larger than 2 square inches or cracks wider than ¼ inch. Top slab is free of holes and cracks. Frame not sitting flush on top slab, i.e., separation of more than ¾ inch of the frame from the top slab. Frame is sitting flush on top slab. Cracks in walls or bottom Cracks wider than ½ inch and longer than 3 feet, any evidence of soil particles entering catch basin through cracks, or maintenance person judges that catch basin is unsound. Catch basin is sealed and is structurally sound. Cracks wider than ½ inch and longer than 1 foot at the joint of any inlet/outlet pipe or any evidence of soil particles entering catch basin through cracks. No cracks more than 1/4 inch wide at the joint of inlet/outlet pipe. Settlement/ misalignment Catch basin has settled more than 1 inch or has rotated more than 2 inches out of alignment. Basin replaced or repaired to design standards. Damaged pipe joints Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering the catch basin at the joint of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of inlet/outlet pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 7/23/2021 2021 Surface Water Design Manual – Appendix A A-10 NO. 5 – CATCH BASINS AND MANHOLES Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Metal Grates (Catch Basins) Unsafe grate opening Grate with opening wider than 7/8 inch. Grate opening meets design standards. Trash and debris Trash and debris that is blocking more than 20% of grate surface. Grate free of trash and debris. Damaged or missing Grate missing or broken member(s) of the grate. Any open structure requires urgent maintenance. Grate is in place and meets design standards. Manhole Cover/Lid Cover/lid not in place Cover/lid is missing or only partially in place. Any open structure requires urgent maintenance. Cover/lid protects opening to structure. Locking mechanism Not Working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to Remove One maintenance person cannot remove cover/lid after applying 80 lbs. of lift. Cover/lid can be removed and reinstalled by one maintenance person. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2021 Surface Water Design Manual – Appendix A 7/23/2021 A-11 NO. 6 – CONVEYANCE PIPES AND DITCHES Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Pipes Sediment & debris accumulation Accumulated sediment or debris that exceeds 20% of the diameter of the pipe. Water flows freely through pipes. Vegetation/roots Vegetation/roots that reduce free movement of water through pipes. Water flows freely through pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Damage to protective coating or corrosion Protective coating is damaged; rust or corrosion is weakening the structural integrity of any part of pipe. Pipe repaired or replaced. Damaged Any dent that decreases the cross section area of pipe by more than 20% or is determined to have weakened structural integrity of the pipe. Pipe repaired or replaced. Ditches Trash and debris Trash and debris exceeds 1 cubic foot per 1,000 square feet of ditch and slopes. Trash and debris cleared from ditches. Sediment accumulation Accumulated sediment that exceeds 20% of the design depth. Ditch cleaned/flushed of all sediment and debris so that it matches design. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to County personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where County personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Vegetation Vegetation that reduces free movement of water through ditches. Water flows freely through ditches. Erosion damage to slopes Any erosion observed on a ditch slope. Slopes are not eroding. Rock lining out of place or missing (If Applicable) One layer or less of rock exists above native soil area 5 square feet or more, any exposed native soil. Replace rocks to design standards. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 7/23/2021 2021 Surface Water Design Manual – Appendix A A-12 NO. 7 – DEBRIS BARRIERS (E.G., TRASH RACKS) Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed. Site Trash and debris Trash or debris plugging more than 20% of the area of the barrier. Barrier clear to receive capacity flow. Sediment accumulation Sediment accumulation of greater than 20% of the area of the barrier Barrier clear to receive capacity flow. Structure Cracked broken or loose Structure which bars attached to is damaged - pipe is loose or cracked or concrete structure is cracked, broken of loose. Structure barrier attached to is sound. Bars Bar spacing Bar spacing exceeds 6 inches. Bars have at most 6 inches spacing. Damaged or missing bars Bars are bent out of shape more than 3 inches. Bars in place with no bends more than ¾ inch. Bars are missing or entire barrier missing. Bars in place according to design. Bars are loose and rust is causing 50% deterioration to any part of barrier. Repair or replace barrier to design standards. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2021 Surface Water Design Manual – Appendix A 7/23/2021 A-13 NO. 8 – ENERGY DISSIPATERS Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed. Site Trash and debris Trash and/or debris accumulation. Dissipater clear of trash and/or debris. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Rock Pad Missing or moved Rock Only one layer of rock exists above native soil in area five square feet or larger or any exposure of native soil. Rock pad prevents erosion. Dispersion Trench Pipe plugged with sediment Accumulated sediment that exceeds 20% of the design depth. Pipe cleaned/flushed so that it matches design. Not discharging water properly Visual evidence of water discharging at concentrated points along trench (normal condition is a “sheet flow” of water along trench). Water discharges from feature by sheet flow. Perforations plugged. Over 1/4 of perforations in pipe are plugged with debris or sediment. Perforations freely discharge flow. Water flows out top of “distributor” catch basin. Water flows out of distributor catch basin during any storm less than the design storm. No flow discharges from distributor catch basin. Receiving area over- saturated Water in receiving area is causing or has potential of causing landslide problems. No danger of landslides. Gabions Damaged mesh Mesh of gabion broken, twisted or deformed so structure is weakened or rock may fall out. Mesh is intact, no rock missing. Corrosion Gabion mesh shows corrosion through more than ¼ of its gage. All gabion mesh capable of containing rock and retaining designed form. Collapsed or deformed baskets Gabion basket shape deformed due to any cause. All gabion baskets intact, structure stands as designed. Missing rock Any rock missing that could cause gabion to loose structural integrity. No rock missing. Manhole/Chamber Worn or damaged post, baffles or side of chamber Structure dissipating flow deteriorates to ½ or original size or any concentrated worn spot exceeding one square foot which would make structure unsound. Structure is in no danger of failing. Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch or any evidence of soil entering the structure through cracks, or maintenance inspection personnel determines that the structure is not structurally sound. Manhole/chamber is sealed and structurally sound. Damaged pipe joints Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering the structure at the joint of the inlet/outlet pipes. No soil or water enters and no water discharges at the joint of inlet/outlet pipes. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 7/23/2021 2021 Surface Water Design Manual – Appendix A A-18 NO. 13 – BASIC BIOSWALE (GRASS) Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Site Trash and debris Any trash and/or debris accumulated on the bioswale site. No trash or debris on the bioswale site. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Swale Section Sediment accumulation Sediment depth exceeds 2 inches in 10% of the swale treatment area. No sediment deposits in grass treatment area of the bioswale. Sediment inhibits grass growth over 10% of swale length. Grass growth not inhibited by sediment. Sediment inhibits even spreading of flow. Flow spreads evenly through swale Erosion/scouring Eroded or scoured swale bottom due to channelization or high flows. No eroded or scoured areas in bioswale. Cause of erosion or scour addressed. Poor vegetation coverage Grass is sparse or bare or eroded patches occur in more than 10% of the swale bottom. Swale has no bare spots and grass is thick and healthy. Grass too tall Grass excessively tall (greater than 10 inches), grass is thin or nuisance weeds and other vegetation have taken over. Grass is between 3 and 4 inches tall, thick and healthy. No clippings left in swale. No nuisance vegetation present. Excessive shade Grass growth is poor because sunlight does not reach swale. Health grass growth or swale converted to a wet bioswale. Constant baseflow Continuous flow through the swale, even when it has been dry for weeks or an eroded, muddy channel has formed in the swale bottom. Baseflow removed from swale by a low-flow pea-gravel drain or bypassed around the swale. Standing water Water pools in the swale between storms or does not drain freely. Swale freely drains and there is no standing water in swale between storms. Channelization Flow concentrates and erodes channel through swale. No flow channels in swale. Flow Spreader Concentrated flow Flow from spreader not uniformly distributed across entire swale width. Flows are spread evenly over entire swale width. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2021 Surface Water Design Manual – Appendix A 7/23/2021 A-21 NO. 16 – WETPOND Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance Is Performed Site Trash and debris Any trash and debris accumulated on the wetpond site. Wetpond site free of any trash or debris. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to County personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where County personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Side Slopes of Dam, Berm, internal berm or Embankment Rodent holes Any evidence of rodent holes if facility is acting as a dam or berm, or any evidence of water piping through dam or berm via rodent holes. Rodents removed or destroyed and dam or berm repaired. Tree growth Tree growth threatens integrity of dams, berms or slopes, does not allow maintenance access, or interferes with maintenance activity. If trees are not a threat to dam, berm or embankment integrity, are not interfering with access or maintenance or leaves do not cause a plugging problem they do not need to be removed. Trees do not hinder facility performance or maintenance activities. Erosion Eroded damage over 2 inches deep where cause of damage is still present or where there is potential for continued erosion. Any erosion observed on a compacted slope. Slopes stabilized using appropriate erosion control measures. If erosion is occurring on compacted slope, a licensed civil engineer should be consulted to resolve source of erosion. Top or Side Slopes of Dam, Berm, internal berm or Embankment Settlement Any part of a dam, berm or embankment that has settled 4 inches lower than the design elevation. Top or side slope restored to design dimensions. If settlement is significant, a licensed civil engineer should be consulted to determine the cause of the settlement. Irregular surface on internal berm Top of berm not uniform and level. Top of berm graded to design elevation. Pond Areas Sediment accumulation (except first wetpool cell) Accumulated sediment that exceeds 10% of the designed pond depth. Sediment cleaned out to designed pond shape and depth. Sediment accumulation (first wetpool cell) Sediment accumulations in pond bottom that exceeds the depth of sediment storage (1 foot) plus 6 inches. Sediment storage contains no sediment. Liner damaged (If Applicable) Liner is visible or pond does not hold water as designed. Liner repaired or replaced. Water level (all wetpool cells) Cell level(s) drops more than 12 inches in any 7- day period. Cell level(s) drops less than 12 inches in any 7-day period. Algae mats (first wetpool cell) Algae mats develop over more than 10% of the water surface should be removed. Algae mats removed (usually in the late summer before Fall rains, especially in Sensitive Lake Protection Areas.) APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 7/23/2021 2021 Surface Water Design Manual – Appendix A A-30 NO. 21 – STORMFILTER (CARTRIDGE TYPE) Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Facility Documentation Update facility inspection record after each inspection. Maintenance records are up to date. Provide certification of replaced filter media. Filter media is certified to meet Stormfilter® specifications. Site Trash and debris Any trash or debris which impairs the function of the facility. Trash and debris removed from facility. Contaminants and pollution Any evidence of contaminants or pollution such as oils, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Life cycle System has not been inspected for three years. Facility is re-inspected and any needed maintenance performed. Vault Treatment Area Sediment on vault floor Greater than 2 inches of sediment. Vault is free of sediment. Sediment on top of cartridges Greater than ½ inch of sediment. Vault is free of sediment. Multiple scum lines above top of cartridges Thick or multiple scum lines above top of cartridges. Probably due to plugged canisters or underdrain manifold. Cause of plugging corrected, canisters replaced if necessary. Vault Structure Damage to wall, Frame, Bottom, and/or Top Slab Cracks wider than ½-inch and any evidence of soil particles entering the structure through the cracks, or qualified inspection personnel determines the vault is not structurally sound. Vault replaced or repaired to design specifications. Baffles damaged Baffles corroding, cracking warping, and/or showing signs of failure as determined by maintenance/inspection person. Repair or replace baffles to specification. Filter Media Standing water in vault 9 inches or greater of static water in the vault for more than 24 hours following a rain event and/or overflow occurs frequently. Probably due to plugged filter media, underdrain or outlet pipe. No standing water in vault 24 hours after a rain event. Short circuiting Flows do not properly enter filter cartridges. Flows go through filter media. Underdrains and Clean-Outs Sediment/debris Underdrains or clean-outs partially plugged or filled with sediment and/or debris. Underdrains and clean-outs free of sediment and debris. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Access Manhole Cover/lid not in place Cover/lid is missing or only partially in place. Any open manhole requires immediate maintenance. Manhole access covered. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2021 Surface Water Design Manual – Appendix A 7/23/2021 A-31 NO. 21 – STORMFILTER (CARTRIDGE TYPE) Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. Large access doors/plate Damaged or difficult to open Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat and cover access opening completely. Lifting Rings missing, rusted Lifting rings not capable of lifting weight of door or plate. Lifting rings sufficient to lift or remove door or plate. Inspection Frequency Maintenance conditions are site-specific, depending on pollutant loading. FIRST YEAR POST CONSTRUCTION: Monthly during wet season, every other month during dry season FOLLOWING FIRST YEAR: Continue monthly until site-specific frequency is established, then follow that schedule AT A MINIMUM, FOLLOWING FIRST YEAR: Annually (or quarterly if used as primary treatment) and following significant storms. Inspect Stormfilter facility for any maintenance deficiencies; maintain or replace as required per established site-specific schedule and manufacturer’s requirements. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 7/23/2021 2021 Surface Water Design Manual – Appendix A A-36 NO. 27 – GRAVEL FILLED DISPERSION TRENCH BMP Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Preventative Blocking, obstructions Debris or trash limiting flow to dispersion trench or preventing spreader function. Dispersion trench able to receive full flow prior to and during wet season. Site Trash and debris Trash or debris that could end up in the dispersion trench is evident. No trash or debris that could get into the dispersion trench can be found. Pipes Inlet is plugged The entrance to the pipe is restricted due to sediment, trash, or debris. The entrance to the pipe is not restricted. Vegetation/roots Vegetation/roots that reduce free movement of water through pipes. Water flows freely through pipes. Plugged Sediment or other material prevents free flow of water through the pipe. Water flows freely through pipes. Broken joint or joint leaks. Damage to the pipe or pipe joints allowing water to seep out. Pipe does not allow water to exit other than at the outlet to the trench. Cleanout caps Cleanout caps are broken, missing, or buried. Cleanout caps are accessible and intact. Structure Flow not reaching trench Flows are not getting into the trench as designed. Water enters and exits trench as designed. Perforated pipe plugged Flow not able to enter or properly exit from perforated pipe. Water freely enters and exits perforated pipe. Flow not spreading evenly at outlet of trench Outlet flows channelizing or not spreading evenly from trench. Sheet flow occurs at the outlet of the trench. Cleanout/inspection access does not allow cleaning or inspection of perforated pipe The cleanout/inspection access is not available. Cleanout/inspection access is available. Filter Media Filter media plugged Filter media plugged. Flow through filter media is normal. Inspection Frequency Annually and prior to and following significant storms. Inspect dispersion trench system for any defects of deficiencies. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2021 Surface Water Design Manual – Appendix A 7/23/2021 A-37 NO. 28 – NATIVE VEGETATED SURFACE / NATIVE VEGETATED LANDSCAPE BMP Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance Is Performed Site Trash and debris Trash and debris accumulated on the native vegetated surface/native vegetated landscape site. Native vegetated surface site free of any trash or debris. Vegetation Native vegetation type Less than two species each of native trees, shrubs, and groundcover occur in the design area. A minimum of two species each of native trees, shrubs, and groundcover is established and healthy. Native vegetated area Less than 90% if the required vegetated area has healthy growth. A minimum of 90% of the required vegetated area has healthy growth. Undesirable vegetation Weeds, blackberry, and other undesirable plants are invading more than 10% of vegetated area. Less than 10% undesirable vegetation occurs in the required native vegetated surface area. Vegetated Area Soil compaction Soil in the native vegetation area compacted. Less than 8% of native vegetation area is compacted. Insufficient area Less than 3.5 square feet of native vegetation area for every 1 square foot of impervious surface. A minimum of 3.5 square feet of native vegetation area for every 1 square foot of impervious surface. Excess slope Slope of native vegetation area greater than 15%. Slope of native growth area does not exceed 15%. Inspection Frequency Annually Inspect native vegetation area for any defects of deficiencies NO. 29 – PERFORATED PIPE CONNECTIONS BMP Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Preventative Blocking, obstructions Debris or trash limiting flow into perforated pipe system or outfall of BMP is plugged or otherwise nonfunctioning. Outfall of BMP is receiving designed flows from perforated pipe connection. Inflow Inflow impeded Inflow into the perforated pipe is partially or fully blocked or altered to prevent flow from getting into the pipe. Inflow to the perforated pipe is unimpeded. Pipe Trench Area Surface compacted Ground surface over the perforated pipe trench is compacted or covered with impermeable material. Ground surface over the perforated pipe is not compacted and free of any impervious cover. Outflow Outflow impeded Outflow from the perforated pipe into the public drainage system is blocked. Outflow to the public drainage system is unimpeded. Outfall Area Erosion or landslides Existence of the perforated pipe is causing or exasperating erosion or landslides. Perforated pipe system is sealed off and an alternative BMP is implemented. Inspection Frequency Annually and prior to and following significant storms. Perforated pipe system is operating as designed. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 7/23/2021 2021 Surface Water Design Manual – Appendix A A-38 NO. 30 – PERMEABLE PAVEMENT BMP Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Preventative Surface cleaning/ vegetation control Media surface vacuumed or pressure washed annually, vegetation controlled to design maximum. Weed growth suggesting sediment accumulation. No dirt, sediment, or debris clogging porous media, or vegetation limiting infiltration. Porous Concrete, Porous Asphaltic Concrete, and Permeable Pavers Trash and debris Trash and debris on the pavement interfering with infiltration; leaf drop in fall season. No trash or debris interfering with infiltration. Sediment accumulation Sediment accumulation on the pavement interfering with infiltration; runoff from adjacent areas depositing sediment/debris on pavement. Pavement infiltrates as designed; adjacent areas stabilized. Infiltration rate Pavement does not infiltrate at a rate of 10 inches per hour. Pavement infiltrates at a rate greater than 10 inches per hour. Ponding Standing water for a long period of time on the surface of the pavement. Standing water infiltrates at the desired rate. Broken or cracked pavement Pavement is broken or cracked. No broken pavement or cracks on the surface of the pavement. Settlement Uneven pavement surface indicating settlement of the subsurface layer. Pavement surface is uniformly level. Moss growth Moss growing on pavement interfering with infiltration. No moss interferes with infiltration. Inflow Inflow to the pavement is diverted, restricted, or depositing sediment and debris on the pavement. Inflow to pavement is unobstructed and not bringing sediment or debris to the pavement. Underdrain Underdrain is not flowing when pavement has been infiltrating water. Underdrain flows freely when water is present. Overflow Overflow not controlling excess water to desired location; native soil is exposed or other signs of erosion damage are present. Overflow permits excess water to leave the site at the desired location; Overflow is stabilized and appropriately armored. Permeable Pavers Broken or missing pavers Broken or missing paving blocks on surface of pavement. No missing or broken paving blocks interfering with infiltration. Level surface Uneven surface due to settlement or scour of fill in the interstices of the paving blocks. Pavement surface is uniformly level. Compaction Poor infiltration due to soil compaction between paving blocks. No soil compaction in the interstices of the paver blocks limiting infiltration. Dead grass Grass in the interstices of the paving blocks is dead. Healthy grass is growing in the interstices of the paver blocks. Inspection Frequency Annually and after large storms, and as needed seasonally to control leaf drop, evergreen needles etc. Permeable pavement is functioning normally. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2021 Surface Water Design Manual – Appendix A 7/23/2021 A-39 NO. 31 – BIORETENTION BMP Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Preventative Vegetation Vegetation to be watered and pruned as needed and mulch applied to a minimum of 2 inches to maintain healthy growth. Healthy vegetation growth with full coverage as designed. Bioretention Area Trash and debris Trash and debris in the bioretention area; leaf drop in the fall season. No trash or debris In the bioretention area. Sediment accumulation Sediment accumulation in the bioretention area interfering with infiltration. Water in the bioretention infiltrates as designed. Ponding Standing water in the bioretention area for more than two days. Standing water infiltrates at the desired rate. Inflow Inflow not getting into bioretention; debris/sediment blockage at inlet features; native soil is exposed or other signs of erosion damage is present. Unobstructed and properly routed inflow into bioretention area; inlet is stabilized and appropriately armored. Overflow outlet Overflow water not controlled by outlet features; native soil is exposed or other signs of erosion damage is present. Outlet features control overflow; overflow is stabilized and appropriately armored. Underdrain Underdrain is not flowing when bioretention area has been infiltrating water. Underdrain flows freely when water is present. Vegetation Plant health Plants not thriving across at least 80% of the entire design vegetated area within the BMP; overly dense vegetation requiring pruning. Healthy water tolerant plants in bioretention area, plants thriving across at least 80% of the entire design vegetated area within the facility. Plant species Plants not water tolerant species. Plants are water tolerant. Weeds Weeds growing in bioretention area. No weeds in bioretention area. Watering Planting schedule requires frequent watering (approx. weekly Year 1, bimonthly Years 2 and 3) for new facilities, and as needed for established plantings or dry periods Plants are established and thriving Pest Control Signs of pests, such as wilting or chewed leaves or bark, spotting or other indicators; extended ponding period encouraging mosquitoes Plant community is pest-free when following an approved Integrated Pest Management plan; bioretention functioning normally and ponding controlled as needed for pest control Containment Berm and Earthen Slopes Erosion; Erosion occurring at earthen slopes or containment berm side slope. Erosion on the containment berm and side slopes has been repaired and the cause of the erosion corrected. Voids created by nuisance animals (e.g., rodents) or tree roots Voids affecting berm integrity or creating leaky pond condition Voids have been repaired; facility is free of nuisance animals following an approved Integrated Pest Management plan. Settlement Any part of the containment berm top has less than 6 inches of freeboard from the maximum pond level to the top of the berm. A minimum of 6 inches freeboard from the maximum pond level to the top of the berm. Amended Soil Soil nutrients Soil not providing plant nutrients. Soil providing plant nutrients. Bare spots Bare spots on soil in bioretention area. No bare spots, bioretention area covered with vegetation or mulch mixed into the underlying soil. Compaction Poor infiltration due to soil compaction in the bioretention area. No soil compaction in the bioretention area. Inspection Frequency Annually and after large storms, and as needed seasonally for pruning, plant maintenance, pest control and to control leaf drop, evergreen needles etc. Bioretention facility is functioning normally; plant community is thriving and pest-free. 17803 & 17805 108th Ave SE – Kite Realty Group Kimley-Horn and Associates, Inc. Renton, WA Preliminary Stormwater Report April 11, 2025 Page 20 5. BOND QUANTITY WORKSHEET 1055 South Grady Way – 6 th Floor | Renton, WA 98057 (425) 430-7200 Date Prepared: Name: PE Registration No: Firm Name: Firm Address: Phone No. Email Address: Project Name: Project Owner: CED Plan # (LUA):Phone: CED Permit # (C):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:NO Water Service Provided by: If Yes, Provide Forest Practice Permit #:Sewer Service Provided by: Total Estimated Construction Costs E A + B + C + D 96,849.03$ Estimated Civil Construction Permit - Construction Costs2 Stormwater (Drainage)C -$ As outlined in City Ordinance No. 4345, 50% of the plan review and inspection fees are to be paid at Permit Submittal. The balance is due at Permit Issuance. Significant changes or additional review cycles (beyond 3 cycles) during the review process may result in adjustments to the final review fees. Roadway (Erosion Control + Transportation)D 96,849.03$ Water A -$ Wastewater (Sanitary Sewer)B -$ AddressAbbreviated Legal Description: Lot Y of King County Boundary Line Adjustment NO. L07L0040 Rec 2007082290006 - Located in NE 1/4 of NW 1/4 of 32-23-05 City, State, Zip 17803 108th Ave SE, Renton, WA, 98055 30 S Meridian St, Suite 1100 Additional Project Owner 317-713-5653 4/10/2025 Prepared by: FOR APPROVALProject Phase 1 Taylor.Bellefeuille@kimley-horn.com Taylor Bellefeuille 25002557 Kimley-Horn 1201 3rd Ave Suite 2800, Seattle, WA 206-800-1889 SITE IMPROVEMENT BOND QUANTITY WORKSHEET PROJECT INFORMATION SOOS CREEK WATER & SEWER SOOS CREEK WATER & SEWER Phone Engineer Stamp Required (all cost estimates must have original wet stamp and signature) Clearing and Grading Utility Providers N/A Project Location and Description Project Owner Information Chipotle 108th Ave SE Indianapolis, IN 46204 3223059065 Tony Halsey Page 1 of 6 Ref 8-H Bond Quantity Worksheet SECTION I PROJECT INFORMATION Version 4/1/2024 Printed 6/9/2025 10.3%2 All prices include labor, equipment, materials, overhead, profit, and taxes. City of Renton Sales Tax is: 1 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 Submittal Page 2 of 6 Ref 8-H Bond Quantity Worksheet SECTION I PROJECT INFORMATION Version 4/1/2024 Printed 6/9/2025 CED Permit #: Unit Reference #Price Unit Quantity Cost Backfill & compaction-embankment ESC-1 7.50$ CY Check dams, 4" minus rock ESC-2 SWDM 5.4.6.3 90.00$ Each Catch Basin Protection ESC-3 145.00$ Each 11 1,595.00 Crushed surfacing 1 1/4" minus ESC-4 WSDOT 9-03.9(3)110.00$ CY Ditching ESC-5 10.50$ CY Excavation-bulk ESC-6 2.30$ CY 10 23.00 Fence, silt ESC-7 SWDM 5.4.3.1 5.00$ LF Fence, Temporary (NGPE)ESC-8 1.75$ LF Geotextile Fabric ESC-9 3.00$ SY Hay Bale Silt Trap ESC-10 0.60$ Each Hydroseeding ESC-11 SWDM 5.4.2.4 0.90$ SY Interceptor Swale / Dike ESC-12 1.15$ LF Jute Mesh ESC-13 SWDM 5.4.2.2 4.00$ SY Level Spreader ESC-14 2.00$ LF Mulch, by hand, straw, 3" deep ESC-15 SWDM 5.4.2.1 2.90$ SY Mulch, by machine, straw, 2" deep ESC-16 SWDM 5.4.2.1 2.30$ SY Piping, temporary, CPP, 6"ESC-17 13.75$ LF Piping, temporary, CPP, 8"ESC-18 16.00$ LF Piping, temporary, CPP, 12"ESC-19 20.50$ LF Plastic covering, 6mm thick, sandbagged ESC-20 SWDM 5.4.2.3 4.60$ SY Rip Rap, machine placed; slopes ESC-21 WSDOT 9-13.1(2)51.00$ CY Rock Construction Entrance, 50'x15'x1'ESC-22 SWDM 5.4.4.1 2,050.00$ Each Rock Construction Entrance, 100'x15'x1'ESC-23 SWDM 5.4.4.1 3,675.00$ Each 1 3,675.00 Sediment pond riser assembly ESC-24 SWDM 5.4.5.2 2,525.00$ Each Sediment trap, 5' high berm ESC-25 SWDM 5.4.5.1 22.00$ LF Sed. trap, 5' high, riprapped spillway berm section ESC-26 SWDM 5.4.5.1 80.00$ LF Seeding, by hand ESC-27 SWDM 5.4.2.4 1.15$ SY Sodding, 1" deep, level ground ESC-28 SWDM 5.4.2.5 9.20$ SY Sodding, 1" deep, sloped ground ESC-29 SWDM 5.4.2.5 11.50$ SY TESC Supervisor ESC-30 125.00$ HR Water truck, dust control ESC-31 SWDM 5.4.7 160.00$ HR Unit Reference #Price Unit Quantity Cost EROSION/SEDIMENT SUBTOTAL:5,293.00 SALES TAX @ 10.3%545.18 EROSION/SEDIMENT TOTAL:5,838.18 (A) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR EROSION & SEDIMENT CONTROL Description No. (A) WRITE-IN-ITEMS Page 3 of 6 Ref 8-H Bond Quantity Worksheet SECTION II.a EROSION_CONTROL Version: 4/01/2024 Printed 6/9/2025 CED Permit #: Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost GENERAL ITEMS Backfill & Compaction- embankment GI-1 7.00$ CY Backfill & Compaction- trench GI-2 10.25$ CY Clear/Remove Brush, by hand (SY)GI-3 1.15$ SY Bollards - fixed GI-4 275.00$ Each Bollards - removable GI-5 520.00$ Each Clearing/Grubbing/Tree Removal GI-6 11,475.00$ Acre Excavation - bulk GI-7 2.30$ CY 17 39.10 Excavation - Trench GI-8 5.75$ CY Fencing, cedar, 6' high GI-9 23.00$ LF Fencing, chain link, 4'GI-10 44.00$ LF Fencing, chain link, vinyl coated, 6' high GI-11 23.00$ LF Fencing, chain link, gate, vinyl coated, 20' GI-12 1,600.00$ Each Fill & compact - common barrow GI-13 28.75$ CY 258 7,417.50 Fill & compact - gravel base GI-14 31.00$ CY Fill & compact - screened topsoil GI-15 44.75$ CY Gabion, 12" deep, stone filled mesh GI-16 74.50$ SY Gabion, 18" deep, stone filled mesh GI-17 103.25$ SY Gabion, 36" deep, stone filled mesh GI-18 172.00$ SY Grading, fine, by hand GI-19 2.90$ SY Grading, fine, with grader GI-20 2.30$ SY Monuments, 3' Long GI-21 1,025.00$ Each Sensitive Areas Sign GI-22 8.00$ Each Sodding, 1" deep, sloped ground GI-23 9.25$ SY 124 1,147.00 366 3,385.50 Surveying, line & grade GI-24 975.00$ Day Surveying, lot location/lines GI-25 2,050.00$ Acre Topsoil Type A (imported)GI-26 32.75$ CY Traffic control crew ( 2 flaggers )GI-27 137.75$ HR Trail, 4" chipped wood GI-28 9.15$ SY Trail, 4" crushed cinder GI-29 10.25$ SY Trail, 4" top course GI-30 13.75$ SY Conduit, 2"GI-31 5.75$ LF 50 287.50 Wall, retaining, concrete GI-32 63.00$ SF Wall, rockery GI-33 17.25$ SF 108 1,863.00 SUBTOTAL THIS PAGE:1,147.00 12,992.60 (B)(C)(D)(E) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR STREET AND SITE IMPROVEMENTS Quantity Remaining (Bond Reduction) (B)(C) Page 4 of 6 Ref 8-H Bond Quantity Worksheet SECTION II.b TRANSPORTATION Version: 4/1/2024 Printed 6/9/2025 CED Permit #: Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR STREET AND SITE IMPROVEMENTS Quantity Remaining (Bond Reduction) (B)(C) ROAD IMPROVEMENT/PAVEMENT/SURFACING AC Grinding, 4' wide machine < 1000sy RI-1 34.50$ SY AC Grinding, 4' wide machine 1000-2000sy RI-2 18.25$ SY AC Grinding, 4' wide machine > 2000sy RI-3 11.50$ SY AC Removal/Disposal RI-4 40.00$ SY Barricade, Type III ( Permanent )RI-5 64.25$ LF Guard Rail RI-6 34.50$ LF Curb & Gutter, rolled RI-7 19.50$ LF Curb & Gutter, vertical RI-8 14.25$ LF Curb and Gutter, demolition and disposal RI-9 20.50$ LF 668 13,694.00 Curb, extruded asphalt RI-10 6.25$ LF Curb, extruded concrete RI-11 8.00$ LF 737 5,896.00 Sawcut, asphalt, 3" depth RI-12 3.00$ LF 780 2,340.00 Sawcut, concrete, per 1" depth RI-13 5.00$ LF Sealant, asphalt RI-14 2.25$ LF 780 1,755.00 Shoulder, gravel, 4" thick RI-15 17.25$ SY Sidewalk, 4" thick RI-16 43.50$ SY 135 5,872.50 184 8,004.00 Sidewalk, 4" thick, demolition and disposal RI-17 37.00$ SY 80 2,960.00 120 4,440.00 Sidewalk, 5" thick RI-18 47.00$ SY 113 5,311.00 Sidewalk, 5" thick, demolition and disposal RI-19 46.00$ SY 92 4,232.00 Sign, Handicap RI-20 97.00$ Each 2 194.00 Striping, per stall RI-21 8.00$ Each 28 224.00 Striping, thermoplastic, ( for crosswalk )RI-22 3.50$ SF 396 1,386.00 Striping, 4" reflectorized line RI-23 0.55$ LF Additional 2.5" Crushed Surfacing RI-24 4.15$ SY HMA 1/2" Overlay 1.5" RI-25 16.00$ SY HMA 1/2" Overlay 2"RI-26 20.75$ SY HMA Road, 2", 4" rock, First 2500 SY RI-27 32.25$ SY HMA Road, 2", 4" rock, Qty. over 2500SY RI-28 24.00$ SY HMA Road, 4", 6" rock, First 2500 SY RI-29 51.75$ SY HMA Road, 4", 6" rock, Qty. over 2500 SY RI-30 42.50$ SY HMA Road, 4", 4.5" ATB RI-31 43.50$ SY Gravel Road, 4" rock, First 2500 SY RI-32 17.25$ SY Gravel Road, 4" rock, Qty. over 2500 SY RI-33 11.50$ SY Thickened Edge RI-34 10.00$ LF SUBTOTAL THIS PAGE:8,832.50 47,476.00 (B)(C)(D)(E) Page 5 of 6 Ref 8-H Bond Quantity Worksheet SECTION II.b TRANSPORTATION Version: 4/1/2024 Printed 6/9/2025 CED Permit #: Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR STREET AND SITE IMPROVEMENTS Quantity Remaining (Bond Reduction) (B)(C) PARKING LOT SURFACING No. 2" AC, 2" top course rock & 4" borrow PL-1 24.00$ SY 2" AC, 1.5" top course & 2.5" base course PL-2 32.00$ SY 377 12,064.00 4" select borrow PL-3 5.75$ SY 1.5" top course rock & 2.5" base course PL-4 16.00$ SY SUBTOTAL PARKING LOT SURFACING:12,064.00 (B)(C)(D)(E) LANDSCAPING & VEGETATION No. Street Trees LA-1 Each 5 7 Median Landscaping LA-2 SY 366 Right-of-Way Landscaping LA-3 SY 124 Wetland Landscaping LA-4 SUBTOTAL LANDSCAPING & VEGETATION: (B)(C)(D)(E) TRAFFIC & LIGHTING No. Signs TR-1 Street Light System ( # of Poles)TR-2 Traffic Signal TR-3 Traffic Signal Modification TR-4 SUBTOTAL TRAFFIC & LIGHTING: (B)(C)(D)(E) WRITE-IN-ITEMS SUBTOTAL WRITE-IN ITEMS: STREET AND SITE IMPROVEMENTS SUBTOTAL:9,979.50 72,532.60 SALES TAX @ 10.3%1,027.89 7,470.86 STREET AND SITE IMPROVEMENTS TOTAL:11,007.39 80,003.46 (B)(C)(D)(E) Page 6 of 6 Ref 8-H Bond Quantity Worksheet SECTION II.b TRANSPORTATION Version: 4/1/2024 Printed 6/9/2025