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HomeMy WebLinkAboutEx_08_TIR Boeing Renton Apron R Crew Shelters and Tool Cabanas Technical Information Report Prepared for: The Boeing Company P.O. Box 3707 Puyallup, WA 98373 Project Manager: Joe Nguyen Phone: (425) 328-4599 Permitting Contact: Mark Clement Phone: (425) 229-4279 Prepared by: Sitts & Hill Engineers, Inc. 4815 Center Street Tacoma, Washington 98409 Contact: Don Davis, P.E. Phone: (253) 474-9449 February 2025 S&H Job Number 20,727 Exhibit 8 Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 Boeing Renton Apron R Crew Shelters and Tool Cabanas Technical Information Report Prepared for: The Boeing Company P.O. Box 3707 Puyallup, WA 98373 Project Manager: Joe Nguyen Phone: (425) 328-4599 Permitting Contact: Mark Clement Phone: (425) 229-4279 Prepared by: Sitts & Hill Engineers, Inc. 4815 Center Street Tacoma, Washington 98409 Contact: Don Davis, P.E. Phone: (253) 474-9449 IN COMPLIANCE WITH CITY OF RENTON STANDARDS February, 2025 S&H Job Number 20,727 Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT i TABLE OF CONTENTS 1.0 PROJECT OVERVIEW ............................................................................................................... 3 1.1 Scope ................................................................................................................................................................ 3 1.2 Existing Conditions ........................................................................................................................................ 4 1.3 Proposed Conditions ..................................................................................................................................... 5 2.0 Conditions and Requirements Summary ............................................................................... 6 2.1 Discussion of Core and Special Requirements .......................................................................................... 6 2.1.1 Core Requirement #1: Discharge at the Natural Location ................................................................ 6 2.1.2 Core Requirement #2: Off-site Analysis .............................................................................................. 6 2.1.3 Core Requirement #3: Flow Control ..................................................................................................... 6 2.1.4 Core Requirement #4: Conveyance System ....................................................................................... 6 2.1.5 Core Requirement #5: Construction Stormwater Pollution Prevention ........................................... 6 2.1.6 Core Requirement #6: Maintenance and Operations ........................................................................ 6 2.1.7 Core Requirement #7: Financial Guarantees and Liability ............................................................... 7 2.1.8 Core Requirement #8: Water Quality ................................................................................................... 7 2.1.9 Core Requirement #9: On-site BMPs ................................................................................................... 7 2.1.10 Special Requirement #1: Other Adopted Area-Specific Requirements ........................................ 8 2.1.11 Special Requirement #2: Flood Hazard Area Delineation .............................................................. 8 2.1.12 Special Requirement #3: Flood Protection Facilities ....................................................................... 8 2.1.13 Special Requirement #4: Source Control .......................................................................................... 8 2.1.14 Special Requirement #5: Oil Control .................................................................................................. 9 2.1.15 Special Requirement #6: Aquifer Protection Areas ......................................................................... 9 3.0 OFF-SITE ANALYSIS ............................................................................................................... 12 4.0 FLOW CONTROL, LID, AND WATER QUALITY FACILITY ANALYSIS AND DESIGN ..... 13 5.0 CONVEYANCE SYSTEM ANALYSIS AND DESIGN ............................................................. 14 6.0 SPECIAL REPORTS AND STUDIES ...................................................................................... 15 7.0 OTHER PERMITS ..................................................................................................................... 16 8.0 CSWPPP ANALYSIS AND DESIGN ....................................................................................... 17 9.0 BOND QUANTITIES and R/D FACILITY SUMMARIES ........................................................ 18 9.1 Bond Quantities ........................................................................................................................................... 18 9.2 Facility Summaries ....................................................................................................................................... 18 10.0 OPERATIONS AND MAINTENANCE MANUAL .................................................................. 19 Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT ii TABLE OF APPENDICES A.1 TIR Worksheet ........................................................................................................................ 20 A.2 Existing and Proposed Surface Coverage Exhibits .......................................................... 27 A.3 Site Historical Aerial Photography ...................................................................................... 31 A.4 Stormwater Engineering Calculations ................................................................................ 35 A.5 Geotechnical Engineering Report........................................................................................ 36 TABLE OF FIGURES Figure 1 – Site Location Map ........................................................................................................................... 4 Figure 2 – Drainage Review Flow Chart ...................................................................................................... 10 Figure 3 – FEMA Map – Proposed Building ................................................................................................ 11 Figure 4- City of Renton Flow Control Application Map ............................................................................ 13 Figure 5 – TIR Worksheet ............................................................................................................................. 26 TABLE OF TABLES Table 1. Existing and Developed Condition Description ............................................................................. 5 Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 3 1.0 PROJECT OVERVIEW 1.1 Scope This Technical Information Report (TIR) addresses improvements associated with the installation of crew shelters, tool cabanas, and associated utility improvements at the Boeing Renton facility, located at 737 Logan Ave N, Renton, WA (Parcel No. 0723059001). Please see Figure 1 for the Site Location Map of the proposed crew shelters. The crew shelters and tool cabanas are premade structures installed on-site, over existing concrete pavement, providing office and storage space in close proximity to aircraft being serviced or prepared for delivery. Power and communication utilities will be delivered to the new facilities via new conduits routed above existing paved surfaces. No earthwork, paving, utility, or other site improvements are proposed for this project. This Technical Information Report has been prepared in accordance with the 2022 City of Renton Stormwater Design Manual (SWDM). Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 4 Figure 1 – Site Location Map 1.2 Existing Conditions The subject sites are located on one parcel, zoned as Urban Center-2 (UC-2), with an area of 153.28 acres that is fully developed. The sites, as depicted on the topographical survey and utility plans, are relatively flat. Current surfacing on-site is concrete pavement. The existing site consists of airplane parking and maintenance stalls, as well as supporting buildings such as hangars, offices, and warehouses. Based on historical photographs and the King County Assessor’s Website, the site has been developed since 1942. See Appendix A.3, which includes a series of aerial photographs dating back to July, 1990. Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 5 1.3 Proposed Conditions The purpose of this project is to install crew shelters at existing airplane parking stalls. Tool cabanas will be installed near the crew shelters. Each shelter will have access stairs and an ADA compliant access ramp. This project proposes no grading, paving, or drainage (water quality, detention, or conveyance) improvements for on-site and off-site areas. See Table 1 for a description of existing and proposed surface conditions of the proposed building. All of the stormwater generated on-site as part of this project will come from non-pollution generating roofing. All runoff from these roofs will follow pre-construction flow paths. Please see Appendix A.2 for Existing and Proposed Surface Coverage Exhibits. Table 1. Existing and Developed Condition Description Description On-site Off-site Total Existing Conditions Total Project Area (ft2) 2,592 0 2,592 Existing impervious surface (ft2) 2,592 0 2,592 Existing landscaping/lawn area (ft2) 0 0 0 Total Project Area (ft2) 2,592 0 2,592 New impervious surface (ft2) 0 0 0 New pollution generating impervious surface (PGHS) (ft2) 0 0 0 Replaced impervious surface (ft2) 2,592 0 2,592 Replaced PGHS (ft2) 0 0 0 New plus replaced impervious surface (ft2) 2,592 0 2,592 New plus replaced PGHS (ft2) 0 0 0 Existing impervious surfaces converted to vegetation/landscaping (ft2) 0 0 0 Land Disturbed (ft2) 2,592 0 2,592 Native Vegetation to Pasture (acres) 0 0 0 Existing vegetation area to remain (ft2) 0 0 0 Existing impervious surface to remain unaltered (ft2) 0 0 0 Value of proposed improvements ($) TBD 0 TBD Amount to be Graded/Approx. (CY) 0 0 0 Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 6 2.0 CONDITIONS AND REQUIREMENTS SUMMARY 2.1 Discussion of Core and Special Requirements This is a project in Urban Center zoning that replaces a total of more than 2,000 square feet of impervious surface. Therefore, the project is subject to a full drainage review and must satisfy all core requirements (1-9) and all special requirements (1-6) of the 2022 City of Renton Surface Water Design Manual (SWDM). See Figure 2 at the end of this Section for the Drainage Review Flow Chart for the proposed crew shelters. Below is a description of each core requirement and how the project proposes to satisfy each requirement. 2.1.1 Core Requirement #1: Discharge at the Natural Location This requirement will be met by maintaining preconstruction flow paths. 2.1.2 Core Requirement #2: Off-site Analysis This project does not trigger Core Requirements #3 or #8. Additionally, this project does not include more than 2,000 square feet of new impervious surface, more than ¾ acre of new pervious surface, or modifications to existing drainage facilities, and does not include work in landslide, steep slope, or erosion hazard areas. Therefore, this project is exempt from Core Requirement #2. 2.1.3 Core Requirement #3: Flow Control The project proposes work within the Peak Rate Flow Control Standards (Existing Site Conditions) Area. Projects in that area must match the developed peak discharge rates to the existing site conditions peak discharge rates for the 2-, 10-, and 100-year return periods. However, this project is proposing less than 5,000 square feet of new plus replaced impervious surface and less than ¾ acres of new pervious surface and is therefore exempt from Core Requirement #3. 2.1.4 Core Requirement #4: Conveyance System This project proposes no new conveyance systems or modifications to existing conveyance systems. 2.1.5 Core Requirement #5: Construction Stormwater Pollution Prevention No activities related to this project are expected to create sediment or other stormwater pollutants, therefore a Temporary Erosion and Control (TESC) Plan will not be included in the construction plan set. A CSWPPP under a separate cover has been prepared to satisfy this requirement. 2.1.6 Core Requirement #6: Maintenance and Operations This project does not propose installation of new stormwater features, or modification of existing stormwater features. Therefore, no Operations and Maintenance Manual has been prepared. Boeing will continue to be responsible for maintenance and operation of the existing on-site stormwater facilities. Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 7 2.1.7 Core Requirement #7: Financial Guarantees and Liability We do not anticipate that Boeing will be required to provide a Construction Bond to the City of Renton prior to issuance of the permit. The contractor/owner will be responsible for all erosion and maintenance liabilities during construction. 2.1.8 Core Requirement #8: Water Quality This project is proposing less than 5,000 square feet of new plus replaced PGIS and less than ¾ acres of new PGPS and is therefore exempt from Core Requirement #8. 2.1.9 Core Requirement #9: On-site BMPs Target surfaces subject to Core Requirement #9 On-site BMPs include replaced impervious surfaces, already mitigated with an approved on-site BMP. This site qualifies for the Large Lot BMP Requirements per 1.2.9.2.2 of the City of Renton SWDM, since it is larger than 22,000 square feet. These requirements state that all proposed pervious surfaces must implement the soil amendment BMP and roof downspout connections must be perforated pipe connections. Neither soil amendment nor downspout BMPs apply to the project as construction will occur above existing concrete pavement. Construction will also not involve removal or replacement of any existing concrete pavement. In addition, these requirements require the consideration of the following BMPs: full dispersion, full infiltration, limited infiltration, bioretention, permeable pavement, basic dispersion, reduced impervious surface credit, native growth retention credit, tree retention credit. None of the listed BMPs are feasible for implementation on the project site, and will therefore not be implemented. The remainder of this section contains a discussion of infeasibility for each BMP. Full Dispersion – The application of this BMP depends on the sheet flow of runoff through an area of native vegetation. The project site does not contain any native vegetation area (e.g., forested) in the existing or proposed condition. Therefore, full dispersion is infeasible for this project. Full Infiltration – Per Section C.2.2.2 of the Manual, full infiltration requires that “Existing soils must be coarse sands or cobbles or medium sands and cannot be comprised of fill materials where the infiltration device will be located.” Site soils meet this requirement, except for the top layer of soil. However, the shallow groundwater level renders infiltration on-site infeasible. Therefore, full infiltration is infeasible for this project. Limited Infiltration – The infeasibility criteria for limited infiltration are the same as those for full infiltration except that appropriate soils may be fine sands, loamy sands, sandy loams, or loams. Note that Section C.2.3.2 of the Manual states “Silt and clay loams, and cemented till (hardpan) are not suitable for limited infiltration systems.” Site soils meet this requirement, except for the top layer of soil. However, the shallow groundwater level renders infiltration on- site infeasible. Therefore, limited infiltration is infeasible for this project. Bioretention – This project is underlain by soil that makes infiltration impractical, as such a bioretention facility is infeasible. Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 8 Permeable Pavement – The soil under a permeable pavement section must provide adequate treatment for groundwater protection. The underlying soils should also infiltrate for this surfacing to be durable and effective. The requirements for adequate treatment are a minimum organic content of 1.0% and a minimum cation exchange capacity of 8 milliequivalents per 100 grams. The uppermost soil layer on the project site is made up of fill material and does not meet these requirements. Again, the depth to groundwater renders BMPs that rely on infiltration ineffective. Permeable Pavement is infeasible for this project. Basic Dispersion – The implementation of basic dispersion requires the dispersed stormwater to flow over a vegetated surface, but there are no existing or proposed vegetated surfaces near the proposed development. Such a flowpath cannot be provided on the project site without a drastic reconfiguration of the site and Foreign Object Debris (FOD) risk to aircraft. We see basic dispersion as infeasible to the project. Reduced Impervious Surface Credit – This BMP presents four possible methods of impervious surface reduction: restricted footprint, wheel strip driveways, minimum disturbance foundation, and open grid decking over pervious surface. The restricted footprint method requires less than 10,000 square feet of impervious area, which is not feasible for the proposed use of the site as airplane maintenance facilities. A wheel strip driveway is not applicable for airplane parking. A minimum disturbance foundation is not feasible for an automotive workshop. Open grid decking over a pervious surface is also not applicable to airplane parking or a structure. The reduced impervious surface credit is infeasible for this project. Native Growth Retention Credit – The existing condition of the site does not contain any native growth. Therefore, the native growth retention credit is infeasible for this project. Tree Retention Credit – The existing condition of the site contains no trees. 2.1.10 Special Requirement #1: Other Adopted Area-Specific Requirements N/A. The project site is not in a designated critical drainage area or in an area included in an adopted master drainage plan, basin plan, salmon conservation plan, stormwater compliance plan, flood hazard management plan, lake management plan, or shared facility drainage plan. 2.1.11 Special Requirement #2: Flood Hazard Area Delineation N/A. Per the FEMA floodplain map at the end of this Section, Figure 3, the project site lies within a boundary delineating “areas determined to have a 0.2% annual chance of flooding.” This is outside of the 100-year flood boundary and therefore flood-related delineation on the project site is not required. 2.1.12 Special Requirement #3: Flood Protection Facilities N/A. This project does not propose to rely on an existing flood protection facility nor does it modify or construct a new flood protection facility. 2.1.13 Special Requirement #4: Source Control Boeing shall continue to maintain current source control features. Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 9 2.1.14 Special Requirement #5: Oil Control This project proposes development on an existing high-use site. Runoff from the project site is treated by an existing oil/water separator. 2.1.15 Special Requirement #6: Aquifer Protection Areas This project is not located within an Aquifer Protection Area per King County GIS. Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 10 Figure 2 – Drainage Review Flow Chart Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 11 Figure 3 – FEMA Map – Proposed Building Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 12 3.0 OFF-SITE ANALYSIS Per City of Renton SWDM Section 1.2.2, this project is exempt from providing an off-site analysis report that assesses potential off-site drainage and water quality impacts associated with the redevelopment of the project site. Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 13 4.0 FLOW CONTROL, LID, AND WATER QUALITY FACILITY ANALYSIS AND DESIGN No stormwater features were designed or analyzed as part of this project. Figure 4- City of Renton Flow Control Application Map Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 14 5.0 CONVEYANCE SYSTEM ANALYSIS AND DESIGN This project proposes no changes to the existing on-site private stormwater system. Therefore, no stormwater calculations have been performed as part of this project. Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 15 6.0 SPECIAL REPORTS AND STUDIES We are not aware of any site characteristics that are particularly sensitive to stormwater runoff. Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 16 7.0 OTHER PERMITS We anticipate that a Land Use Master Application, Building Permit, Shoreline Protection Permit, and a Joint Aquatic Resources Permit Application (JARPA) will be required. Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 17 8.0 CSWPPP ANALYSIS AND DESIGN The Construction Stormwater Pollution Prevention Plan report is included under a separate cover. Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 18 9.0 BOND QUANTITIES AND R/D FACILITY SUMMARIES 9.1 Bond Quantities A Bond Quantity Worksheet has not been prepared for this project as it does not include the construction of drainage facilities, or other facilities that would impact the City of Renton and the surrounding environment if left unfinished. 9.2 Facility Summaries This project proposes to implement no stormwater facilities, or modifications to stormwater facilities. Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 19 10.0 OPERATIONS AND MAINTENANCE MANUAL An Operations and Maintenance Manual has not been prepared for this project. Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 20 A.1 TIR Worksheet Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 21 Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 22 Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 23 Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 24 Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 25 Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 26 Figure 5 – TIR Worksheet Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 27 A.2 Existing and Proposed Surface Coverage Exhibits Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 28 Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 29 Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 30 Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 31 A.3 Site Historical Aerial Photography Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 32 Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 33 Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 34 Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 35 A.4 Stormwater Engineering Calculations Stormwater calculations were not prepared for this project as it does not trigger flow control or water quality requirements. Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34 BOEING RENTON CREW SHELTERS TECHNICAL INFORMATION REPORT 36 A.5 Geotechnical Engineering Report A Geotechnical Report was not prepared for this project. Docusign Envelope ID: 6BFD5F36-E5AA-4F5D-9CAD-4567CCEC6B34