220 OLYMPIC BLVD VA OUTPATIENT CLINIC 2023-02-09

Response: A stormwater site plan has been prepared for the proposed development.The stormwater site plan includes the design drawings and this report. Minimum Requirement#2: Construction Stormwater Pollution Prevention (SWPPP) All new development and redevelopment projects are responsible for preventing erosion and Idischarge of sediment and other pollutants into receiving waters. I Projects which result in 2,000 square feet or more of new plus replaced hard surface area, or which disturb 7,000 square feet or more of land must prepare a Construction SWPP Plan (SWPPP) as part of the Stormwater Site Plan (see 1-3.4.1 MR1: Preparation of Stormwater Site Plans). IProjects below those thresholds (listed above) are not required to prepare a Construction SWPPP, but must consider all Construction SWPPP Elements (listed below) and develop controls for all Construction SWPPP Elements that pertain to the project site. 111 Response: The 13 elements of a SWPPP are addressed in the Construction SWPPP section of I this report.A full Construction SWPPP will be prepared per 2019 Manual requirements, if required, and included with the final version of this report. I Minimum Requirement#3: Source Control of Pollution All known, available and reasonable Source Control BMPs shall be applied to all projects. Source Control BMPs shall be selected, designed, and maintained according with this Manual. I Response: All available and relevant source control BMPs will be applied to this project.This I includes, but is not limited to, Dust Control at Disturbed Land Areas, Landscaping and Lawn/Vegetation Management, and Maintenance of Stormwater Drainage and Treatment Systems. See Operations and Maintenance Manual, submitted under separate cover, for details. IMinimum Requirement#4: Preservation of Natural Drainage Systems and Outfalls Natural drainage patterns shall be maintained, and discharges from the Project Site shall occur at I the natural location, to the maximum extent practicable.The manner by which runoff is discharged from the Project Site must not cause a significant adverse impact to downstream receiving waters and downgradient properties. All outfalls require energy dissipation. Iiii Response: Runoff from the existing site is currently collected on-site by catch basins before being discharged into the existing 24-inch culverted Dogwood Elm Creek running through the I site. Stormwater runoff from the proposed project will be collected and routed through a series of catch basins, underground conveyance pipes, and water quality treatment and flow control facilities before being discharged to the existing culverted Dogwood Elm Creek.The existing Iculverted Dogwood Elm Creek discharges into the daylighted Pigeon Creek northwest of the project site and ultimately drains to Possession Sound.The proposed project will not alter the onsite or downstream path of the culverted Dogwood Elm Creek. No negative impacts to Idownstream receiving waters are anticipated. I NAVIX Everett VA Clinic—Everett, WA 9