2320 RAILWAY AVE INTERWEST CONSTRUCTION INC 2023-02-02

I I I I I I I INTERWEST—EVERETT CONTRACTOR'S YARD SITE IMPROVEMENTS Sitts& Hill Engineers, Inc. I I CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN Job Number 18,831 Section 7— Construction Stormwater Pollution Prevention Elements Erosion and sediment control for this project will consist of the application and maintenance of BMPs previously installed as a part of the fill project (PW1807-046). These BMPs are listed below. See the Erosion Control Plan exhibit at the end of this section for a plan view of the proposed TESL BMPs. Below is a discussion of each of the thirteen Construction Stormwater Pollution Prevention Elements and a summary of applicable BMPs. Design, installation, and maintenance of any specific BMP should be carried out in accordance with the DOE Manual and any further instructions detailed in the construction plans. Included in Appendix 1 of this report are the DOE Manual specifications,tables,and figures for each BMP identified in this report. Element 1-Preserve Vegetation/Mark Clearing Limits Work limits will be identified in the field from the construction plans. Silt fence will be used to delineate the limits of construction. Existing vegetation should be preserved where possible to limit the area of exposed soils. Applicable BMPs: BMP C101: Preserving Natural Vegetation BMP C233: Silt Fence Element 2-Establish Construction Access Two stabilized construction entrances are existing-one on the southwest corner of the site, and the other on the southeast corner. Any debris generated as a result of construction activity will be swept clean to prevent tracking onto paved areas. Applicable BMPs: BMP C105: Stabilized Construction Entrance/Exit Element 3-Control Flow Rates The proposed project is flow control exempt. Applicable BMPs: N/A Element 4-Install Sediment Controls Silt fencing has been provided along the entire perimeter of the site. A temporary sediment pond is also proposed and has been sized according to the requirements of the DOE Manual. See the CSWPPP for the Interim Fill Project (permit no. PW1807-046)for sizing calculations. Applicable BMPs: BMP C233: Silt Fence BMP C241: Temporary Sediment Pond Element 5-Stabilize Soils I Any exposed soil requiring stabilization due to poor weather conditions,or left unworked for more than 2 days from October 1 to April 30(7 days from May 1 to September 30),will be covered at the end of each work shift. Covering material will be anchored to ensure adequate protection. Erosion control measures will remain in place until soil stabilization can be achieved by the installation of permanent surfacing. There will be no soil stockpiles after SITTS& HILL ENGINEERS, INC. 8 I TACOMA, WASHINGTON