8102 EVERGREEN WAY EVERETT 4 CORNERS 2025-08-06

Four Corners Short Plat Stormwater Site Plan SECTION 4 - CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN Site specific details and provisions for the temporary erosion and sediment control (ESC) facilities are provided with the improvement plans that accompany this SSP. The proposed facilities have been selected and sized in accordance with the recommendations provided in the SWMM. In addition to the site -specific ESC measures, the following general BMPs for sediment control shall also be implemented in accordance with the provisions of the SWMM: 1. Mark Clearing Limits To protect adjacent properties and to reduce the area of soil exposed to construction, the limits of construction will be clearly marked before land -disturbing activities begin. Trees that are to be preserved, as well as all sensitive areas and their buffers, shall be clearly delineated, both in the field and on the plans. In general, natural vegetation and native topsoil shall be retained in an undisturbed state to the maximum extent possible. The BMPs relevant to marking the clearing limits that will be applied for this project include: • BMP C101: Preserving Natural Vegetation • BMP C103: High Visibility Plastic Fence Tree protection will be provided for all trees to remain, including all trees adjacent to the work and outside the construction limits as noted on the drawings. 2. Establish Construction Access Construction access shall be stabilized to minimize the tracking of sediment onto public roads; street sweeping shall be employed to prevent sediment from entering state waters. The specified BMPs related to establishing construction access that will be used on the project include: • BMP C105: Stabilized Construction Entrance • BMP C106: Wheel Wash A construction access and wheel wash shall be implemented to prevent tracking any sediment onto City or State roads or onto the adjacent properties. 3. Control Flow Rates In order to protect the properties and waterways downstream of the project site, stormwater discharges from the site will be controlled during construction. Flow rates during construction are proposed to be controlled using the proposed permanent storm water facilities, i.e. detention facility and flow control riser. In general, discharge rates of stormwater from the site will be controlled where increases in impervious area or soil compaction during construction could lead to downstream erosion, or where necessary to meet local agency stormwater discharge requirements. The following specific BMPs will be used to protect slopes for this project: • BMP C240: Sediment Trap • BMP C241: Temporary Sediment Pond 4. Install Sediment Controls All stormwater runoff from disturbed areas shall pass through an appropriate sediment removal BMP before leaving the construction site or prior to being discharged to an infiltration facility. The specific BMPs to be used for controlling sediment on this project include: • BMP C233: Silt Fence • BMP C220: Storm Drain Inlet Protection CPH Project No. 0024-18-042 October 23, 2020 CPIH CONSULTANTS Page 6