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3. Control Flow Rates—Interceptor swales and a sediment trap will control runoff during <br /> typical storm events. <br /> 4. Sediment Controls— Silt fencing and storm-drain inlet protection will prevent sediment <br /> from leaving the site where interceptor swales cannot collect and treat runoff. <br /> 5. Stabilize Soils— Disturbed areas not immediately worked shall be covered with plastic <br /> sheeting, mulch, or other BMP, as required in the Washington State Department of Ecology <br /> Manual(DOE Manual). <br /> 6. Protect Slopes—All soils on slopes shall be stabilized per Element 5 by covering exposed <br /> soils with plastic sheeting, mulch, or other BMP, as required by the DOE Manual. Slopes <br /> will also be protected through use of interceptor swales, check dams, and other BMPs to <br /> provide an alternative drainage path away from slopes. <br /> 7. Protect Drain Inlets—All catch basins in and adjacent to the construction area will be <br /> protected by storm drain inlet protection per BMP C220. <br /> 8. Stabilize Channels and Outlets—Temporary interceptor swales shall be stabilized using <br /> BMP5 suggested by the DOE, including outlet protection and channel lining as necessary. <br /> 9. Control Pollutants—All pollutants and construction materials shall be handled in a manner <br /> to prevent stormwater contamination. Construction debris shall be handled and disposed <br /> of in a legal manner offsite. Construction BMPs shall be used to prevent or treat <br /> contamination of stormwater. <br /> 10. Control Dewatering- Dewatering for construction of foundations and trenches, which has <br /> similar characteristics to stormwater, will be discharged into a controlled conveyance <br /> system to be treated in a sediment trap or portable sediment tanks. <br /> 11 Maintain BMPs—The Contractor shall be responsible for maintaining all BMPs. <br /> 12. Manage the Project—The Contractor shall be responsible for inspecting and maintaining <br /> Temporary Erosion and Sedimentation Control (TESC)facilities. The Construction SWPPP <br /> shall be retained onsite and shall be kept up to date. The Contractor will provide the name <br /> and contact information for the designated Certified Erosion and Sedimentation Control <br /> Lead (CESCL) to the City prior to beginning construction. <br /> 4.0 ANALYSIS AND DESIGN OF RUNOFF CONTROL BMPS <br /> Flow control and water quality are not required for this project, as it is within the combined <br /> sewer area in the City of Everett. However, in light of recent flooding events within the <br /> combined sewer system area, several runoff control BMPs will be provided to reduce the rate and <br /> volume of runoff from the site. These include infiltration and bio-retention systems(rain <br /> gardens) and underground detention/infiltration pipes, which are summarized below. <br /> 4.1 Treatment Control System <br /> Water quality treatment is not required by the City of Everett. Treatment from proposed <br /> pollution-generating impervious and pervious surfaces will occur at the sewage treatment plant. <br /> To improve the hydrologic conditions of the site, including reducing runoff, increasing <br /> evapotranspiration, and providing treatment of pollutants, a portion of the stormwater runoff <br /> Stormwater Site Plan Report <br /> 1:118013 <br /> Everett Community College <br /> Index Hall Replacement&Surface Parking Lot"M" 4 <br /> 209459.10/209459.11 <br />