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Easlern Washington Phase 11 MunicipalSlornm,oier Permil <br />a. Stormwater runoff from disturbed areas shall pass through a sediment pond, or other <br />appropriate sediment removal BMP, prior to leaving a construction site or prior to <br />discharge to an infiltration facility. Runoff from fully stabilized areas may be <br />discharged without a sediment removal BMP, but shall meet the flow control <br />performance standard of 3.a, above. <br />5. Sediment control BMPs (sediment ponds, traps, filters, etc.) shall be constructed as one of <br />the first steps in grading. These BMPs shall be functional before other land disturbing <br />activities take place. BMPs intended to trap sediment on site shall be located in a manner to <br />avoid interference with the movement of juvenile salmonids attempting to enter off -channel <br />areas or drainages. <br />6. Stabilize Soils: <br />a. Exposed and unworked soils shall be stabilized by application of effective BMPs that <br />prevent erosion. <br />b. No soils shall remain exposed and unworked for more than the time periods set forth <br />below: <br />At sites with mean annual precipitation greater than or equal to 12 inches: <br />0 10 days during the dry season (July 1 through September 30) <br />0 5 days during the wet season (October 1 through June 30) <br />At sites with mean annual precipitation less than 12 inches: <br />0 30 days during the dry season (July 1 through September 30) <br />0 15 days during the wet season (October 1 through June 30) <br />The time period(s) may be adjusted by a local jurisdiction, if the jurisdiction can <br />show that local precipitation data justify a different standard. <br />C. Soils shall be stabilized at the end of the shift before a holiday or weekend if needed <br />based on the weather forecast. <br />d. Soil stockpiles must be stabilized from erosion, protected with sediment trapping <br />measures, and where possible, be located away from storm drain inlets, waterways <br />and drainage channels. <br />7. Protect Slopes: <br />a. Design and construct cut and fill slopes in a manner that will minimize erosion. <br />b. Off-site stormwater (run-on) or groundwater shall be diverted away from slopes and <br />undisturbed areas with interceptor dikes, pipes and/or swales. Off-site stormwater <br />should be managed separately from stormwater generated on the site. <br />Appendix I- Minimum Technical Requirements <br />Eastern Washington Phase II Municipal Stormwater Permit —August 1, 2014 <br />Page 6 <br />