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Eastern lfashinglon Phase 11 MlWicipal Scor-r►7ivaler Permil <br />At the top of slopes, collect drainage in pipe slope drains or protected channels <br />to prevent erosion. Temporary pipe slope drains shall handle the expected peak <br />flow velocity from a 6 -month, short duration storm for the developed condition. <br />C. Excavated material shall be placed on the uphill side of trenches, consistent with <br />safety and space considerations. <br />d. Check dams shall be placed at regular intervals within constructed channels that are <br />cut down a slope. <br />8. Protect Drain Inlets: <br />a. Storm drain inlets made operable during construction shall be protected so that <br />stormwater runoff does not enter the conveyance system without first being filtered or <br />treated to remove sediment. <br />b. Inlet protection devices shall be cleaned or removed and replaced when sediment has <br />filled one-third of the available storage (unless a different standard is specified by the <br />product manufacturer). <br />9. Stabilize Channels and Outlets: <br />All temporary on-site conveyance channels shall be designed, constructed, and <br />stabilized to prevent erosion from the following expected peak flows. Channels <br />shall handle the expected peak flow velocity of the 6 -month, short duration <br />storm for the developed condition. <br />a. Stabilization, including armoring material, adequate to prevent erosion of outlets, <br />adjacent stream banks, slopes, and downstream reaches shall be provided at the <br />outlets of all conveyance systems. <br />10. Control Pollutants: <br />a. All pollutants, including waste materials and demolition debris, that occur onsite shall <br />be handled and disposed of in a manner that does not cause contamination of <br />stormwater. <br />b. Cover, containment, and protection from vandalism shall be provided for all <br />chemicals, liquid products, petroleum products, and other materials that have the <br />potential to pose a threat to human health or the environment. On-site fueling tanks <br />shall include secondary containment. <br />C. Maintenance, fueling and repair of heavy equipment and vehicles shall be conducted <br />using spill prevention and control measures. Contaminated surfaces shall be cleaned <br />immediately following any spill incident. <br />d. Wheel wash or tire bath wastewater shall be discharged to a separate on-site treatment <br />system or to the sanitary sewer with local sewer district approval. <br />Appendix 1- Minimum Technical Requirements <br />Eastern Washington Phase II Municipal Stormwater Permit -- August 1, 2014 <br />Page 7 <br />