2201 100TH ST SW AD SYSTEMS 2022-03-07

AD SYSTEMS EXPANSION EVERETT,WA CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN All erosion and sediment control measures shall be governed by the requirements of the City of Everett. A temporary erosion and sedimentation control plan has been prepared to assist the contractor in complying with these requirements.The Erosion and Sediment Control (ESC) plan is included with the construction plans. Element 1: Mark Clearing Limits • Prior to beginning land disturbing activities, including clearing and grading, all clearing limits, sensitive areas and their buffers, and trees that are to be preserved within the construction area shall be clearly marked, both in the field and on the plans,to prevent damage and offsite impacts. • Plastic, metal, or stake wire fence may be used to mark the clearing limits. • The duff layer, native top soil, and natural vegetation shall be retained in an undisturbed state to the maximum extent practicable. If it is not practicable to retain the duff layer in place, it should be stockpiled on-site, covered to prevent erosion, and replaced immediately upon completion of the ground disturbing activities. Element 2: Establish Construction Access • Construction vehicle access and exit shall be limited to one route, if possible, or two for linear projects such as roadways where more than one access is necessary for large equipment maneuvering. • Access points shall be stabilized with a pad of quarry spalls or crushed rock prior to traffic leaving the construction site to minimize the tracking of sediment onto public roads. • Wheel wash or tire baths should be located on-site, if applicable. • If sediment is tracked off site, public roads and paved areas shall be cleaned thoroughly at the end of each day, or more frequently during wet weather, if necessary to prevent sediment from entering waters of the state. Sediment shall be removed from roads and paved areas by shoveling or pickup sweeping and shall be transported to a controlled sediment disposal area. Street washing will be allowed only after sediment is removed in this manner. • Street wash wastewater shall be controlled by pumping back onsite, or otherwise be prevented from discharging into systems tributary to state surface waters. Element 3:Control Flow Rates • Properties and waterways downstream from development sites shall be protected from erosion due to increases in the volume, velocity, and peak flow rate of stormwater runoff from the project site, as required by local plan approval authority. • Downstream analysis is necessary if changes in flows could impair or alter conveyance systems, stream banks, bed sediment or aquatic habitat. See Chapter 3 for offsite analysis guidance. • Where necessary to comply with Minimum Requirement #7, stormwater retention/detention facilities shall be constructed as one of the first steps in grading. Detention facilities shall be functional prior to construction of site improvements (e.g. impervious surfaces). • The local permitting agency may require pond designs that provide additional or different stormwater flow control if necessary to address local conditions or to protect properties and • waterways downstream from erosion due to increases in the volume, velocity, and peak flow rate of stormwater runoff from the project site. NOVEMBER 20, 2017 STORMWATER DRAINAGE SUMMARY PAGE 10