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a � <br /> The following measures will be used to control sedimentation/erosion during construction: <br /> • Clearing.Limits: All areas to remain undisturbed during construction will be delineated <br /> prior to any site clearing or grading. <br /> • Cover Measures: Disturbed areas shall be covered as required. <br /> • Construction Entrances: A stabilized construction entrance consisting of quarry spalls will <br /> be placed at the entrances to the project area as necessary. <br /> • Perimeter Protection: Filter fabric fencing will be provided along the downhill edges of the <br /> construction area to prevent the migration of sediment-laden runoff. <br /> • Storm Drain Inlet Protection: Catch basin insert protection will be provided on all new and <br /> existing catch basins within and downstream of construction activities. <br /> • Surface Water Control: The number of portable sedimentation storage tanks was <br /> determined by using the developed 2-year storm event for the limits of construction <br /> (assumed entire basin to be impervious: 1.66 cfs). Based on the design requirements for a <br /> sediment pond, the minimum storage volume required for the anticipated site conditions is <br /> 63,980 gallons. The TESC plans show three-21,000 gallon tanks. During construction,the <br /> Contractor shall monitor these facilities and upgrade as necessary for unexpected storm <br /> events and changing site conditions to meet NPDES permitting requirements. See <br /> Appendix C for detailed calculations. <br /> • Dust Control: Dust control measures will be implemented when exposed soils are dry to <br /> the point that wind transport is possible and offsite properties are likely to be impacted. <br /> • All disturbed areas should be revegetated as soon as possible. If it is outside of the growing <br /> season, the disturbed area should be covered with mulch, as recommended in the erosion <br /> control plan. <br /> Based on past experience, it is necessary to make adjustments and provide additional measures to <br /> the TESC plan in order to optimize its effectiveness. The success of the TESC plan depends on a <br /> proactive approach to project planning and Contractor implementation and maintenance. <br /> All ESC measures will be maintained and reviewed on a regular basis as prescribed in the Dept. <br /> of Ecology's maintenance requirements for each BMP. <br /> A Construction Stormwater Pollution Prevention Plan (SWPPP) will be prepared prior to <br /> construction as required by the Construction Stormwater General Permit. Each of the twelve <br /> elements will be considered and applied to the project site as needed. <br /> 4.2 ESC Maintenance <br /> As of October 1, 2006, the Washington State Department of Ecology Construction Stormwater <br /> General Permit (NPDES permit) requires weekly TESC inspections and turbidity monitoring for <br /> all sites more than 1 acre in size that discharges stormwater to surface waters of the state. The <br /> TESC inspections must be completed by a Certified Erosion Control Lead (CESCL) for the <br /> duration of construction. TESC reports must be kept onsite with the SWPPP. Ecology also <br /> requires turbidity monitoring by a CESCL of stormwater leaving the site at least once a week and <br /> Technical Information Report <br /> Cascade High School—Track Replacement Project 5 Integrityworks Consulting Engineers,LLC <br /> Project No.212104 <br />