1001 N BROADWAY EVCC 2025-10-03 - Laserfiche WebLink

• Inspect the slope after significant storms and repair any areas where wattles are not tightly abutted or water has scoured beneath the wattles. Approved as Ecology has approved products as able to meet the requirements of BMP Equivalent C235. The products did not pass through the Technology Assessment Protocol—Ecology(TAPE)process. Local jurisdictions may choose not to accept this product approved as equivalent, or may require additional testing prior to consideration for local use. The products are available for review on Ecology's website at http:HivNvw.ecy.wa.gov/programs/wg/store-twater/newtech/egti ivalent.litn..l BMP C236: Vegetative Filtration Purpose Vegetative Filtration may be used in conjunction with BMP C241 Temporary Sediment Ponds,BMP C206 Level Spreader and a pumping system with surface intake to improve turbidity levels of stormwater discharges by filtering through existing vegetation where undisturbed forest floor duff layer or established lawn with thatch layer are present. Vegetative Filtration can also be used to infiltrate dewatering waste from foundations,vaults, and trenches as long as runoff does not occur. Conditions of Use • For every five acre of disturbed soil use one acre of grass field, farm pasture, or wooded area. Reduce or increase this area depending on project size, ground water table height, and other site conditions. • Wetlands shall not be used for filtration. Do not use this BMP in areas with a high ground water table, or in areas that will have a high seasonal ground water table during the use of this BMP. • This BMP may be less effective on soils that prevent the infiltration of the water, such as hard till. • Using other effective source control measures throughout a construction site will prevent the generation of additional highly turbid water and may reduce the time period or area need for this BMP. • Stop distributing water into the vegetated area if standing water or erosion results. Desigsr Criteria . Find land adjacent to the project that has a vegetated field, preferably a farm field, or wooded area. If the project site does not contain enough vegetated field area consider obtaining permission from adjacent landowners(especially for farm fields). • Install a pump and downstream distribution manifold depending on the project size. Generally, the main distribution line should reach 100 to 200-feet long(many large projects, or projects on tight soil,will Volume 11—Consb•uction Storimmiter Polhifion Prevenflon -August 2012 4-98