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1 <br />1 <br />LJ <br />1 <br />1 <br />. Inspect the slope after significant storms and repair any areas where wattles are <br />not tightly abutted or water has scoured beneath the wattles. <br />Approved as Equivalent <br />Ecology has approved products as able to meet the requirements of BMP C235: Wattles. <br />The products did not pass through the Technology Assessment Protocol — Ecology <br />(TAPE) process. Local jurisdictions may choose not to accept this product approved as <br />equivalent, or may require additional testing prior to consideration for local use. The <br />products are available for review on Ecology's website at http://www.ecy.wa.gov- <br />/programs/wq/stormwater/newtech/equivalent.html <br />BMP C236: Vegetative Filtration <br />IPurpose <br />1 <br />1 <br />1 <br />1 <br />1 <br />1 <br />1 <br />1 <br />�-1 <br />U <br />1 <br />1 <br />Vegetative Filtration may be used in conjunction with BMP C241: Temporary Sediment <br />Pond (p.388), BMP C206: Level Spreader (p.348) and a pumping system with surface <br />intake to improve turbidity levels of stormwater discharges by filtering through existing <br />vegetation where undisturbed forest floor duff layer or established lawn with thatch layer <br />are present. Vegetative Filtration can also be used to infiltrate dewatering waste from <br />foundations, vaults, and trenches as long as runoff does not occur. <br />Conditions of Use <br />. For every five acre of disturbed soil use one acre of grass field, farm pasture, or <br />wooded area. Reduce or increase this area depending on project size, ground <br />water table height, and other site conditions. <br />. Wetlands shall not be used for filtration. <br />. Do not use this BMP in areas with a high ground water table, or in areas that will <br />have a high seasonal ground water table during the use of this BMP. <br />. This BMP may be less effective on soils that prevent the infiltration of the water, <br />such as hard till. <br />• Using other effective source control measures throughout a construction site will <br />prevent the generation of additional highly turbid water and may reduce the time <br />period or area need for this BMP. <br />• Stop distributing water into the vegetated area if standing water or erosion results. <br />Design Criteria <br />Find land adjacent to the project that has a vegetated field, preferably a farm field, <br />or wooded area. <br />. If the project site does not contain enough vegetated field area consider obtaining <br />2014 Stormwater Management Manual for Western Washington <br />J <br />Volume 11 - Chapter 4 - Page 379 <br />