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SOIL LOSS COMPARISON -BOWIE NO. 1 WEST MINE <br />NATURAL VS. RECLAIMED CONDITIONS <br />The following calculations are presented to show that the drainage from the reclaimed <br />slope, treated with a temporary 100% coconut erosion control blanket, will not <br />contribute a higher level of suspended solids than the undisturbed, adjacent natural <br />slope. Therefore, a sediment pond will not be required to contain sediment from the <br />reclaimed West Mine facilities area. <br />Erosion control blanket's, ECB's, are one of the many geosynthetic solutions to <br />reducing the amount of sediment loss in channels, slopes, and a wide variety of civil <br />construction projects. ECB's are widely accepted by the FHWA, USFS, CDOT and <br />many other local Colorado municipalities for sediment control on slopes, just like this <br />project. A traditional geosynthetic solution to capturing lost sediment is using silt fence <br />on the slope, either at the toe, or at intermediate points along the slope. However, this <br />solution does not prevent the loss of sediment, but it does capture it nonetheless. <br />What's being proposed, is that by using a 100% coconut blanket on the face of the <br />reclaimed slope, the drainage of the reclaimed area will not contain higher levels of <br />suspended solids than the adjacent natural slope. The ECB will reduce the sediment <br />loss from the reclaimed slope. And, because the blanket will hold the seed in place, it <br />will protect it from natural events, thereby helping promote vegetation growth. <br />Installation of erosion control blankets is farily straightforward. The coconut blanket will <br />be placed directly on the face of the slope and be stapled to the ground. The staples <br />will be 6" x 1" x 6", 11 gauge steel. At the top of the slope, the blanket will be anchored <br />2'-3' over the top of the slope, and then pinned on 1' centers at the anchor trench at the <br />toe of the slope. Un-rolling the blanket down the slope, the blanket will unroll slowly, <br />and be in intimate contact with the slope. (The blanket will need to be free from slack to <br />function properly). Once rolled out correctly, it will be stapled on 3' centers. The edges <br />of the blanket will be overlapped 3" (care should be taken to make sure the blanket is <br />shingled away from prevailing winds). Overlap blanket ends 6" with upper blanket over <br />the lower blanket and staple on 1' intervals across the width of the blanket. Cut the <br />excess blanket with scissors and anchor at the end of slope. Once installed, this type <br />of blanket will fast 3-5 years, which should be enough time to establish a full stand of <br />vegetation. <br />The following calculations are done to show that the sediment loss from the reclaimed <br />slope is less than or equal to the adjacent natural slope. The natural data listed below <br />is from a July 1986 vegetation investigation done by Harner & Associates, Inc. <br />SAE - 32 5/Ol <br />