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1.2. Sediment Control System for Gold Operation (This Section revised for TR -10 in January 201 5) <br />The sediment control system for the mine, including the water handling system from the River, is <br />shown on Maps C -2 and C -4. <br />The permit area is basically divided into 2 areas, the area north of Access #1 that drains into Ponds 3 <br />and 4, and the area south of Access #1 that will drain into constructed South Ponds #1 and #2 which <br />have not yet been constructed as of January 2015. <br />Area North of Access #1 <br />For the northern area, all runoff around the plant and the regraded area will flow into Ponds 3 and 4. <br />These ponds do not discharge. New controls have been put into effect that prevent any discharge <br />from these ponds or any other disturbed area on the site. <br />The water handling system works as follows: Water from the Point of Diversion in the South Platte <br />River is pumped from the Pump House into a 10" PVC Pipe which runs along the north edge of <br />Access Road #1 to a tee located immediately south of Pond #4. The valve on this tee is marked with <br />very large letters showing whether the water from the pump is being delivered to Pond #4 or if it <br />continues directly into the plant. The discharge into Pond #4 is elevated 3.0 feet above the highest <br />level in Pond #4 so that no water can flow back through the pipe into the pump house and back into <br />the River. In addition, a backflow preventer has been installed to prevent this from occurring even if <br />water were to reach the elevation of the pipe. The overflow culvert drains Pond #4 and allows any <br />excess water to drain to the south to the various existing ponds located in the future mining area, <br />which allow the water to infiltrate into the ground. The top of the overflow culvert is located at least <br />1.0 feet below the invert of the 10" PVC pipe discharge into the Pond, so that water must flow in the <br />overflow culvert before it can enter the 10" PVC pipe. In addition to these items, site personnel have <br />been trained in the full operation of the pump, the valves and the plant, as well as the frequency of <br />cleaning out all 4 ponds so that large water volumes are maintained in the ponds to allow sediment <br />to settle out. <br />The other side of the tee in the 10" PVC pipe goes directly into the plant building for the gold <br />Alma Placer Mine 1115 18 <br />