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Area South of Access #1 <br />The area around the active mine pit will drain to the pit, which is well below the surrounding area and <br />will allow water to infiltrate into the ground. <br />The gold mining operation will control sediment through a number of measures. <br />First, the minimum 8' berm created on the west side of the permit area next to the ROW of Highway 9 <br />will channel all runoff from any disturbed areas into two sediment ponds located at the southeast corner <br />of the permit area. This is also the low point of the permit area. Water will enter South Pond #1 which <br />will then flow into South Pond #2. South Pond #1 will serve as the cleanout pond, while South Pond #2 <br />will serve to collect runoff from a 100 year event, al- though much of this flow will be captured in either <br />Pond #4 (below the prep plant) or the active mining pits. At the southern end of the mining area, the <br />South Ponds #3 and #4 will be installed to handle pumped water from the active mining pit. This will <br />allow the clean water to seep back into the ground, thus avoiding a discharge from the site. No runoff <br />from the site will be allowed to enter ponds #3 and #4. <br />The 8' high berm will have a maximum 2.OH:1.OV and will be created from the existing disturbed gravel <br />on the site. Topsoil may also be used to create the berm on the southern portion of the mining area if <br />excess topsoil is available from stripping. In all cases, gravel and topsoil will not be mixed to create the <br />berm. A ditch of 2.0 feet depth and 2H:1 V sideslopes (Collection Ditch #1) will be constructed on the <br />west side of the berm to direct all disturbed area flows into Pond #1, then Pond #2. <br />This ditch will cross access roads in two locations as shown on Map C -2, where an 18" culvert will be <br />placed in the ditch for the road crossing. <br />The terrain rises to the east from the permit area, but the Columbia #1 Ditch is located near the east <br />permit boundary and this ditch prevents any undisturbed runoff from entering the site. See Map C -2. <br />Sediment Pond #1 is simply a sediment cleanout pond and will not be used for detention volume. <br />Sediment Pond #2 will handle the runoff from the majority of the gold mining area. Ponds 3 and 4 will <br />handle runoff from the prep plant area as well as from the main gravel operation. Map C -4 shows the <br />drainage areas for the site in addition to all ditches, berms and ponds. <br />Alma Place Mine 01/15 19 <br />