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<br />C-81-047 Blue Ribbon <br />The mine bench diversion mentioned previously labeled "B+C" is an undisturbed <br />J and disturbed permanent diversion, calculated using a 100-year, 24-hour <br />event. However, the collection ditch below the waste pile is calculated using <br />a 10-year, 24-hour event. On-site inspections indicated a trapazoidal ditch, <br />"B+C", 6.5 feet to 10 feet wide, and 47 inches deep. The other ditch is <br />triangular, being from 26 inches to 44 inches wide. Both ditches exceed the <br />designed requirements. <br />C-81-016 Hawk's Nest <br />Although the "V"-shaped diversion ditch is calculated using a 100-year, <br />24-hour event, there are no designs for and no collection ditches on site. <br />Therefore, there is no sediment control for the waste pile. The waste is <br />placed in incised pits, the tops of which are covered with soil. The slope in <br />this area is minimal. Therefore the need for sediment control is also minimal. <br />C-81-022 Somerset <br />Although the entire diversion and collection system for the mine is calculated <br />using a 100-year, 24-hour event, we have verified there is no waste pile <br />diversion on site. Any drainages from the waste pile is collected by the East <br />Bench berm, and diretted into the East t4ine sediment pond. The berm is <br />measured to be approximately 2 feet high. The waste pile is quite small, and <br />has received no additional material for the past several years. <br />1978E/scg <br />