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Information on the operation's description can be found on pages 4 to 5 and 11 through 13 <br />and in Exhibits 2, 6, 7, 10, 11 and 13 of the permit application. <br />Mine Facilities, Coal Handling Structures, Support Facilities <br />The surface operations associated with the underground mining include crushing, stockpiling <br />and loading coal. This activity is contained within the 3.22 acres of disturbance. The <br />existing structures on the surface include the tipple, office, storage shed, repair shop, oil <br />storage area, and explosives storage area. Anon-coal waste pile area has been approved <br />by the Division in the event that the operator must temporarily or permanently cease <br />backfilling the material in the underground works (see the Backfilling and Grading portion <br />of this document). The operator is contemplating installation of a truck scale in the future <br />in the current area of disturbance. The operator does not presently propose to increase the <br />disturbed area during the permit term. <br />Information on support facilities, coal handling structures and mine facilities can be found <br />on page 12 on Exhibits 9 and 10. <br />Sediment Control System <br />The sediment control system at the mine site has two collection ditches and a sediment <br />pond with a capacity of one acre-foot. The sediment control system drains 8.4 acres, of <br />which 2.3 acres are disturbed by the mining operation. The sediment pond is designed to <br />detain the runoff from a 10-year, 24-hour storm. The pond is equipped with a dewatering <br />device that allows for 24 hours detention time. The emergency spillway will pass the <br />25-year, 24-hour storm while maintaining one foot of freeboard. All the diversion and <br />interception ditches will pass the 10-year, 24-hour peak flow while maintaining 0.3 feet of <br />freeboard. <br />There has been no recorded discharge of runoff or snowmelt from the pond during the <br />period 1981-1986. In the event of a discharge from the sediment pond, water would flow <br />through a vegetated Swale 2 miles into Carbon Creek that is a tributary to Ohio Creek. <br />Water flowing down this Swale would move at non-erosive velocities because of dense <br />vegetation and moderately permeable soils. The effects of pond discharge on water quality <br />cannot be determined now because there has been no discharge from the pond. Yet, the <br />average computed discharge from the 10-year, 24-hour storm is small at 0.4 cfs in <br />comparison to the 16-year average flow of 89 cfs measured at a USGS gaging station on <br />Ohio Creek. Also, because the discharge point is separated widely from a perennial stream, <br />most, if not all, of the water would infiltrate before it reached Ohio Creek. Therefore, any <br />adverse effects from sediment pond discharge should be negligible. As of the first quarter <br />of 1992 the sediment pond has not discharged. <br />O.C. Mine No.2 Findings 13 May 15, 1992 <br />