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DESCRIPTION OF THE ENVIRONMENT The O.C. No. 2 mine is 16 miles north of Gunnison. It is on a southwest facing hillslope at an elevation of approximately 9,200 feet within the Ohio Creek drainage basin. It is near the West Elk Mountains and receives most the 20 inches of annual precipitation as snowfall. The coal is mined from the B seam of the Mesaverde Formation. The area in which the mine is characterized by many faults and fractures. The strata overlying and underlying the coal seam are non-marine shales and sandstones. Groundwater The only groundwater aquifer of significant regional extent is the Rollins Sandstone that is stratigraphically 200 feet below the coal seam to be mined. This unit will not be affected by the mining operation. Minor amounts of groundwater are encountered near the B seam because of the percolation of water through local fractures and faults. The operator has submitted groundwater quantity and quality data collected in 1980 and 1981. This baseline data was collected at four locations within the mine and at the point where the water leaves the abandoned Nu Mine adit approximately one mile northwest of the O.C. Mine No. 2 surface facilities. Small quantities of water seep from the exposed face of the mined areas. The water appears to enter the coal bed through the faults or fractures in the area. This interpretation is supported by the geologic map and cross-sections of the permit area. The mapping information shows that the mine is bounded on three sides by faults. The small amount of water that collects in the mine is pumped when necessary to the bottom of the slope, where it then flows through a connecting entry into the abandoned Nu Mine workings. The water flows through the Nu Mine workings and exits from the caved portal. The maximum flow that has been measured from the Nu Mine adit has been 1.5 gallons per minute. Groundwater quality samples were collected over the baseline period according to the guidelines provided by the Division. The samples met all the effluent standards set forth in the applicable NPDES permit. None of the water quality variables sampled were at levels which pose a hazard to the environment. Samples taken from the Nu Mine discharges have consistently had less than 700 milligrams per liter total dissolved solids and a neutral pH. A modified water quality monitoring program was initiated during 1986 based on these results. More extensive analyses are required only if pH or conductivity suggests conditions different from baseline monitoring. This modified program is described in Appendix 16. As of May 1992 no deviations in water quality have been noted. Information on groundwater can be found in Exhibits 4, 7 and 14 of the permit. O.C. Mine No.2 Findings 7 May 15, 1992