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this time. The water quality data for R-1, a well completed in Rollins <br /> Sandstone and drilled by Mountain Coal Company in 1976, indicates <br /> total dissolved solids generally outside the range acceptable for <br /> drinking water. MCC has completed two wells in the Rollins <br /> Sandstone to monitor water levels and provide water quality data. <br /> Based on information contained in the Annual Hydrology Reports <br /> prepared for the mine, mining activities in both the F and B seams are <br /> thought to have had no impact on groundwater in the Rollins <br /> Sandstone to date. <br /> The majority of Mountain Coal Company's hydrologic monitoring <br /> concentrates on mine water discharges and wells associated with <br /> B Seam mining. Disturbances and changes to water quality, if they <br /> occur, will be manifested in B Seam discharge water and B Seam <br /> monitoring wells prior to any potential impacts to the Rollins <br /> Sandstone. The B Seam is separated from the Rollins by siltstones, <br /> shales, and another coal seam. It is unlikely that the Rollins Sandstone <br /> would be used as a primary drinking water source because of its great <br /> depth outside stream valleys and the ready availability of better quality <br /> surface water near the stream valleys. <br /> MCC has mapped the B Seam overburden thickness with potential <br /> areas of ground water inflow highlighted. These areas of potential <br /> inflows, similar to the F Seam, are associated with fracture zones <br /> beneath drainages and near outcrops and areas of low overburden. A <br /> map of the potentiometric surface of the B Seam has been produced <br /> and can be reviewed in Exhibit 17A of the permit document. <br /> MCC has made inflow estimates for the B Seam mine plan for the <br /> five-year permit area. The "probable maximum" estimate of mine <br /> inflow shows a peak or initial inflow rate of about 15 gallons per <br /> minute (gpm) and a long term steady rate of about 10 gpm. This <br /> estimate is based on a rate of mining of 1.4 million tons per year and <br /> no ventilation portals extended to the northern outcrop. Recent <br /> experience shows that mine inflows have the potential to be much <br /> higher. As indicated by measurement of inflows of as much as 2,500 <br /> gpm encountered in April 1996 while mining through a fault/fracture <br /> system in the B Seam. <br /> An estimate of mine inflow for the projected life of mine was also <br /> performed. This case showed an initial inflow rate of about 45 gpm <br /> and a long term steady inflow rate of about 30 gpm. Maximum inflow <br /> is estimated to be 100 gpm. This case was based on a mining rate of <br /> 2.8 million tons per year, installation of a ventilation portal along the <br /> outcrop, and an increased inflow constant for unknown conditions. <br /> On the north side of Jumbo Mountain colluvium from an ancient <br /> landslide that removed the minable portion of the B Seam lies directly <br /> 35 <br />