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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 <br /> Sandstone would be used as a primary drinking water source because <br /> of its great depth outside stream valleys and the ready availability of <br /> better quality 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. <br /> Based on experience in the F Seam in these areas, the inflows are <br /> predicted to be minor in nature. A map of the potentiometric surface <br /> of the B Seam has been produced and can be reviewed in <br /> Exhibit 17A. <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. <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 <br /> inflow is estimated to be 100 gpm. This case was based on a mining <br /> rate of 2.8 million tons per year, installation of a ventilation portal <br /> along the outcrop, and an increased inflow constant for unknown <br /> 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 /> atop the lower portions of the B Seam. Water could be expected to <br /> infiltrate through the colluvium and migrate from bedrock units into <br /> the colluvium, emerging as springs or seeps down-dip of the proposed <br /> mining <br /> The B Seam mine will not cause significant hydrologic impacts to <br /> groundwater systems in the five-year permit area based on the data <br /> provided. <br /> 31 <br />