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overlying Barren member in areas of shallow overburden. <br /> This is secondary permeability and is the result of ground <br /> water flow through the fractured and weathered portions of <br /> these strata. The fractured rock acts as a conduit to the <br /> surface colluvial aquifers. The third type of inflow is <br /> also due to secondary permeability and it is the result of <br /> ground water flow along fault zones. These fault zones may <br /> be in contact with surface aquifers or. with water bearing <br /> zones in the overburden. The streams in the North Fork <br /> area are generally fault controlled and may be a source of <br /> recharge for fault related inflows. Prior to the <br /> construction of the mine entries, piezometers were <br /> installed in the colluvial/landslide strata immediately <br /> upslope of the entries. All piezometers but one were <br /> destroyed during construction of the entries. <br /> Three of the five entries experienced inflows during <br /> construction, which began in September of 1981. Adit entry <br /> No. 4 experienced the greatest inflow, about 5 gpm, which <br /> decreased to less than 1 gpm and dried up within a week. <br /> The No. I entry produced a small quantity of water from the <br /> bottom of the coal at a rate of less than 1 gpm and dried <br /> up within two weeks. However, the sandstone roof at entry <br /> No. 1 was dry. Entry No. 5 produced drips, approximately <br /> 0.1 gpm, for about one week. The other two entries were <br /> dry. During the period from August to December 1981 water <br /> levels dropped in some of the piezometers located above the <br /> portals. In all cases the drop was not greater than two <br /> feet. Water levels have changed very little since January <br /> 1982. <br /> MCC has submitted two plans for the sealing of the portals <br /> upon closure of the mine. The first plan calls for sealing <br /> the portals to allow gravity discharge of mine inflows. <br /> MCC anticipated, from water samples taken in the Oliver <br /> Mine, that mine waters will not be toxic. This plan calls <br /> for the construction of a block wall at the portal and a <br /> four-inch PVC pipe to drain the collected mine waters. The <br /> second plan is contingent on the mine producing toxic mine <br /> waters. This plan calls for the construction of several <br /> engineered seals located within the mine designed to <br /> withstand pre-mining head pressures. <br /> MCC has conservatively estimated that the B-seam mine, <br /> including Jumbo Mountain, and the existing F-seam mine <br /> would flood and fill in 139.6 years. This estimate assumes <br /> no seepage or outflow and the worst case maximum steady <br /> inflow for the F-seam mine (Table 77) and the median of the <br /> 5-year and life-of-mine, worst case maximum steady inflows <br /> for the B-seam mine. <br /> Water moves downslope and discharges as seeps and springs. <br /> It also appears that mine inflows are controlled by the <br /> amount of precipitation (mostly snowmelt) , depth of <br /> overburden and location and extent of fracture zones and <br /> not by the extent of the underground workings. <br /> Mountain Coal Company predicts that the West Elk Mine will <br /> have no significant impact on the quality and quantity of <br /> ground water and springs. Representative water quality <br /> samples from wells located in the lower coal member show <br /> that ground water is suitable for discharge to the North <br /> Fork. <br /> The B seam, which will be mined during the next five year <br /> permit term, lies ten feet above the Rollins Sandstone <br /> 29 <br />