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the magnitude of mine discharge and to assess the potential impact on <br /> natural patterns of ground water recharge and discharge. <br /> In the past, the West Elk Mine has experienced three types of mine <br /> inflows. The first type of inflow is due to primary permeability which <br /> is ground water flow through the competent portions of the F Seam <br /> and lower Barren Member. The second type of inflow occurs in the <br /> coal seam and overlying Barren Member in areas of shallow <br /> overburden. This is secondary permeability and is the result of ground <br /> water flow through the fractured and weathered portions of these <br /> strata. The fractured rock acts as a conduit to the surface colluvial <br /> aquifers. The third type of inflow is also due to secondary <br /> permeability and it is the result of ground water flow along fault <br /> zones. These fault zones may be in contact with surface aquifers or <br /> with water bearing zones in the overburden. The streams in the North <br /> Fork area are generally fault controlled and may be a source of <br /> recharge for fault related inflows. Prior to the construction of the mine <br /> entries, piezometers were installed in the colluvial/landslide strata <br /> immediately upslope of the entries. All piezometers but one were <br /> destroyed during construction of the entries. <br /> The operator at the West Elk Mine expects that mine inflows will <br /> increase at a rate slower than the McWhorter model predicted for <br /> advancing mine workings. Most of the inflow has occurred along the <br /> subcrop in the same location each year. The inflow is seasonal and <br /> varies with the magnitude of seasonal precipitation. The experience <br /> near the F Seam subcrop indicates that the colluvium, coal and <br /> bedrock are recharged locally. In prior years, inflow to the advancing <br /> mine workings has been minimal and unmeasurable. However, In <br /> March 1996, MCC experienced a large inflow of water in the B East <br /> Mains while mining through a fault/fracture system. In April 1996, <br /> MCC encountered the same fault in a subsequent entry, the inflow was <br /> estimated to be a maximum of 2,500 gpm. The flows have since <br /> receded. In May 1996, the flow was measured at approximately 240 <br /> gpm. The mine inflow and subsequent discharge of water will be <br /> thoroughly investigated by the Division during 1996. <br /> Three of the five entries experienced inflows during construction, <br /> which began in September of 1981. Adit entry No. 4 experienced the <br /> greatest inflow, about 5 gpm, which decreased to less than I gpm and <br /> dried up within a week. The No. 1 entry produced a small quantity of <br /> water from the bottom of the coal at a rate of less than I gpm and <br /> dried up within two weeks. However, the sandstone roof at entry <br /> No. 1 was dry. Entry No. 5 produced drips, approximately 0.1 gpm, <br /> for about one week. The other two entries were dry. During the <br /> period from August to December 1981 water levels dropped in some <br /> of the piezometers located above the portals. In all cases the drop was <br /> 33 <br />