Laserfiche WebLink
West Elk Mine <br />i, is no reason to expect groundwater quality to significantly change if groundwater drops from one <br />formation to a lower formation. The technical literature is supportive on this finding. <br />12. "Total mine water inflow in the F-Seam has not exceeded 15 acre-feet in any one year. The <br />quality of mine water offers no problem for treatment and discharge. Mine water discharge is <br />treated in sedimentation pond MB-1:' (p.38). This remainsittve. Minor F-Seam colluvial <br />inflows in the main entries aze collected in small, open depressions in entries and/or crosscuts <br />(i.e., operational sumps) typically containing less than 0.10 acre feet and are pumped either to <br />Sylvester Gulch or the main mine site sedimentation ponds for, discharge. As very little water <br />was encountered when the F-Seam was mined, no operational Bumping was needed during <br />mining. Also, no water (including B-Seam inflows) has ever been pumped into the sealed F- <br />Seam workings for storage. It is important to note that the majority of F-Seam panels were <br />mined in areas up-dip (i.e., uphill) of the main F-Seam entries, so that water, if any, would flow <br />out and could not be held within the ventilation seals. <br />13. "Life of Mine Operations in F, B, and E-Seams are not expected to have an impact on streams <br />as subsidence and propagation of fractures aze to be minimized under the proposed Mine Plan <br />sections contained within the pemut application." (p. 34). <br />This statement certainly applies to the Apache Rocks permit revision azea and the associated B and <br />E-Seam mining for the many reasons listed in Section 2.05.6, Surface Water Quantity Effects, <br />Streams. This statement also applies to B-Seam mining in the Box Canyon permit revision area. <br />~. Regional Mining Experience <br />Considerable mining of the coal-bearing units within the Mesaverde Formation has occurred not <br />only at the West Elk Mine, but along the North Fork Valley. ?s a result, there is substantial <br />information known about the hydrologic consequences of mining the coal-bearing units within this <br />formation. <br />The CFiIA (1992) provides valuable information regazding the general hydrologic conditions and <br />consequences of mining in the North Fork Valley. The following statements (including page <br />references) are from this document. Unless otherwise noted, and based upon WWE's analyses, <br />these statements apply directly to the permit azea: <br />1. "Four categories of potential aquifers occur in the Somerset) coal field. These aze; (a) the <br />alluvium and terrace deposits associated with the North Fork~of the Gunnison River; (b) the <br />localized, shallow alluvium along creeks tributary to the North Fork; (c) the discontinuous <br />lenticular and laminar sandstones of the Mesaverde Formation; and (d) the Rollins Sandstone." <br />(P• 6)• <br />~. <br />7.05-144 November 1004 PR11 <br />