Laserfiche WebLink
Mayo and Associates, LC <br />east is the Left Fork of Fish Creek, which also occupies a damage zone of the Pleasant <br />Valley Fault. <br />Appreciable groundwater inflows occurred from the Blind Canyon Seam sandstone <br />channel. Groundwater from saturated river bank deposits on the margins of the channel <br />was first encountered in the mine roof 1,400 feet laterally from the main channel. When <br />mining operations advanced laterally towazd the sandstone channel, water would drip <br />from the mine roof. However, these roof drips commonly dried up rapidly after they <br />were first encountered. Typically, after mining had advanced about two cross cuts from a <br />water inflow, flow from the roof drips would completely cease behind nursing operation. <br />More persistent and large inflows (i.e., initial inflow rates of 20 to 250 gpm) were <br />encountered when mining reached the channel. Two of these SBC-8 and SBC-10 <br />declined rapidly about two years (Figure 11a, c), however, at SBC-9 an inflow of about <br />150 gpm persisted for about 10 yeazs (Figure l lb). Over this tune the flow rate gradually <br />declined. <br />Water from this sandstone channel contained little 3H (0.36 to 0.87 TL7) when sampled in <br />1992 and 1996. A radiocarbon age of 1,400 years was calculated for water collected <br />from SBC-9 Source in November 1996 (Mayo and Associates, 1999a). However, when <br />sampled in January 1999, the 3H content increased to 3.62 TU and the radiocazbon age <br />increased to 2,200 years. What this suggests is that the groundwater system supporting <br />the dischazge from the sandstone channel was not in active hydraulic communication <br />Evaluation of Potential Groundwater Inflows 41 February 24, 2004 <br />Associated with E Seam Mining, <br />West Elk Mine, Somerset, Colorado <br />