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-3- and bedrock aquifers or to the surface water system in the area of the irrigated pasture land (AVF). This flow of water will not only degrade water quality, but will also accelerate the degradation of the stability properties of rock in the backfill. The establishment of a spoil aquifer may lubricate the toe and thus desta- bilize the backfill. If the final southwest pit wall has a low permeability, an upward flow gradient will be established, further destabilizing the back- fill. Any additional mining along the southeastern edge of the existing pit may increase the upgradient pit inflow. This, in turn, may increase the post- mining flow through the pit and may increase the instability of the back- fill. Potential Impacts of Proposed Operations The revision to the permit application is a request to mine "A,~~ ~~B," and "C," seams on the.western side of the irrigated pasture land (AVF). Given the similar lithology of the rock strata to be disturbed, the increased discharge area for the rock strata under the AVF, and tl~e inflows encountered in the existing pit, the proposed pit has a high potential for significantly impact- ing the quality and quantity of surface and ground water, and reducing the productivity of alluvial valley floors both up and do~.m stream. The base- line data and the conclusions made by the applicant from the baseline data are inadequate, and as such, do not support statements that there will not be any impacts of mining on the hydrologic balance and on AVFs. The folloia- ing discussion will outline the baseline and alluvial valley floor infor- mation needed in order for the Division to complete the review process on the proposed permit revision. Baseline Data To determine the impacts of pit inflows now encountered in the active pit and to extrapolate this information to the proposed operations in the Barren Ridge area, the following information is necessary: A. Accurate measurements of the pit inflow rates (both the southeast and southwest inflows). B. A measurement of the cross-sectional area of the pit wall below the level of Stollsteimer Creek (both the southeast and southwest pitwalls). C. The elevation difference (hydrologic gradient) between Stollsteimer Creek upstream of the active pit and the level of the downstream AV F. D. A determination of total surface area of the top of the spoil aquifer. This information should be plotted on a map.