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Drawdowns in Monitoring Wells According to information in the permit application, wells completed in the rnal seam close to the mine workings and monitored by the Golden Eagle Mine have shown drawdowns caused by mining operations. Exhibit #6 in the Golden Eagle permit application, titled Basin Resowret New Elk and Colden Eagle Mines Response to Renewal Stipulations 52 and 67, Probable Hydrologic Consequences of Minim CDMG Permit Nar. C-81-012 artd C-81-013, was reviewed az part of this investigation. This report summarizes monitoring data collected for fourteen years. Several monitoring wells rnmpleted in the rnal seam mined have shown drawdowns as mining progressed closer to the wells. Because the wells are completed in the coal seam and because the coal seam has a much higher permeability than the overburden, drawdowns in these wells caa be expected to be much higher than drawdowns in wells completed in the overburden. Wells LA-218 and LA-221 have shown drawdowns of 2t~0 feet and 287 feet, respectively. Mine workings have approached to within 900 feet and 126 feet of these wells, respectively. Despite the facts that the windmill well is completed in a zone 450 feet above the affected coal seam, and that the Raton Formation contains numerous impermeable interbedded shales and siltstones, it is reasonable to assume that groundwater in the area of the well may experience some drawdown. Probable Hydrologic Consequences Related to the Installation of the Borehole (PHC). The Golden Eagle Mine statement of probable hydrologic consequences (PHC) can be found slatting on page 2.05 - 34 of the permit application and was last updated Apri127, 1994. In the PHG Basin Resources predicted that miring activities adjacent to or under windmills could render them unusable. Basin Resources stated that they would, however, take appropriate mitigative measures if ailing seriously impacted the potential for their use. The previous mine operator, Wyoming Fuels Company, conducted a water user survey during May of 1984 to identify all wells and windmills within one mile of the New Elk and Golden Eagle mine permit boundaries. The water well survey was conducted to identify users and to assess the potential effects of mining on the quality and quantity of water in the surveyed wells. The Tatum well was identified as unused in this survey and no additiotal data on this well is included in the permit. The survey was last updated in 1993 during the permit renewal and included additional water wells that had been drilled since 1984. Well sustained yields and water quality information on other wells is given in exhibit 8 of the permit application. Basin Resources proposed the construction of the ventilation shaft borehole on October 2, 1990 with the submittal of technical revision TR-15. Section 4.05, of the Hydrologic Balance portion of this revision states that "every reasonable attempt will be made to eliminate or reduce water inflow into the shaft". To minittize groundwater inflows into the open borehole, prior to drilling the borehole, the formation was injection grouted. According to the operator, there were four drillholes that were used for the injection grouting around the location of the central borehole. This technique is one of several appropriate techtiques that can be used to reduce inflows. This techtique was not entirety successful because after the construction of the shaft, water inflows into the area of the mine that included this shaft were estimated by the operator to be 20 gallons per