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Jim Stazk Page 3 September 12, 2006 not intended for use as an aquifer. As described below, backfill seepage and spoil water discharge may have an impact on surface water or alluvial groundwater. Alluvial Groundwater Mining activities at Colowyo have the potential to impact alluvial groundwater in those areas of Taylor Creek, Wilson Creek, and Good Spring Creek that are hydrologically down-gradient of mining activity. Sources of impact include discharges of runoff from surface disturbed areas; discharges or seepage from within backfill and excess spoil areas; and from surface and subsurface flows from the coal stockpiles at the Gossard Loadout. The findings by DRMS, for alluvial groundwater as described above, is substantiated by the PR-OZ application. On page 88 of Volume 12, Colowyo states that "the alluvial aquifer associated with Good Spring Creek has a high transmissivity and is unconfined. Possible impacts to this aquifer would be associated with the infiltration of water from the pit and water quality deviations caused by infiltration of runoff water. Colowyo further states, "meteoric water infiltrating into the reclaimed pit should enter the bedrock aquifer and eventually contribute to seeps and springs tributary to Good Spring Creek and possibly Taylor Creek." These statements are consistent with DRMS findings. The DRMS has the following comments regazding the groundwater monitoring program and establishment of points of compliance. Based on our review of the PR-02 application, there does not appear to be a lack of alluvial groundwater as indicated on page 4.05-9a of the permit document, and it does appear that the Colowyo Mine may have the potential to negatively impact the alluvial groundwater. Sources of impact include runoff from surface disturbed azeas; discharges or seepage from within backfill and excess spoil azeas (spoil springs) and from surface and subsurface flows from the coal stockpiles at the Gossazd Loadout. Therefore the Division believes that it is necessary at this time to revaluate the cuttent monitoring program to determine the need for points of compliance. Please review your ground water monitoring program specific to establishing points of compliance at your site. The DRMS will work with you to identify the need and if necessary, to determine the specific location(s) for ground water points of compliance. Initially we are recommending two locations for additional alluvial monitoring wells to be utilized as points of compliance for alluvial groundwater as follows: one should be located in the Quaternary alluvium below the juncture of East Taylor Creek and Wilson Creek, and the other should be located in the Quaternary alluvium along Good Spring Creek at some point down hydraulic gradient from the mining impact areas.