Laserfiche WebLink
<br />Proposed Decision and Findings of Compliance July 2018 <br />Permit Renewal No. 7 P a g e | 38 <br />been completed in the Williams Fork interbedded sandstones yield less than five gallons per <br />minute and their uses are limited to domestic and/or livestock use. Nearby residents haul drinking <br />water supplies from Craig and Meeker. <br /> <br />The lack of a continuous, regional ground water system on the property within the stratigraphic <br />section of the Williams Fork Formation was documented in the 1979 report prepared by Leonard <br />Rice Consulting Water Engineers (Exhibit 7A of the PAP). <br /> <br />In addition, 17 test holes were drilled and their corresponding records collected when the property <br />was originally explored. All well data confirmed that where water was encountered it was limited <br />both vertically and laterally and it was encountered under perched conditions (a discussion of well <br />test data is in Section 2.04.7 of the PAP). <br /> <br />A slight potential for degradation of alluvial ground water was recognized in the 1982 Findings <br />Document. A plan to monitor alluvial ground water on Good Spring and Wilson Creek was <br />developed by Colowyo. Results of monitoring in AHRs indicate some detectable impacts on <br />alluvial ground water to date. A slight increase in TDS at the New Good Spring Well from 1989 <br />to 2012 is not significant. An increase in TDS in Gossard well from 1983 to 2006 was detected, <br />but the concentrations have been decreasing in recent years. <br /> <br />Pursuant to Rule 2.07.6(2)(c), the assessment of the probable consequences of the proposed mining <br />operation and the assessment of the probable cumulative impact of all anticipated mining in the <br />area on the hydrologic balance, as described in Rule 2.05.6(3), have been made. The proposed <br />operation has been found to be designed to prevent material damage to the hydrologic balance <br />outside the permit area. <br /> <br />During the review of PR-02, the Division further evaluated potential impacts to groundwater <br />within and adjacent to the permit area and with regard to establishing groundwater points of <br />compliance. Three specific zones of groundwater that have the potential to be impacted were <br />evaluated. These include bedrock groundwater, backfill and excess spoil groundwater, and alluvial <br />groundwater. A synopsis of the Division’s review is provided below. <br /> <br />Bedrock Groundwater <br /> <br /> The Division has determined that coal mining operations at the Mine do not have the potential to <br />negatively impact bedrock groundwater, and that no point of compliance need be established for <br />bedrock groundwater. <br /> <br />Backfill and Excess Spoil Groundwater <br /> <br />The Mine is a multi-seam, open-pit, operation. The pits are excavated to approximately 450 feet <br />deep, and are then backfilled to approximate original contour. The original stratification of <br />geologic units is not reconstructed during this backfill process. Placed backfill materials are not <br />as dense as in situ geologic formations. Being less dense, they have more voids, are more