Laserfiche WebLink
Potential Effects on Ground Water <br /> Colowyo's operations may affect bedrock ground water of one formation, the Williams Fork <br /> Formation, which contains the ten coal seams to be mined and is the surface outcrop on the permit <br /> area. However, impacts to the Williams Fork are deemed minimal because water produced from coal <br /> zones is of known poor quality (documented in USGS and U.S. Environmental Protection <br /> Administration (EPA)reports) and well yields are low. <br /> There is little development of the ground water resource in the local area. The wells that have been <br /> completed in the Williams Fork interbedded sandstones yield less than five gallons per minute and <br /> their uses are limited to domestic and/or livestock use. Nearby residents haul drinking water supplies <br /> from Craig and Meeker. <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 /> 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 /> 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 alluvial <br /> ground water to date. A slight increase in TDS at the New Good Spring Well from 1989 to 2012 is <br /> not significant. An increase in TDS in Gossard well from 1983 to 2006 was detected, but the <br /> concentrations have been decreasing in recent years. <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 area <br /> on the hydrologic balance, as described in Rule 2.05.6(3), have been made. The proposed operation <br /> has been found to be designed to prevent material damage to the hydrologic balance outside the <br /> permit area. <br /> During the review of PR-02, the Division further evaluated potential impacts to groundwater within <br /> and adjacent to the permit area and with regard to establishing groundwater points of compliance. <br /> Three specific zones of groundwater that have the potential to be impacted were evaluated. These <br /> include bedrock groundwater, backrill and excess spoil groundwater, and alluvial groundwater. A <br /> synopsis of the Division's review is provided below. <br /> Bedrock Groundwater <br /> The Division has determined that coal mining operations at the Mine do not have the potential to <br /> 37 <br /> Permit Revision No.5(PR-05),C-1981-019 <br />