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projected and none have been observed to date. <br />The Division's 1982 Findings Document predicted that no significant impacts on surface water <br />quality in or adjacent to the permit area due to mining operations would occur. Water quality in <br />and near the permit area is highly variable, changing in response to seasonal trends and <br />precipitation events. Surface water monitoring data from the Operator's monitoring program and <br />observations by the Division have confirmed the prediction of no significant impacts to surface <br />water quality to date. <br />The anticipated hydrologic consequences to surface water quality for the South Taylor area are; <br />• Total dissolved solids (TDS) in the base flow of Good Spring Creek will increase by <br />1.6% to 13.5% for several hundred years after mining has been completed, with sulfate <br />the dominate ion <br />Impact to surface water quality, specifically spoil spring development and increased salinity due <br />to leaching in the backfilled South Taylor pit area, is the most significant impact to the <br />hydrologic balance in and adjacent to the mine area. Spoil spring development is likely in the <br />southeast portion of the South Taylor pit area, generally located in the NW1/4, Section 21, T3N, <br />R93W of the 6th PM. Degraded spoil water will move down gradient through undisturbed strata <br />and emanate as springs on the steep hillsides. Spoil springs may also develop at the "spill point" <br />within the regraded pit area and flow down to the Section 21 sediment pond, causing the pond to <br />discharge on a seasonal, or potentially, a perennial frequency. This degraded water will mix with <br />flow in the East Fork of Goodspring Creek, as represented by the surface water monitoring site <br />EFGSC. Colowyo has provided calculation of salinity increases in Goodspring Creek down <br />gradient of the confluence of the West Fork of Goodspring Creek in Section 2.05.6(3)(b)(iii) of <br />Volume 12. Impacts to irrigated areas immediately downstream of EFGSC are possible and are <br />discussed the alluvial valley floor section of this document. <br />3. Potential Effects on Ground Water <br />The mines operations may affect bedrock ground water of one formation, the Williams Fork <br />Formation." The Williams Fork contains the ten coal seams to be mined and is the surface <br />outcrop on the permit area. Impacts to the Williams Fork are deemed minimal because water <br />produced from coal zones is of known poor quality and well yields are low. These sandstones are <br />predominately fine to medium grained, poorly sorted and calcareous. The thickness of the <br />sandstones is estimated to be 1,600 feet. There is no continuous, regional ground water system <br />on the property within the stratigraphic section of the Williams Fork Formation. This was <br />documented in the 1979 report prepared by Leonard Rice Consulting Water Engineers' study <br />(LRCWE). The report concluded that there was an absence of ground water from the site (see <br />Exhibit 7A of the Permit). In addition, 17 test holes were drilled and their corresponding records <br />collected when the property was originally explored. All well data confirmed that where water <br />was encountered, it was limited both vertically and laterally and encountered under perched <br />conditions. For further information on the well test data, see pages 2.04.7-5 and 6 of the PAP. <br />Proposed Decision and Findings of Compliance 14 September 2009 <br />Permit Renewal 05 Page 41