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2.05.6 (3)(b) <br />• ,RESPONSE continued <br />Mining in the recharge portion of this formation has the potential <br />for degrading water quality in the area down-dip. The frag- <br />mentation of the overburden will increase the surface area ex- <br />posed to subsurface water movement, causing an increase in the <br />dissolved solids in the ground water system. But, the low <br />permeabilities and resulting low impact on the down-dip area. <br />The data available does not justify an attempt to calculate the <br />increase in total dissolved solids as suggested by Barrett, et. <br />al. in Procedures Recommended for Overburden and Hydrologic <br />Studies of Surface Mines, U. S. Forest Service, 1980. <br />Some localized, lenticular sandstones in the Williams Fork For- -- <br />oration above the coal seams appear to be the only portion of the <br />ground water system that will be significantly impacted. These ~. <br />sandstones supply three springs/seeps (SP-1, SP-2, SP-3; <br />• Exhibit AA (Exhibits Volume II) and Table 18 see Section 2.04.7) <br />adjacent to the mined ara. The discharge of these springs/seeps <br />may decline during the period at active mining. A quantatitive ~ <br />evaluation of the changes in flow and watec quality cannot be _ <br />made with the data available. As the combined flow of the three <br />sites is less than one gallon per minute, any changes in the <br />springs/seeps will not have a measurable impact on the hydro- <br />logic balance of the area. _ <br />One seepage area (SP-4) is within the area to be mined will be <br />disrupted during the period of active mining. Reclamation <br />procedures are expected to facilitate the reestablishment of the <br />seepage area when mining has been completed. <br />The position of the mine on the upper edge of a syncline (Figure <br />6, Section 2.04.7) indicates that interactions between the af- <br />fected ground water system and surface streams will not be <br />significant. The contribution of subsurface flow from the permit <br />. area either pre-mining or post-mining, to base flow of Hayden <br />and Dowden Gulches is limited (see flow measurements, Table 18, _ _ <br />