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i <br />In future permit terms when CWI mines under .Steven's and East Roatcap Creek, <br />water may be encountered even if there is ao subsidence. Faults and fractures <br />may be encountered underground that are in communication with the stream and <br />its associated alluvial/colluvial deposits. Dewatering of these faults and <br />fractures cou]d potentially deplete streamflow and the alluvium/colluvium when <br />water is present. Water bas bees encountered in other underground mines where <br />mining has occurred beneath ephemeral, intermittent or perennial streams. <br />Hawk's Nest mine, Somerset mine, Y.id-Continent, Blue Ribbon mine and North <br />Thompson Creek mine have all had inflows as the result of undermining <br />streams. However, is this case the streams do not contain aquatic life nor <br />are they supplying agricultural areas. The limited depletions are not <br />predicted to be significant enough to cause a major change is stream <br />characteristics or impact the hydrologic balance. The only Concern with <br />depleting Steven's Gulch or East Roatcap Creek streamflow would be to water <br />users within those drainages. CWI has responded to this concern in their <br />water replacement p]an. <br />Based on data from other mines in the valley, stream-related inflows are <br />anticipated to be only a few hundred gallons per minute at worst case during <br />certain times of the year when the streams are flowing. The operator through <br />a detailed investigation and analysis, has predicted that worst case inflows <br />would only amount to 8.7 gpm by 1989, and would increase to 33.5 gpm for the <br />life-of-mine. A mitigation plan was presented by CWI that will replace the <br />water depleted by mining. <br />The hydrologic consequences of the mine are expected to be minimal. The <br />applicant reports that ao degradation of water quality is surface streams is <br />expected. Aay effluent will be treated as necessary to meet quality standards <br />• prior to discharge. Although mine inflows are currently small, if significant <br />inflows are encountered the application contains a plan for a collection and <br />treatment prior to discharge. <br />Socio-economics <br />CWI's proposal would extend the life of the existing operation without <br />increasing the work force or expanding the existing surface facilities. <br />Therefore, no further socio-economic impacts to the Paoaia area, as a result <br />of approval with or without conditions, is expected. <br />C <br />8 <br />