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<br />-~- <br />VII. Protection of the Hydrologic r;alance <br />C~ <br />1) TVitis item made two requests of the applicant, that the <br />discussion of probable hydrologic consequences be quantified, <br />and that analysis be provided for specific additional concerns <br />(items 2-5). The applicant has responded by providing a <br />quantitative analysis of those items specifically requested. <br />The applicant has not quantified those surface water effects <br />identified in the original discussion of probable hydrologic <br />consequences. For some of those surface water effects, <br />quantification may not be possible or appropriate. However, <br />given the Division's concerns about salt loading in the area, <br />the increase in total dissolved solids in runoff from the permit <br />area (p. 2.05-55), and its effect upon receiving streams needs <br />to be quantified. (This applies to sources other than the <br />discharge of mine water from underground workings.) <br />Quantification of this effect sha~ld be possible using the <br />results of the applicants surface water and NPDES monitoring. <br />(Sandy, you should check with koy to see if he is satisfied with <br />the quantification of ground water effects.) <br />2) Item two made several requests concerning the effect of the <br />discharge of water from underground workings to the Foidel Creek <br />stream/alluvial aquifer system. The applicant was requested to <br />provide a worst case estimate of the quantity and quality of <br />this discharge. The applicant has identified a worst case <br />discharge of 65U yp~n having a total dissolved solids <br />concentration of 800 mg/l. Although total dissolved solids is <br />an important indicator of overall water quality, it does not, by <br />itself, fully describe the quality of the discharge. The <br />applicant should provide a full suite chemistry of the <br />anticipated discharge. This could be obtained from the <br />discharge records of nearby underground mines. The applicant <br />should also provide documentation for the selection of a maximum <br />anticipated total dissolved solids concentration of 800 mg/1. <br />The worst case discharge of 650 gp~n (936,000 gpd) used for the <br />analysis is considerably less than the projected mine inflow of <br />2,335,000 gpd projected for the fourth year of operation. The <br />analysis of the effects of discharge mine water and water from <br />the spoil well to the surface water system should be redone <br />using worst case water quantity and quality. Although the <br />analysis may be limited to total dissolved solids, as requested <br />above, the applicant should identify the anticipated full suite <br />chemistry of the spoil vrater and of the mine water. <br />The applicant was requested to predict the effects of mine water <br />discharge (from the mine workings and the spoil well) upon <br />surface flow r•egieme, geomorphic stability of the stream, <br />alluvial water levels, and alluvial water quality. 71re <br />applicant did not address these concerns, but should do so now. <br />