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l. Rule 2.05.6(3)(b)(iii) requires a determination of the probable hydrologic consequences of the <br />operation. WFC bases its prediction of surface water impacts (TDS|cading) from the New Horizon North <br />Mine on the prediction of probable hydrologic consequences for the New Horizon (NH2) Mine, and <br />references results of data collected to date at the NH2 Mine. This approach is reasonable given the <br />similarity of geology, hydrology, regional agricultural practices and proposed mining operations. Given <br />the monitoring data we have obtained from the NH2 mine to date, it is clear that these original <br />predictions for NHZ were too low. Sample results from NH2 show a greater impact to surface water in <br />and adjacent to the permit area. The prediction for the NH2 Mine was that TDS would increase by3Y6 <br />on Tuttle Draw during irrigation season, and 3.6% during non-irrigation season. The predicted maximum <br />for Tuttle Draw was 2316mo/|. The data to date have exceeded this maximum, and the trend has <br />shown an upstream to downstream increase nf144Y& during irrigation season, and G5Y6 during non- <br />irrigation seosnn;farexceedin0VVFC'spredictiVn. |fVVFC intends to model its prediction Vfprobable <br />hydrologic consequences of the New Horizon North Mine on the data obtained for the N H2 Mine, a <br />more accurate prediction should be made based on an interpretation of the actual data to date from <br />NH2^ We believe these predictions are low given the available data and information we have obtained <br />from NH2, Please revise the prediction of probable hydrologic consequences for TDS loading for the <br />New Horizon North based on the data collected to date and impact trends observed at the NH2 Mine. <br />2. Rule I.05.6()(B(W) requires the development ofa water monitoring plan based on the <br />probable hydrologic consequences determination and baseline hydrologic and geologic information to <br />comply with Rules 2.O4.S,Z,04.G'and 2.04.7, In accordance with Rule 3.O4,7, surface water information <br />shall be provided including the seasonal variation in water quantity and quality within the proposed <br />permit and adjacent areas. VVFC,on page ]Oof section 2.05.6(3), discusses impacts to Tuttle Draw, <br />Meehan Draw, Coal Creek Canyon, and the San Miguel River. According to Table 2on page Zof <br />Appendix 2.05.6(3)-3, WFC proposes to monitor surface water upstream and downstream on Tuttle <br />Draw, Meehan Draw, Glasier Draw, Nygren Draw, and at locations along the CCC Ditch. This plan is <br />adequate to determine any impacts to and verify predictions of water quality on Tuttle Draw and other <br />surface water bodies within the permit area. VVF[ does not propose any monitoring on Coal Creek <br />Canyon and therefore does not assess the potential for off-site impacts to adjacent areas. Rule 2.05.6(3) <br />requires that probable hydrologic consequences be determined for surface water, within both the <br />proposed permit area and adjacent areas. Therefore, this proposed plan does not adequately address <br />the determination of probable hydrologic consequences for the operation, since it does not monitor for <br />the predicted impacts to Coal Creek Canyon. |n addition to the currently proposed surface water <br />monitoring plan, WFC will need to monitor Coal Creek Canyon upstream and downstream of the <br />operation (downstream of the confluence with Glasier and Meehan Draws) quarterly in order to <br />determine whether the operation is adversely affecting the hydrological balance within and adjacent to <br />the proposed permit area (Rule l05.6(B)(aViU. This monitoring shall commence at least one year prior <br />to disturbance of any areas draining to Coal Creek Canyon and must include analysis of all of the <br />parameters established in Table 3of Appendix lOS.G(3)-3. <br />