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Mr. Gary Isaac <br />May 5, 2008 <br />Page 2 <br />operation, and timing and subareas for which it is anticipated additional permits will be <br />sought. <br />2. Potential impacts from mine inflow are briefly described only with regard to groundwater flow <br />regime and groundwater quality. Groundwater inflow to the mine is only minimally described in <br />section 2.05.6 (3) Protection of hydrological balance at the bottom of page 2.05-99 and there is no <br />estimate of the rate of inflow provided. There is also a brief description of mine inflow in <br />Section 2.04.7 Hydrology Description with some discussion of water quality based on a <br />comparison to McClane Canyon Mine's discharge monitoring reports. There is no indication of <br />the estimated rate of mine inflow other than a short description in Volume III Exhibit 12 Alluvial <br />Valley Floor (AVF) Determination. In the AVF study it is stated that "After several years of <br />mining, Red Cliff anticipates that the mine will encounter saturated conditions, which will <br />require pumping from the mine... Red Cliff expects to produce about 250 gpm of water that <br />will be discharged into the drainage below the mine portal." <br />Based on our experience from the nearby McClane Canyon Mine the current estimated mine <br />inflow from AHR data is 20 gallons per minute (gpm) and when water is not being used in the <br />mining process it is discharged up to 150 gpm. The Red Cliff project will be much larger in <br />scale. If mining progresses quickly and wet coal is encountered, then inflows and subsequent <br />discharges could be significantly larger than those encountered at McClane Canyon Mine. <br />The long term mine inflow rate needs to be estimated and included in the pertinent sections of <br />the Red Cliff Mine permit application. <br />Please update sections 2.04.7 and 2.05.6 of the application with an estimated mine inflow <br />rate and a description of how mine inflow water will be handled (consumptively used by <br />the mine or discharged to the surface). The Division recommends that in addition to the <br />long term mine inflow estimate, CAM-Colorado provide a worse case scenario reflecting <br />the maximum coal production rate of 8,000,000 tons per year. Given the fact that water <br />has been encountered in the Cameo coal seam and if the worse case scenario of 8,000,000 <br />tons of coal per year are mined, then there will likely be much larger mine inflows. Please <br />identify in the probable hydrological consequences (PHC) section of the application the <br />potential impacts resulting from the estimated maximum mine inflow rate. <br />3. There is insufficient discussion provided regarding the potential for mine discharge both in the <br />first permit term and throughout the estimated life of mine and very minimal information was <br />provided regarding the disposition of mine inflow water. <br />In section 2.04.7, page 2.04-39 CAM-Colorado indicates that "there should not be any mine <br />water discharge during the initial permit term." However as discussed above in Item 2, the <br />AVF study indicates that after several years groundwater will be intercepted at a rate of about <br />250 gpm and will be discharged to the nearest drainage below the portal. From the information <br />presented in the AVF study it appears that mine discharge may occur during the first permit <br />