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since; 1. No intermittent or perennial streams cross the retreat mining area or aze adjacent to the <br />area, and 2. Discharges to surface waters will be in compliance with NPDES/CPDES pemvt <br />requirements. <br />Mountain Coal Company water withdrawals from the North Fork aze not expected to cause any <br />impact since they aze a small percentage of stream flow even during low flow conditions. <br />No U.S. Forest Service water resources aze located in the permit area projected to be retreat mined. <br />Resource No. 131 is located over the projected B-Seam main entries, but is not expected to be <br />impacted. See the additional discussions of mitigation measures in Section 2.05.6(6)(f) and in <br />Exhibit 19C. <br />Water Augmentation Plan <br />The Mountain Coal Company Water Augmentation Plan was adjudicated in February, 1987, in <br />Division 4, State of Colorado Water Court. A copy of the Adjudicated Water Augmentation Plan is <br />included in Exhibit 52. The water augmentation plan covers mitigation of potential impacts from <br />mining in the Minnesota Creek Basin. The water augmentation plan is based on worst case <br />conditions where mining in the basin depletes the Dry Fork of Minnesota Creek and requires <br />augmentation by Mountain Coal Company water rights up to 10.96 cubic feet per second {4919 <br />gallons per minute) maximum headgate diversion. <br />The plan is not in effect during development mining in the basin. However, there is a provision to <br />implement the plan should circumstances warrant, such as lazge inflows into the mine workings in <br />the Minnesota Creek Basin. <br />Annual Hvdrologv Renort <br />Mountain Coal Company provides in the Annual Hydrology Report (AHR) a detailed assessment of <br />mining impacts of the past water year as well as potential mining impacts and an estimate of <br />production for the upcoming water yeaz. A map is included in the Annual Hydrology Report <br />showing the piezometric surface of the colluvial aquifer in the azea of the Lower Refuse Pile, if one <br />develops. An assessment of the impacts of the Lower Refuse Pile to the hydrology balance during <br />the previous year is included in the report. Also included in the report aze the analyses of hydrologic <br />data gathered during the yeaz to assess the impacts of mining on the quality and quantity of streams, <br />springs, groundwater aquifers, mine inflows and mine discharges (water balance) which may exist <br />in the permit azea. Mine maps showing the locations of mine inflows aze provided in the Annual <br />Hydrology Reports along with estimates of the quantity, quality and duration. Water quality <br />samples will be taken as close to the inflow source as safely possible, to properly characterize the <br />water quality. Estimates of water imported for use within the mine and mine dischazge are also <br />provided in the reports. The Annual Hydrology Report will include seasonal measurements of <br />spring flows, streamflows, well levels, and water quality analyses of selected parameters for each <br />monitored resource. Mountain Coal Company also evaluates the adequacy of the current monitoring <br />plan in the report, The Annual Hydrology Report will also include an anion and cafion balance on <br />all water analyses. This will provide a quality assurance/quality control check on the laboratory <br />data. <br />2.05-8/ Revised Dec. 1997 MR208; Revised Jun. 1999 TR90 <br />Revised May 2003 MR•194; Rev. Apri11006 PRI G <br />