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Colowyo, C1981 -019, PR3 adequacy No. 3 17 July 22, 2011 <br />2.05.6(2) Fish and Wildlife Plan <br />11. During the Division's Adequacy Review for PR -3, the Division received comments from the <br />Division of Wildlife (attached letter Feb 15, 2011) pertaining to the mitigation of impacts to <br />wildlife. The Division will not make further comments about CCC's wildlife mitigation plan <br />until Colowyo has had a chance to review this letter and make appropriate changes to PR -3. <br />CCC replied in the cover letter but did not change any permit text. Please document any new <br />meetings with CDOW. At the time of the Division's second Adequacy Review for PR -3 (April <br />2011), Colowyo was in the process of contacting the Colorado Division of Wildlife (CDOW) <br />to discuss the issues raised in CDOW letter dated Feb 15, 2011. The Division will not make <br />comments about Colowyo's wildlife mitigation plan until Colowyo submits a plan <br />incorporating the results of the meeting. <br />(VC providal the Division a copy ot' CDOAA "s Ictm. dated Alav I 1 I Please uddru;, <br />('DOW\ col emis end reconuuendutinn. in the prolu,.ed permit tact. This iicm remain: <br />Inadequate. <br />Rule 2.05.6(3)(a) Protection of the Hvdroloeic Balance <br />1. The application contains limited permit text narrative with regard to impacts to registered <br />ground water users due to pit dewatering and development and is deficient with regard to <br />impacts to ground water users (see discussion above under Rule 2.04.7(3)). Please expand the <br />permit text narrative under the section discussing probable hydrologic consequences to ground <br />water quantity, with particular emphasis on discussion of impacts to wells owned by others. <br />In order to recognize that most postmining spoil leachate seepage into the downdip pitwall <br />probably will occur in the more permeable beds (the coal seams and cleaner sandstone beds), <br />please use in the pitwall seepage calculation for the Collor Lite Pit a value for K that is within <br />the range of most values for the coal seams and sandstone beds (for example, 0.01 ft/day, rather <br />than the 0.0001 ft/day in the submittal). Also, please use in the calculation of the cross - <br />sectional area of the downdip pitwall only the aggregate net thickness of sandstone and coal <br />beds (that is, exclude the shale and siltstone beds from the measurement of the pitwall height <br />because those beds are not capable of transmitting a significant amount of spoil leachate). The <br />aggregate net thickness can be measured on a geophysical log. <br />Plcase retar to question 1.04.7(3) abo%c under the heading Ahcmative Witter Supply. <br />Discussion is also limited with regard to the potential for development of a spoil aquifer and <br />potential long -term discharge of the spoil aquifer to the surface water system. Proposed text <br />narrative provides an analysis indicating that development of a spoil spring, if it occurs, would <br />take 100 years or more to develop to the point where it would discharge to the surface water <br />system. The Division believes a spoil aquifer will develop over time within the confines of the <br />backfilled Collom Lite pit, based on past experience in northwestern Colorado. Long -term <br />discharge of degraded spoil water could therefore impact areas downstream. Alluvial valley <br />floors, as defined by the Coal Rules, are located downstream of the permit area in Collura <br />