2009-10-19_GENERAL DOCUMENTS - C1981028 (2)

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Water Quality Impacts The operator submits a surface and groundwater report to the Division annually. The Division's review of the annual hydrology reports concludes that the areas under consideration for bond release are not contributing suspended solids to streamflow or runoff outside the permit area in excess of premining conditions. Sediment pond No. 2 and the dugout pond at the Keenesburg Strip Mine have not discharged in many years. Both sediment pond No. 2 and the dugout pond were previously approved to remain as permanent structures (TR32 and TR28). The Division determined during previous Phase II bond release reviews that runoff from the bond release areas were not contributing additional suspended solids outside of the permit area. The Division finds that there have been no adverse effects to groundwater down gradient of the permit area. The Division concluded the Keenesburg Mine does not have the potential to negatively impact ground water and has not required establishment of a groundwater point of compliance (Memo to 2004 AHR file, dated July 6, 2005). If coal spoil leachate or ash leachate migrated from the pit through eolian sand, Ennis alluvium or the Laramie sandstone, coal attenuation and dispersion would result in levels of total dissolved solids (TDS) and sodium adsorption ratio (SAR) in ground water that would be near pre-mining conditions within a few hundred feet of the Keenesburg Mine pits. Monitoring of groundwater quality in the down gradient wells from the reclaimed pits found the 2008 TDS values were well below the pre- mining levels. The Probable Hydrologic Consequences section of the permit application predicts no appreciable impacts to the hydrologic balance. Monitoring data in the hydrology reports confirm this prediction. No impacts to groundwater have been found in down gradient groundwater monitoring wells. Based upon this information, the Division finds that with regard to bond release application SL4, pollution of surface water and subsurface water is not occurring and the probability of such pollution occurring is low. Surety Reduction (SRI) The Division determined the reclamation liability for the Keenesburg Mine prior to this bond release application at $2,327,437.00 (Permit Renewal No. 5). The Division updated some of its equipment costs in August 2009. Update of the reclamation liability costs on September 28, 2009 using the updated equipment costs changed the cost to complete remaining reclamation work at the Keenesburg Strip Mine prior approval for SL4 to $2,289,771.00. The Division thus holds an excess of $37,666.00 in liability bond over the amount required to be held by the Division for remaining reclamation and maintenance on the Keenesburg Strip Mine. The Division proposes, with SR1 (Surety Reduction No. 1), to reduce the reclamation liability by $37,666.00 based upon this current reclamation cost estimate. (Rule 3.02.2(4)) Coors Energy Company was notified on October 13, 2009 of the proposed surety reduction. In accordance with Rule 3.02.2(4)(a), CEC was provided the opportunity to request an informal conference regarding the surety reduction. On October 15, 2009, CEC responded via electronic mail that they did not want an informal conference. C1981-028, SL4 9 10/19/2009