2013-02-27_REPORT - C1981028 (7)

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samples following the standard three -well volume purge procedure. While the well bore water level recovery following testing remains slower, higher static water levels provide evidence that the highly disturbed zone in the reclaimed overburden area is recharging. The timeline for this recharge is consistent with previous predictions. Copies of the "Detection Summary" (formerly the "Executive Summary ") of analytical laboratory test results are found in the pages following this text. Each ground water monitoring well was sampled in accordance with the "permit procedure ". The `B" designation following the well identification confirms that the laboratory sample was obtained after initial field sampling, well purging and a subsequent (second) field sampling. The 2012 ground water monitoring test results remain consistent with results from previous year's analyses in that there have been no confirmed statistical exceedences, with but one exception, the samples obtained from the SMW -2 well during 2004. The SMW -2 well is completed in the disturbed spoil material which is being subjected to slow re- saturation by ground water, and appears to be leaching dissolved minerals as the water table rises. This has caused manganese concentrations to somewhat exceed the calculated tolerance limit. CEC addressed this tolerance limit exceedence with CDPHE during 2005, and was granted permission to continue the current detection monitoring program [Doty & Associates letter dated 04/08/05, "Alternate Source Demonstration, Statistically Significant Increase Over Background Manganese in SMW -2, Fourth Quarter 2004, Keenesburg Disposal Facility"] . The direction of ground water flow, to the extent that it has been documented in the area of the Keenesburg Mine property, trends downgradient to the northeast. Recharge of the aquifer in the "spoil area" continues to be limited to a single source, the localized infiltration of precipitation to the subsurface. There is no evidence of any significant ground water recharge to the site from the Ennis Draw fluvial ground water system. Ground water elevations in the sampled Ennis Draw wells close to the Keenesburg Mine site are significantly higher than in either the spoil monitoring well (SMW -2) or in the ash monitoring wells (AMW -1 or AMW -2). It is CEC position that no adverse affect on the overall hydrologic balance of the Keenesburg Mine site will result from, a continuation of the ash disposal operation, from the limited addition of mine waste rock to the B -Pit ash disposal, or from the continuing reclamation operations. Ground water levels in the former coal extraction areas should be expected to recover to their approximate pre- mining AHR-2012 -44-