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monitoring plan because sites SW-N3, SW-N5, and SW-N7 provide adequate upstream and <br /> downstream hydrologic information for the inactive mining area. Surface water sites SW-N8 <br /> and SW-N9 were added to determine the monitoring network on July 22, 1988 to determine if <br /> blasting activities affect the flow or quality of the lower second park irrigation ditch <br /> within the permit boundaries. Peabody monitored sites SW-N8 and SW-N9 throughout the 1989 <br /> irrigation season. Since blasting activities will be absent during temporary cessation, <br /> Peabody will discontinue monitoring SW-N8 and SW-N9 until temporary cessation ends and the <br /> mine is reactivated. <br /> Concurrent with this proposal for reduced hydrologic monitoring, Peabody is submitting an <br /> application to the Colorado Department of Health to reduce NPDES monitoring at the Nucla <br /> Mine. Peabody is requesting that NPDES monitoring be conducted monthly, rather than <br /> weekly as is currently required. Peabody will continue to monitor NPDES sites in <br /> accordance with NPDES Permit No. CO-0000213 until approval is received for reduced NPDES <br /> monitoring from the Colorado Department of Health. <br /> Nucla East Area <br /> The Nucla East area is located to the southeast of the Nucla area. An examination of <br /> water level contour maps for the Overburden, Dakota Coal, and Underburden aquifers <br /> (Exhibits 7-2, 7-3, and 7-4, respectively, from the 1988 PAP) shows that ground water does <br /> not flow from Nucla Mine towards Nucla East. Ground water and surface water move in a <br /> predominantly southwest direction in this area. Therefore, monitoring sites in the Nucla <br /> East area cannot be considered downgradient monitoring sites for the Nucla Mine. <br /> Since no mining activity has been conducted within the Nucla East area and Peabody has <br /> complied with CMLRD's request for quarterly sampling of selected monitoring wells, Peabody <br /> proposes that ground water and surface water monitoring cease at the Nucla East area <br /> during temporary cessation. Peabody has collected hydrologic data at Nucla East since <br /> July, 1986; up to three years of ground water and surface water data has been collected, <br /> which is adequate information to characterize baseline hydrologic conditions. <br /> Conclusion <br /> Peabody will continue to report hydrologic data during temporary cessation as required by <br /> the Nucla permit and in accordance with NPDES requirements. As stated previously, Peabody <br /> will resume normal hydrologic monitoring (i .e., as specified in the approved permit) at <br /> Nucla when the mine is reactivated. <br /> 15-4-2 <br />