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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-NB <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 Underbu rden 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 />