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Permit Revision Adequacy July 6, 2004 Page l3 of 18 stream flow to the bedrock fractures. While this impact may equilibrate over time, stating that the streams and alluvium would not be impacted may not be accurate. Rather than no impact, the DMG believes that the potential for impact exists based on data provided and past experience. Please reevaluate. 100. Rule 2.05.6 (6)(a)(ii)(B) requires that a map show the location and configuration of structures and renewable resource lands within the permit azea and adjacent area. Information on areas within the permit azea and adjacent areas to the east and south are present on Map 37, but no information is provided in adjacent areas to the west. Please confirm there are no such items to the adjacent west. 101. The application needs to describe the existing premining environmental resources [Rule 2.04.3(1)] within the proposed permit area and adjacent areas that may be affected or impacted [Rules 2.05.6(2)(a), 2.05.6(3)] by the proposed underground mining activities and remedial actions, if appropriate. In this regard, please identify the wetlands [Rules 2.05.6(2)(a)(iii)(C) and 4.18(5)(e)], riparian areas [Rules 2.04.11(1) and 4.18(5)(e)], alluvial valley floors (Rules 2.06.8 and 4.24.2) and agricultural lands [Rule 2.06.8(5)(c)]. 102. Please better demonstrate that there is no probable impact to the Minnesota reservoir from the proposed mining plan. Potential failures that need to be addressed include failure of the dam embankment structure itself due to ground subsidence, failure of the dam embankment structure from seismic phenomenon, hydraulic communication with voids in underlying materials from ground subsidence, reduction in pool size from subsidence-induces land slides about the reservoir, and overtopping of the dam structure from rapid pool displacement due to subsidence-induced landslides into the reservoir. The analyses of angles of draw demonstrate no probable impact to the dam embankment or reservoir from ground movement due to subsidence of underlying materials. A level of horizontal acceleration that causes internal failure of the dam structure and abutments or landslides about the reservoir pool would identify failure threshold(s) for seismic induced threats. Analyses that seismic impacts would be below the thresholds} would then demonstrate, with applicable factors of safety, that there would be no probable impact to the dam embankment structure, abutments, or the reservoir pool from seismic phenomenon. To validate the predictions of (no) probable impacts and to provide positive monitoring, the Division requests that a line of monuments be placed on a 100-foot spacing across the crest of the Monument Dam, and then at 500-foot centers along the north shoreline of the maximum pool elevation to Horse Gulch, thence north across the two panels north of Minnesota Reservoir in section 29. In addition, a line of monuments is recommended on 500-foot centers from rite south abutment of the Monument Dam to the NW corner of panel E-9. The purpose of the most northern monuments is to validate the model used to predict subsidence as mining advances to the south towazd the Minnesota Reservoir. The purpose of monitoring the panel immediately north of the Minnesota Reservoir would be to validate the prediction that ground movement did not reach the Minnesota Reservoir impoundment or the Monument Dam embankment. Monuments across the Monument Dam validate the prediction of no movement on the structure. Monuments to the south serve to validate a prediction of no ground movement reaching ttte Minnesota Reservoir or Monument Dam from mining in panel E-9. It is further