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Permit Revision Adequacy Comment Response November 30, 2004 Page 20 of 24 104. Regarding the reporting schedule, page 2.04-124, the Division requests that the condition be added that if an anomaly is experienced that diverges from the predictions, the Division will be notified within three days. Further the Division requests that monitoring of the north panel be submitted to the Division prior to initiation of mining of the southern panel. MCC Response: MCC is proposing new Minnesota Creek Dam and Reservoir monitoring. 105. On page 2.05-112, the seismic effects on the Minnesota Reservoir need to be quantified (as noted above) and the relationship between strain and percent needs to be clazified. MCC Response: MCC added text to address seismic activity. 106. A map showing existing subsidence features within the permit area (Rule 2.05.6(6}(e)(i)(F)(I) needs to be added to the PAP. This should include landslide locations identified on page 2.05- 97 and any surface rockfalls thought to have resulted from longwall mining. MCC Response: MCC added an Exhibit showing the areas and they are examined for the Annual Subsidence Reports. 107. Rule 2.05.6(6)(e)(i)(F)(III) requires a map displaying the surface azeal extent of the area determined by the projected angle-of--draw. Please add this to the PAP. Such a map should include rockfal] areas, slide areas and isoseismic lines as per 2.05.6(6)(e){i)(F)¢V). MCC Response: MCC included the angle of draw on Map 51. The landslides and rockfall potential are shown in Exhibits 60B and 60D. 108. The Division requests that monitoring to determine commencement and degree of subsidence be added to the proposed plan for the vicinity of the Minnesota Reservoir in compliance with Rule 2.05.6(6}(f)(iii)(C)(V). MCC Response: Exhibit 60B has provided recommendations. 109. The Division has several suggestions regarding measures to be taken to mitigate the effects of material damage or diminution of value or foreseeable use of lands (Rule 2.05.6(6)(iv). MCC proposes to monitor roads monthly and to clear rockfalls or damage, and post signage, the Division suggests the signage proposal be expanded to include example wording, and that the posting period be better defined. For example, the signs could go up approximately a month before mining in a particular area and be removed approximately 18 months after subsidence has occurred. There is some concern within the Division that a heightened latent potential exists for rockfall from outcrops in addition to concurrent falls from subsidence of the feature. The latent increase of potential over natural conditions is developed due to degradation (reduction in block size and shifting) of the undisturbed formation. • MCC Response: Text was added to address signage.