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III IIIIIIIIIIIIIIII <br />999 <br />To: Dan Hernandez <br />From: Susan J. McCannon~,,-~-- MEMORANDUM <br />Subject Subsidence monitoring at Eagle 5 & 9 Mines <br />Date: May 28, 1997 <br />Last month you and I talked brieFly about the desire of Rick Mills at the Eagle mines to <br />discontinue monitoring without the submittal of a revision application. At that time I told you <br />that we could not allow discontinuance of monitoring without a revision application. <br />Last week, Rick and I discussed this issue at the Northwest Coal Conference. He indicated to <br />me that the monitoring in question is addressed in the Eagle permit in the following manner. <br />The permit indi~tes that if a particular monitoring location has indicated that the expected <br />subsidence has occurred and continued monitoring at this location for at least three <br />monitoring cycles has indicated no additional subsidence movement, then monitoring at that <br />particular lotion could be discontinued. <br />With this information in mind, upon my return to the office, I discussed this situation with Jim <br />Pendleton. Jim indicated that the above described approach would be acceptable and could <br />have been approved within the Eagle permit, with three limitations, as follows. <br />Discontinuance of monitoring, or reduction in monitoring frequency, at monitoring locations <br />which were installed to document subsidence occurrence and magnitude may be appropriate <br />under the above described circumstances. Discontinuance of monitoring, or reduction in <br />monitoring frequency, at monitoring lotions which were installed to document effectiveness <br />of subsidence protection measures, and thereby indicating no subsidence, such as monuments <br />installed adjacent to the highway or river, would not be appropriate under the above <br />described circumstances. Further, monitoring monuments should never be removed or <br />destroyed without the Division's express knowledge and consent. In addition, the operator, <br />in the regularly submitted subsidence monitoring report, should indicate an intent to <br />discontinue monitoring at particular locations where all expected subsidence and no additional <br />subsidence has been demonstrated. <br />Presuming that my understanding of the monitoring commitments included in the Eagle <br />permit are correct, and based on my discussion with Jim Pendleton, I now believe that it may <br />be appropriate for us to entertain an indication from Mr. Mills that certain monitoring will be <br />discontinued, subject to the above limitations. <br />If you have any questions please talk with me or Jim Pendleton. <br />CC: Jim Pendleton <br />^ <br />