1987-12-01_PERMIT FILE - C1981017 (295)

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C„ap:er IV Mid-Continent requested suspension of the subsidence monitoring program cn • the basis that there is no evidence or likelihood of damage to or diminution of renewable resource lands or aquifer recharge areas, or to foreseeable use of S structures or renewable resource lands. A Technical Revision, approved February 3, 1988, allowed suspension of the semi-annual subsidence monitoring requirement, (See Appendix IV-F-5) on condition that the monuments be re-surveyed at the end of the permit term (1988) . The survey was done in August, 1988. The data compiled are contained in Appendix IV-F-4. In subsequent years (starting 1989) Mid-Continent will make an annual visual subsidence inspection of the area above the Coal Basin Mines which could potentially be affected by ground subsidence. The inspection will be carried out during the summer months, as necessary because of snow conditions. The area will be determined by projecting the boundaries of underground extraction upward from the mined seam to the ground surface along an angle of draw of 20.5 degrees from vertical. A report summarizing the results of the annual subsidence inspection will be submitted to MLRD prior to December 31. Prior to implementation of multi-lift longwall mining, Mid-Continent will revise the Collins Subsidence Study (submitted in December, 1985 and contained in Appendix IV-F-4) to reflect the subsidence data obtained during the `✓38 subsidence resurvey and any subsequent resurveys. Such revision will be submitted to the Division for review. Such revision will also be done and submitted with any request by Mid-Continent to MLRD for an amendment to the Coal Basin mine plan which Involves expansion of the potentially subsided area. In addition, Mid-Continent will provide a monitoring program Dian acceptable to MLRD prior to implementation of multidi-iL mining. The plan will be submifted in advance of the summer season preceding implementation of the multi-lift program. 30"