Laserfiche WebLink
<br /> <br />-3- <br />11. Subsidence monitoring must be in compliance with Rule 2.05.6(6)(c). Monitoring at a <br />location must be at least quarterly, until the operator inquests, and the Division approves, <br />temtinating the monitoring at that location. In addition, longwall mining subsidence can <br />occur two panel widths away from any point. <br />Please make the following changes in the proposed monitoring frequency and duration to <br />reflect this: <br />- On page 2.05-51, it is stated that them will be four successive surveys, followed by <br />an annual survey. This should be clarified and revised to read that monitoring will be <br />performed quarterly, with the results of the monitoring program submitted to the <br />Division semi-annually. <br />- On page 2.05-52, it is stated that monitoring will occur while there is mining in the <br />adjacent panel. This should be changed to read that monitoring will continue over a <br />panel during the mining of two successive panels. <br />12. On page 2.05-52, it is stated that no monitoring or control plans will be submitted for new <br />structures until 6 months prior to the angle of draw being within 100 feet of that new <br />structure. Because the subsidence monitoring program uses a 100 foot spacing between <br />monument locations, the degree of accuracy of predicting the distance of the surface effect of <br />the angle of draw ahead of long wall mining is plus or minus 100 feet. Therefore, please <br />change your submittal to reflect that no monitoring or control plans will be submitted for <br />new structures until 6 months prior to the angle of draw being within 200 feet of that new <br />structure. ):f the subsidence monument spacing is increased to 50 feet instead of 100 as <br />discussed herein in Items 9 and 10, then the original language regarding 6 months plus <br />100 feet could remain. <br />If you have any questions, please call me. <br />Sincerely, <br />~.° <br />XJoseph J. Dudash <br />Environmental Protection Specialist <br />JJDLern <br />cc: Dan Hernandez <br />m:\oss\ern\bri.jjd <br />