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ii i i iiiiiiiiiiii iii <br />999 <br />STATE OF COLORADO <br />DIVISION OF MINERALS AND GEOLOGY <br />Department of Natural Resources <br />1313 Sherman St ,Room 215 <br />Denver, Colorado 80203 <br />Phone: 1303) 866-3567 <br />FAX~1303)832-8106 <br />DATE: July 7, 1999 <br />DIVISION OF <br />MINERALS <br />GEOLOGY <br />R E C L A M A T I O N <br />MI NING•SAFE TY <br />sil l Owens <br />Governor <br />TO: Jim Burnell Greg E. Walther <br />Ezecubve Direcl°r <br />FROM: Jim Pendleton "''"bae' R. L°ng <br />Division Dvea°~ <br />RE: Mountain I Co ny - 1998 Year-End Subsidence Report <br />. it No: C-80-007) <br />I have reviewed the November, 1998 report entitled "Subsidence Field <br />Observations -- September, 1998" which you forwarded to my attention. This <br />report was prepared by C. Richard Dunrud, PhD., for Wright Water Engineers, <br />consultant to Mountain Coal Company (MCC). Dr. Dunrud, who retired from the <br />USGS approximately a decade ago, has extensive subsidence prediction and <br />investigation experience within the Paonia area. He has served as a consultant to <br />MCC since shortly after his retirement and is familiar with their mine plan and the <br />Division's concerns regarding subsidence impacts above the mine. <br />MCC has submitted Dr. Dunrud's subsidence field observation report as a portion <br />of their year-end subsidence monitoring report. This report provides a detailed <br />description and location for the various ground disturbance phenomena observed <br />above and adjacent to the mine workings. In my recent adequacy comments, <br />prepared in regards to MCC's TR-89 application, I recommended that MCC be <br />required to submit a detailed visual inspection summary if they wanted to forego the <br />preparation and submittal of the traditional survey data report format <br />"(3) The annual reports of the visual subsidence monitoring inspection shall <br />be more detailed than previous annual text reports prepared by MCC. The <br />annual reports shall include sufficient photography to document the subsidence <br />phenomena observed by MCC, including cracks, landslides, rock falls, etc. <br />Care shall be taken to provide scale of the phenomena observed. A map shall <br />be included within the report to identify the location of the photographer and the <br />aspect of the image for each photograph. A separate map shall also be <br />included within the report to identify the location and extent of the observed <br />phenomena. An attempt shall be made to reoccupy sites and replicate image <br />aspects for annual comparison of the subsidence phenomena documented, in <br />order to allow documentation of the progression of subsidence and subsequent <br />healing. The text of the report shall document the conduct of the visual <br />