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Mouataln Coal Company w.k F~c ww Pak ~s1o. exec 5a1 8eerrak,Calaado e1at~ Tawgeorr e70 e24e015 Feuc e70 aseem Ocotber 25, 1996 Mr. Michael Boulay Colorado Division ofMinerals and Geology 1313 Sherman Street, Room 215 Demror, CO 80203 RE: Annual Subsldence Monitorlag Report (Yeartiend IltepoR); Wat Elk Mioe; )Permit Na C-80-007 Dear Mr. Boulay: ~` Mountain Coal Company (MCC) provides the following reepoasea to the Division's quostioas regarding the review of the year-end Subsidence Monitoring Report. 1. The subsidence grid shown on Map 29 wan originally developed to monitor subsidence !}om F-seam mining. When MCC moved to the B-seam and longwell mitdttg, the grid was extatdod to include the Brat few longwall peaele, and coven en area where two seems (F- Beam and B-seam) have been mined. Currently, MCC ie mining in an area where only one seam (B-aeon) has been and will be mined. The predicted subsidence fbr only B-seam longwell mining is 7,97 feet at shown on page 23 of Exhibit 60 in Volume 13. This prediction can be applied m the Jumbo Mountain mining area bocertee mining methods in the B-seam and the geology of the area are similar to the area which is covered by the subsidence grid. 2. The visual survry ie doao by both Seld personnel and aerial photography. The visual survey is intended to consist of observations made by pereonml (usually MCC' a or contract wuveyon) as thry travel in the areas of miaieg to complete their wrveyigg of the grid shown on Map 29 end to set the photo control points as shown on Map 30, including the hydrologic monitoring sites ott Jumbo Moutttaia. In addition, the aerial photos from the ilsll photagrammetric survey are utilized to document landslides, rocld'alls, etc. No new subsidence features had been observed sad features previously noted are healing. The hydrologic impacts from subsidence are included in the Annual Hydrologic Report (AHR). The year-end subsidence report and the AHR are both due on Apri130 of each year. In the 1995 AHI~ this information appears on page 2. 4. MCC is swam ofthe commitment to monitor the Mautz cabin and will watinue mo~toriag the cabin until survey information shows that subsidenoe is complete. At that time, a revision will be submitted to the Division which requeeu to cesee monitoring of the sttucturc.