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__> - . W M/N/NG SmOOrn CmY Mln~ January 24, 2000 Joseph J. Dudash Environmental Protection Specialist Slate of Colorado Division of Minerals and Geology 1313 Sherman Street, Room 215 Denver, Colorado 80203 RECEIVED J~~ 2 g ?_ODU Division of Minerab 8 Geobgy Re: 1999 Annual Subsidence Report Dear Mr. Dudash: ~II II~II~II~~~~~ II~ This subsidence monitoring report is submitted as required by permit section 2.05.6(6)(c)(i), page 2.05-61 i. The Operator is to visually inspect the permit area for [he Sanbom Creek Mine and [he Sanbom East Tract for mass movement features in June and November of each year. Particular attention is to be focused upon the modem landslide on the east valley slope of Coal Gulch, the landslide features within the unnamed drainage between the Sanbom Creek and Coa] Gulch drainages, and the modem landslide on the west valley slope of Hawksnest Creek. If new mass movement features are noted, they are to be brought to the attention of the Division. During the past five years, a visual subsidence-monitoring program has become part of the routine monitoring of Springs 1 through 11. Springs 1 through 6 are reached from the U. S. Forest Service road up Coal Gulch. During trips to these springs from April to October, the higher elevations of the permit area for the Sanbom Creek Mine and the Sanborn East Tract are visually inspected for mass movement features, with particular attention focused on the landslides in Coal Gulch and Hawksnest Creek. Springs 7 tlvough l 1 are along old Highway 133 in the lower elevations of the permit area for the Sanbom Creek Mine and the Sanbom East Tract. During monthly monitoring the lower elevations are visually inspected for mass movement features, with particulaz attention focused on the landslides in Coal Gulch and the unnamed drainage between the Sanbom Creek and Coal Gulch drainages, above Springs 7 and 9 respectively. During 1995 and 1996 the area in the lower elevations of Coal Gulch were mined in the vicinity of the Coal Gulch slide. There has been no indication of recent mass movement in the landslide as a result of the mining. Mining under the ridge in Section 10 between Coal Gulch and the unnamed drainage was completed in 1996, with no indication of differential settlement in the massive sandstone beds that can be readily observed from the Coal Gulch road. During 1997 the area in the vicinity of the landslide features in the unnamed drainage was mined, again with no indication of recent mass movement in the landslide as a result of the mining. P. O. Box 5 3 5 3 7 3 7 H i g h w a y t 3 3 Somerset , C o l o r a tl o 8 1 x 3 4 U S A TEL (970) 929-5122 FAX (970) 929-5177