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• 1995 Subsidence Report Page 6 elevation 8812.23. This station was not surveyed in 1994 because m;n;ng was not advanced in the 1st West Mains so it is not in the angle of draw of the active mine workings. DTE Engineering was unable to survey this point during 1995. Station 98: Station 98 was newly established in 1993 and is located at the Grosse-Rhode bunkhouse identified as structure 34 on permit No. C-81-038; Map No. 9-7. Advance mining of Panel Y in the vicinity of this location occurred during December 1993 and retreat mining occurred in early 1994. This station overlies approximately 2050 feet of overburden. The nonitoring point established at this site was surveyed DeoenbPS 8, 1993 at elevation 8757.50. The October 1994 survey indicates an minor elevation gain of 0.08 feet co~ared to the December 8, 1993 survey. The June 1995 survey performed by [TPE Eng;~ring shwred and increase in elevation of 0.84 feet. See the report from tiTE Engineering behind tab 7 for an explanation of this data. Station 99: Station 99 is located at the Northwest corner of Section 15. The elevation of Station 99 was defined by satellite survey in July 1992 at 7921.9 feet. Station 99 was re-surveyed in January 1994 and showed a 0.96 foot elevation lass. The June • 1995 survey performed by UPE Engineering checked within 0.01 feet of the satellite survey. Based on the UTE survey, station 99 appears to be stable. Cover in the vicinity of station 99 is approximately 1200 feet. Mining has not been performed in the vicinity of station 99. Pitkin Mesa Pipeline Subsidence Monitoring Summazy Seven subsidence monitoring stations were established at locations along the Pitkin Mesa Pipeline which overlies Panel C. Panel C development canmienced in October with twenty four crosscuts completed by January 1, 1993. Panel C was mined utilizing a partial extraction design intended to preclude the development of subsidence in order to protect the pipeline. The subsidence monitoring stations along the pipeline are depicted on Map No. 2-SA. The stations were surveyed twice in 1995; June 5th and October 10th. Results of the surveys are appended to this report. The 1995 surveys were performed by itPE Engineering and Surveying Co~any. The June survey showed significant differences in elevation fmn the prior surveys performed by mine personnel. The October survey shows elevations which are consistent with the June survey. VPE should provide consistent survey Values in the future which will shwa the area is stable. Surveys will crontinue approximately semi-annually until stability is documented. Visual Monitoring 1995 . Visual subsidence monitoring is accaiplished by periodic "walkovers" of recently mined areas within the present permit area. walkovers are generally done in conjunction with survey monitoring due to the seasonal accessibility of the