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• ~- The reason the Mincic survey was not used: 1. The most recent survey by Basin Resources Inc. was conducted on April 24, 1995. The basin survey resurveyed all the points near the first North Panel (IN-1, IN-2, PT-B). 2. The Mincic survey assumed that monument PT-B was at a constant elevation at 7231.88 ft. This station was established on May 26, 1988 and consists of a 4 ft. roof bolt pounded into a mixture of ballast and earth material. The result of the Mincic survey at the one North Panel shows a deflection of -0.36 ft. (-4.32 in) at IN-1 and -0.46 ft (- 5.52 in) at IN-2. 3. The Basin resurvey showed a deflection of monument PT-B to be +1.26 in. This is the point the Mincic survey assumed to be constant. Allowable error for leveling is a function of the length of levels or the number of times the level was set. Allowable error would be ±0.112 ft. (±1.34 in). Monument PT-B could be as low as 7231.768 ft or as high as 7231.992 ft, these two elevations are the range of acceptable survey error (Surveyinc7, Evett 1979). The Mincic survey, by not reestablishing the elevation of monument PT-B would not be considered to be as complete as the Basin resurvey. 4. The Mincic survey at the 3 North Panel was not used because that panel is located over 1.6 miles from the Tatum home and was not considered pertinent to the investigation at the 1 North workings. 5. The Mincic survey calculates an angle of draw at the first North Panel from survey points located only within the shadow area of the underground workings. This is suspect because to calculate an angle of draw by surveying techniques it is necessary to have a survey point outside the shadow area to use as a reference point to calculate an angle. The assumptions made by Mincic cannot be used as a basis for concluding that subsidence has occurred (Subsidence and Ground movement, Stefanko 1973).