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• Station 15 Station 15 vas established for the 1991 surveying year. Station 15 overlies <br />approximately 700 feet of overburden and is located within the 600 - 800 foot <br />overburden depth Stevens Cnilch alluvium protective buffer zone. Panel B was <br />retreat mined with partial floor extraction during May, 1992 in the immediate <br />vicinity of station 15. The 1998 survey resuhs show an elevation gam of 0.38 feet <br />when compared to the January 1992 elevation. <br />Station 16 Station 16 overlies approximately 950 feet of overburden. Surveys at station 16 <br /> <br />were initiated in August, 1982 and continued biannually through 1984. Annual <br />surveys occurred in ] 992 - 1994. The 1st North - 3 West panel adjacent to and <br />east of station 16 was retreat mined in October ] 981. Panel A, located beneath <br />station 16 was retreat mined in July and August, 1991. The 1998 survey data <br />indicates a 0.01 ft. elevation gain at this site compared to the 1997 data. Station <br />16 is located within a trapped landslide area as well and some minor coordinate <br />variability has been recorded. <br />Station DH55 Drill hole 55 is located over Pane3 Z with approximately 1750 feet of cover. Panel <br />Z was retreated mined in the vicinity of DH 55 in July 1994. The collar elevation <br />of DH 55 was originally established in 1981 at 8578.57 feet. The monitoring point <br />established at this site was surveyed in January 1994 at elevation 8543.1 I (-35.46 <br />feet). An appazent error in survey elevation data exists for this site. The October <br />1994 survey indicates a minor (0.07 foot) gain in elevation compared to the <br />January 1994 survey. The July 1998 survey indicates a loss of 0.24 ft when <br />compared to the 1997 elevation. <br />Station DH65 Drill hole 65 is located over the I East Main in the west thick coal pod with <br />approximately 1380 feet of cover. In May 1994 the I East Mains were advanced <br />under DH 65. During 1995 retreat mining occurred both north and south of DH <br />65. The October 1994 survey indicates a minor (0.13 foot) gam in elevation <br />compared to the January 1994 survey. The 1998 average survey performed by <br />Cragg Surveying shows a decrease of 0.03 feet in elevation. <br />Station DH66 Drill hole 66 is located over Panel ZZ- I North in the west thick coal pod with <br />approximately 1290 feet of cover. Advance mining occurred under DH 66 during <br />May 1995 and retreat mining occurred during July or August 1995. The collar <br />elevation of DH 66 was originally established in 1982 at 8209.89 feet. The <br />monitoring point established at this site was surveyed in January 1994 at elevation <br />8189.50 (-20.39 feet). An apparent error in survey elevation data exists for this <br />site. The October 1994 survey indicates a minor (0.07 foot) gam in elevation <br />compared to the January 1994 survey. The 1998 survey performed by Cragg <br />Surveying shows a decrease in elevation of 0.49 feet. <br />• <br />-2- <br />