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~' Memo: Deserado AHR -2- "Monitor holes 2-17m and TW2-17m, completed in the were bypassed by mining in the East Mains near the anticipation of of intersecting the monitor holes taken: February 25, 7986 siltstone and coal facies end of November, 1985. In the following actions were Water levels of 2-17m and TW2-17m were monitored more frequently in order to more closely correlate water level responses to the mining acti vi ty. On October 1, 1985, because of a concern for the miners' safety, an attempt was made to plug (by cementingf all the deeper monitor holes on the 21012-17 locations. The holes plugged included 2-17m, and 2-17L. Monitor hales TW2-17m and 2-77 were not plugged. Western Fuels committed to drilling and completing a new monitor hole into the lower sandstone facies about 300 feet west of 2-17L to replace the plugged hole. This hole will be drilled and completed in early summer of 1986. Holes 2-17m and TW2-17m have provided some interesting observations. From the hydrographs, sharp declines in the water levels of both holes were noted at the last of 1983 and the first of 1984 while mining was proceeding in the South Submains approximately 2,200 feet to the west of the holes. The direction of the face cleat is about N80°E. The strike of the face cleat from the 21012-17 location would intersect the South Mains in the same area that was being mined when the sharp declines took place. This indicates that some slight pressure decrease occurred along the strike of the cleat but was insufficient to allow significant decline of the piezometric level. The water level in TW2-17m rose to 135 feet as the result of efforts to plug the hole. This hole was bypassed by mining. The ho]e is located within a pillar surrounded by open mined areas, yet the water level continues a slow decline still 360 feet above the elevation of the mine which attests to extremely low permeability of the coal and the roof and floor rock adjacent to the coal. Because TW2-17m was not severed by mining, it is still a viable monitoring hole and will not be replaced. Monitoring of TW2-17m will continue as scheduled." This discussion and supporting data indicates that the Middle Facies is not a very transmissive unit. Due to the Massive Sandstone which is present in the Upper Facies, the reaction of Well 2-17U to mining is of interest. WFU, however, did not present any data from this well for 1985. It would also be of interest to observe the Lower Facies reaction to mining, however, no data from Well 2-17L for 1985 was presented. To summarize, surface water depletion due to mining activities is negligible. Diminution of the surface water quality is also negligible, as no adverse affects have been observed.