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• Hydrologic Data Interpretation and Impact Amexsmmi for Permit Area and Adjacpa Arew This new area was relatively dry with only small During the 4th quarter of 1987 flow was estimated damp roof areas. Areas previously mapped as wet at 3 to 5 gpm. The flow increased to 5.5 gpm and or damp are shown on Exhibit 11. Most areas were 9.8 gpm during the 1st and 2nd quarters of 1988, dry. The wet areas of the 1st West Submain were respectively. Since this time the flow declined thought to be associated with sandstone channels steadily,to 1.2 gpm during the 3rd quarter of 1988 which immediately or closely overlie the coal seam and to an unmeasurable amount by the end of and with fracture zones in the Lone Pine Gulch 1988. During 1989 the area outside the panel seals area. dried up completely. Panel 1W1S Panel MS Monitoring of well 38-H-1 during the 1989 water Development mining in panel 1W3S began in year indicates well water levels were still at pre- March, 1987. Wet and damp roof areas were mining levels.The water level in this well dropped encountered from approximately 11 crosscut to 24 about 100 feet from January to July 1987 while crosscut.These wet areas (roof drippers) produced retreat mining was occurring (November 1986 to very little flow but were fairly extensive over a wide March 1987). Well 38-H-1 is screened at three area. Some were associated with a badly fractured 20-toot intervals midway between the surface and immediate mine roof(overburden averages about the"F'seam coal.The"F' seam depth of cover is 700 feet). The water is probably associated with about 1000 feet at the 38-H-1 well location and sandstone channels directly above the coal seam averages about 900 feet over this panel. The total and with Lone Pine Gulch features.Retreat mining depth of well 38-H-1 is 580 feet. was completed during September 1988.To date,no evidence of water is visible near the panel seals or • No water was observed in the mine during devel- in adjacent areas. opment or retreat mining. Water observed in adjacent areas was thought to be coming from Panel 1W4S panel 1 W2S because it did not appear until retreat mining occurred in panel 1W2S. During 1989, Development mining began in panel 1W4S during water levels in well 38-H-1 remained near pre- October 1987. The "F' seam depth of cover mining levels.Thus,data from well 38-H-1 indicate averages about 500 feet over this panel. Roof groundwater in the barren member above the drippers and wet areas were encountered in roof rubble zone will not suffer long-term impacts from fractures and near the sandstone channel margins. secondary mining. The wet areas were not as large as those present in panel 1W3S and did not produce any measurable Wells 38-H-2 and 38-H-3 provided little useful flows. Retreat mining was completed during 1989. information (see hydrographs in Appendix I). No significant flows were encountered. Subsidence apparently damaged the casings of both wells and connected them with the mine ventila- Panel 1W5S tion system. In well 38-H-2 the casing was ob- structed at 415 feet below the surface. Development and retreat mining of this panel occurred during 1989.The overburden continues to Panel 1W2S thin to the west; depth of cover averages about 400 feet over panel 1 W5S(ranging from <200 feet Retreat mining of panel 1 W2S was completed in to 750 feet at the southern panel end).Coal height November, 1987. Very little water was encountered also thins to the west. Mining conditions were in this panel during development or retreat. How- similar to those in panel 1 W4S. Roof drippers and ever, flow from panel 1 W2S appeared on the floor wet areas occurred,but no significant inflows were of the 1st West Submain near the IW2S seals encountered. After the panel was retreat mined, a shortly after secondary mining was completed. small wet area developed on the floor in the 1st 9