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Mountain Caa! Comparry 1997 Annual Hydrology Report 11'est E/k Miire inflows were observed to be as high as 250 gpm at Cross-cut #3 of Entry #1 with subsequent • decreases occurring within 7 days to 140 gpm. A second fault system, with a similaz northeasterly trend, was encountered on January 20, 1997 neaz Cross-cut #11 of Entry No. 2 of 14 Southeast Headgate (a.k.a. 1SE Headgate). This fault system was subsequently named for its location (i.e., 14SE Headgate fault). Initial inflows at this location were estimated to be approximately 8,000 gpm. Within a months time these inflows had decreased to approximately 1,750 gpm. By July of 1997 inflows at this location had decreased to 150-200 gpm where they have remained constant throughout WY97. The location of these mining azeas and the associated mine inflows are shown on Map 1. Aside from the fault system inflows, known azeas of historic inflows due to low overburden and proximity to outcrops were once again observed. Groundwater inflows, excluding the B East Mains and 14 SE Headgate faults contributions, initially ranged from 1 to 5 gpm and later dried up, with the exception of the inflow in the ]0 NETG. This flow began at 80 gpm and later dropped to approximately 35 gpm. Total inflows from the B East Mains and 14 SE Headgate faults during WY97 were estimated to be 161 and 504 acre-feet, respectively. Longwall Mining Longwall mining operations during WY97 were concentrated in the western portion of the mine property (Map 1). Specifically, this included the remaining one-quarter of the 8NW longwall panel (Jumbo Mountain north) and all of the 9NW longwall panel (Jumbo Mountain south). The • 9NW longwall panel was completed in August of 1997. The longwall was moved to the IONE longwall panel where it started production in September. Only about one-eighth of the IONE {ongwall panel was mined in WY97. Observed mine inflows were nearly non-existent in the 8NW and 9NW longwall panels. While not completely unexpected, mining conditions were drier than previously experienced while mining the other Northwest Panels. Mine inflows in the LONE longwall panel were nonexistent except as noted in development mining (see below). Development Mining Development mining utilizes room-and-pillaz mining methods to create tailgates, headgates and bleeder entries azound the longwall panels for utilities, safety equipment, conveyors, ventilation and access routes. As a result, development mining is usually done in azeas of the mine where limited information is known about potential water-bearing features such as faults and fractures, unless encountered in exploratory drilling from the surface. It is from these areas that the groundwater inflows were noted. Specifically, wet areas, seeps and/or drippers were noted from the floor in the 9 Northwest headgate at Cross-cut #31, from the roof in the 12 Northwest headgate at Cross-cuts #10, 12, 19, 20 and 42, from the roof in the 11 Northeast tailgate neaz cross cuts #5, 7 and 9, from the roof in 11 Northeast headgate at Cross-cut #18, from the roof and rib in the 10 Northeast tailgate at Cross-cut #20 and from the roof and floor at multiple locations along the B East Mains and 14 . SEHG fault projections in the Box Canyon Mains and longwall panels (see Map 1). All of the 3 -032.40 age 0 rig t ater ngineers