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overlain by a massive sandstone 25 to 225 feet thick which lies directly on the C seam and mazks the bottom of the upper coal member. Three categories of potential aquifers exist in the general azea: alluvial deposits associated with the North Fork of the Gunnison River and its tributaries, the Rollins Sandstone, and lenticular discontinuous sandstones of the Upper Mesaverde Formation. The largest alluvial aquifers aze associated with the North Fork of the Gunnison River. Smaller, more isolated alluvial aquifers aze associated with several tributaries of the North Fork. The Rollins Sandstone is the only known sandstone with sufficient porosity and lateral extent to be considered a regional bedrock aquifer. Pacific Basin Resources has completed three wells into the rollins Sandstone, and a fourth well is planned in response to a concern raised during the Division's review of Permit Revision No. 3. Well SC-1 in completed in the Rollins Sandstone near the Sanborn Creek Mine portals. Wells SC-2 and SC-4 aze completed in the Rollins Sandstone in the Coal Gulch area. Well SC-4 was drilled to verify the poor water quality results obtained during monitoring of Wells SC-1 and SC-2. Well SC- 4 confirmed the poor water quality of the Rollins Sandstone, and due to its close proximity to Well SC-2 is not part of the current monitoring program. Well TC-1, in the Thompson Creek area at the east end of the revised permit area for Permit Revision No. 3, has been approved to be drilled. Water quality in this well is expected to be the same as the previously completed wells. Water quality is poor, with high total dissolved solids as sodium chloride. Inflow and recovery of water level tests, conducted during March of 1995, in response to the review of the 1994 Annual Hydrology Report, indicates very low permeability and porosity of the sandstone. Localized perched bedrock aquifers exist in the discontinuous, lenticulaz, fine-grained sandstones of the Upper Mesaverde Formation. The amount of ground water in these sandstones is controlled by faulting and fracturing of the strata (secondary porosity) and the topography of the recharge area. No known wells aze completed in the sandstones of the Upper Mesaverde Formation above the mine workings. The valley in which the towns of Paonia and Somerset are situated is semi- arid, with annual precipitation averaging about 15 inches per yeaz. Mean annual precipitation increases with elevation, reaching over 40 inches per year near the summit of Mt. Owen. The May-September precipitation is five inches for the lowlands and 13 inches for the mountain peaks. This indicates that snowfall patterns play an important part in determining the hydrologic conditions of the area. Temperature extremes at Paonia have ranged from -28oF in January to 100oF during July and August. The average annual temperature is approximately 49~F. Snowfall averages 58 inches per year. The general area in which the Sanborn Creek Mine is located is chazacterized by steeply Senbom Creek Mine B Petmit Revivon No. 3