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Ground Water Hydrology The applicant has supplied sufficient information to describe the quality and quantity of ground water within the pemmit application (Section 2.04.7(1) and will continue to provide data as new holes aze drilled. The following description of ground water was prepared using information within the permit application, information in the Chimney Rock Mine permit application (C-81-023), and site observations by DMG staff. Ground water in the general azea of the mine occurs in the Pictured Cliffs Sandstone, the interbedded and lenticulaz sandstones and coal seams of the Fmitland Formation, the Quaternary Terrace Deposits and alluvium of the Animas River. The Pictured Cliffs Sandstone is a regional sandstone aquifer which overlies and underlies the lowest coal seam to be mined, the "C" seam. No water wells aze presently completed in this aquifer in the general area. Springs along Cazbon Junction Canyon aze, in part, supplied by discharges from this aquifer, given the outcropping and subcropping of this sandstone in the stream valley. Spring flows in Cazbon Junction Canyon vary from seeps of less than a gallon per minute to over five gallons per minute during dry periods in the fall. Flows are expected to vary seasonally, with increased flow rate recorded in spring and eazly summer. Ground water flow may not be uniform throughout the Pictured Cliffs sandstone. The applicant's consultant had an 18-inch section of core from the Lower Fruitland-Upper Pictured Cliffs transition zone tested in the laboratory. This sample consisted of hard, poorly sorted, clayey, very fine grained sandstone. The porosity of this sandstone averaged 14 percent and had essentially no permeability. This sample, however, represents a relatively small part of the massive Pictured Cliffs Sandstone and may not be representative of its entire cross-section. No exploration drill holes penetrate the entire section of the Pictured Cliffs Sandstone. Regionally, the Pictured Cliffs Sandstone in outcrop is a massive, hazd, well sorted, clean, fine to medium grained sandstone (Fassett and Hinds, 1971, and Shomaker, et. al,, 1971). This massive section of Pictured Cliffs Sandstone is permeable and could support ground water flows. The interbedded and lenticulaz strata of the Lower Fruitland Formation support local discontinuous aquifer systems. Water bearing zones were observed at the base of the Lewis ("C) coal zone, 1.3 feet thick; above the Shamrock ("A") coal zone, 96 feet thick; and above the Shamrock rider coal zone, 17 feet thick. Two monitoring wells, 17-B and 82-5, aze completed in the first two water bearing zones respectively. The water- bearing zone associated with the Shamrock coal overburden was air-lift bailed at about 50 gpm with no measurable drawdown. This indicates that the Shamrock coal overburden may produce significant inflows to the pit. Oakridge Energy, Inc. has applied for and received a well permit to drill and use water from the water-bearing zone associated with the Shamrock rider seam. This zone was encountered in borehole 84-2 (see Map 4-2). An estimated yield of 150 gpm was measured in an airlift during drilling. The recharge azea is likely restricted to the outcrop and subcrop of this zone. At the Chimney Rock Mine, about 30 miles east of the Cazbon Junction Mine, pumping tests were run on the Lower Fmitland Formation. These pumping tests yielded a value for transmissivity (T) of 210 gallons per day per foot (gpd/ft) and a value for storativity (S) of 1.3 x 10-0. These values indicate that the Lower Fmitland Formation will support limited ground water movement and use. There aze presently no known users of ground water from this aquifer in the pemmit and adjacent areas.