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alluvium near the North Fork Gunnison River on or adjacent to the permit area. These were intended primarily for industrial or domestic use. These wells are listed in Table III.A-1 and are indicated in Figure III.A-1. Groundwater in the Mesa Verde formation is considered to be controlled by interstitial porosity, meaning that water is contained and transmitted through interconnected pore spaces between grains within the sedimentary bed- rock. Water yields of 0 to 50 gpm may be expected, with an average of 10 gpm. The quality of the groundwater is similar to that of the rest of the re- gion. Generally, the quality of groundwater in the Mesa Verde group can be expected to be poor. Analysis of water throughout this aquifer shows that excessive iron, manganese, sulfate, and fluoride are common and total dissolved solids (TDS) are usually high, with 1,000 to 3,000 milligrams per liter range (Price and Waddel 1973, Price and Arnow 1974). Typically, the water is of poor • chemical quality for domestic or public uses. Well data obtained from 17 observation wells on the Atlantic Richfield Company's Mt. Gunnison property, which is adjacent to the Hawk's Nest permit area, has established that within the Mesa Verde coals, the head decreases rapidly with increasing depth, indicating poor hydraulic connection within the different coal beds. Hydraulic gradient was established to be northeastward down-dip at a slope of about 300 feet per mile (BLM 1979). An underground coring program was conducted during the winter of 1978- 1979 by Western Slope Carbon on the Hawk's Nest leases. Four core holes were completed (Table III.A-1 ). These corings tested the Mesa Verde interval between the E Seam and the Rollins Sandstone Member (Figure IV.B-1). Two of these core • holes were continuously observed by members of the Colorado Geologic Survey. None of these wells had artesian flow of water to surface. In each case, a 32