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domestic or public uses. The Graystone report, Appendix 7-3, found similar • results from the Rollins Sandstone with a wide variation in quality between the four sites analyzed. (b) Groundwater in the Mesa Verde group is naturally divisible into two areas according to two modes of recharge, which are in turn functions of the stratigraphy, structure, and physiography. Where the sandstone and coal beds dip below the Colorado River, they receive recharge from it and are saturated. Where these beds occur higher than the river level they are not completely saturated, and receive recharge only from local precipitation events or geologic structures such as shear zones or faults. Neither the coal bed nor the underlying Rollins Sandstone meet the definition of an aquifer because there is not sufficient.quality and quantity of water for beneficial use. Though recharge occurs at a slow rate because permeability is low, beds lower than the river are continuously recharged. In contrast, recharge is discontinuous and occurs at an • even lower rate to beds above the level of the Colorado River. This is due to the low amounts of precipitation, the high relief, and the rapid runoff rate of this area. Giles of the U.S.G.S. stated that his work with the Mesa Verde nearer the Grand Junction area indicates that the water bearing properties of the formation to the south are basically the same as those encountered further north. According to Giles, the Mesa Verde formation in the permit area is a very tight unit, provides low yields to wells and usually contains water of poor quality. A good well in the area would produce about 30 gallons per minute, but most yield less. The Graystone report calculated a well in the North Decline area to have a potential pumping rate of 0.62 gpm in the Rollins Sandstone and a well in the center of the Roadside South portal mine to have a potential pumping a rate of 0.23 gpm. In the same study, a well in the Unit Train Loadout area was calculated to have a potential pumping rate of 95-195 gpm. • 7-6 (Rev. 9/17/97)