Bedrock aquifers of eastern San Juan County, Utah

Baseline groundwater hydrology and water quality in and around Bluff, Utah

“…Vertical hydraulic gradients also can be used to evaluate susceptibility of an aquifer to degradation. Avery (1986) developed an initial potentiometric surface map of several bedrock aquifers in San Juan County in 1986. Groundwater conditions and flow systems, however, can change substantially over 30 years as the regional population and associated groundwater development increases.…”

“…2). The principal bedrock aquifers include the Dakota Sandstone (D aquifer), Morrison Formation (including the Bluff Sandstone) (M aquifer), and the Entrada, Navajo, and Wingate Sandstones (N aquifer) (Avery, 1986). Aquifers in the Bluff, Entrada, Navajo, and Wingate Sandstones are typically confined in the study area.…”

“…The Bluff Sandstone is the primary water-bearing unit of the Morrison Formation. Groundwater in the shallower D, M, and N aquifers is typically fresh outside of the Aneth Oil Field, whereas water in deeper formations underlying the Cedar Mesa Sandstone (P aquifer) is typically briny (Whitfield and others, 1983;Avery, 1986). The Paradox Formation is the primary hydrocarbon-producing reservoir in the region.…”

“…Published Glen Canyon Group aquifer properties, along with the potentiometric surface map, were used to estimate groundwater travel times. Hydraulic conductivity, a measure of a materials ability to transmit water, has been estimated from aquifer tests to be between 0.02 and 0.34 feet per day (ft/d) in the N aquifer (Avery, 1986).…”