Groundwater quality, and subsequently the use(s) for which it is suited, varies widely throughout Wyoming. This is most evident in the large sedimentary structural basins, where the majority of the state’s population resides and the greater part of economic activity occurs. An aquifer may produce high quality groundwater suited for human consumption at a basin’s margin while water pumped from the same aquifer a few miles basinward may be unfit for livestock usage. One measure of water quality is its “salinity.” Salinity is the amount of dissolved material that remains as residue after the liquid portion of a water sample evaporates.
This report examines the salinity of groundwaters that occur at depths of 5000 ft or less “below ground surface” (bgs) in the Denver-Julesburg structural basin (D-J Basin) of southeastern Wyoming. Special emphasis is placed on saline groundwaters (TDS ≥ 5000 mg/L) that may be suited to industrial uses thereby conserving higher quality waters for domestic, agricultural and livestock uses. Saline groundwaters are encountered most frequently during oil and gas exploration and production operations (Kharaka and others, 2003) in deep basin aquifers located more than 1,000 feet bgs. In contrast, due to costs, few deep wells are drilled by domestic, irrigation or livestock water users looking for good quality groundwaters which are generally found in shallow wells close to recharge areas located along basin margins and alluvial deposits (Taboga and others, 2014a, b).