The Need for a Uniform Conservative Definition of Protected Groundwater During Oil and Gas Development

Freshwater shortages in the United States have led to increased use of desalination facilities to treat brackish groundwater for domestic, agricultural, and municipal uses. Groundwater resources are especially important in arid regions experiencing rapid population growth and where surface water rights for irrigation are fully appropriated. Hence, the protection of groundwater resources is necessary, including during oil and gas development. Definitions of protected groundwater are established individually by states. Since, it is both technically and economically feasible to desalinate water having a total dissolved solids (TDS) level of 10,000 mg/L, criteria for an Underground Source of Drinking Water (USDW) is a reasonable standard for the protection of brackish groundwater during oil and gas development. To better understand locations where oil and gas development may be occurring in proximity to USDWs, we examined the United States Geological Survey’s National Produced Waters Geochemical Database. We then reviewed the criteria for protected groundwater in 17 states containing these production wells. In general, we found that definitions of protected groundwater were ambiguous and often did not protect groundwater resources to criteria equivalent to an USDW. This indicates the need for states to protect groundwater to a conservative uniform standard equivalent to that of an USDW to safeguard brackish groundwater for present and future use.