Recent advances in the well completion process, combining hydraulic fracturing and horizontal drilling, have made extraction of oil and natural gas from unconventional oil and gas (UOG) resources more technologically and economically feasible. UOG process wastewater may be generated in large quantities and contains constituents that are potentially harmful to human health and the environment. Process wastewater from UOG wells often contains high concentrations of total dissolved solids (TDS) (salt content). The wastewater may also contain various organic chemicals, inorganic chemicals, metals, and naturally-occurring radioactive materials (NORM). These large quantities of potentially harmful wastewater create a need for appropriate wastewater management infrastructure and management practices. This regulation would strengthen existing federal controls on pollutant discharges from certain oil and gas extraction facilities by establishing pretreatment standards that would prevent the discharge of pollutants in process wastewater from on-shore unconventional oil and gas extraction facilities to publicly owned treatment works (POTWs).