Underground Injection Control
The Utah Division of Oil, Gas and Mining (Division) attained Underground Injection Control (UIC) primacy for Class II injection wells in 1982. Primacy is authority granted by the U.S. Environmental Protection Agency (EPA) to a state to run its own UIC program and provide oversight of the permitting, construction, operation, compliance and closure of injection wells on all lands except those identified as “Indian Country,” which the EPA currently regulates. Since receiving primacy for Class II injection wells, the Division has maintained an effective program safeguarding underground sources of drinking water while fostering close collaboration with operators and offering guidance and support as needed.
There are three primary uses of Class II wells:
- Waste disposal by injection of fluids, primarily salt water brines, are brought to the surface during natural gas and oil production. Once on the surface, the brine is separated from hydrocarbons and injected into the original, or a similar, underground formation.
- Injection of fluids such as CO2, steam, chemicals, salt water brines, or water into oil and gas producing formations to increase ultimate production and extend the life of the oil or gas field.
- Storage of hydrocarbons by injection into deep underground formations, including salt caverns. This use is often part of the U.S. Strategic Petroleum Reserve and overseen by the U.S. Department of Energy.
The Division is currently applying for primacy from the EPA for Class VI Carbon Sequestration, as directed by the Utah Legislature under H.B. 204 (2022), now Utah Code 40-11 Geologic Carbon Storage. Utah Administrative Rule R644 Oil, Gas and Mining; Carbon Sequestration, was approved on 7/31/2025. The primacy application was submitted in December 2025 and is currently under review by the EPA.
The graphic below illustrates the six classes of UIC wells. The Utah Department of Environmental Quality maintains primacy of UIC Class I, III, and V wells.
