Underground Injection Control Well Regulations

Federal Statutes and Regulations

The Safe Drinking Water Act (SDWA) (42 U.S.C. § 300f et seq.) established in 1974 the Underground Injection Control (UIC) Program and gives the U.S. Environmental Protection Agency (EPA) responsibility for regulating underground injection wells, including those for waste disposal or storage associated with oil and gas production.  

The main elements of the Underground Injection Control (UIC) Program regulations are summarized below:

• 40 CFR Part 144 – Underground Injection Control Program (provides minimum requirements for the UIC Program);
• 40 CFR Part 145 – State UIC Program Requirements (outlines procedures for EPA to approve, revise, and withdraw UIC programs that have been delegated to the states);
• 40 CFR Part 146 – Underground Injection Control Program: Criteria and Standards (includes technical standards for various classes of injection wells)
• 40 CFR Part 147 – State Underground Injection Control Programs (outlines the applicable UIC programs for each state);
• 40 CFR Part 148 – Hazardous Waste Injection Restrictions (describes the requirements for Class I hazardous waste injection wells).

EPA has classified underground injection wells into six different categories and provides requirements and standards for the construction and operation of injection wells depending upon the category of waste and disposal method. The categories are delineated as follows:

Class I – Industrial and municipal waste disposal wells;

Class II – Oil and gas related injection wells; Class II wells are subcategorized either as Class II-R for enhanced recovery or as Class II-D for brine disposal;

Class III – Injection wells for solution mining;

Class IV – Shallow hazardous and radioactive injection;

Class V – Wells for injection of non-hazardous fluids into or above underground sources of drinking water;

Class VI – Wells used for geologic sequestration of CO2.

The Energy Policy Act of 2005 excludes hydraulic fracturing from regulation under the UIC program, except when diesel fuels are used for oil, gas or geothermal production.