Support for Underground Injection Control Compliance and Enforcement

Under the Safe Drinking Water Act, the U.S. Environmental Protection Agency (EPA) regulates the injection of fluids underground through its Underground Injection Control (UIC) program, which is designed to protect underground sources of drinking water (USDWs). UIC wells have been categorized into six classes based on the type of fluid they inject: Class I (industrial and municipal waste), Class II (fluids associated with oil and natural gas production), Class III (fluids associated with solution mining), Class IV (hazardous or radioactive wastes injected into or above a formation with a USDW), Class V (non-hazardous fluids, often injected into or above a USDW), and Class VI (geologic sequestration of carbon dioxide). Protecting USDWs from contamination from UIC wells is an ongoing challenge, in large part because the UIC landscape differs vastly based on region, well class, project type, and local geology and hydrogeology, so each setting and project type brings its own challenges. Communities across the country may not be aware of or equipped to address the potential effects of UIC activities on their drinking water sources.

ERG provides UIC compliance and enforcement support to EPA for various well classes throughout the country. We review current regulatory practices and compile UIC well inventories. In the field, ERG-led inspection and sampling teams have witnessed over 100 mechanical integrity tests (MITs) and conducted UIC compliance evaluation inspections at more than 190 facilities. This work has included performing Class I, II, III, and V well inspections; witnessing MITs at oil and gas facilities (Class I and II wells) and at solution-mining facilities (Class III wells); and collecting Class V well water samples to analyze potential groundwater contaminants. Our teams have also witnessed and reviewed records from temperature logs, cement bond logs, water flow logs, and step rate tests. To ensure that waste categorization and cataloging meet regulatory requirements, our inspectors have toured grind and inject facilities associated with Class I wells, and reviewed waste manifest and disposal documents for waste disposed of via these wells. ERG has also audited UIC permits and witnessed plugging and abandonment activities to confirm proper closure of wells that are no longer in operation. Our teams use inspection checklists to ensure consistency across inspection and sampling activities. They prepare reports with the high level of quality and documentation required to withstand the technical and legal scrutiny associated with enforcement programs.