Persistent Chemicals: DOE Should Complete Efforts to Review PFAS Use

What GAO Found

Department of Energy (DOE) sites have long used per- and polyfluoroalkyl substances (PFAS) for purposes such as firefighting and uranium enrichment. These chemicals can harm human health and the environment, and are highly mobile, persistent, and resistant to degradation.

To understand the status of PFAS efforts throughout the department, DOE surveyed 57 of its sites, focusing on Manhattan Project and Cold War-era sites. As of 2024, 20 of 57 surveyed sites had completed their initial reviews of historical and current use, 21 are in progress, and 16 have not started. Additionally, there are over 100 DOE sites that were not surveyed—such as electrical substations and transformers managed by the Power Marketing Administrations, and their actions to review historical PFAS use are unknown. A 2021 policy memo from the Deputy Secretary of Energy directed all DOE program offices to characterize PFAS use at DOE sites, but the memo did not have a deadline for completing such work. If sites do not review their historical and current use of PFAS, DOE will not know the extent of where PFAS contamination poses a risk to human health and the environment or be able to effectively prioritize cleanup actions and estimate cleanup costs.

Example of the Department of Energy’s Historical Use of Firefighting Foam Containing Per- and Polyfluoroalkyl Substances During Training

Seventeen of the 57 surveyed DOE sites have on-site drinking water systems, and they have all tested for PFAS. Three of these sites reported contamination levels exceeding the federal maximum contaminant levels of 4.0 parts per trillion for perfluorooctanoic acid (PFOA) or perfluorooctane sulfonate—also known as perfluorooctanesulfonic acid—(PFOS) in drinking water, though these levels do not go into effect until 2029. These three sites treat or provide bottled water to workers.

Regarding groundwater, 17 of the 57 surveyed sites tested for PFAS in groundwater. Ten of these sites reported levels in their groundwater that were higher than the federal maximum contaminant level for drinking water. While this standard is not directly applicable to groundwater, DOE has used drinking water standards as groundwater cleanup targets for other environmental cleanup efforts.

DOE is early in the process of investigating and cleaning up PFAS contamination. GAO selected nine sites with known PFAS contamination for additional analysis. Two of the nine selected sites have started PFAS groundwater cleanup efforts. For example, since October 2022, Brookhaven National Laboratory has treated over 700 million gallons of water for PFAS through groundwater treatment systems. For the nine selected sites, DOE reported spending a total of about $20 million through 2024 on PFAS efforts. Most of these costs were related to active treatment efforts at Brookhaven National Laboratory. DOE has not generally included estimated PFAS investigation and cleanup costs in its environmental liabilities, which means that future cleanup costs will be higher than the currently reported liabilities.

Why GAO Did This Study

Certain PFAS have been associated with negative impacts to human health and the environment, including infertility and cancer. DOE sites across the country have used PFAS for a variety of purposes, including in firefighting and uranium enrichment, potentially leading to releases into the environment.

In 2024, the Environmental Protection Agency (EPA) finalized rules that establish legally enforceable maximum contaminant levels for six PFAS in drinking water and designate two of them—PFOA and PFOS—as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980, as amended. In May 2025, EPA leaders announced that they plan to rescind the maximum contaminant levels for several types of PFAS but intend to keep the ones for PFOA and PFOS. DOE sites with on-site drinking water systems and those with releases of PFOA or PFOS will need to comply with EPA’s new rules.

GAO was asked to review DOE’s cleanup of PFAS. This report examines the laws and regulations relevant to cleanup efforts, and DOE’s cleanup plans, identification, disposal, testing, and cleanup of PFAS contamination; spending on PFAS-related efforts; and estimated future costs.

GAO assessed documents related to PFAS plans, activities, and regulatory requirements. GAO examined nine DOE sites (and visited seven) selected to represent a variety of offices and locations with PFAS contamination to better understand DOE’s PFAS plans, contamination, and cleanup activities. GAO interviewed DOE officials at these nine sites, as well as six DOE offices, and the respective state and federal regulators for those selected sites.