Coast Guard’s Environmental Cleanup Projects, September 2025

GAO-26-108173

Federal agencies must estimate the costs of cleaning up contamination for which they may be responsible. Those costs are reported in annual financial reports as environmental liabilities. Since 2017, GAO has been monitoring the federal government’s environmental liability as a high-risk issue.

When the Coast Guard identifies a potential environmental contamination at one of its properties—such as lead-contaminated soil—it generally investigates, remediates, and then monitors the contaminated site. The Coast Guard refers to this type of contaminated site as a cleanup project when it has developed a site-specific cost estimate for investigation or remediation.

This map shows the locations and descriptions of the Coast Guard’s cleanup projects, as of September 2025.

How to Interact with This Map:

Hover over a location to see details associated with a cleanup project at that site.

Use the tabs to view cleanup projects by phase

Source: GAO analysis of U.S. Coast Guard data | GAO-26-108173

Cleanup Project Phases

Investigation phase: During the investigation phase, the Coast Guard completes an initial inspection to confirm the release of hazardous substances, pollutants, or contaminants. Then it decides whether to proceed with further investigation.

Remediation phase: During the remediation phase, the Coast Guard designs and selects an option for remediating the environmental liability.

Monitoring phase: During the monitoring phase, the Coast Guard monitors the contaminated site for up to 30 years or longer. For example, it monitors soil and groundwater contamination levels at regular intervals to see that they remain within established thresholds.

Cost-to-study: Agencies may be unable to estimate the cost of remediating environmental liabilities. For example, they may have incomplete information on the nature or extent of contamination, or not know which remediation technologies to deploy. In these cases, agencies can estimate only the cost to investigate the contamination until more information is available. The Coast Guard refers to these as cost-to-study cleanup projects.

Types of Hazardous Substances and Contaminants:

Aqueous film-forming foam (AFFF): AFFF is an extinguishing agent used in fire-fighting that often contains PFAS and has been linked to health problems.

Asbestos: Asbestos is a group of naturally occurring mineral fibers that are resistant to heat and corrosion. According to the Centers for Disease Control and Prevention (CDC), those who breathe asbestos fibers can develop serious or fatal diseases, such as lung cancer or mesothelioma, which might not develop until decades after an individual is exposed.

Diesel range organics: Diesel range organics are typically compounds found in diesel fuel, which can have adverse environmental effects.

Lead-based paint: As lead-based paint deteriorates into flakes and dust it becomes a health hazard to people, especially children. Lead exposure can damage a child’s developing brain and nervous system and slow development and growth.

Metals: Metals, such as lead, have varying degrees of toxic and carcinogenic properties that may produce adverse human health effects.

Per- and polyfluoroalkyl substances (PFAS): PFAS are a group of synthetic chemicals that have been linked to harmful health effects. For decades, PFAS have been used in a wide range of products including stain-resistant furniture, waterproof clothing, nonstick cookware, and certain firefighting foams like AFFF. PFAS are resistant to degradation and can accumulate in humans, animals, and plants.

Polychlorinated biphenyls (PCB): PCBs are a group of synthetic organic chemicals that can cause a number of different harmful effects. There are no known natural sources of PCBs in the environment. Both EPA and the International Agency for Research on Cancer (IARC) have determined that PCBs are probably carcinogenic to humans.

Polycyclic aromatic hydrocarbons (PAH): These are a group of chemicals that are formed during the incomplete burning of coal, oil, gas, wood, garbage, or other organic substances, such as tobacco and charbroiled meat. There are more than 100 different PAHs. They are found throughout the environment in the air, water, and soil. They can occur in the air, either attached to dust particles or as solids in soil or sediment. Studies have shown that individuals exposed by breathing or skin contact for long periods to mixtures that contain PAHs and other compounds can develop cancer.

Semi-volatile organic compounds: Volatile organic compounds (VOCs) are a group of chemicals that can readily transform into vapor (a gas) at lower temperatures. Semi-volatile organic compounds (SVOCs) are more likely to be liquids or solids at lower temperatures. Some examples of products that include SVOCs are many pesticides, oil-based products, and fire retardants. SVOCs can deposit on outdoor surfaces. PCBs and PFAS are examples of semi-volatile organic compounds.

This graphic represents the 152 environmental cleanup projects identified by Coast Guard, as of September 2025. This graphic only includes cleanup projects with a site-specific, non-zero-dollar value cost estimate that represents an environmental liability for the Coast Guard. The Coast Guard has identified thousands of additional environmental liabilities at its shore infrastructure sites. For more information on how the Coast Guard identifies and characterizes its environmental liabilities, see our report, GAO-26-108173. Additional information, such as details for locations with multiple cleanup projects, is available in Appendix I and our downloadable data set.

Download data:

July 14, 2026