Castle Air Force Base, located in Merced County, California, has been identified as a site of serious PFAS contamination stemming from decades of military operations.
Groundwater beneath and around the former base contains dangerously high levels of per- and polyfluoroalkyl substances (PFAS), which are synthetic chemicals used widely in firefighting foams and industrial processes.
These “forever chemicals” are known for their persistence in the environment and the human body, raising major concerns about long-term health and environmental risks.
According to data collected by the Environmental Working Group (EWG), PFAS levels in groundwater at Castle AFB significantly exceed the Environmental Protection Agency’s (EPA) maximum contaminant levels (MCLs), underscoring the urgent need for cleanup and accountability.
According to data collected by the Environmental Working Group (EWG), PFAS levels in groundwater at Castle Air Force Base as of 2020 are as follows:
- PFOS: 2,300 ppt
- PFOA: 340 ppt
- PFBS: 200 ppt
- PFHpA: 310 ppt
- PFHxS: 2,200 ppt
- PFHxA: 810 ppt
- PFNA: 25 ppt
These concentrations are hundreds of times higher than the EPA’s health-based guidelines of 4 parts per trillion for PFOA and PFOS, indicating widespread contamination that could pose serious threats to public health and the environment.
Sources of PFAS Contamination at Castle AFB
The primary source of PFAS contamination at Castle AFB is the historical use of aqueous film forming foam (AFFF), a firefighting foam commonly used at military installations to suppress jet fuel and chemical fires.
AFFF contains high concentrations of PFAS chemicals like PFOS and PFOA, which easily seep into soil and groundwater during training exercises and emergency responses.
Over decades of use, this foam was routinely sprayed during fire drills and accident response, resulting in long-term accumulation of toxic chemicals in and around the base.
Maintenance and waste disposal practices at the installation may have contributed to the release and migration of PFAS into local water systems.
Impacted Populations at Castle AFB
Populations most at risk of PFAS exposure at Castle AFB include former military service members, base employees, contractors, and nearby residents who may have relied on private drinking water wells or local public water systems.
Many individuals may have unknowingly consumed contaminated water for years, increasing their risk of developing serious health conditions such as thyroid disease, kidney cancer, immune system disorders, and fertility issues.
Vulnerable groups like pregnant women, children, and people with underlying health conditions face even greater health risks from long-term PFAS exposure.
The proximity of surrounding communities to the base increases the potential for widespread and sustained exposure.
Addressing PFAS Contamination at Castle AFB
Castle AFB is undergoing environmental investigation and cleanup under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), also known as Superfund.
The U.S. Department of Defense, along with the Environmental Protection Agency and state agencies, is responsible for identifying contamination sources, conducting PFAS testing, and implementing cleanup strategies.
Progress has been slow, and community advocates are calling for more aggressive action to remove PFAS from drinking water supplies and prevent future exposure.
Remediation efforts include the installation of filtration systems, monitoring of water quality, and plans to remediate contaminated soil and groundwater.
Broader Implications of PFAS Contamination at Castle AFB
The contamination at Castle Air Force Base is part of a broader national crisis involving PFAS pollution at military installations across the United States.
As more bases are found to have elevated PFAS levels, concerns continue to grow about the long-term effects on public health, the environment, and water infrastructure.
Castle AFB serves as a case study highlighting the need for federal oversight, corporate accountability, and comprehensive regulation of PFAS compounds.
Legal action, increased funding for cleanup, and stricter enforcement of contaminant levels are essential to address the lasting impact of PFAS pollution on affected communities.
