EPA Superfund Site

YUMA MARINE CORPS AIR STATION

AZ | EPA ID AZ0971590062

About this site’s exposure pathways: As of July 2024, the Yuma Marine Corps Air Station Superfund site is considered “Current Human Exposure Not Under Control” (HENC). A group of chemicals known as per- and polyfluoroalkyl substances (collectively referred to as “PFAS”) has been detected in drinking water wells located off-base. Although PFAS concentrations in groundwater were considered low detections, the levels are above the recently finalized federal maximum contaminant levels (MCLs). This exposure pathway is considered unacceptable based on EPA risk-based criteria because PFAS concentrations detected are above the non-cancer-risk threshold (hazard index).

Currently, the planned activities to address this pathway are being discussed between EPA and the Navy, but will likely include additional collection of groundwater data to determine the spatial extent of impacted groundwater, particularly in relation to groundwater wells used to provide drinking water. EPA currently anticipates that human exposure will be under control by 2028 because that is when the Navy will have implemented additional investigations and remedial action to address this contaminant of concern. However, in the interim, EPA plans to discuss mitigation measures to reduce health risks to those currently impacted by this risk.