Fort Riley is contacting owners of properties located near Marshall Army Airfield to ask permission to test the quality of drinking water in wells on those properties, to determine if the wells may have been impacted due to Army operations.
According to a news release from Fort Riley the testing will look for concentrations of Perfluorooctanoic acid (PFOA) and Perfluorooctane sulfonic acid (PFOS), which are part of a larger group of chemical compounds known as per- and polyfluoroalkyl substances or PFAS.
PFAS are used in aqueous film-forming foam (AFFF), a critical firefighting agent used to quickly suppress petroleum fires at airports and military installations. AFFF has been used at Fort Riley. PFAS are also found in many everyday products, such as food packaging, cookware, carpet protectants and waterproofing chemicals.
The Environmental Protection Agency issued a health advisory establishing a threshold concentration of PFOS and PFOA for drinking water of 70 parts per trillion (ppt). Fort Riley's drinking water supply has been tested since 2013 for PFOS and PFOA and the highest concentrations found are 11 ppt.
A site inspection on Fort Riley this year found that nine locations beneath Marshall Army Airfield with potential PFAS releases showed PFOA/PFOS concentrations above 70 ppt in groundwater samples. This has led the Army to seek to test off-post drinking water wells that could be affected due to Army operations.
The Army follows the federal environment cleanup law, the Comprehensive Environmental Response, Compensation and Liability Act, known as CERCLA. The Army works closely with appropriate state and federal agencies where the Army has identified PFAS were potentially released into the environment.
Though drinking water on Fort Riley does not have PFAS levels above the EPA's health advisory level, the Army wants to ensure past practices have not affected groundwater that could be used as drinking water off the installation. The Army has contracted with Arcadis, a private firm, to collect samples from the wells and conduct the testing. Test results will be shared with the EPA and the Kansas Department of Health and Environment. Well owners will be notified individually of their results.
Fort Riley is contacting potentially affected well owners by mail. Off-post sampling is expected to begin within 30 days. Being contacted does not mean an individual's well is affected; only that the Army wants to test the water quality.
The Army assesses if past activities may have resulted in a release and the potential for human exposure, and takes action to protect human health and the environment, as necessary. Further CERCLA actions are prioritized and sequenced based on risk.