The Department of Defense has released a long-awaited report on PFOS contamination at Stewart Air National Guard Base. The report confirms what state tests confirmed two years ago: high levels of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) exist at locations on the air base and flow into the City of Newburgh drinking watershed. The data reveals that both chemicals - also known as per- and polyfluoroalkyl substances or PFAS - are present at high concentrations in groundwater, “primarily in two areas of the site,” the report states. Those two areas center around Recreation Pond and a former landfill at the base. “PFAS groundwater contamination in the southeast portion of the base appears to be associated with the former base landfill, which is located east/northeast of the Recreation Pond drainage area,” the report reads. However, surface water results at a tributary flowing from Recreation Pond revealed the highest concentrations detailed in the report: 48 times the EPA health advisory level for PFOA and more than 168 times the EPA advisory level for PFOS. Both chemicals were found in surface water above the health advisory level inside Recreation Pond, “and throughout the Silver Stream network to the point where it discharges to Lake Washington through a diversion,” the report states. Silver Stream flows directly to Lake Washington, the main drinking water reservoir for the City of Newburgh. In 2016, the lake was found to contain PFOS levels more than double the EPA’s current advisory limit. The base is home to the New York Air National Guard’s 105th Airlift Wing. For years, the base served as a training ground for firefighting with aqueous film forming foam (AFFF) containing PFOS, which was banned for most uses in the early 2000s. According to the DEC, an accidental release of 4,000 gallons of the fire foam occurred at the air base in 1990 and a major fire took place at the base in 1996. Along with smaller releases of fire foam, both incidents are believed to be major contributors to contamination at the base, declared a state Superfund site in 2016. The report states PFOS and PFOA were also found above the EPA health advisory limit at a nozzle testing area, the base’s current fire station, former fire station, a retention basin that receives runoff from several hangars where fire foam releases were documented, and two storm water outfalls emptying into Recreation Pond. The DEC identified these polluted sites in 2016, but their test results were not enough to motivate the Department of Defense, which insisted on doing its own investigation, to take action to remediate polluted locations on the base. Perfluorinated chemicals continue to flow from the pond into the local watershed. State officials appeared unimpressed by the report this month, saying it doesn’t do enough to address the contamination at the base or in the watershed. “While we are still reviewing this report, it’s clearly just another case of ‘too little, too late,’ and falls well short of the comprehensive investigation that is needed to fully identify the scope and extent of the contamination and advance cleanup measures to stop the flow of contamination emanating from the base,” DEC Commissioner Basil Seggos stated last week. “DoD has wasted the last two years confirming what we already know from the state’s investigation in 2016. It’s time for DoD to get serious and begin taking actions to clean up their mess.” The report makes no direct reference to steps for cleanup or remediation. However, it does recommend continued evaluation of surface and groundwater PFAS at Recreation Pond and outfalls to and from the pond. The report also recommends monitoring PFAS migrating from the former base landfill and other areas identified with elevated levels of the chemicals. Prepared by Amec Foster Wheeler Environment and Infrastructure Solutions, the report details results from tests carried out by consulting engineers in 2016 and 2017.

BY SHANTAL RILEY sriley@tcnewspapers.com