Source: https://www.lohud.com, February 1, 2018
By: David McKay Wilson
Westchester has discovered groundwater contamination at the county airport, with officials suspecting it was caused by chemicals used in firefighting foam decades ago.
Preliminary results from one monitoring well, located near a former Air National Guard septic field, found contaminants in concentrations that were 14 times the limit set by the US Environmental Protection Agency health advisory.
The airport borders the Kensico Reservoir, which provides drinking water to New York City and some Westchester residents. Most residents in nearby Greenwich, Connecticut, get their water from reservoirs in town managed by Aquarion Water Co., although some rely on private wells.
Tests of the Kensico Reservoir have found no evidence that the contamination has seeped into the water supply, a state official said.
“We had a few high hits on some wells,” said Vincent Kopicki, the county’s commissioner of public works and transportation, at the Jan. 24 meeting of the county Airport Advisory Board.
The contamination was detected at a well just north of the airport in July 2017, which led to testing of wells across the airport property. Samples taken in November found contamination at the airport, with the public notified of the findings at the Jan. 24 meeting of the Westchester Airport Advisory Board.
Investigators want to determine which direction the contamination is flowing — to the west toward the Kensico Reservoir, or to the southeast, toward public wells in Greenwich.
The EPA sets safe drinking water standards of 70 parts per trillion. One well found concentrations of 990 parts per trillion, said Sean Mahar, the state Department of Environmental Conservation’s assistant commissioner for public affairs. Those results are now being validated by another company, he said.
The chemicals detected were perfluorooctane sulfonic acid, known as PFOS, and perfluoroalkyl substances, known as PFAS. They are the same chemicals that put Stewart International Airport on the state Superfund list in 2016. Readings as high as 5,900 parts per trillion were detected at Stewart, which is near the public drinking water supply for the city of Newburgh.
Health effects of the chemicals include developmental effects to fetuses during pregnancy or to breastfed infants, testicular or kidney cancer, liver damage, or effects to the immune or thyroid system, according to the EPA health advisory.
The chemicals are man-made substances, used in many manufacturing processes, which are persistent in the environment, and in the human body. PFAS are used in non-stick cookware, stain-resistant clothing and carpets, shoes, mattresses and to fight fires on airfields where petroleum-fueled fires are a risk.
The wells were located in the center and north of the airport property.
The discovery was made by the state Department of Health as part of Gov. Andrew Cuomo’s Water Quality Rapid Response team, which began in 2016 after the contamination was discovered at Stewart.
The first detection — at 96 parts per trillion — was made at a well serving an office building at 1-3 New King Street in North Castle, which lies just north of the airport, and across Interstate 684 from the Rye Lake section of Kensico Reservoir, said Mahar.
Due to the likelihood that the contamination migrated from the airport, the state DEC ordered Westchester to install an activated granulated carbon filter system at the office building and to provide bottled water until the system was in service, according to a letter issued on Aug. 18, 2017.
The inspection program will include wells at residences, businesses and schools near the airport. Connecticut health and environmental officials were also notified. The Brunswick School, a private high school located off King Street in Greenwich, was also notified.
Brunswick spokesman Dan Griffin declined comment.
Though phased out in 2002, PFOS was a key ingredient in firefighting foam used at Stewart Air National Guard Base for emergency response and in training exercises.
Westchester County Airport was built in 1942 as a home to the Air National Guard during World War II. The Air National Guard left the airport site in 1983.
Westchester on Nov. 15 tested the groundwater at the airport, using eight wells, between 13 and 52 feet below ground, which were part of the county’s groundwater monitoring program, from 2001 to 2011. The administration of former County Executive Rob Astorino discontinued the program.
Jonathan Wang, of Purchase, who heads Citizens for a Responsible County Airport, has urged Westchester to resume its groundwater testing program.
“The groundwater monitoring program never should have ended,” Wang said. “If you don’t find anything, it doesn’t mean you stop testing. In this case, you have chemicals that they didn’t test for in the past.”