Updated at 5:30 pm
More than 50 people, some of them standing along the back wall, packed into the Public Safety Building in West Tisbury Thursday afternoon to hear an update on the status of per- or polyfluoroalkyl substance (PFAS) testing of private wells near Martha’s Vineyard Airport.
PFAS is a chemical used in firefighting foam, which the airport is required to use by the Federal Aviation Administration to deal with aircraft fires.
The briefing was held in West Tisbury to give residents affected by the contamination better access to the meeting. Gerard Martin, southeast regional director for the Massachusetts Department of Environmental Protection (MassDEP), was on hand to give a presentation on what the compounds are and to answer questions.
“It’s a very persistent chemical,” Martin said. “When it gets into the environment, it doesn’t break down.”
The airport investigation began last spring, and in July elevated levels were found in samples taken on airport property.
Brock Callen, a resident of West Tisbury, criticized airport officials for being slow to report those July results publicly. “It is somewhat frustrating that six months went by before anything was known by the public,” Callen said.
Those concentrations were more than 1,000 parts per trillion, which is well above the 70 ppt that’s been set by MassDEP as a health advisory.
Long after the crowd left, airport commissioners mostly applauded the response to this environmental crisis by airport management, but commissioner Richard Knabel said the airport needs to answer that question for the public.
Two weeks ago, airport officials announced three positive results for PFAS in private wells in a neighborhood south of the airport, which launched a more aggressive investigation of sampling.
Earlier in the meeting, Martin said PFAS affects thyroid, liver, kidneys, hormone levels, and immune systems. PFAS is also a suspected carcinogen with long-term exposure, he said.
Martin stressed that it’s long-term consumption of contaminated water that makes PFAS a concern. Bathing in the water is not an issue, he said in answering a question posed by a woman.
“An important note about consuming water with PFAS in it is it doesn’t always mean there’s going to be a health effect. The degree of risk depends on how long you’ve been exposed to PFAS, the duration, and what the concentration is,” Martin said. “And when we try to come up with these numbers we use very, very conservative calculations to determine that. We look at it as if you’re drinking 2 liters of water every day, same concentration, for seven years — 30 years for cancer.”
Thus far, samples taken from private wells have shown a mixed bag. A total of 18 samples have been tested, with seven of them above 70 ppt, Ron Myrick, an environmental engineer with Tetra Tech said. Tetra Tech is the airport’s consultant on the project.
Earlier this week, results from eight additional private wells were released, which showed only one above that guideline. That sample, taken near Edgartown–West Tisbury Road, was 245 ppt.
Previous testing showed levels of PFAS from undetected to 1,358 parts per trillion (ppt), with six over the standard of 70 ppt. Tetra Tech has since tested dozens more wells, and is awaiting the results, which can take up to two weeks, though the lab has expedited results.
In cases where elevated levels have been found, the airport is supplying bottled water.
“We’re still at the very beginning of this one, and trying to figure out how widespread the problem is,” Martin said. This is not going to be cleaned up in a year, he said.
“We are aggressively testing,” Myrick added later when it was his turn to present.
Martin said are ways to mitigate the exposure through carbon filters.
Myrick repeated what he said when the contamination became public, that it will take time and more data to determine the best long-term solutions. “You need to do it right, otherwise you’re throwing money at solutions that don’t effectively solve the issue,” Myrick said.
The airport has also started testing the firefighting foam using a containment system.
The testing has centered on the neighborhood directly south of the airport in West Tisbury, off Edgartown–West Tisbury Road. Waldrons Bottom Road, Vineyard Meadow Farms Road, Charles Neck Road, Joe Walker Road, and Coffin Fields Road are among the roads where testing has either been done or requested.
More than 100 homes in the neighborhood received letters two weeks ago alerting them to the results and the ongoing investigation.
“How do you develop the confidence that this is the proper study area?” Chris Pettit of West Tisbury asked. “How do we know it hasn’t gone beyond this study area?”
Myrick said samples are also being taken east and west of the main investigation area to get a handle on migration. “We want to see strong evidence it’s not beyond there,” he said.
Approximately 25 private well water samples were collected on Friday, and those results are expected Monday, and another 25 to 30 private well water samples were being collected on Thursday and should be returned by Dec. 21, Myrick said. Specific results will be shared with homeowners, and range of detections and general trends will be shared with the public, he wrote.
All of that testing comes with a price. Later in the meeting, the airport commission authorized a new contract for Tetra Tech for $105,000. That money will take the investigation through the end of January, Ann Richart, airport manager, said.
Several commissioners urged Richart to seek federal assistance with the money needed for the testing.
“This is really hitting us significantly,” Robert Rosenbaum, chairman of the airport commission, said.
During his presentation, Martin again pointed out that the airport was under no obligation to do this testing, but began the investigation on its own. “Tough situation, but they are doing a good job,” he said. “Good things are happening with bad situation.”