Updated 8:45 pm
Test results from additional private wells show that only one of them showed contamination from per- or polyfluoroalkyl substance (PFAS) above the state’s health advisory.
In results released Tuesday, Ron Myrick of the town’s consultant Tetra Tech, wrote that results from eight additional private wells were received from samples taken Dec. 3. Of those, one sample exceeded the 70 parts per trillion for PFAS, the advisory level. That sample in a private well at a home near Edgartown–West Tisbury Road was 245 ppt, he wrote: “Based on the results of the sampling to date, an apparent preliminary trend of decreased PFAS concentrations with increased distance from Edgartown–West Tisbury Road in the target investigation area south of the Martha’s Vineyard Airport has been documented.”
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.
The testing has centered on the neighborhood directly south of the airport in West Tisbury, off Edgartown–West Tisbury Road. Waldrons Bottom 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.
On Thursday, Gerard Martin, southeast regional director for the Massachusetts Department of Environmental Protection (MassDEP), is attending the airport commission’s meeting at 2 pm at West Tisbury Public Safety Building on State Road. At the meeting, Martin will be available to update the commission on the situation and to answer the public’s questions.
Last Friday, The Times got a rare look at the testing as a technician from Tetra Tech visited the home of a Times employee. In keeping with the airport and consultant’s efforts to keep testing sites confidential, The Times won’t reveal the name of the employee or owner of the property.
The technician took the samples from the home’s holding tank in the basement. Initially, five gallons of water were drained from the tank in order to get a fresh sample from the well.
The technician, wearing gloves, filled two small plastic containers, which will be sent to Alpha Analytical, where results are expected to take about two weeks.
The entire process took about 15 minutes.
The airport has committed to having Tetra Tech test wells in the area south of the airport. If elevated levels of PFAS are found, bottled water is being supplied.
Approximately 25 private well water samples were collected on Friday, and another 25 to 30 private well water samples will be collected on Thursday, Myrick wrote. Specific results will be shared with homeowners, and range of detections and general trends will be shared with the public, he wrote.
Updated to include new results. -Ed.