The firefighting foam believed to be the cause of well contamination south of the Martha’s Vineyard Airport is a newer version of a foam used for decades to extinguish flammable liquid fires.

Leaders at the Martha’s Vineyard Airport said immediate steps are being taken to address hazardous chemicals that have turned up in groundwater monitoring wells and some residential wells near the airport.

At a packed meeting Monday, leaders at the Vineyard airport and their environmental consultant sought to allay concerns following the disclosure that contaminants have been detected in private wells.

The Martha’s Vineyard Airport is providing bottled water for some West Tisbury residents as a precaution after hazardous chemicals were detected in groundwater at and around the airport this week.

Legal spending is on the rise at the Martha’s Vineyard Airport, much of it due to ongoing litigation with the former owner of Airport Mobil.