Fire-suppression system at battery plant is main cause of toxic plume, DEC says

A fire-suppression system inside a battery storage plant in East Hampton has been preliminarily identified by New York State as the primary cause of a toxic groundwater plume detected in public water wells as far as 2,500 feet away, officials said Thursday.

The findings, presented by the state Department of Environmental Conservation, confirm in part what some have suspected for years since the May 2023 fire at a battery storage plant on Cove Hollow Road.

In a preliminary report released Thursday, the DEC said it found concentrations of the forever chemical known as PFPrA as high as 10,000 parts per billion just south of the plant — considerably higher than Suffolk County well tests that showed a high of 1,170 parts per billion. A state screening level for the toxin by the state Department of Health is 3 parts per billion.

"The big lesson learned here is this isn’t about batteries but a fire suppression system that is not unique to batteries," DEC commissioner Amanda Lefton said in an interview Thursday. The DEC is completing its investigation and expects to have a final report out in the fall.

The exact cause of the thermal runaway battery fire hasn’t been released, and there were three other fires in the state in 2023 that led to the formation of a state task force to examine the causes as Gov. Kathy Hochul led a plan to double the state’s mandate for battery storage plants to 6,000 megawatts by 2030. Another fire took place at a facility in December, a month before a new fire safety code for the batteries was implemented.

At the NextEra/National Grid-owned battery in East Hampton, a fire-suppression system known as NOVEC 1230 was used in combination with an internal sprinkler system to fight the May 31, 2023, fire, the DEC said. Some 5,000 pounds of the NOVEC gas were used in the effort, the DEC said it was told by NextEra. The combination of the gas and the more than 1.4 million to 2.2 million gallons of water created the PFPrA, according to the DEC’s preliminary report.

Lefton emphasized that tests thus far have not shown  the plume is impacting 27 private drinking water wells in the area, though four Suffolk County Water Authority wells 2,500 feet away have been affected. The authority, which discontinued use of the wells, has sued the plant owners.

Asked how the DEC could be sure constituents in the lithium-ion batteries themselves may have tainted the water, Lefton noted only 0.04% of the batteries in the plant burned, and the DEC soil tests showed little evidence of heavy metals from the batteries.

"We did not find any traces of heavy metals," she said.

NextEra didn’t immediately respond to a request for comment, but in response to Newsday questions last month said it "remains committed to transparency, scientific rigor, and community safety, and we will continue to work with local authorities."

Andy Guglielmi, director of environmental remediation at the DEC, said the agency is working on a remediation plan and expects to hold a public meeting sometime in the fall after the full investigation is complete and a report on the plume finalized.

Lefton said the 3M-made fire suppression system has been discontinued, but it’s unclear whether that system remains in place in the rebuilt East Hampton battery or another owned by NextEra and National Grid in Montauk. Lefton said the state has confirmed the system was not used in other plants across the state that experienced fires.

While acknowledging much investigative work remains to be done, Lefton stopped short of saying the East Hampton plant should be shut down until a full investigation is completed, as others have requested.

East Hampton Village Mayor Jerry Larsen and Suffolk County Executive Edward P. Romaine have called for the plant to be shut down until the probe is complete and containment and other protections built around it.

Romaine, who has supported battery storage systems in the past, said the recent experience with the East Hampton plant shows the state "needs to get up to speed with better regulations" for the plants. He criticized the DEC for not testing the water directly after the fire and noted, "Firefighters fought this blaze for 30 hours. Did anyone think to test the air?"

The DEC said such air tests after a fire aren't part of its protocol.

Lefton said new battery system designs are more modular and containerized, vastly limiting the impact of any fire.

"Industry standards have moved beyond these kinds of suppression systems," she said, noting the "most effective way is really to let the batteries themselves burn out or otherwise engulf them with water." She noted the industry also has "moved beyond" enclosed battery designs.

Gerald Turza Jr., an administrator for the East Hampton Village Fire Department who battled the 2023 blaze, said the mayor "wants this plant shut down until we can get a full comprehensive analysis and know what safeguards are in place."

Turza noted the department received an alarm at the facility on Aug. 21, and was told by NextEra they believed it was a false alarm.

"But they never called us back" to confirm that, he said. And NextEra still hasn’t responded to a  fire department request for air tests during and after the fire, he said.

Turza said the new protocol of allowing battery plants to simply burn themselves out in the event of a fire could have drawbacks.

"Letting it burn sounds like a good plan until it’s not a good plan," he said.

By Mark Harrington

mark.harrington@newsday.comMHarringtonNews

Mark Harrington, a Newsday reporter since 1999, covers energy, wineries, Indian affairs and fisheries.