High levels of a potential carcinogen have been found in groundwater in Bethpage near a former naval industrial site, and local water districts worry that public-supply wells could be affected.
The toxic waste, an industrial solvent called trichloroethylene, or TCE, has been found in groundwater under and around the former defense plant that once housed Northrop Grumman and U.S. Navy operations.
While the Navy has been monitoring groundwater and treating it to remove TCE, new results this year from a monitoring well the Navy installed north of Hempstead Turnpike show TCE levels as high as 4,600 parts per billion in groundwater hundreds of feet below the surface.
"We've never seen a groundwater concentration this high," said Rich Humann, president and CEO of H2M, an engineering firm retained by several water suppliers, including the Bethpage Water District.
The Bethpage district has a drinking-water well 1,700 feet away from where the elevated TCE levels were found, he said, prompting concerns that the spike could find its way into that well.
Water suppliers must treat drinking water to no more than 5 parts per billion of TCE. Bethpage treats to levels that are undetectable, Humann said.
The Navy plans to investigate the elevated levels, which were detected in March and reported to the state in August, an official said at a Wednesday public meeting in Bethpage hosted by the Navy.
The investigation will focus on whether the high levels are due to a failure of the existing treatment system or a new finger of contamination, and the solution will involve either adding new removal systems or additional treatment wells, said Lora Fly, remedial project manager for the Naval Facilities Engineering Command, the entity overseeing the Navy cleanup.
The Bethpage site has two plumes of contamination -- a shallow one found in 1986, and a larger, deeper one discovered in 2009 under Bethpage Community Park, where Grumman had legally dumped chemicals decades ago. The Grumman facility used TCE, among other chemicals, in its operations.
The state Department of Environmental Conservation has written a letter to the Navy regarding the findings, said Jim Harrington, director of the state Division of Environmental Remediation bureau that covers Long Island.
"We expect them to do some action with these spots," Harrington told water district officials and residents at the Wednesday meeting.
The discovery has local water districts -- which use expensive systems to treat groundwater to make it safe before it is delivered to the public -- concerned about the future.
Bethpage will likely have to alter its engineering plans for advanced treatment systems to account for the additional contamination, Humann said.
"If the hot spot isn't addressed and continues to move, it's going to impact other water suppliers," he said.
That list includes several districts south of the area, including the Massapequa Water District.
"The concentrations are increasing as they go further south, and we are very alarmed at that," Massapequa's superintendent Stan Carey said at the meeting. "We're still pushing to have this thing contained. There are at least a dozen more public-supply wells that could be contaminated as this thing moves south."Sen. Charles Schumer (D-N.Y.) said he plans to monitor the situation closely.
"I will keep holding the Navy's feet to the fire to ensure that monitoring and remediation continues," he said.