Phase two of cleanup began at Bethpage Community Park on Wednesday, kicking off a months-long process of removing contaminants from deep soil at the former Grumman Aerospace landfill.

The technique, called thermal remediation, uses electric currents to heat metal rods drilled into the ground to evaporate contaminants and water in the soil. Vacuum suction then draws the contaminants into a surface treatment system before the cleaned air is released, officials said.

Grumman, the aerospace giant, used the 18-acre park as a chemical waste dump before turning it over to the town of Oyster Bay in 1962. Northrop Grumman, its corporate successor, is responsible for cleaning up the contaminated site. The field was built over a solvent-soaked rag tank and a sediment settling pond. The park was closed to the public in 2002 after toxic industrial compounds were discovered there.

Thermal remediation had been planned since 2013, years before contractors discovered 22 concrete barrels of chemicals beneath the park this spring. The first phase of cleanup began in 2020 and has lasted nearly two years.

The thermal solution was turned on Wednesday, said Patrick Foster, deputy commissioner of the state Department of Environmental Protection. He called the move “an important milestone in the final cleanup of Bethpage Community Park.”

Thermal remediation is expected to take about eight months, according to the DEC, which is overseeing the cleanup work conducted by contractors from Northrop Grumman.

Oyster Bay city officials are skeptical of Northrop Grumman’s plan and have called for a full excavation of the park’s contaminated soil. Last week, city officials urged Northrop Grumman to postpone thermal remediation out of concerns it could slow soil investigations.

Oyster Bay Superintendent Joseph Saladino said in a statement that “Grumman has a much higher standard to prove to the public that it is serious about fully remediating the park.”

The statement continued: “They still have a lot to achieve.”

Phase One

The contractor dug a total of 385 wells over a three-quarter-acre area, from the park’s tennis courts to the soccer field, officials said.

Jason Pelton, DEC project manager, said 261 of those wells will heat the soil. The remaining wells will capture contaminated steam.

The first phase of thermal remediation began at the park’s baseball field in 2020 after delays, Newsday reported. Metal rods were dug about 35 to 45 feet into the soil. The process removed more than 1,500 pounds of soil contaminants from August 2020 through May 2022, according to the DEC.

The second phase will dig deeper underground — up to 60 feet below the surface, the DEC said. The third phase of thermal remediation will eventually include areas beneath the park’s parking lot.

In late March, a Northrop Grumman contractor constructing thermal wells discovered a layer of six barrels embedded in concrete buried underground on the park’s baseball field.

Ultimately, a total of 22 barrels containing toxins were discovered and removed.

The problem of shallower soil

Last week, Oyster Bay sent a letter to Northrop Grumman demanding a postponement of its thermal remediation plans. The city wants the company to develop a plan to clean up the park’s shallower soil, which contains polychlorinated biphenyls, or PCBs. The city sued Northrop Grumman in federal court last year over the pace and scope of the cleanup.

Heat treatment “will inevitably delay further investigation,” Russell Selman, an attorney representing the city, wrote in an Aug. 28 letter to Northrop Grumman.

“Grumman’s failure to fully investigate, characterize, and address the environmental issues at the Park has deprived the City of its ability to fully enjoy the Park for far too long,” the letter reads.

Northrop Grumman did not respond to a request for comment on the letter.

DEC said in a statement that while thermal remediation is underway, “Northrop Grumman will develop plans to excavate soil containing PCBs and metals from the former Grumman settling area and dispose of it off-site.”

Thermal remediation is a “proven, safe, and scientifically sound method that has successfully removed thousands of pounds of contaminants from the park,” the DEC said in a statement.