Cleanup plan for 1,4-dioxane and PFAS at former Kings Park landfill

State officials unveiled a plan to remediate contamination at the former Steck and Philbin landfill in Kings Park, including a system to treat 1,4-dioxane and PFAS detected in groundwater on-site, officials said.

The state Department of Environmental Conservation had been studying the extent of contamination at the  25.4-acre property on Old Northport Road. Last year, the DEC and state health department determined the site "poses a significant threat to public health or the environment," according to a department fact sheet.

The site is a "brownfield property," part of a state program that manages the cleanup of contaminated properties to be developed for future use.

State officials said they are concerned about landfill contaminants migrating into the groundwater. Cox Brothers LLC, which is hoping to redevelop the property into a warehouse, prepared the remediation plan. The DEC is reviewing the company's proposal.

Smithtown Supervisor Ed Wehrheim said the town will review the plan and issue its own recommendations to the DEC. Wehrheim said he hopes the plan is effective in treating the groundwater and other public health hazards.

"I think it's important to make sure that the groundwater is safe for aquifer purposes, since that's our sole source of drinking water," Wehrheim said.

 Exposure to PFAS has been linked to deadly cancers, developmental damage to infants and children, as well as liver and heart damage, according to the U.S. Environmental Protection A gency.

The EPA has deemed 1,4-dioxane as a likely carcinogen. Manufacturers have used the chemical for decades as an industrial solvent and in adhesives, such as ink and spray polyurethane foam. The DEC said PFAS and 1,4-dioxane were "present site-wide in groundwater" at the former landfill, as was landfill gas.

The landfill closed in the early 1990s. The Suffolk County Legislature approved the sale of the landfill and a nearby tire dump to Cox Brothers in 2019. The company wants to build a warehouse and office space on the property, as well as a construction yard with repair garages, records show. Cox Brothers did not respond to requests for comment.

The plan calls for installing a groundwater extraction and treatment system to remediate PFAS and 1,4-dioxane in the groundwater. Contractors will build two extraction wells as well as a pump station house. 

Also, an off-site recharge basin will be built to collect treated groundwater and stormwater runoff. The developer will close and remove any underground storage tanks and install a landfill gas collection and venting system. Contractors will also regrade the site and install a 40-millimeter liner over the former landfill.

The public has until Oct. 15 to comment on the plan.

Michael Rosato, president of the Kings Park Community Association, said the EPA should declare the property a federal Superfund site "so it's properly cleaned up." Rosato said he was also concerned about how the cleanup may affect residents in a nearby neighborhood on the north side of the former landfill.

The federal designation allows the EPA to develop a long-term plan for cleaning up contaminated sites and requires the parties who polluted the site to perform or pay for the remediation.

Suffolk Legis. Rob Trotta (R-Fort Salonga) said he is concerned about the health of the nearby residents. He said he plans to monitor the cleanup closely.

"I’ll be keeping an eye on [the cleanup] to make sure it’s done properly," Trotta said.

Suffolk County Executive Edward P. Romaine said in a statement that while the county has no role in the cleanup, he expects the process to follow state guidelines.

"Anytime a brownfields site is remediated, it is a good day for the community and a great day for the environment," Romaine said.