Treatment Plant Construction Coming To Washington Superfund Site

WASHINGTON, NJ - Federal officials are slated to build a new groundwater treatment plant and install new wells to clean up a superfund site in Chester and Washington Townships.

The U.S. Environmental Protection Agency has already set up shop at the Combe Fill South Superfund Site, a longtime inactive municipal landfill, to prepare operations to extract contaminated groundwater, Washington Township officials said.

A solar panel developer has purchased the site and plans to install solar panels on the landfill when the cleaning process is completed.

Demolition of the site is scheduled to begin this summer before the treatment facility is constructed. The work is expected to be completed by fall 2024.

Residents can expect noise, vibrations and increased traffic in surrounding roadways during project work, officials said.

“Some site workers may be dressed in protective clothing to keep contaminated soil off their clothes and may wear dust masks during the work at the site, but this does not indicate a risk to the surrounding residents,” township officials said.

The site was used as a municipal landfill from the 1940s until 1981 and was licensed to accept domestic and non-hazardous industrial wastes, sewage sludge, septic tank wastes, chemicals and waste oils.

The Combe Fill Corporation bought the landfill in 1978 and began accepting pharmaceutical waste and organic waste drums, cleared forested wetlands for additional landfill space and allowed exposed waste to enter bedrock fractures, which contaminated the groundwater with 1,4-dioxane, officials said.

In September 1981, the New Jersey Department of Environmental Protection issued an order for the site to stop landfilling due to groundwater contamination; site investigations started in 1983. The EPA placed the site on the National Priorities List in 1983.

Both the EPA and NJDEP addressed the contamination in 1986 by providing an alternate water supply system for affected residents, covering the landfill to prevent rain contamination, treating the groundwater, collecting landfill gas and leachate, and controlling stormwater runoff, federal officials said.

The EPA finished constructing the landfill cap and groundwater extraction and treatment system in 1997. The agency routinely samples the landfill and, in 2009, 1,4-dioxane was detected in groundwater located under nearby properties.

A waterline to residential properties affected or threatened by groundwater contamination was installed in 2015.