EPA to Continue Soil and Groundwater Cleanup at the Cinnaminson Groundwater Contamination Superfund Site in NJ

NEW YORK – The U.S. Environmental Protection Agency (EPA) has finalized its plan to address the soil and groundwater contamination associated with an industrial property within the Cinnaminson Groundwater Contamination site. The contaminated groundwater is also a source of chemical vapors potentially entering homes and businesses in the Townships of Cinnaminson and Delran, N.J.

“EPA will remove the contaminated soil – which is contaminating groundwater – and will treat that groundwater to reduce contaminants that are also causing harmful vapors that can get into buildings,” said EPA Regional Administrator Lisa F. Garcia. “EPA is committed to delivering a long-term cleanup solution, and today’s decision brings us one step closer to delivering on that promise.”

EPA’s finalized plan calls for removing contaminated soil and replacing it with clean backfill. The plan includes a groundwater cleanup technique called in-situ chemical treatment, where chemicals are injected into the area with the highest amount of contamination to break down and decrease the contamination over time. The contamination in the soil and groundwater is causing harmful vapors to enter some homes through a process called vapor intrusion. EPA will continue to investigate vapor intrusion and address it where it is found by installing specialized vapor mitigation systems, similar to radon systems, in homes. EPA is also monitoring the groundwater in the long term to ensure the cleanup is working as intended. Residents don’t drink contaminated groundwater but get their drinking water from a private water company.

The Cinnaminson Groundwater Contamination Superfund site is located in the Townships of Cinnaminson and Delran in Burlington County, N.J. The site covers approximately 400 acres and includes residential properties, light to heavy industrial properties and historical landfill properties. During an investigation as part of a closure plan for the landfills by the state in the early 1980s, the New Jersey Department of Environmental Protection discovered soil and groundwater contaminants, including trichloroethene (TCE), cis-1, 2-dichloroethene (cis-1, 2-DCE), benzene and arsenic.

EPA placed the site on the Superfund National Priorities List in 1986. Due to the nature and complexity of the contamination at the Cinnaminson Groundwater Contamination Superfund site, the investigations and cleanup of the site have been conducted in four phases, otherwise known as Operable Units. This final cleanup plan focuses on Operable Unit 3, which includes the soil and groundwater contamination associated with an industrial property located on the northwestern part of the site and the vapor intrusion in nearby residential developments.

On August 1, 2022, EPA released its proposed cleanup plan to the public and held a virtual public meeting on August 10, 2022, to explain the plan and take comments. The Record of Decision released today addresses the comments received during the public comment period and formalizes EPA’s selected cleanup plan.

Visit the Cinnaminson Groundwater Contamination Site profile page for additional background and to view the Record of Decision. 

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