The D'Imperio Property is a 15-acre undeveloped site in Hamilton Township, New Jersey. About one acre was used as an unauthorized dump in the mid-1970s, where partially buried and ruptured metal drums left behind metals and volatile organic compounds, including solvents. The site was added to the EPA's National Priorities List (NPL) in September 1983. It remains on the NPL today, with physical construction of the cleanup complete but some goals and required controls still to be finalized.
Eleven contaminants have been identified in groundwater across the site. These are 1,2-dichloroethane, 2-butanone (methyl ethyl ketone), arsenic, benzene, chromium, ethylbenzene, lead, tetrachloroethene, toluene, trichloroethene, and xylene. Groundwater contamination affects two aquifers. About 6,000 people within three miles rely on groundwater for drinking, and twenty private wells sit within one mile of the site.
Cleanup work started in 1987 with the removal of 82 buried drums and 3,900 cubic yards of contaminated soil. A groundwater pump and treatment system has been fully operational since August 1997. In 2004, a soil vapor extraction (SVE) system was added to tackle remaining contaminated subsurface soils. That system was expanded in 2022 with five additional deeper wells. As of February 2025, only four areas still show residual soil contamination above performance standards, meaning most soils have been cleaned up. Both systems continue to operate and are monitored monthly, with soil and groundwater monitoring wells sampled twice a year.
A Conditional Exposure Assurance (CEA) restricts the installation of potable wells near the groundwater plume. A fence limits access to contaminated soil on the property. EPA has determined that human exposure is currently under control and that groundwater migration is stabilized. The most recent five-year review, completed in August 2024, confirmed that both treatment systems continue to reduce contamination and meet performance criteria. Operation and maintenance activities are estimated to continue through July to September 2028.
Community members who want to review site documents can visit the Hamilton Township Clerk's Office in Mays Landing or the EPA's Superfund Records Center in New York City. The site's Community Involvement Coordinator, Shereen Kandil, can answer questions by email or phone. The Remedial Project Manager, Michael Zeolla, handles technical matters and is also reachable directly.
