The chemicals appeared to have been migrating slowly from the patch of land toward Caulfield Avenue, but have been contained, said John Malkin, principal environmental specialist for the DEP. Cleanup of the groundwater has begun, he said.
Malkin emphasized that while the chemicals needed to be cleaned up, the public was in no immediate danger of ingesting them. The groundwater, about 10 feet below the surface, had not seeped into the township's water source, he said.
The soil at the eight-acre site was contaminated by volatile organic compounds, which may have come from solvents used to degrease ovens at restaurants. The former owners of the land collected garbage from hotels and restaurants to feed their hogs, and DEP officials speculated that toxic residue could have accumulated, without the owners' knowledge, from the grease and trash dumped in the yard.
Some of the compounds found at the site included a group of chemicals known as TCEs. According to the federal Environmental Protection Agency, TCEs are irritants and possible cancer-causing agents.
The farm was first cited for dumping violations in 1976 by the Gloucester County Board of Health, Malkin said. According to DEP records, inspections in 1984 showed evidence of soil and water contamination. Soil excavations began two years later, and by 1994 the DEP had ruled that the soil contamination had been removed.
But groundwater contamination remained, Malkin said.
He characterized the contamination as "pretty bad." One chemical, called trichloroethylene, was found in a concentration of 110,000 parts per billion. Federal regulations allow one part per billion.
Residents could be exposed to the harsh chemicals only if the water seeped outside the contained area or if new wells were dug at the site, Malkin said.
There are no plans to dig wells at the site, township officials said.
Jack Sheppard, trustee for the site, declined to comment about remediation efforts.
Craig Stevens, a technical consultant for the contractor that Sheppard hired to clean the site, said everyone involved was "only trying to do the right thing."
His firm, Construction Services International of Pennsylvania, has begun interim testing that would determine the best method for final cleanup.
The process, he said, could take years and cost tens of thousands of dollars.
The DEP oversees remediation, but landowners pay for cleanup costs.
According to Jeff Weinflash, an attorney for K. Hovnanian Cos. of Edison, N.J., which built Locust Grove, several residents contacted the property managers with concerns about the water-testing equipment behind their homes.
All prospective home buyers were notified about soil cleanup efforts behind their homes in the public-offering statements, he said. Those documents are available for inspection in the Locust Grove sales office, he said.
Weinflash said that the state had not notified the builders of the water-cleanup efforts and that he did not know whether current or new residents would be notified.
State laws require residents be notified only if they could be affected by contamination.