But residents said they were not confident that a cap at the site would provide long-term health protection for the 1.7-square-mile borough or for neighboring Vineland, where a small part of the property sits.
The West Boulevard facility manufactured metals and alloys from the 1950s until 2006, and has been on the federal Superfund list since 1984. Past efforts to clean the site include a groundwater pump-and-treat system and the removal of storage tanks.
The EPA gained oversight of the facility from the state in 2010. It seeks to place a one- or two-foot cap over a 1.3-acre storage area, remove 9,800 cubic yards of sediment from the Hudson Branch of the Maurice River, and limit future use of the area to commercial purposes.
Loretta Williams, 71, who lives near the site on Oakwood Drive, said businesses would not be interested in moving to a site with contamination lurking below.
"If that stuff was not there, the borough would be able to" lure a business, said Williams, a longtime advocate for the site's cleanup. "With their alternative, that's not possible."
Michael Sivak, an EPA representative, said the agency "concluded that a reasonably anticipated future land use" would be commercial or industrial.
Residents said they supported an alternative plan that includes excavating the soil where the cap is proposed. It would cost twice as much, according to agency documents.
"I don't want anything left here," Williams added.
The EPA estimates that 56,000 people live within two miles of the plant.
Aside from the proposal, which is under a comment period until July 28, other aspects of a cleanup remain uncertain. The extent of perchlorate contamination is still being studied and would need to be addressed separately, the EPA said.
Perhaps the biggest question is which agency will regulate more than 75,000 cubic yards of radioactive slag - a by-product in the metal-making process - left separate from the Superfund site. Oversight has bounced between the U.S. Nuclear Regulatory Commission and the state Department of Environmental Protection.
Most recently, Shieldalloy, which has proposed capping the waste, has asked a federal court to remand authority back to the NRC.
"A change of regulator would result in years of wasted effort and disrupt the decommissioning process," Noah Lichtman, a company spokesman, said via e-mail.
A DEP spokesman said that the department currently oversees the slag and that the NRC supports that arrangement. Oral arguments are set for September.
State officials have long said they want the radioactive materials to be shipped to a facility authorized to handle such waste, possibly in Utah, but the company has said that measure would prove too costly and has argued that a cap would be sufficient and the "safest solution."
U.S. Sen. Robert Menendez (D., N.J.) said in a statement Wednesday night that he was pleased to hear about the EPA's remediation proposal, but that the radioactive waste still needs to be dealt with.
"This announcement does not end the nightmare for the residents of Newfield," he said.