The site was placed on the national Superfund list in December 1994 because of concern about contamination to groundwater, a source of drinking water, an EPA news release said.

Officials discovered contamination from sampling of the Kunia Well in 1980 and the Environmental Protection Agency was informed of an accidental spill of ethylene dibromide in April 1977 within 60 feet of the well. The Kunia Well was immediately disconnected from the drinking water supply system when the contamination was discovered and is no longer being used, the news release said.

Under the terms of an agreement with the EPA, Del Monte Fresh Produce will carry out the cleanup plan, estimated to cost approximately $13 million with a completion date expected in 2014. The company has also agreed to pay the EPA's past and future oversight costs at the site, the news release said.

Cleanup of shallow groundwater at the site has started by using koa haole plants in a process called phytoremediation, the release said. The deep groundwater in the area will be pumped and cleaned using air stripping and carbon filters. The cleanup will also restrict land use to prevent exposure to the contaminated groundwater and prevent activities that might interfere with the effectiveness of the cleanup.