CHICAGO (CBS) — After nearly 30 years of legal wrangling and cleanup efforts, one of the most polluted sites on Lake Michigan has been declared safe.

WBBM Newsradio’s Mike Krauser reports U.S. Senators Mark Kirk and Dick Durbin joined Gov. Pat Quinn, other elected officials, activists, and U.S. Environmental Protection Agency Regional Administrator Susan Hedman to celebrate the $150 million cleanup of a Superfund site in Waukegan Harbor.

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“Waukegan Harbor was designated an Area of Concern primarily due to of PCB contamination from Outboard Marine Corporation,” Hedman said.

Cameron Davis, who helped form the Waukegan Harbor Citizens’ Advisory Group in the 1990s, has since become a senior advisor at the EPA.

“Waukegan Harbor was once called ‘The World’s Worst PCB Mess,’” he said.

Outboard Marine used PCBs, a toxic chemical in hydraulic fluids, at a boat motor manufacturing plant at the harbor. The company went bankrupt in 2000, and abandoned the plant in 2002.

The company first cleaned up the harbor in 1992 by dredging contaminated sediment, but after the plant was abandoned, the EPA determined PCB levels were still high, and more dredging was needed.

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Costs of the cleanup fell almost entirely on taxpayers, Durbin said.

“There’s a lesson here, isn’t there? In terms of corporate conduct, whether they used this harbor as a dump out of ignorance, or negligence, or malice, whatever,” he said. “We’ve got to make sure that there’s responsible corporate conduct.”

Outboard paid for only 2 percent of the $150 million cleanup cost.

Kirk predicted huge benefits for Waukegan, beyond cleaning up pollution.

“Take a polluted harbor, and make it clean, and make the property values skyrocket,” he said.

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Waukegan Mayor Wayne Motley said it’s a new beginning, and opens the door to new development along the lakeshore.