Wynn Resorts officials, speaking Tuesday night at Tufts University about the casino company's plans to turn a polluted former chemical plant site into a gleaming $1.6 billion resort, promised the cleanup efforts will meet the "highest standards" set by federal environmental regulators.
Robert DeSalvio, a Wynn executive who is overseeing the development, said the company estimates the cleanup will cost roughly $30 million but is prepared to spend more if needed.
The roughly 30-acre site, located in the city of Everett along the Mystic River, for decades was the site of a Monsanto Chemical Co. plant.
"The company commitment is that we'll get the job done," DeSalvio told the more than 100 people in attendance at the event, which was sponsored by the Mystic River Watershed Association. "We have a very significant task ahead of us, getting this site cleaned up and ready for development."
Wynn, which won the lucrative Boston-area casino license in September, proposes to revive the long-vacant industrial site with public amenities like an esplanade, public park and year-round "winter garden."
The casino resort plan also calls for water taxis to ferry visitors to popular destinations in Boston, restoring salt marshes and building bike paths and walkways.
But officials acknowledged Tuesday that one, much-touted piece of the planned restoration will likely not move forward: new oysterbeds to help filter and clean the Mystic River.
Jaime Fay, a project consultant, said the casino was unable to convince state regulators that its security measures would prevent people from harvesting the new oysters, which would not be safe to eat.
Environmental tests have shown the soil, groundwater and river sediment at the site contain substantial levels of arsenic, lead, copper and other heavy metals.
According to Fay, the land was used by four different chemical companies dating back to about 1868. Monsanto was longest owner, operating there from 1929 to about 1983, he said.
Fay said much of the pollution is concentrated around three areas of the property and that the company will use two basic cleanup methods.
One involves mixing the polluted soil with cement to permanently "entomb" the contaminants; the other is removal and disposal of the contaminated soil off-site.
The environmental cleanup is expected to take around three to four months to complete.
Wynn hopes to begin the cleanup in the spring, assuming it clears a series of state and local permit approvals that are currently underway.
Jean Haggerty, an Arlington resident who attended Tuesday's forum, said afterward that she was encouraged by what she heard.
But Haggerty wondered what would become of the site if Massachusetts residents vote on Tuesday to repeal the state casino law that authorizes the Wynn project and other new gambling developments.
"It's a great opportunity and and I hope it works out and that they follow through with their promises," she said.