The cleanup of Brooklyn’s Gowanus Canal hit a snag this week when a barge full of toxic gunk sunk into the putrid waterway, federal officials said Tuesday.
The 1.8-mile-long canal is lined with up to 20 feet of soft toxic sediment, informally dubbed “black mayo,” from decades of unchecked factory pollution and sewage runoff.
A barge containing tons of black mayo sank at the mouth of the waterway in recent days, said Environmental Protection Agency spokesman Stephen McBay. The EPA was informed of the problem Monday, but McBay couldn’t say which day the barge sank.
An official with knowledge of the project said the barge was half-full when it sank.
The barge resurfaced during low tide and the EPA was investigating whether any black mayo spilled during the snafu, McBay said Tuesday.
“Dredging activities have been temporarily suspended so that crews can concentrate on operations to secure the barge,” McBay said.
“The EPA’s goals are to do all that we can do to ensure that this type of mishap does not happen again and that any impacts from yesterday’s accident are appropriately and promptly addressed.”
The EPA estimates there is at least 580,000 cubic yards of toxic sediment in the canal, enough crud to fill roughly 58,000 dump trucks.
The EPA classified the Gowanus as a Superfund site 2009, and the Massachusetts-based company Cashman Dredging was hired in November to begin pulling out the muck.
As of Monday, Cashman had removed roughly 15,000 cubic yards of sediment, according to an EPA report.
Cashman was also contracted by the EPA to dredge an upstate section of the Hudson River also dubbed a Superfund site from pollution dumped by General Electric manufacturing plants from the 1940s until the 1970s.
A 2005 survey of the canal by National Grid used military-grade sonar technology to identify large objects in its murky depths.
The analysis identified sunken tires, timbers and barges that are “widespread throughout the canal,” according to a 2012 EPA report.