The U.S. Coast Guard says divers will briefly unplug a tiny leak on a sunken barge to take a sample of the escaping liquid in Lake Erie, near where an oil-based substance has been spotted in recent weeks.
The agency warned before sampling Monday that people nearby might smell a sweet, gasoline-like odor once a small amount of the material is released and surfaces. Crews have monitored the site near the U.S.-Canadian border since discovering a sheen on the surface late last month.
A colorless liquid is believed to be coming from the barge, which sank in 1937. It’s on a federal registry of the most serious pollution threats to U.S. waters.
The Coast Guard says sediment samples from the wreckage of the barge didn’t show what its compartments held.