TOLEDO, Ohio (AP) — Salvage crews have finished pumping hazardous oil-based substances from a sunken barge that apparently had been sitting undiscovered on the bottom of Lake Erie for nearly 80 years, the U.S. Coast Guard said Thursday.
Federal officials overseeing the underwater operation say the barge no longer poses an environmental threat.
Crews discovered this week that six of the eight cargo tanks already were empty, suggesting that the oil-based substances either spilled when the barge sank or slowly trickled out over time.
"There's no way for us to find out," Coast Guard spokesman Lt. Mike Hart said.
The Coast Guard and U.S. Environmental Protection Agency have been monitoring the site near the U.S.-Canadian border since coming across a small leak in October that appeared to be from a barge called the Argo that sank during a storm in 1937. The wreckage was one of 87 shipwrecks on a federal registry that identifies the most serious pollution threats to U.S. waters.
One tank holding an unknown cloudy substance was pumped out over the past few days and loaded onto a barge on the surface, Hart said. Further tests are planned to determine what the substance is and how to get rid of it, he said.
"They got everything out pretty quick and easy with no harm to the environment," Hart said.
A shipwreck hunter spotted the barge 45 feet below the lake's surface in late August.
Historical documents have said the Argo was transporting both benzol and crude oil when it went down. A report produced by the National Oceanic and Atmospheric Administration in 2013 said it was believed to be carrying 100,000 gallons of the oil-based products.
Crews within the past month sealed a leak on the barge and removed what was believed to be benzol from one of the tanks.
The process of removing the oil-based substance starts with drilling into the tank and pumping lake water inside, which pushes the substance into pipes that carry it to another barge.
The Coast Guard has been keeping boaters away from the area near Ohio's Kelleys Island because of fumes in the air.
The Argo's exact whereabouts had been unknown since waves toppled it during a storm in 1937 in western Lake Erie — about midway between Toledo and Cleveland.
What will be done with the remains of the steel barge, which is mostly intact and sitting upright, is still to be determined. Sonar images show outlines of the pilot house, railings and pipes.