SAN DIEGO—Marine scientists say they have found what they believe to be more than 25,000 barrels that possibly contain DDT dumped off the Southern California coast near Catalina Island, where a massive underwater toxic waste site dating back to World War II has long been suspected.
They mapped more than 56 square miles (145 square kilometers) of seafloor between Santa Catalina Island and the Los Angeles coast in a region previously found to contain high levels of the toxic chemical in sediments and in the ecosystem.
Historical shipping logs show that industrial companies in Southern California used the basin as a dumping ground until 1972, when the Marine Protection, Research and Sanctuaries Act, also known as the Ocean Dumping Act, was enacted.
Disposing of industrial, military, nuclear and other hazardous waste was a pervasive global practice in the 20th century, according to researchers. Resting deep in the ocean, the exact location and extent of the dumping was not known until now.
The territory covered was “staggering,” said Eric Terrill, chief scientist of the expedition and director of the Marine Physical Laboratory at Scripps Institution of Oceanography. “It really was a surprise to everybody who’s worked with the data and who sailed at sea,” he told reporters Monday.
Underwater drones using sonar technology captured the images of barrels resting 3,000 feet (900 meters) below the surface all along the steep seafloor that was surveyed.
The survey provides “a wide-area map” of where the barrels are resting, though it will be up to others to confirm through sediment sampling that the containers hold DDT, Terrill said.
