Ocean Dumpsites Are Leaking Toxins off the California Coast—And It’s Worse Than Originally Thought

Recent discoveries of dumpsites in the waters off Los Angeles revealed hundreds of thousands of leaking waste barrels scattered across an ocean floor area larger than San Francisco.

The scale of the contamination of the insecticide DDT, or Dichlorodiphenyltrichloroethane, found at depths of up to 3,000 feet, is significantly greater than previously believed, researchers say. Approximately 25 percent of California sea lions in the region have been found to have cancer, a staggering rate that has been attributed to the chemical sites.

Environmentalists were already aware of the dumpsites, many of which are suspected to have accumulated over a span of nearly four decades—from the mid-1940s to early ’80s—through materials discarded by the notorious Montrose Chemical Corporation, a company that was the target of substantial legal action after it was discovered to have dumped millions of pounds of DDT into county sewers. But the sites’ close proximity to Los Angeles, as well as the extent of their toxicity, is greater cause for concern, according to Jacqueline Savitz, chief policy officer at Oceana.

“We are left with horrifying contamination in some of the most diverse ocean waters off the U.S. West Coast,” Savitz said. “There are no easy solutions to clean up these barrels resting at the depths of the seafloor and the repercussions will haunt future generations, but it is essential that the government act immediately.”

Sen. Dianne Feinstein (D-Calif.) took initial legislative steps to address the issue in March, calling on both the Environmental Protection Agency and the Commerce Department to prioritize the cleanup of the area.

“Scientists at UC Santa Barbara have discovered what they estimate to be hundreds of thousands of industrial waste barrels in varying states of decay on the ocean floor near Catalina Island, about 22 miles off the California coast,” Feinstein wrote in a letter to EPA officials.

“Alarmingly, some areas off Catalina Island have recorded concentrations of DDT at rates 40 times higher than the highest level of contamination at Palos Verdes.”

Spurred on by Feinstein’s exhortation, the National Oceanic and Atmospheric Administration, which falls under the Commerce Department, partnered with UC San Diego’s Scripps Institution of Oceanography, the Department of Defense, UC Santa Barbara, and others to map nearly 50,000 acres of ocean floor in the vicinity of Catalina Island. The goal? Determine the location and condition of the waste to inform possible solutions.

From March 10 to 24, the research cohort deployed two autonomous underwater vehicles to the designated area between Santa Catalina Island and the Los Angeles coast, sending the two submersibles over a half-mile below the surface.

Mapping just one of what is believed to be more than 10 total dumpsites, the research team located more than 25,000 barrels and over 100,000 debris items on the ocean floor.

“The expedition’s findings confirm fears that a large number of barrels containing DDT-laced industrial waste were dumped off the coast of California and are now impacting marine life and potentially public health,” Feinstein said in response.

“Simply put, this is one of the biggest environmental threats on the West Coast.”

Solutions capable of undoing decades of damage will be difficult to come by, but like Feinstein, Savitz is calling for a “comprehensive action plan for mitigation and cleanup.”

“This must be made a priority to ensure that our Southern California waters can be free of these contaminants, to protect marine life and public health.”