Scientists Reveal Major DDT Pollution Along Los Angeles Coast

RANCHO PALOS VERDES, CA — Scientists are sharing more information this week about the threat DDT poses to marine ecosystems and human life following the discovery of a toxic dump site off the coast of Los Angeles, between Rancho Palos Verdes and Santa Catalina Island.

It's one of the largest known chemical dumpsites in the world, officials said.

What is DDT?

DDT is a suspected human carcinogen known to cause liver and reproductive abnormalities in animals, according to the Centers for Disease Control and Prevention.

A Los Angeles Times report at the end of 2020 raised questions about the barrels discovered along the coast and the high levels of DDT found there.

Patrick O’Donnell, who represents District 70, which includes Long Beach, Signal Hill, San Pedro and Catalina Island, hosted a virtual town hall Thursday focusing on the DDT chemical waste in local waters off the coast of California. The Long Beach chapter of the Sierra Club, Scripps Institution at UC San Diego, California State Long Beach and Heal the Bay all joined the event.

O’Donnell grew up in the area and expressed a personal connection to this environmental threat.

“I grew up swimming in these waters and still do today. And so do my kids, so does my family,” O’Donnell said. “This is a very important topic to me personally but also to me as an assembly member because this has major public policy implications potentially. It’s something that we need to engage in and study tonight."

He said he was shocked to find out the DDT laced-chemical waste site sits off the coast in local waters. And since the discovery, scientists, activists and elected officials have been looking at ways to address the environmental problem. O’Donnell has introduced Assembly Joint Resolution 2 to call on the federal government to address this problem, study it, and educate people.

What do scientists know about this toxic dumpsite?

Eric Terrill, Ph.D., the director of the Marina Physical Laboratory at Scripps Institution of Oceanography at UC San Diego, shared the group’s San Pedro Basin Survey and results from the seafloor survey of DDT dumpsite off Southern California from March 2021. Terrell said researchers took an in-depth look at this very large area — 3,000 feet of water. They found that the size and area of pollution was much larger than they thought before.

The research looked at the area between Palos Verdes and Santa Catalina Island, which is referred to as dumpsite two.

“A known dumpsite with a diameter of about 3 nautical miles,” Terrill said.

The 31-person research team, including two NOAA representatives, surveyed an area about twice the size of Manhattan Island, about 36,000 acres. They used 15 autonomous underwater vehicles during dives to survey, he said.

“We’re looking for barrels that are a few feet in size," Terrill said.

Using a high-precision sonar over a wide area and robots, they scanned the ocean floor for barrels for about 12 to 18 hours. They measured the data, recorded it and then relaunched them to continue mapping the area.

“Essentially we’re overwhelmed by this large number of targets that we’re being able to detect in the water," he said. "The debris fields approaches California state waters."

There’s a lot of unfinished business, Terrill said. It’s unclear just how many barrels are under the water.

“I also want to reinforce we do not know what’s in the barrels," he said. "DDT has been detected in the sediments. We also know barrels are on the seabed. And so it behooves us now to start doing a kind of whole government, whole science approach to understanding what’s on the seafloor.”

Lihini Aluwihare, marine chemist at Scripps Institution of Oceanography at UC San Diego, described what the next steps could be.

Where can we go from here?

Researchers want to increase research in the area and find out the answer to several remaining questions.

Between the 1930s and 1970s, industrial waste from petroleum companies and Montrose Chemical Corporation, the world's largest DDT manufacturer in Torrance, was dumped in the Los Angeles ocean basin. It is also documented that acid waste containing DDT was dumped at these sites but it’s unknown in what form. Montrose Chemical stopped production in 1982.

"How they were dumped and in what form, is still something that needs to be addressed," Aluwihare said.

Scientists are discovering compounds of DDT in dolphin blubber and want to research the risk these toxic dumpsites could present for people and ocean ecosystems.

It's also apparent that the debris field could be larger than they anticipated, Terrill said.

"We really should extend this to understand the flow and full accounting of the debris field," he said.

Dr. Chris Lowe has studied the Palos Verdes shelf, located near the PV coast, and referred to DDT as a legacy contaminant.

DDT was discharged through wastewater treatment from 1947 to 1972 with Los Angeles County Sanitation district pipes, which fed through all of Los Angeles but discharged at White's Point, he said. More than 1,800 tons of DDT were discharged off the coast of Palos Verdes.

"The consequences of these, we're seeing, basically, is we saw declining nesting birds, seabirds, raptors, due to eggshell thinning. There was a dramatic decline in brown pelicans, eagles and other sea birds," Lowe said.

This particular contamination field is in a shallow area, less than 150 feet. The sediments have been buried overtime and some fishes and animals use it.

"We know that over time animals have been acquiring DDT from these sites and the sediments and it's been passed through the food chain," Lowe said. "And this is has been traceable throughout the entire Southern California Bay, basically from Santa Barbara all the way down past Mexico."

Watch the town hall meeting on DDT chemical waste in local waters:

SEE ALSO:

• Cleanup Of DDT Dumped Off LA Coast Must Be Prioritized
• Toxic Waste Discovered Off CA Coast A Major Threat To Environment