Coastal residents sue L.A. over massive sewage spill into Santa Monica Bay

The Hyperion Water Reclamation Plant
The Hyperion Water Reclamation Plant, which discharged 17 million gallons of raw sewage into Santa Monica Bay in July.
(Jason Armond / Los Angeles Times)
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More than 100 people living in and around El Segundo have filed a lawsuit against the city of Los Angeles accusing it of exposing them to toxic hydrogen sulfide gas and other dangers during and after a sewage spill last year at the Hyperion Water Reclamation Plant.

In July, a backup caused by debris forced officials to use an emergency discharge procedure, sending a flood of raw sewage into Santa Monica Bay. The L.A. County Department of Public Health issued a health advisory and urged people to avoid swimming in areas around Dockweiler State Beach and El Segundo Beach.

For more than two weeks after the initial 17-million-gallon discharge, the damaged L.A. Sanitation and Environment Department plant — the city’s oldest and largest sewage treatment facility — continued to release millions of gallons of partially treated wastewater into the Pacific Ocean, a Times investigation found.


The lawsuit, filed Tuesday in Los Angeles County Superior Court, alleges that “responsible monitoring would have identified both the volume and source of any debris before it reached Hyperion” and that officials have yet to identify either.

Many residents who lived near the spill were sickened by noxious odors, court documents said.

Rob Wilcox, a spokesman for the L.A. city attorney’s office, said Wednesday that officials were reviewing the complaint but had no further comment. L.A. Department of Public Works spokeswoman Elena Stern said she could not comment on pending litigation.

Hyperion’s executive plant manager said the facility became inundated with ‘overwhelming quantities of debris’ Sunday afternoon.

July 12, 2021

On the first day of the spill, July 11, plant officials said a large amount of debris unexpectedly clogged their filtering screens, also known as bar screens. They scrambled to add additional screens and redirect flows to a storm drain system within the plant, but after several hours of recirculating the water, the system was still too overwhelmed. Workers activated the emergency measure.

The measure discharged the sewage one mile out and 50 feet deep into the ocean, instead of the typical five miles out and 190 feet deep.

According to the suit, it wasn’t the first time the plant’s bar screens had failed. A similar issue occurred in April — something that should have indicated to managers that “catastrophe was inevitable,” the lawsuit said.


“This is a massive raw sewage spill from one of the world’s largest water treatment facilities,” Alexander Wheeler, an attorney for the plaintiffs, said in a news release. “The warning signs were glaring leading up to the spill, and now El Segundo residents are paying the price for LASAN’s disregard for public safety.”

After spilling 17 million gallons of sewage into Santa Monica Bay, the damaged Hyperion Reclamation plant is still struggling to clean wastewater.

July 30, 2021

Hydrogen sulfide gas — which results from the bacterial breakdown of organic matter — is a known byproduct of wastewater treatment facilities, according to the Environmental Protection Agency. It is deadly at high levels. Lower, longer-term exposure can cause eye irritation, headaches and fatigue.

Reached by phone Wednesday, Wheeler said about 150 people have joined the mass tort suit already, and the number is likely to increase. Many suffered from eye pain, headaches and stomach problems after the spill, he said.

“What this case is all about is the negligence that leads to the injuries,” he said, “and when you’ve got that much sewage flooding and accumulating in one place, it’s well known that that gives off hydrogen sulfide.”

The gas is also known for its noxious, rotten-egg-like smell — something Carson residents similarly experienced last fall after what is believed to have been a decaying vegetation buildup in the Dominguez Channel caused by a warehouse fire.

Hydrogen sulfide, the source of the noxious odor emanating from the Dominguez Channel, has dipped below California s “nuisance” level.

Nov. 11, 2021

The smell plagued the area for weeks, and more than 3,000 residents suffering from headaches and nausea were moved to hotel rooms. Some filed a class-action lawsuit against the owner of the warehouse.


After the Hyperion spill, officials said they were conducting tests to monitor bacteria levels in the ocean water, but the suit alleges that they failed to test for hydrogen sulfide until at least two weeks later.

When testing finally began July 26, the results were nearly 22 times higher than the amount set by the state for acute health effects over one hour, court documents say.

In the days and weeks after the spill, state water quality regulators issued 47 citations against the Hyperion facility for illegal disposal into the Pacific Ocean, according to the suit, while the South Coast Air Quality Management District issued 38 notices of violation for the release of noxious odors.

Times staff writer Leila Miller contributed to this report.