Miles of beaches in Los Angeles were closed to swimming on Monday as around 17 million gallons of untreated sewage spilled into the sea.
The sewage was spilled into the ocean from the Hyperion Water Reclamation Plant in Playa del Rey, California, on Sunday night after a mechanical failure at the facility, according to a series of tweets from Los Angeles County Supervisor Janice Hahn.
She confirmed that "beaches from El Segundo to the Dockweiler RV Park are closed for swimming," and said that "water samples are being tested and I'm getting more information about the scope of the problem."
This was a massive discharge of 17 million gallons of sewage into the ocean. I understand that the plant was able to prevent an even larger spill, but we are going to need answers about how and why this happened. https://t.co/oHw4krxMOa
— Janice Hahn (@SupJaniceHahn) July 12, 2021
In a later tweet, Hahn revealed that "17 million gallons of sewage" were spilled into the ocean and said that although the plant was able to "prevent an even larger spill," they were "going to need answers about how and why this happened."
Closure signs were put up at the beaches in the affected areas, spanning around 4 miles, as officials urged visitors to stay away from the water until it is cleared as safe to return.
In a news release, the County Department of Public Health in Los Angeles said that the beaches will remain closed until the results of tests on water quality samples that were collected on Monday morning come up negative for bacteria.
Hyperion Executive Plant Manager Timeyin Dafeta told the Associated Press in a statement on Monday evening that the spill occurred after the facility "became inundated with overwhelming quantities of debris, causing backup of the headworks facilities.
"The plant's relief system was triggered and sewage flows were controlled through use of the plant's one-mile outfall and discharge of untreated sewage into Santa Monica Bay."
Dafeta confirmed to The Los Angeles Times that the mechanical failure was fixed on Monday morning after around 6 percent of the facility's daily load was discharged as an emergency measure to prevent the site from going offline and releasing even more untreated sewage into the sea.
The Hyperion plant is both the oldest and largest sewage facility in Los Angeles and has been in operation in the city since 1894. Around 275 gallons of wastewater flows through the plant every day, according to KTLA 5.
Although the facility released 17 million gallons of sewage on Sunday through to Monday, it is far from the city's largest spill, which occurred in 1998 when more than 30 million gallons of sewage spilled during the El Niño storms.
More recently, a leak at Dodger Stadium in the city caused the final innings of a game between the Los Angeles Dodgers and Los Angeles Angels to be canceled as the field and first few rows of seats were flooded with untreated sewage.
Newsweek has contacted the Hyperion Water Reclamation Plant for comment on the incident.
