‘Super’ El Niño could overwhelm L.A.’s aging Hyperion sewage treatment plant
On the shores of Playa del Rey sits L.A.’s last line of defense against sewage streaming into the Santa Monica Bay — and a jacked El Niño this winter threatens to be more than a match for it.
Built in 1950, the Hyperion Water Reclamation Plant handles roughly 95% of the city’s sewage on any given day — up to 800 million gallons of effluent from toilets, washing machines, sinks, industrial operations and more.
Storms can overwhelm the aging facility, which suffered an equipment breakdown in 2021 that led to 17 million gallons of raw sewage gushing into the Santa Monica Bay. Los Angeles officials are bracing for more trouble if the forecast “super” El Niño brings heavy rains and flooding.
“We have done our best; a great job of maintaining it” said Joone Kim-Lopez, general manager of the Los Angeles Sanitation and Environment, or LASAN, told the L.A. City Council recently. “But as with anything, this infrastructure needs attention.”
L.A.’s stormwater and wastewater systems are separate, but when it rains, water seeps into the ground and can sneak into the cracks of aging wastewater pipes, said Tracy Quinn, chief executive of environmental group Heal the Bay.
This is how underground pipes can burst during heavy rains — or worse, how large wastewater plants like Hyperion can be overloaded and potentially spill into the ocean or back up sewage into homes and businesses, Quinn said.
Hyperion’s operators takes the risk of heavy rainfall seriously, and adds extra staff when extreme weather is forecast, according to Tonya Shelton, public information officer for LASAN. In addition, each year between April and October crews are testing generators, redundancy systems and other equipment to prepare for the worst, Shelton said.
“Ahead of the upcoming rainy season, LASAN is actively working to safeguard the public, our crews, and our critical infrastructure,” Shelton said in a statement to The Times.
Sanitation crews are also working to clear debris and shore up burn scar areas to mitigate flood risks, Mayor Karen Bass’ office said in a statement.
Hyperion failed in 2021 after human error and equipment failure flooded the plant, eventually pouring 17 million gallons of sewage into the ocean. On a dry summer day, workers ran for their lives as a deluge of water knocked out pumps and electrical equipment.
Quinn, who served on the technical advisory committee that reviewed the 2021 spill, said the city made many of the suggested changes to prepare itself for spills.
“This will be the first time that the system is truly tested with extreme storms, and it’s really going to depend on the ability of the staff that are working there to quickly address any issues,” she said.
The 2021 spill was related to poor maintenance, not an overwhelming amount of rain, said Mark Gold, director of the California Ocean Ecosystem Monitoring Program at UCLA. It signaled a decades-long worsening of the city’s infrastructure.
“Sewers and water distribution systems are out of sight and out of mind, and so unless you have a major spill or some other sort of catastrophe, it often is difficult to prioritize infrastructure,” Gold said.
The city agreed to significantly raise sewer fees over four years starting in 2024, eventually doubling its rates, in order to fund additional repairs and sewer maintenance. Gold said the additional funds, while painful for residents, was sorely needed after over a decade of no such increases.
Councilmember Eunisses Hernandez, who chairs the Public Works Committee, said in a call with The Times that improving and replacing aging pipes and other equipment at Hyperion is expensive. Nearly 30 other entities and municipalities — including Beverly Hills, Culver City and West Hollywood — rely on Hyperion to treat their sewage. Hernandez said the city may need to raise fees to those other entities instead of relying only on city ratepayers.
“It comes to getting these other jurisdictions to pay their fair share for using our infrastructure,” she said.
The city manages 6,700 miles of wastewater or sewage pipes — about the distance from L.A. to China, or enough to wrap around Earth’s moon — and another 1,200 miles of stormwater pipes, which carry rain water and other runoff straight into the ocean.
Of those pipes, around half are over 50 years old, Kim-Lopez said. Around a third are over 90 years old and are far past their expected life cycles.
Hyperion is the “granddaddy” of the four city facilities like it, Kim-Lopez said. It received major updates in the 1950s, and is the largest water reclamation plant of its kind west of the Mississippi River, according to LASAN.