EPA Orders City of Los Angeles to Implement Improvements to Hyperion Wastewater Treatment Plant
Largest Western U.S. Plant spilled 12.5 million gallons of untreated sewage in July 2021.
SAN FRANCISCO – The U.S. Environmental Protection Agency (EPA) has entered into an Administrative Order on Consent with the City of Los Angeles, LA Sanitation and Environment (LASAN) that requires improvements be made at the Hyperion Wastewater Treatment Plant in Playa del Rey, California.
In July 2021, LASAN violated its National Pollution Discharge Elimination System (NPDES) permit and the Clean Water Act (CWA) by discharging 12.5 million gallons of untreated sewage into the Santa Monica Bay, and by exceeding several NPDES effluent limitations for months after the July incident.
“When plants of this magnitude fail, it causes ripple effects that impact access to Los Angeles’ beaches and the health of ocean wildlife,” said EPA Pacific Southwest Regional Administrator Martha Guzman. “These improvements will help prevent failures and reduce large beach contamination events for Los Angeles residents and visitors.”
On July 11-12, 2021, bar screens located in the Headworks Building—the Plant’s initial treatment process which filters out larger solids—jammed and shut down. As a result of the bar screen failure, the flow of untreated sewage entering the Plant rose and overflowed from the Headworks Building and flooded portions of the Plant, causing damage to various components. The floodwaters eventually entered the Plant’s storm drain system where it flowed through an outfall and discharged one mile from the shoreline into the Santa Monica Bay. Additionally, damage caused by the flooding to downstream processes resulted in at least 53 effluent violations from July 17 to October 31, 2021.
Under the Administrative Order on Consent, LASAN will conduct work to improve the Hyperion Wastewater Treatment Plant high flow capabilities and make the Plant more resilient during large, intense storms that may be the result of climate change.
Required work under the Order includes:
- Integrating the Headworks Building equipment with digital, remote monitoring and alarm systems;
- Completing the construction of high-level overflow improvements, including a high-level overflow channel with static screens for debris removal in the event of a bypass;
- Cleaning and removing debris from accessible interceptors leading to the Headworks Building;
- Ensuring proper staffing and training;
- Updating standard operating procedures related to the Headworks Building and emergency operations;
- Conducting critical analyses of various assets at the Plant.
Read the EPA’s Administrative Order on Consent regarding the City of Los Angeles Hyperion Wastewater Treatment Plant.
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