08 • 03 • 2021

LA Beaches Continue to Have Water Quality Concerns

By Bill Hickman

On July 11th and 12th, 2021, about 17 million gallons of raw sewage were discharged into the ocean off Los Angeles beaches from the Hyperion Treatment Plant in El Segundo. Mechanical failures forced the wastewater treatment plant to release the untreated sewage to prevent further damage to treatment equipment as activated sludge pumps and the waste solid processing system had already become non-operational.. Public health officials posted a beach closure advisory on their website urging residents to avoid swimming at Dockweiler and El Segundo beaches, but not until later in the day on July 12th!

After results from the ocean water samples collected over two days met state bacteria standards for acceptable water quality, the beaches were back open on July 14th. Learn more from the Los Angeles County Department of Public Health.

On July 29th the California Water Quality Control Board provided an update. The plant is still not functioning fully and exceedances for other water quality parameters (biochemical oxygen demand, total suspended solids and turbidity) have continued. Fortunately fecal indicator bacteria levels at surrounding beaches remain low. The LA Times reported this as “releasing partially treated sewage into Santa Monica Bay” on July 30th.

The CA Water Quality Control Board is requiring LA Sanitation to conduct extensive daily monitoring of the wastewater plant, ocean outfall and beaches surrounding the spill area for at least the next 3 weeks or until the plant resumes normal operation and causes no other water quality exceedances.

If you are visiting LA County beaches, please check the County of LA Beach Water Quality web page before you go. You can also follow Surfrider LA and Surfrider South Bay on social media for updates if additional beach closures are announced.

Below is the official summary of the spill/incident from the City of Los Angeles. Overall it sounds like it was quite a mess both inside the plant and offshore:

“At 8:12 p.m. on July 11, 2021, the Regional Water Board was notified by the California Office of Emergency Services (Cal OES) of a mechanical failure at Hyperion Treatment Plant (HTP) which may cause a release of raw sewage to the Pacific Ocean via the one-mile emergency outfall (Hazardous Materials Spill Report Cal OES Control #21-3698). On July 12, 2021, at 8:50 a.m., Regional Water Board staff received an updated spill report estimating a release volume of 17 million gallons to the Pacific Ocean ending at approximately 7:00 a.m. on July 12, 2021.

On July 12, 2021, Regional Water Board staff inspected HTP and observed evidence of a raw sewage spill within the plant. Multiple areas, including HTP’s effluent pumping plant and pipe galleries, were flooded with raw sewage. Multiple pieces of equipment were rendered non-operational as a result of the flooding, including:

a. Effluent pumps for Discharge Point 002. However, effluent for Discharge Point 002 is typically discharged via gravity flow during dry weather and thus this typically does not have an effect on the plant’s operation;

b. Return activated sludge pumps, which negatively impacted the efficiency of the secondary biological treatment process; and

c. Waste solid processing system, which resulted in solids accumulation in the primary sedimentation tanks and secondary clarifiers, thus impacting secondary effluent quality.

Based on the 5-day preliminary report, submitted by LASAN on July 16, 2021 to the Regional Water Board regarding the incident, an estimated 16.874 million gallons of untreated raw sewage was discharged into the Pacific Ocean within the Santa Monica Bay through Discharge Point 001. An additional 80,000 gallons of untreated raw sewage was discharged through Discharge Point 002 after blending with HTP’s normal effluent during the incident.”