City of LA’s Hyperion water treatment plant faces AQMD violations

The South Coast Air Quality Management District issued a violation notice to the Hyperion Water Reclamation Plant in Playa del Rey for emitting elevated levels of hydrogen sulfide, officials announced Wednesday.

According to AQMD, the regulatory agency responsible for air quality in Southland counties, fence-line monitoring at Hyperion showed elevated levels of hydrogen sulfide, or H2S, with a maximum one-hour average of 64.60 parts per billion (ppb) on June 19. That exceeded the facility’s permit limit for H2S of 20 ppb.

“Prior to the exceedance, Hyperion submitted a notification reporting that it had shut down several air pollution control devices (known as scrubbers) for planned maintenance and repairs,” according to an AQMD statement. “The scrubbers were returned to service within seven hours, and the fence-line monitoring system showed H2S levels had returned to typical levels.”

An AQMD enforcement team conducted an on-site inspection and found that Hyperion also violated recordkeeping requirements under a September 2022 order and failed to notify the agency within one hour of discovery of the elevated H2S levels.

Hyperion is located at 12000 Vista Del Mar in Playa del Rey and is operated by the city of Los Angeles.

Since AQMD began investigating the plant in July 2021, inspectors have responded to more than 5,500 complaints from members of the community and issued about 70 notices of violation to Hyperion for public nuisance in violation of the agency’s Rule 402, along with one notice for excess visible emissions under Rule 401, and three violations of permit conditions.

Violations can result in civil penalties, and in some cases, the company can choose to implement voluntary measures to reduce emissions or prevent further violations. If no settlement is reached, a lawsuit could be filed.

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