The Hydrogen Sulfide Problem
The Hyperion Crisis and El Segundo's Fight for Clean Air
An examination of outdated hydrogen sulfide regulations in California and the community struggle following the 2021 Hyperion sewage spill
Life Before the Crisis: El Segundo's Hidden Neighbor
When we moved to El Segundo in 2014, we were charmed by its small-town feel nestled within the greater Los Angeles area. The community had a distinct character—neighborhoods with tree-lined streets, local businesses where owners knew your name, and the reassuring routine of life in what many called "Mayberry by the Sea." Like most residents, we chose El Segundo for its excellent schools, walkable neighborhoods, and proximity to the beach.
What we didn't think about—what none of us thought about—was the massive wastewater treatment facility quietly operating at the edge of our town. The Hyperion Water Reclamation Plant, Los Angeles' largest sewage treatment facility, processing over 260 million gallons of wastewater daily, was essentially invisible to our daily lives. Despite its size and proximity, Hyperion remained a non-issue for years. We never smelled sewage. We never worried about air quality. We simply lived our lives, unaware of the environmental time bomb ticking at our community's border.
For seven years, our family enjoyed beach days, community events, and backyard barbecues without ever considering what might happen if something went wrong at the plant less than a mile away. This peaceful coexistence would end abruptly on a summer day in 2021, transforming our community forever.
The Day Everything Changed: July 11, 2021
On July 11, 2021, the invisible neighbor made itself known in the most dramatic way possible. The Hyperion Water Reclamation Plant experienced what officials would later describe as a "catastrophic failure" when excessive debris overwhelmed the facility's screening systems. In the chaos that followed, plant operators made a fateful decision: rather than risk complete system failure, they diverted approximately 17 million gallons of untreated sewage directly into Santa Monica Bay.
For our community, the first sign that something was wrong wasn't an official alert or emergency notification. It was the smell—a noxious, overwhelming stench that blanketed our neighborhoods like an invisible fog. By morning, residents were waking up nauseated, with headaches and burning eyes, wondering what had happened overnight.
I remember opening my window that morning and immediately closing it and the smell was unlike anything I'd experienced before—not just unpleasant but physically sickening. What we didn't know then was that this wasn't a one-day problem. It was the beginning of a nightmare that would stretch from days into weeks and ultimately transform into a years-long battle for accountability and regulatory change.
From Nuisance to Health Crisis: The Aftermath
In the days following the spill, the communication from authorities was frustratingly inadequate. The Los Angeles County Department of Public Health took nearly 24 hours to close beaches and issue sewage spill advisories. Meanwhile, residents were left wondering why they felt sick inside their own homes.
For families like ours who had never once associated Hyperion with any negative impact on our lives, the sudden and persistent presence of hydrogen sulfide gas was both confusing and alarming. Children complained of headaches and difficulty concentrating. Adults experienced dizziness, nausea, and respiratory issues. Pets seemed lethargic and disturbed.
Before this happened, I didn't once think about hydrogen sulfide and now suddenly I'm researching gas masks and air purifiers at midnight while my kids are throwing up. For the record, hydrogen sulfide isn’t the only air toxin of concerns from Hyperion, as they have outdated biogas flares, but that is the focus of this article.
What made the situation even more frustrating was learning that the regulatory framework treating these emissions as merely a "nuisance" rather than a health hazard dated back to 1969. California's ambient air quality standard for hydrogen sulfide—set at 0.03 parts per million (ppm)—was established when Richard Nixon was president and hasn't been updated since.
Moreover, we discovered something even more shocking: Hyperion's air permit didn't even include a specific limit for hydrogen sulfide emissions. The facility that had suddenly turned our lives upside down wasn't violating any permit conditions by releasing the gas that was making our families sick.
A Community Mobilizes: From Neighbors to Advocates
As the crisis stretched from days into weeks, with hydrogen sulfide levels fluctuating but the smell never fully disappearing, El Segundo residents began organizing. What started as concerned neighbors in text groups and community social media pages evolved into a coordinated advocacy movement.
Kitchen tables became command centers. Parents became amateur toxicologists, learning to interpret air quality data. Professionals with relevant expertise stepped forward to help translate complex regulatory language for their neighbors. Community members began documenting their symptoms, creating timelines, and collecting evidence.
As an environmental professional, I know regulations can’t be updated or created without data. Recognizing the need for scientifically sound data on health impacts, I initiated a partnership with USC's Environmental Justice Research Lab to study how hydrogen sulfide exposure was affecting residents.
We quickly realized that if we wanted change, we needed more than complaints—we needed data. The existing regulatory framework wasn't designed to address what we were experiencing, so we had to build the case ourselves.
The study, examining both physical and mental health impacts including lung function, blood pressure, sleep quality, and cognitive effects, became one of several community-led initiatives to fill the knowledge gaps left by outdated regulations.
Meanwhile, attendance at city council meetings swelled. Residents who had never before participated in local government found themselves becoming regulars at public comment sessions, sharing personal stories of health impacts and demanding accountability.
Discovering the Regulatory Maze: A System Designed to Fail
As our community dove deeper into understanding the regulatory framework governing Hyperion's operations, we encountered a frustrating reality: the system seemed designed to prevent meaningful accountability.
The structure of overlapping jurisdictions created perfect conditions for buck-passing. The plant itself is operated by LA Sanitation, a department of the City of Los Angeles. Air quality complaints fall under the South Coast Air Quality Management District (SCAQMD). Water quality violations are handled by the Los Angeles Regional Water Quality Control Board. Public health concerns belong to the Los Angeles County Department of Public Health.
Each agency pointed to limitations in their authority or jurisdiction when pressed for action. Even more frustrating was the realization that when fines were eventually imposed, they simply circulated between government entities—from one public agency to another.
It's a shell game with taxpayer money where LA Sanitation gets fined by the Regional Water Board, but both are government agencies. The fine doesn't create actual accountability—it just shuffles our tax dollars around, and ultimately, we pay twice: once for the agency that caused the problem and once for the agency that's supposed to regulate them.
This circular flow of penalty funds highlighted a fundamental flaw in the regulatory system: when a government entity violates environmental regulations, the financial penalties don't create the same deterrent effect they might for a private company. At the end of the day, it's always the taxpayers who foot the bill.
Small Victories and Ongoing Struggles
Despite these structural challenges, the community's persistent advocacy began yielding results. The SCAQMD eventually identified 39 separate air quality violations related to the incident and approved an order of abatement requiring Hyperion to implement several measures:
Establish a 24/7 hotline for odor complaints
Conduct regular odor patrols
Increase air quality monitoring stations
Repair broken equipment contributing to emissions
The city of Los Angeles committed to spending $20.8 million on improvements at Hyperion, addressing staffing, training, and equipment maintenance issues. A tentative $21.7 million fine was imposed by the Los Angeles Regional Water Quality Control Board for violations related to the spill.
Perhaps most significantly, community advocacy helped push forward Assembly Bill 1216, the Fence Monitoring Rule, signed in October 2023. This legislation will require facilities like Hyperion to monitor pollutants (including hydrogen sulfide) at their property boundaries and share that data in real-time with the public.
But even these victories came with caveats. The fence monitoring requirement won't take effect until January 1, 2027—nearly six years after the initial crisis. Moreover, as we examined the legislation's details, we found it lacks robust enforcement mechanisms and quality assurance/quality control provisions to ensure the data's accuracy.
Getting the law passed was a huge step, but we're already seeing the loopholes. Without enforcement teeth and strict data verification requirements, it could become a checkbox exercise rather than a meaningful protection.
The Fight for Real Accountability Continues
Today, nearly three years after the spill that transformed our community, residents of El Segundo still report occasional odor events and associated symptoms. The relationship between the community and Hyperion remains fraught with distrust. While plant operators point to improvements and investments made since the crisis, residents question whether fundamental operational and management issues have truly been addressed.
The U.S. Environmental Protection Agency has ordered significant fixes at Hyperion, including improved monitoring systems and overflow channels, to be completed by the end of 2025. Long-term plans include transitioning to full wastewater recycling by 2035, aiming to eliminate ocean discharge entirely.
Yet for many residents, these future-focused solutions don't address the ongoing impacts or create true accountability for what happened. Some families (us) have made the difficult decision to leave the community they once loved, unwilling to gamble with their health while waiting for systems to improve. Others stay and continue fighting, determined to create lasting change.
The most fundamental regulatory issue—California's outdated hydrogen sulfide standard—remains unchanged. Advocates continue pushing the California Air Resources Board (CARB) to update the 1969 standard based on current scientific understanding of health effects at lower concentrations. This outdated standard, focused on odor rather than health impacts, continues to limit communities' ability to seek meaningful remedies when experiencing symptoms at levels below the regulatory threshold.
Lessons for Other Communities
El Segundo's experience offers important lessons for communities across California and beyond. Environmental regulations are only as good as their enforcement mechanisms, and when government entities regulate other government entities, traditional accountability structures may fail to protect public health.
The classification of certain emissions as "nuisances" rather than health hazards creates a dangerous regulatory blind spot, one that leaves communities vulnerable even when they experience very real physical symptoms. And the gap between acknowledging a problem and implementing meaningful solutions can stretch for years, during which residents continue to bear the health burden.
Perhaps most importantly, El Segundo's story demonstrates that community advocacy matters. While the regulatory system may be flawed, organized citizens can push for important improvements—from increased monitoring to new legislation. The fence monitoring rule, despite its limitations, represents a significant step toward transparency that would not have happened without persistent community pressure.
The Path Forward
For the residents of El Segundo, the path forward involves continued vigilance and advocacy. Community-led research, including the USC study expected to produce results by 2024 or 2025, will provide crucial data to support the case for regulatory updates.
Advocates continue to push for strengthening the fence monitoring rule with enforcement provisions and data verification requirements before its 2027 implementation. They also maintain pressure on relevant agencies to ensure promised improvements at Hyperion stay on schedule and address root causes rather than symptoms.
Most fundamentally, residents continue working to reform a system where government entities regulating other government entities creates circular accountability that ultimately protects institutions rather than people. Breaking this cycle remains the greatest challenge but also the most necessary reform to prevent similar crises in other communities.
The Hyperion sewage spill, while a disaster for affected communities, may ultimately serve as the catalyst for long-overdue regulatory change. Through a combination of community activism, scientific research, and policy advocacy, California has the opportunity to better protect public health from this overlooked but significant environmental hazard.
For those of us who once lived in blissful ignorance of the massive sewage treatment plant nearby, there's no going back to that simplicity. But through our ongoing fight for accountability and regulatory reform, we hope to create a future where no community has to learn about hydrogen sulfide the hard way we did—through physical suffering and a years-long battle for justice that still continues today.
References
California Ambient Air Quality Standards California Air Resources Board
Bay Area Air Quality Management District Air Quality Standards and Attainment Status
USC researchers looking at impacts of hydrogen sulfide on El Segundo residents Press Telegram
Residents’ experiences during a hydrogen sulfide crisis in Carson California Environmental Health
One-Year Anniversary of the Hyperion Plant Spill Heal the Bay
Los Angeles to spend $20.8 million on fixes after massive sewage spill Los Angeles Times
After sewage spill, feds order fixes at L.A. plant to limit further issues Los Angeles Times
Air quality watchdog demands Hyperion to fix lingering odor a year after sewage spill Daily Breeze
Air-quality regulators allege permit violations at Hyperion sewage plant Hey SoCal
I wrote this blog in memory of my old neighbor, Lisa Lappin:
Legal Disclaimer This blog post reflects the experiences of me as a resident and community activist affected by the 2021 Hyperion sewage spill and their ongoing advocacy for regulatory reform and accountability. This blog is not related to my employer and reflects only my opinions. The content provided on this blog is for informational purposes only and represents my personal opinions. It is not intended to be legal advice and should not be relied upon as such. For specific legal advice, please consult with a qualified legal professional.