The explanation that a sudden, massive build up of debris overwhelmed and crippled the Hyperion Water Reclamation Plant in July, forcing officials to release 17 million gallons of raw sewage into the ocean, was upended Friday, Feb. 11, when a new report said there was “little to no evidence” to back that theory — and instead blamed a combination of human and technological mistakes.
The report, formed by an advisory committee of the Los Angeles Department of Public Works to investigate the spill, hedges a bit, saying “a full understanding of all the factors that led to the spill and flood may never be completely reached.” But the document also identified a series of potentially preventable system failures and deficiencies in the plant’s central control room.
The report also offered recommendations for both LA Sanitation & Environment and Los Angeles County Department of Public Health, which was also criticized for not being proactive enough in closing beaches.
Both of those agencies have previously acknowledged the need to improve certain systems, and an official with LA Sanitation, which operates Hyperion, said Friday evening that some of the report’s recommendations have already been implemented.
Still, the biggest takeaway was that debris, which Hyperion officials had long said came from people dumping items into the sewer system, was not the direct reason the plant failed to the degree it did.
“It would have been better for (Hyperion) if that had happened,” said Michael K. Stenstrom, the main author of the report, “because that would be more defensible.”
Hyperion, situated on LA city land near El Segundo, is the largest water reclamation plant in the nation.
The approximately 260 million gallons of wastewater Hyperion handles daily is about three times more than the next largest Los Angeles facility — the Donald C. Tillman Water Reclamation Plant, which serves a portion of the San Fernando Valley — takes in each day during the dry season .
When wastewater initially enters the plant, the headworks facility — a series of eight screen-like mechanisms, called bar screens — sifts out trash, large debris and other items. The water then begins a journey of being treated and having its bacteria turned into energy.
But on July 11, that process broke down.
The bar screens all stopped working and the plant flooded. Officials had to dump 17 million gallons of raw sewage into the ocean to prevent the plant from going entirely offline.
It took weeks to fully repair the plant. During that time, residents complained of a noxious odor that left them with headaches, dizziness and other symptoms.
Stenstrom — a UCLA civil and environmental engineering professor who has worked primarily on wastewater treatment plants since 1977 — said he also initially assumed the cause of the spill was outside debris. But when he and others started investigating, they knew that wasn’t the case, Stenstrom said in a Friday phone interview.
Among the most critical issues, the report says what the failure of the plant’s bar screens and chopper pumps.
The bar screens did fail, as did the chopper pumps, cutting systems that macerate the thick debris captured by bar screens.
But the equipment itself was modern and in good condition, Stenstrom said.
A computerized system — called a distributed control system — wasn’t fully installed, however.
Such high-tech systems, Stenstrom said, are typically installed over several months, sometimes over a couple of years.
Installing the DCS system for Hyperion, he said, was delayed because one of the contractors had a disagreement with the city over its implementation.
“There was some preexisting system of some sort,” Stenstrom said. “But they are using computer technology, so things get obsolete quickly.”
The most high-tech DCS systems, Stenstrom said, are actually capable of remotely sending an alarm that calls a manager back into the plant.
Had the DCS system been complete, the head operator at Hyperion said, according to Stenstrom, it might have detected the debris build up and prevented the spill.
Another issue was that a tiered system for alarms doesn’t currently exist.
On the day of the spill, the water inside Hyperion’s plant rose rapidly. It started at about noon and by 4 pm, the water level was so high that it began spilling onto the plant’s internal streets, according to the report.
The rising water levels triggered a visible-but-inaudible alarm at 2:11 pm in the plant’s central control room, the report says — but operators didn’t acknowledge it.
It’s unclear why plant operators didn’t respond to initial warnings that something was wrong.
The report doesn’t give a specific answer, but notes various factors could have caused the delay, including the chaos of the unfamiliar situation, a lack of fast-acting technology, inadequate internal communication protocols and too few properly trained staff.
“If everything is the same level of alarm,” Stenstrom said, “then, when something happens, everything’s just alarming and no one knows what’s going on. That’s what happened at the Three Mile Island disaster.”
When asked why a plant worker just couldn’t have eyeballed the buildup of debris in the headworks, Sttenstrom said that for some reason, the operators just hadn’t noticed it.
“An operator walks though periodically to check it,” he said of the headworks. “The log said the operator went through, and things appeared normal.”
Then, just a few hours later, catastrophe struck.
The advisory committee has directed Hyperion to bulk up its staff and prepare better emergency protocols, among other recommendations.
But Hyperion’s interagency communication wasn’t the only problem, the report says.
The Los Angeles County Department of Public Health — the only agency with authority to close beaches — opted to leave them open to the public for a full day after being notified of the 17-million gallon raw sewage spill.
The delay, the report says, may have resulted from DPH’s policy to test bacteria levels in impacted water before making a judgment call, which typically takes up to a day.
“On the other hand, there has been a past policy of LA County Department of Public Health to close beaches proactively after a spill of a significant magnitude and reopen after testing assures the beach is safe,” the report says. “That policy was not followed in this case.”
DPH officials, for their part, quickly acknowledged their mistakes in the wake of the sewage spill.
“I want to apologize to the board and the public for our failures at the Department of Public Health for not responding to this appropriately,” Public Health Director Barbara Ferrer told the LA County Board of Supervisors on July 27. “There aren’t any excuses. There were multiple failures. Most have already been fixed.”
The ad hoc committee, in its 53-page report, made several recommendations on next steps for all agencies involved. They include massive overhauls and improved monitoring of Hyperion’s bar screen and conveyance systems.
Hyperion should also move to address the adequacy of the plant’s staffing levels, ensure that critical systems are adequately monitored, and fortify emergency protocols, emergency backup equipment and electricity supply in case of another incident.
Some of the recommendations have already been implemented by Hyperion, said Elena Stern, Los Angeles Sanitation & Environment spokeswoman. The main barricades that had been underwater are now open and operational.
And a critical alarm system at the headworks and the control center – that had only displayed a visible cue on a computer screen – now has an auditory component, Stern said.
That way, she said, if someone is away from their computer dealing with an emerging situation, they can hear if something else is amiss.
The committee, though, is still waiting for final results from CDM Smith and Brown and Caldwell, third-party engineering firms hired by LASAN. Those consultants, Stern said, will do a full assessment of both external and internal systems. CDM Smith was on-site at Hyperion on Friday, she said.
Their reports are expected sometime in the next few weeks, Stern said.
Once those reports are complete, Stern said, the next step is for LASAN to take the recommendations and “incorporate those that are feasible into our own developing action plan.”
“And by feasible,” Stern added, “that’s all related to money and getting the funding we need.”
Potential sources for funding would come from a variety of places, Stern said, including the federal government. Rate payers, however, will not see their bills increase as a result, she said.
It wasn’t immediately clear, meanwhile, how the El Segundo community at large would react to Friday’s report.
But at least one person said she was concerned.
Corrie Zupo, an El Segundo resident who helped rally neighbors complaining about the effects of odors coming from Hyperion for weeks after the spill, said she was shocked to hear some of the findings from the report.
“When I think of the city of Los Angeles and I think of the mayor’s commitment to us to be the leader of the nation on sustainability,” Zupo said, “what is startling and shocking is that our own government facilities are not equipped to even meet that standard.”
Zupo, who works as an environmental manager in the private sector, said a government agency should be held to a higher standard.
“Basically, as a government, they are supposed to be the platinum standard,” Zupo said. “If they can’t get it right, it’s just not a comforting feeling.”
Stenstrom, for his part, said he has visited at least 250 wastewater treatment plants during his 44-year career and knows well the complexities of managing a major facility like Hyperion.
“The Hyperion plant is not the best operated plant in the world,” he said, “but it’s far from the worst.”
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