Hyperion
Dafeta on Thursday said he expects the repair work to be done no later than the end of the month. That’s crucial, since the day before, the plant manager described a race to finish before the rainy season.
If a surprise storm system pummels LosAngeles, it’s unclear whether Hyperion can handle it.
“We have contingencies in place,” said Hi Sang Kim, operations and engineering manager for Hyperion’s treatment division. “And we may get lucky in that regard,” alluding to the ongoing drought.
The second concern has to do with lingering air and water quality issues.
Much of that is because of the sludge buildup, Dafeta said.
Even though the plant has been repaired enough to function well, it will take time to reduce the sludge that accumulated for weeks, he said.
And the delicate biological chemistry of the digesters is to blame.
Dafeta compared the bacteria that eat the solids to a person’s stomach: You eat a meal, let your food digest and, eventually, you become hungry again. But if you overeat, you may become bloated or gassy.
The bacteria can become full, too. That would disrupt the process of turning the solids into the natural gas that powers Hyperion.
“We’ve been working fervently, every day,” Dafeta said. “We’re going to move this stuff out as fast as possible, but we don’t want to upset the balance either.”
Wednesday, the stench from the primary tanks was overpowering and the breeze blew from the ocean toward El Segundo.
“As time goes on,” Dafeta said, “the odor will go away.”
The wastewater, meanwhile, is being completely treated, he said.
But the sludge, again, is causing problems.
The sludge also built up in the clarifiers, the giant tanks that act as the last line of defense before the water goes down the 5-mile outfall. That treated water cascades over the edge of the tanks and heads to the outfall.
But currently, the sludge at the bottom of the tanks also is spilling over, mixing with the treated wastewater, Dafeta said. That’s why, he said, testing has shown water quality exceeding state levels for some solids.
That problem, too, will soon be fixed, Dafeta said.
L.A. Sanitation said, and inspectors are using cameras to look for clues about what happened.
L.A. Sanitation staff also has been analyzing flowmonitoring sites in the sewers and conducting visual inspections of 900 maintenance holes. As of Thursday, L.A. Sanitation had checked 362 of those holes.
“So far, there’s nothing obvious,” Traci Minamide, L.A. Sanitation’s chief operating officer, said Wednesday.
Someone could have dumped a large amount of debris down a maintenance hole. But another possibility, Dafeta said, is that trash built up in one of the sewers and then was somehow dislodged.
If that’s the case, it’s unknown if something similar could happen again.
Minamide, though, did say L.A. Sanitation cleans 4,000 to 6,000 miles of sewers a year, on average.
“If we have to clean better, we will do that,” Dafeta said. “We want to learn from this.”
During Thursday’s L.A. City Council committee meeting, Romero and Dafeta both said L.A.
Sanitation was working to improve Hyperion, including by talking with the manufacturers of the headworks screens, installed in 2019, to see if they need to upgrade the motors; lowering the threshold for opening the headworks bypass; and figuring out how to limit flooding.
“This was a pivotal moment for us,” Dafeta said, “in seeing what our vulnerabilities are.”