Key to getting the West Point wastewater treatment plant working again will be the health of a suite of microbial life that handles much of the dirty work.
The region’s largest treatment plant was crippled in a catastrophic flood Feb. 9. So when it rains a lot, it pours — right out of the plant’s emergency outfall. On three days of heavy rain last month, the plant dumped about 235 million gallons of untreated wastewater straight into the Sound, including 30 million gallons of raw sewage.
Even on ordinary days now, the plant’s usual sparkling output is dingy with solids it can’t cleanse — as much as 107 tons poured into Puget Sound on a single day March 3.
The plant’s deep-water outfall, in fast-moving water far offshore, reduces the environmental hit. Tests show high bacteria counts after emergency bypasses quickly dissipated in the powerful currents. Beaches are back open after a brief closure right after the flood. And it’s a time of year when few people are swimming and boating in the open water.
But the plant is in violation of its permit, falling far below the required standard for water treatment. The soonest it will be back in normal operation — after tens of millions of dollars in repairs — is April 30, county wastewater managers say.
And that’s if they are lucky.
At stake is protection of the marine environment, already polluted and challenged by regional human impact — from development that has shaved forests and paved the lowlands and bulkheaded beaches, to oil and toxics that wash into the sound every time it rains.
Substandard treatment at the plant also could cost the ratepayers, through possible fines from the state Department of Ecology.
At the heart of the plant’s recovery are the unsung heroes of wastewater treatment at West Point: bugs.
A crawling, oozing, flagellating suite of microbial life is central to the plant’s work. They reduce the volume of solids produced in the treatment process, kill harmful pathogens and bacteria, and produce methane that heats the plant and drives the pumps bringing in more raw sewage.
But right now, the bugs are suffering with little food or heat since the flood. They must be revived before the plant can be put back into normal operation.
That’s not an easy task, and West Point has had problems for the past year and a half — long before the flood crippled the plant.
The trouble is in five squat concrete towers at West Point.
These towers, called digesters, are filled with sewage sludge and bugs doing work similar to what’s going on in your own gut — if they are kept toasty warm at 98.6 degrees and fed a steady diet to their liking.
But for about 18 months, something has been amiss with the digesters, which have been erupting with as much as eight feet of foaming sludge, sometimes spilling down the sides and piling up inches thick over an area big as a backyard.
To deal with the problem, the county has spent $451,570 hauling 616 loads of more than 4 million gallons of sludge in all from West Point to King County’s South Plant in Renton for treatment.
“It has become a chronic problem — we can’t figure out what the root cause is,” Robert Waddle, operations manager for the Waste Water Treatment Division said of the foaming.
While common in digesters and normal to some extent, the foam challenge at West Point is different, both in the persistence and amount of the foam -— so voluminous it is taking up enough space in the digesters to reduce treatment capacity.
From bringing in experts, to making modifications to the digesters, and even just trucking three to seven loads of sludge away each day, managers have been working for months to fix or mitigate the problem. So far it has defied solution.
The problem didn’t affect West Point’s ability to meet its permit, or cause environmental damage beyond smells and mess, Waddle said. “It’s an operational issue,” he said.
Trucking costs have somewhat been offset by reduced costs for cleanup at West Point and increased sales of methane gas from South Plant because it is processing more sludge.
But some Metropolitan King County Council members said they were vexed no one told them about it. “They should have at least alerted us,” said Kathy Lambert, chairwoman of the Regional Water Quality Committee, local officials from around Seattle and King County charged with overseeing wastewater issues.
Then came the flood last month that destroyed half the plant.
Repairs and figuring out what caused the flood — so far electrical and equipment failures are implicated — has made foam in the digesters the least of anyone’s worries. Right now, they are sweating getting them working at all.
Starting over after an event as profound as this flood is unprecedented at the plant.
The flood took out boilers that heat the digesters, so the bugs have been cold. It also killed the pumps and other equipment that carries the sludge that is the bugs’ food to the digesters. So the bugs are starving.
And now plant managers who aren’t really sure what had been wrong with the digesters for months must revive them before the plant can be put back in operation.
The digesters, at the end of the solids-management chain, have got to be working before primary treatment, at the front, or secondary, in the middle, can be started. Because without the digesters, there is nowhere to put the solids coming out of the plant.
It wasn’t until nearly a month after the flood that managers got one of the boilers working again. Now with a little bit of heat, they are hoping the bugs will slowly recover. But it’s a tricky process.
“It’s kind of uncharted territory for us,” said Eugene Sugita, process-control supervisor at West Point. It’s his job, working with two teams of scientific and biological consultants brought in to help, to revive the bugs.
And, not unlike your own gut, a shocked and upset system can take weeks to set right.
In the worst case, the bugs will go septic — die and rot.
If that happens, the next step would be to reseed with fresh sludge, to start over and build up populations of healthy bugs, ready to work. That would add delay, costing more money and continuing the dirty flow into Puget Sound even longer.
A microscope slide on a recent morning offered a glimpse inside one of West Point’s secondary-treatment clarifiers, where the results of a plant out of whack were telling. The animals on the screen were not moving much and populations were nowhere near as numerous or diverse as they should be.
Meanwhile the primary system — where wastewater is usually screened of trash and grit and settled to drop out a portion of the solids — is disabled. Because of damage to pumps, motors, electrical panels and more, the plant is only screening out trash, minimally settling the incoming flow, and disinfecting and dechlorinating the wastewater before discharging it into Puget Sound from the plant’s deep-water outfall.
The discharge is required to be 85 percent clean under the state permit, but right now on a good day it is about 30 percent clean for solids.
Water sampled at the plant on a recent day before and after treatment looked virtually the same. It’s a stunner at a plant that for 14 straight years won platinum awards for perfect permit compliance.
Pressure to bring the plant back to normal as quickly as possible is enormous. Workers have been at it around the clock since the flood.
Waddle, the operations manager, said so far he has no indication the bugs in the digesters have died — or gone sour, as they say in the business. And he hopes daily light feedings and air pumped in tanks in the secondary system will keep those bugs alive, too. “They are resilient,” he said.
But no one will really know what they are facing in terms of the time it will take to get to full recovery at the plant until the digesters can be warmed enough to attempt to restart the plant, and coax the bugs slowly, carefully into action.
“We are hoping it comes back,” Sugita said of the bugs’ essential work. “We are hoping it’s quick. But we won’t know until we start.”