Solar panels sit atop the newest building at King County’s West Point Treatment Plant in Discovery Park. Inside, you won’t find pipes funneling the region’s sewage and stormwater; instead stand rows of newly installed high-voltage batteries intended to keep the pumps pumping during storms — and contaminated water out of Puget Sound.
These batteries are part of ongoing efforts to improve wastewater treatment here and prepare for storms, which are likely to become more frequent or more intense with human-induced climate change. The county plans to invest $10 billion in these projects over the next decade.
The plans got a huge boost Thursday when King County and the U.S. Environmental Protection Agency announced the first installment of a nearly $500 million loan package from the agency that will finance 14 wastewater infrastructure projects across the county. It’s the largest financial commitment to the county’s wastewater system from the EPA, and the initial installment is expected to save sewer utility ratepayers $19.8 million.
The facility, perched on a peninsula on Puget Sound in North Seattle, treats millions of gallons of wastewater each day. The loans will help replace raw sewage pumps and will provide seismic upgrades for the administration building, among other things.
“When you’re standing at this facility and you’re looking at the water, it is really crystal clear what it is you’re working to protect,” said Casey Sixkiller, regional administrator of the EPA, at a news conference Thursday at West Point.
Wastewater and stormwater are pumped into the treatment plant where screens remove large trash, sand, gravel and twigs. Cooking oils, grease, soaps and hair are removed from the wastewater before raw sewage and stormwater move to tanks where sludge bugs — sewage-eating microbes — reduce the volume of solids produced in the treatment process and kill harmful pathogens and bacteria. Then the water is disinfected and sent thousands of feet offshore into Puget Sound.
West Point, one of the largest wastewater treatment plants on the West Coast, receives sewage and stormwater flows from Seattle, Shoreline, north Lake Washington, North King County and parts of South Snohomish County.
“This one really handles some unique challenges because the combined system of flows into this plant can go from 90 million gallons per day level up to over 400 million gallons,” said Kamuron Gurol, director of the King County Wastewater Treatment Division. “You get a rainstorm … and that plant has to be able to accommodate and successfully treat flows that can literally quadruple in size and in an hour. The type of equipment that’s necessary to handle that kind of flow variation needs to be as robust as we can.”
The regional wastewater system was created by community leaders who envisioned a way to address water pollution in Lake Washington, Puget Sound and the Duwamish River, and to serve a growing population, said Christie True, recently retired director of the county Department of Natural Resources and Parks.
In the 1950s, wastewater flowed into Lake Washington, Puget Sound and many rivers and smaller lakes, without enough treatment; beaches were fouled with waste and black bacterial slime.
The West Point Treatment Plant and South Treatment Plant in Renton came online in the 1960s, and the results were dramatic, True said. But the system wasn’t built all at once.
When construction began, about 30 billion gallons of combined sewage and stormwater would overflow into the Sound every year, True said. Today it’s closer to 1 billion gallons.
More recent discharges have shown the vulnerability of the system in extreme weather.
Several system failures at West Point during heavy rainfall in 2017 caused significant flooding at the facility and resulted in an estimated 244 million gallons of untreated or partially treated sewage discharging into Puget Sound. Nearly 8 billion gallons of wastewater received limited primary treatment and disinfection over the next 77 days.
In 2019, True said, a three-quarters-of-a-second power interruption brought the equipment to a halt and caused a discharge of untreated sewage and stormwater into Puget Sound.
A 2019 audit found the risks at the plant would not be fully mitigated for years, and today, there’s still work to be done.
The past five years have been the most productive for these improvements since the regional treatment system was built in the 1960s, according to the county. The Wastewater Treatment Division has already begun making seismic upgrades, replacing aging pumps and pipes, and building the 24,000-square-foot structure full of batteries at West Point that will provide operators with a more reliable power supply.
In 2021, King County closed on a $96.8 million loan to help design and construct the Ship Canal Water Quality Project, a tunnel that will store up to 30 million gallons of untreated sewage and polluted stormwater.
It’s part of a $615 million-plus effort by Seattle and King County to keep untreated liquid from spilling into the Lake Washington Ship Canal, Lake Union and Salmon Bay when the antiquated drainage system in nearby neighborhoods is overwhelmed by heavy rains.
King County was the first to receive a loan from the Water Infrastructure Finance and Innovation Act program, for the Georgetown Wet Weather Treatment Station, and the loan package announced Thursday marks the third round of awards the county has been selected in.
The $498.3 million loan package from the EPA is expected to help the county complete seismic upgrades at two regional wastewater treatment plants, improvements to the recycled water system and upgrades to miles of conveyance and sewer pipes.
The first installment, a $194 million loan package funded by the Water Infrastructure Finance and Innovation Act, is expected to save King County ratepayers millions and lower the county’s annual debt payments through an extended repayment period.
The projects include:
- Replacing West Point’s raw sewage pumps installed in the 1960s with electric pumps;
- Replacing an aging grit classifier at West Point — a machine that sifts out twigs, sand and gravel;
- Adding capacity to treat wastewater flowing from East Lake Sammamish;
- Repairing one of the largest conveyance pipes in the system in Bellevue;
- Installing 4.5 miles of sewer pipe serving Redmond and Bellevue;
- Seismic upgrades to protect the West Point plant in Magnolia and South Treatment Plant in Renton.
The loans will also help the county comply with a settlement agreement with the Suquamish Tribe that outlined an estimated $600 million in improvements to be made at the treatment plant over the next decade.
In 2020, the tribe filed an intent to sue the county, documenting nearly a dozen times in 2018 and 2019 when untreated or improperly treated sewage overflowed into the Sound from the West Point plant.
Without these investments, Suquamish Chairman Leonard Forsman said, the degrading water quality impacts shellfish, fish and the people who rely on them for subsistence and commercial harvest.
“It’s a constant battle, in addition to climate change, we just try to push back as hard as we can to preserve what we’ve been gifted by the Creator and have a responsibility to preserve it for the next generations,” Forsman said.
But these projects won’t address new and emerging contaminant issues like nutrient pollution or PFAS.
The county is currently drawing up plans for a project to control overflows from five combined sewer outfalls where the Duwamish River meets Elliott Bay.
“Thanks to bold action by President Biden and by the EPA, we will achieve even more for people, for salmon, for the orca, and for all living things that call this remarkable corner of the continent home,” King County Executive Dow Constantine said.
Seattle Times photographer Erika Schultz contributed reporting.
The opinions expressed in reader comments are those of the author only and do not reflect the opinions of The Seattle Times.