Puget Sound wastewater plants may need billions to meet state mandates

An effort to protect Puget Sound’s marine life has ignited a debate over a new environmental mandate that wastewater treatment plants say will cost billions and lacks clear science to back it up.

The Washington State Department of Ecology issued a permit, effective in January 2022, that requires municipal wastewater treatment plants that discharge into the Sound — there are 58 of them — to reduce the amount of certain nutrients in their discharge.

“We cannot ignore what science and common sense are telling us: with more people living in Puget Sound, we have more nutrients going into the water,” Vince McGowan, the Department of Ecology’s water quality program manager, said in a July 2021 news release. “Wastewater treatment plants are the gatekeepers for nutrients and the solution to this problem. Upgrading these facilities takes smart planning and significant investment, which is why we need this permit now, so the work to restore Puget Sound gets underway.”

The inlet of the Pacific Ocean and its relatively sheltered waters spurred the development of the Seattle metropolitan region, which has more than 4 million residents.

The permit, which is how the state regulates discharge, is aimed getting the 58 plants to lower the amount of nitrogen, which comes largely from human urine, in the wastewater. High nitrogen levels in water trigger a chain reaction that lowers the amount of dissolved oxygen in the water, threatening marine life.

The sound already has several so-called dead zones and the problem is only going to worsen as more people move to the Pacific Northwest and climate change accelerates, according to the ecology department.

The Puget Sound Nutrient General Permit requires sewer operators to upgrade their systems with technology that cleans nitrogen from discharge.

The upgrades would cost billions, in some cases requiring new treatment plants, as would be the case for the area’s largest district, King County. Sewer bills would double by 2030 under the plan, according to some district officials.

On top of the price tag, the science driving the mandate is unsettled, opponents said.

Several wastewater treatment plants, counties and cities, including King County and the City of Tacoma, have sued to block the mandate.

“The capital costs could be quite tremendous,” said John McClellan, interim general manager of the Alderwood Water & Wastewater District, one of the plaintiffs.

The uncertain science and the rulemaking process also prompted the litigation, McClellan said.

“They didn’t do the science they needed to do to make this as firm as it needs to be,” he said. “We’re trying to make sure that the money that spent, which is a lot of money, will actually do good.”

The state ecology department says it has been studying the problem since the 1990s and is using the “best science available” when crafting its nutrient reduction program, according to a response to comments document released in December 2021. “Model results show that nutrient loads from municipal WWTPs, especially the largest plants, have a significant ecological impact within the [Washington] waters of the Salish Sea,” the document said. Puget Sound is a component of the Salish Sea.

McClellan said that Alderwood’s treatment plant is relatively small, so upgrade costs would be relatively minimal. “But that’s not the case for others, particularly King County,” he said.

The King County wastewater treatment division, which is the largest on the sound, would be forced to build a new plant in Seattle, erecting the facility in a dense area covering around 150 acres, Kenneth Rice, the district’s capital finance debt coordinator, said in November at a University of Chicago conference on climate change.

“It would be a multi-billion project, which we haven’t yet included in our plan,” Rice said. “Addressing affordability is something that needs to be considered as well.”

The price of a fourth King County treatment plant may be between $9 billion to $14 billion, according to the county’s response to the draft permit. The county’s sewer rates are already forecast to double, to $100 a month, in the next 10 years and the cost to implement the new permit could drive the rates up to as high as $250 month, the county said.

The district, which serves around two million residents, funds its capital improvement plan through a combination of cash, bonds backed by sewer rates and state loans. The district had $3.6 billion of outstanding debt as of July 2021, according to Moody’s Investors Service, which rates its limited-tax general obligation bonds Aaa and its senior lien sewer revenue bonds Aa1.

The King County Council has approved a 2023-2032 sewer rate financial forecast that includes $50 million for initial investments related to the permit, such as nitrogen reduction planning and monitoring, said King County spokesperson Marie Fiore.

“We recognize that nutrients are a problem along with other pollutants,” Fiore said. “We want to work with Ecology to address nutrient pollution and we are committed to doing our part. Right now, most agencies with missions to reduce pollutants in Puget Sound unfortunately work in silos with funding restrictions which limits achieving multiple benefit outcomes and does not result in the greatest overall impact.”

Of the 58 treatment plants affected by the new mandate, only one, the LOTT Clean Water Alliance, already has the technology in place to reduce its nitrogen levels.

LOTT, a nonprofit group that manages wastewater treatment for the cities of Lacey, Olympia and Tumwater, has been under a state mandate to reduce its nutrients since 1994, according to spokesperson Lisa Dennis-Perez. The alliance recently completed an upgrade of the technology, which cost $30 million. The original 1994 project also carried a $30 million price tag, Dennis-Perez said.

“Over the last three decades we’ve invested over $60 million in nutrient reduction upgrades,” she said.

The district’s current six-year capital plan totals $150 million.

Noting that wastewater plants are “the major source” of adding nitrogen to the Salish Sea, Department of Ecology spokesperson Collen Keltz said the state realizes the investments are costly.

“As a state agency, we’re trying to do everything we can to get the funding to move this forward,” Keltz said.

The department has a grant and loan program that supports upgrades and also hopes to win federal funding, she said.

The program outlines three five-year permit cycles, so much of the big-ticket spending won’t occur for several years, she said. “These are significant investments, and it’s going to take some planning.”

For now, the timing of the program remains uncertain while the litigation appeals play out.

Some of the permit requirements have been stayed pending the outcome of an administrative appeal of the permit to the Pollution Control Hearing Board, said City of Tacoma Chief Deputy City Attorney Chris Bacha in an email.

That appeal is under a stay pending the outcome of a separate appeal under the Administrative Procedures Act challenging the underlying basis for the issuance of the permit.

“Until the appeals are resolved, we cannot know what, if any, fiscal impacts will arise” from the permit, Bacha said.

A group of wastewater treatment plants in a group called the Puget Sound Clean Water Alliance has partnered with science-based organizations to develop a regional strategy to protect the Puget Sound, said Alderwood’s McClellan.

“We’re not opposed to regulating things that need to be regulated,” McClellan said. “We just want it done in the right way to make sure ratepayer money is spent well.”