Port Gardner Storage Facility will allow Everett to meet state outflow requirements

EVERETT — To comply with state requirements and prepare for climate change, Everett’s Public Works department is building the Port Gardner Storage Facility, an 8-million-gallon wastewater storage facility.

Earlier this month, the Everett City Council approved allocating $111 million toward the project, which will operate next to the naval station.

The north part of Everett has a combined sewer system, meaning sewage and stormwater flow through the same pipes. When storms hit and spike the volume of water and runoff in the pipes, the whole system can quickly become inundated.

As a result, combined sewage flows untreated into a nearby body of water, like Port Gardner Bay or the Snohomish River, city public works information officer Kathleen Baxter wrote in an email. This is how the system was supposed to work, but the system was built between 1890-1963. Since then, environmental regulations and protections have increased.

The Department of Ecology limits the number of times cities can release combined sewer overflows, and has required Everett to limit the number of overflows to an average of one event, or overflow incident, per outfall per year by the end of 2027.

To comply with state requirements, the city had to find more water storage.

In 2012, Kimberly Clark closed down its Everett paper mill. When the property came onto the market in 2017, the city saw an opportunity to up-cycle its industrial water treatment plant for storage. In 2019, the city bought the 8.5-acre site for $4.7 million.

“What this is essentially, for layman’s terms, is a bubble in the pipe,” Public Works Principal Engineer Zach Brown said during a facility tour on Thursday. “Instead of having overflows out to Puget Sound when we get big weather events and exceed the capacity in our combined sewer system, it’ll overflow to here.”

Brown and utilities engineering manager Souheil Nasr have been working on the project since 2019 and are waiting for the last approvals from the state’s Department of Ecology. The city is planning to put the project out to bid for contractors this summer, Brown said.

A sister project, under different management, will lay pipes along West Marine View Drive to connect the storage facility with the sewer and stormwater system.

“The idea is that combined sewer will come into here, we’ll temporarily store it, and then whenever there’s capacity out in the conveyance system again, we’ll pump it over the hill to our wastewater treatment,” Brown said. Brown and Nasr both emphasized that the vast majority of the flow coming into the facility will be stormwater, not sewage.

The connecting pipe project is expected to start construction a year after Port Gardner Storage Facility construction starts, but both will have to be finished before the end of 2027 deadline, Brown said.

When construction is complete, the pipes will bring overflow to the facility, where large debris will be filtered out before running into 30-foot-deep cement tanks.

The tanks will be connected through windows 17 feet up the cement walls, Brown explained, and collected water will flow into additional tanks as needed until the facility reaches capacity. Only if all roughly 8 million gallons of storage are filled will an overflow event occur, but city employees said the storage will significantly decrease the number of events, and forecast exceeding state requirements.

Climate change, which causes more frequent and severe storms, has been a big driver in the need to create a storage facility, Nasr said.

In 2017 the University of Washington Climate Impacts Group created a report of precipitation projections for Everett, showing that high-intensity storms will become more frequent as the years progress. Data shows that historical 100-year storm events will increase in frequency by 25 to 30% by 2050.

The Port Gardner Storage Facility is one of many water and sewer projects set to be built by the public works department over the next four years. Those projects, along with an increase in construction costs, were reasons for a water and sewer rate increase approved by the City Council in January. Everett’s combined water and sewer rates are set to increase 43% by 2028.

“It’s really important for our customers to understand that increasing environmental regulation requires us to do work that’s very expensive,” public works public information officer Kathleen Baxter said. “We do have a robust rate assistance program with discounts for military veterans and for disabled and senior citizens because we do want to help those who can’t afford the increase.”

More information about the Port Gardner Storage Facility and utility rates can be found at everettwa.gov/325/Public-Works.

Eliza Aronson: 425-339-3434; eliza.aronson@heraldnet.com; X: @ElizaAronson.

Eliza’s stories are supported by the Herald’s Environmental and Climate Reporting Fund.