King County is preparing to pay more than $5 million to settle a threatened lawsuit from the Suquamish Tribe over millions of gallons of sewage spills that have overflowed from county treatment plants into Puget Sound.

The proposed settlement also sets strict timelines for an estimated $600 million in improvements over the next decade that the county has been planning for its West Point Treatment Plant in Seattle’s Discovery Park. Those improvements — new pipes, pumps and batteries and other power supplies to keep pumps running in case of a power outage — are intended to prevent overflows which have historically happened in bad weather or when there’s a power failure.

Christie True, director of the county’s Department of Natural Resources and Parks, said the upgrades were ones the county had identified but would be assured because of the settlement.

“The settlement agreement comes with a really strict timeline and methods for holding us accountable,” True said. “It enables us to say we have to get it done by this deadline.”

The proposed settlement comes with a $40,000 penalty for missed deadlines and then $10,000 for each additional month of delay.

About half of the proposed $5 million settlement would go into a mitigation fund, controlled by the tribe, while the other half would go toward a new environmental project of the county’s choosing, to be completed within five years. The county would also agree to pay $240,000 toward the tribe’s attorney fees.


The county and the tribe stressed that they had worked hard to come to an agreement and avoid litigation.

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, the largest sewage treatment plant in Washington, and the third largest on the West Coast. The discharges added up to more than 6 million gallons.

The spills typically would have been mostly stormwater, but some would have included raw sewage.

The biggest spill noted by the tribe came on July 19, 2019, just as the Suquamish Tribe, located on the Kitsap Peninsula, was welcoming 40 canoe paddlers and hundreds of guests to its reservation for the annual Tribal Canoe Journey. The spill, of about 3 million gallons, closed beaches and prompted a health department warning to have no contact with the water.

The 2019 spill and most of the other large spills were the result of power outages or sags, sometimes just momentary, that can shut off pumps that control the millions of gallons of wastewater flowing through the plant. About $250 million of the planned upgrades at the plant are for “uninterruptible power supplies,” essentially massive batteries that should keep systems operating if power fails.

The tribe also alleged other environmental permit violations at the county’s treatment facilities at Alki and in Elliott Bay.


Ultimately, the tribe never sued the county; rather, it filed three updates on its intent to sue while it negotiated with the county.

The proposed settlement, agreed to by the tribe and County Executive Dow Constantine earlier this year, passed unanimously out of the Metropolitan King County Council’s environment committee Thursday.

It still must be approved by the full council, which could come later this month.

The tribe, in threatening litigation, cited the 1855 Treaty of Point Elliott, which guaranteed fishing rights for tribes in the region. The sewage spills, the tribe wrote, have fouled beaches where tribal members harvest shellfish, prompted recalls of commercially sold shellfish, interfered with salmon fishing and sales and disrupted cultural activities, such as the canoe journey.

“The waters of Puget Sound and the entire Salish Sea are the Tribe’s most treasured resource,” Suquamish Chairman Leonard Forsman said in a statement Thursday. “We are obliged to protect these waters, not only for ourselves but for all who rely on them for work, subsistence, recreation, and cultural practices.”

Forsman, in a letter to the County Council this week, said the tribe and the county had worked on the proposed settlement for more than two years and it has already been passed unanimously by the Suquamish Tribal Council.