Summary

King County Executive Dow Constantine transmitted legislation to the King County Council and signed an emergency declaration to provide West Point Treatment Plant with more reliable power in response to increasing power disruptions to the 1.45 million-square-foot facility.

Story

Along with submitting a supplemental budget request to the County Council for up to $65 million for power improvements, Executive Constantine signed an emergency declaration that enables the Wastewater Treatment Division to quickly purchase services and equipment to provide more reliable on-site power sources at the West Point Treatment Plant in Seattle.

The Wastewater Treatment Division will work with Seattle City Light on power upgrades. Included in the funding package announced today is $3 million to analyze schedules and cost estimates if high-voltage power lines are needed at West Point. Both agencies are also evaluating the feasibility of more targeted solutions such as a battery storage system, or other power conditioning devices.

West Point treats wastewater from homes and businesses in Seattle, Shoreline, north Lake Washington, north King County and parts of south Snohomish County. The facility’s maximum capacity is 440 million gallons a day during peak storms, and it requires about 10 megawatts of electricity daily – roughly the equivalent of powering 11,000 single-family homes.

In the past 20 years, the West Point Treatment Plant diverted a highly diluted mixture of stormwater and wastewater into Puget Sound 15 times because Seattle City Light power disruptions caused equipment shutdowns when the plant was operating at or near capacity. More than half of these bypasses – 53 percent – occurred over the past five years.

As climate disruptions become more frequent, West Point is expected to experience more days of maximum flows. In addition, these same climate effects increase the likelihood of disturbances to power facilities.

"West Point is a vital facility that protects the health of people and Puget Sound. Even a momentary disruption in the electrical power supply can have catastrophic results. Difficult technical issues remain to be resolved with Seattle City Light, but I am taking urgent action today to help the plant better withstand power problems, and strengthen our ability to protect water quality for generations to come," said Executive Constantine. "I thank Seattle City Light for working with King County to ensure greater reliability and resiliency for this critical infrastructure."

Executive Constantine’s proposal, sponsored by Councilmember Jeanne Kohl-Welles, includes modifying on-site power generation at West Point and an option to use batteries to help buffer the power supply, allowing plant equipment to continue operating during power disruptions. This work is expected to be completed within 24 months because of the declaration of emergency.

These moves come after Seattle City Light produced a report last year that determined the feasibility of bringing high-voltage electricity directly to West Point via transmission wires to resolve longstanding power issues. Today’s proposal requires additional analysis to determine if transmission grade power is necessary at West Point and, if so, the identification of cost estimates, regional implications, and an expedited timeline for delivery.

The other two King County wastewater treatments at South Plant in Renton and Brightwater, north of Woodinville, are serviced directly by high-voltage power; neither has bypassed stormwater and wastewater as a result of power problems.

In recent years, King County has made significant improvements to safety and operations at West Point.

Relevant links

• King County Wastewater Treatment Division
• VIDEO: B-roll of West Point Treatment Plant
• West Point Treatment Plant

Quotes

West Point is a vital facility that protects the health of people and Puget Sound. Even a momentary disruption in the electrical power supply can have catastrophic results. Difficult technical issues remain to be resolved with Seattle City Light, but I am taking urgent action today to help the plant better withstand power problems, and strengthen our ability to protect water quality for generations to come. I thank Seattle City Light for working with King County to ensure greater reliability and resiliency for this critical infrastructure.

For more information, contact:

Marie Fiore, King County Wastewater Treatment Division, 206-263-0284