Power quality improvement
West Point Treatment Plant Current Projects
Construction to improve West Point’s power supply quality ramps up this summer
King County continues working hard to improve the West Point Treatment Plant’s power quality. Improved power quality for West Point helps keep untreated wastewater out of Puget Sound, protecting public health and the environment. The summer presents an important step forward in our efforts.
Power disruptions at the West Point Treatment Plant can cause electrical equipment to protectively shutdown, and when this happens during heavy rain, the facility is overwhelmed with untreated wastewater and stormwater. To prevent the plant from flooding, flow is diverted to Puget Sound in an emergency bypass.
The objective of the project is to eliminate the emergency bypasses of wastewater that are caused by power disruptions. This project has identified a solution and is rapidly implementing it to improve the reliability of the plant’s electrical power supply.
The project team analyzed numerous potential solutions and chose the solution that is the most effective and quickest to implement. The County will install a battery-based system to condition power as it is fed to critical systems in the plant so that they continue to operate during power disruptions, preventing the emergency bypasses of wastewater to the Puget Sound.
Construction begins in 2022. The power quality improvements are expected to be protecting West Point from power disruptions by 2025.
- Emergency declared by King County Executive and project initiated: Feb 2021
- Battery solution selected: May 2021
- Demolition of existing structure: 2022
- Construction (estimated): 2023-24
- System online, project complete (estimated): 2025
For more information about this project contact Ryan Harlow at:
206-848-0814 or TTY: 711
If you’d like to receive email or text updates on the power quality improvement project and other current projects at the West Point Treatment Plant:
Frequently asked questions
The following FAQs are also available as a PDF .
About power quality at West Point
In the past 20 years, West Point diverted combined stormwater and wastewater into Puget Sound 15 times (as of Feb. 21, 2021) because Seattle City Light power disruptions caused 2 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.
Identifying a power quality solution
Designing and building a power quality solution
Compared with the other potential solutions we looked at; this one has a short timeline. It is estimated that it can be installed and started up by 2024. The project team is working nimbly and with great urgency to put this solution to work – while ensuring safety and sustainability.
We expect to install and begin using the equipment by 2025. Work to demolish the existing structure and make room for the new battery building begins in the summer of 2022.
Construction will take place within West Point’s boundaries during daytime hours on weekdays. Neighbors may notice an increase in truck traffic and may hear typical construction noise or see materials stockpiled. Crews will work safely and efficiently to get the job done with minimal impacts to neighbors and park visitors.
King County Wastewater Treatment Division blog, 8/19/21: Charging ahead with reliable battery power for West Point Treatment Plant
King County media release, 2/25/21: Executive Constantine requests $65 million and signs emergency declaration to protect West Point Treatment Plant from power disruptions.
King County Wastewater Treatment Division blog, 2/26/21: UPDATED: We’re working to improve power supply quality at West Point Treatment Plant to continue our clean-water mission.