Protecting Puget Sound During Winter Storms
West Point Power Quality Improvements
Hoffman built a 24,000 SF building at the West Point Treatment Plant to house critical backup power systems. The battery-based system, the first project of its kind in the United States, is now fully online, enhancing power reliability to the critical pump systems in the plant.
The facility’s centerpiece was a 16.8 MVA total UPS capacity installation, featuring 56 battery cabinets with 8 per VFD. Each cabinet contained 36 modules of 24 cells each, totaling 864 cells per cabinet and 6,912 cells per VFD. This robust system was designed to support 7 IPS and EPS pumps at full load for up to 2.5 minutes, ensuring continuous operation of critical treatment processes.
The construction involved over 600 dedicated staff members and contract workers, and totaled 250,000 hours of work, delivering on King County’s emergency declaration to protect Puget Sound and prepare the facility for climate impacts.
A "First of Kind" Battery Backup System
To support this massive electrical infrastructure, including the 44-ton battery system and building switchgear with Ovation control system panels, Hoffman poured a 4-foot-thick foundation requiring 1,600 tons of concrete, completed in three early morning pours. The new building also included essential support features such as fire suppression, maintenance access, and HVAC equipment.
This project represented a crucial capital improvement at the 1.45 million-square-foot treatment plant, where King County is investing more than $800 million over 10 years. The backup power system was particularly critical because the treatment plant’s location at the end of the City Light transmission line makes it especially vulnerable to voltage sags.
