Water Treatment Plant Ozone System Upgrade

Ardurra replaced end-of-life ozonation, air preparation, and ozone destruction systems at the City of San Luis Obispo Water Treatment Plant, restoring reliable primary disinfection after more than 23 years of service. The project was procured as design-build and began with an Ozone Pilot Study Protocol to determine ozone demand across multiple blend ratios of the City's three water sources.

Key Highlights:

• Conducted a pilot study establishing optimal ozonation rates to achieve 0.5-log Giardia inactivation across the City's three source water blend ratios

• Designed new liquid oxygen (LOX) feed gas facilities, storage tanks, vaporizers, ozone generators, and ozone destruction units

• Phased demolition of existing systems to maintain continuous plant operations during the transition

• Modified ozone contactors, sampling systems, piping, valves, and instrumentation to improve treatment precision and operational flexibility

• Coordinated with PG&E's Sustainable Solutions Turnkey (SST) Program to reduce electrical demand and lower long-term operating costs

The upgrades restore long-term reliability to the City's primary disinfection process, improve public health protection for residents, and reduce operating costs through efficient LOX-based ozone generation.