Yucaipa facility reports major reduction in nitrification upsets after nanobubble upgrade

The Henry N. Wochholz Regional Water Recycling Facility in Yucaipa has reduced seasonal nitrification upsets by 95% after implementing nanobubble pretreatment technology from Moleaer, according to the company and Yucaipa Valley Water District.

The 4-mgd wastewater facility, which produces Title 22-compliant recycled water, had struggled with seasonal process instability caused by elevated surfactant concentrations and other inhibitory compounds that disrupted nitrifying bacteria and led to biomass die-off, poor sludge settling and occasional recycled water shutdowns.

To address the issue, the district installed Moleaer’s NanoShield nanobubble pretreatment system upstream of primary treatment. The system has operated continuously for 15 months through Moleaer’s Nanobubbles-as-a-Service program.

According to project results, ammonia upset frequency dropped from 17% of operating time to about 1%, while average recovery time decreased from more than 10 days to approximately one day. Facility operators also reported improved cold-weather nitrification performance, with bacteria performing as though water temperatures were roughly 10 degrees Celsius warmer during winter months.

Additional reported benefits included a 24% reduction in blower energy use per pound of ammonia removed, an estimated 20% increase in effective treatment capacity and elimination of recycled water shutdowns.

“Since implementing nanobubble pretreatment, the process has been far more stable,” said Charles Thomas, operations manager and chief plant operator for Yucaipa Valley Water District, in a statement.

The project recently received a 2025 Innovative Technology Award from the Water Environment Federation.