The 37 million gallon per day William B. Cater Water Treatment plant serves City of Santa Barbara with the majority of its drinking water while also supplying treated water to the districts of Montecito Water, Carpinteria Valley Water, Goleta Water, and La Cumbre Water. Constructed in 1964, the plant has been continually upgraded over the years to meet new regulations and a growing customer base. The most recent upgrade was the Advanced Water Treatment Project to add ozone pre‐treatment facilities at the Cater Water Treatment Plant. Construction was completed in September 2013. The ozone project is a regional solution for the City of Santa Barbara and Montecito and Carpinteria Valley Water Districts to reliably comply with the federally‐mandated Stage 2 Disinfection By‐product Rule for drinking water. Amid all the changes, the plant operations staff has come to value reliability in plant systems.