Approximately 8 MGD of recycled water is used at over 190 different sites. Reuse applications include landscape irrigation of parks, schools, golf courses, greenbelts, and such; irrigation and dust control at the Spadra Landfill; and industrial use by local manufacturers. The remainder of the recycled water is discharged into the San Jose Creek, where it is allowed to percolate into the groundwater in the unlined portions of the San Gabriel River for groundwater recharge.

• Learn more about the Sanitation Districts' recycled water program
• Water Recycling Brochure

The original plant, known as the Tri-City Plant, was owned by the Cities of Pomona, Claremont, and La Verne. It was placed into operation in July 1926, with water reuse beginning in 1927. The Sanitation Districts took over operations in 1966 and increased the plant capacity to 4 MGD of wastewater. In 1970, the plant capacity was expanded to 10 MGD of wastewater with the construction of additional primary, aeration, and final sedimentation tanks. In 1977, the plant capacity increased to 15 MGD of wastewater with the implementation of tertiary-level water treatment, including activated-carbon gravity filters, chlorine contact tanks, and a de-chlorination system. In the early 1990s, the plant underwent a third expansion with the construction and retrofit of the activated-carbon gravity filters to deep bed anthracite filters and the addition of a third chlorine contact tank for additional disinfection capacity.