Rialto WWTP - Municipal Wastewater Treatment in Rialto, California

Rialto WWTP is a municipal wastewater treatment facility located at 598 East Santa Ana Avenue in Rialto, San Bernardino County, California. The plant serves a population of approximately 97,873, placing it in the medium-to-large agglomeration category for US inland facilities. As a US-based plant, Rialto WWTP operates under the Clean Water Act and is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the California State Water Resources Control Board or the local regional board. For a plant of this scale, secondary treatment is typically required, with potential additional nutrient removal if discharging to sensitive water bodies. The treated effluent from Rialto WWTP likely discharges into the Santa Ana River watershed, which flows through Southern California to the Pacific Ocean near Huntington Beach. The Santa Ana River supports diverse aquatic life and provides water for agriculture and urban use, making proper treatment essential for downstream ecosystem health.

The plant's discharge enters the Santa Ana River system, which drains into the Pacific Ocean at Huntington Beach. The Santa Ana River is a critical water source in arid Southern California, supporting riparian habitats and migratory birds. Downstream waters are ecologically sensitive due to urban runoff and water diversions, requiring effective nutrient and pollutant removal to prevent algal blooms and protect coastal water quality.