In 1972, the United States Congress adopted the Clean Water Act to improve the water quality of surface waters (such as rivers, lakes and the ocean) for both the environment and recreational use.

National Pollution Discharge Elimination System

The Clean Water Act established the National Pollution Discharge Elimination System (NPDES) program to help identify and reduce the source of pollution to waterbodies. Compliance with the Clean Water Act and NPDES requirements is enforced at the federal level by the US Environmental Protection Agency (EPA).

Regulation of the Clean Water Act

To comply with the Clean Water Act and the National Discharge Elimination System Program (NPDES), states have implemented and continue to enforce legislation mandating compliance with water quality requirements. California's water quality compliance is legislated through the Porter-Cologne Water Quality Control Act.

California coordinates water quality compliance through the California State Water Resources Board (State Board). For improved regulation at the regional level and a better understanding of local needs, the State Board has regional branches, called the Regional Water Quality Control Boards (Regional Boards). The City of Riverside is located within the Santa Ana Regional Water Quality Control Board (Santa Ana Regional Board).

The city has been issued multiple NPDES permits, including one for the citywide municipal activities and one for the wastewater treatment plant's operations.