The City of Fullerton’s drinking water met every state and federal safety standard during 2025, with no violations of maximum contaminant levels recorded across the system, according to the water department’s annual water quality report. The report, prepared in compliance with the Safe Drinking Water Act, covers testing conducted throughout 2025 and was released as the Fullerton Water Department marked 120 years of service. The city said it monitors more than 100 compounds in its water supply and reported only those substances actually detected.

Fullerton’s water is a blend of local groundwater drawn from the Orange County groundwater basin and surface water imported by the Metropolitan Water District of Southern California, which supplies water from the State Water Project in Northern California and the Colorado River Aqueduct. The city operates eight active wells in southern Fullerton and north Anaheim and seven imported water connections.

Lead and copper

Lead was not detected in any home sampled, and none of the 54 sites tested exceeded the federal action level of 15 parts per billion, the report said. Copper was found in 35 homes, but no site exceeded the action level of 1.3 parts per million. The most recent lead and copper samples were collected in 2024; the city said it complies with both action levels.

Disinfection byproducts and other contaminants

Total trihalomethanes averaged 32 parts per billion against a maximum contaminant level of 80, and haloacetic acids averaged 10 parts per billion against a limit of 60. Chlorine residual averaged 1.3 parts per million. In groundwater testing, uranium averaged 3.1 picocuries per liter (limit 20), nitrate averaged 2.5 parts per million (limit 10) and hexavalent chromium averaged 0.51 parts per billion (limit 10). All detected contaminants fell below their regulatory limits.

PFAS

The report addressed per- and polyfluoroalkyl substances, or PFAS, a group of human-made chemicals detected in water supplies nationwide. The city said earlier testing found levels at or above response levels and that it temporarily removed affected sources from service. Fullerton brought its first PFAS treatment plant online in June 2021 and a second in October 2024. The U.S. Environmental Protection Agency issued final national drinking water regulations for six PFAS in April 2024, with full compliance expected by 2029. Effective October 29, 2025, California revised notification levels for three PFAS compounds — perfluorohexane sulfonic acid, perfluorooctanoic acid and perfluorooctane sulfonic acid — to 3.0, 4.0 and 4.0 parts per trillion, respectively.

Testing and oversight

Drinking water quality standards are set by the U.S. EPA and the State Water Resources Control Board’s Division of Drinking Water. The Orange County Water District, which manages the groundwater basin, monitors for regulated and unregulated solvents, herbicides and pesticides.

Residents with questions about the report or their water quality can contact the City of Fullerton Water Quality Supervisor at (714) 738-2835. The city council meets on the first and third Tuesday of each month at 5:30 p.m. at City Hall, 303 West Commonwealth Avenue.