The Santa Monica City Council unanimously approved the city's 2025 Water Quality Report on Tuesday, confirming that the municipal drinking water supply meets all federal and state safety standards despite exceeding some voluntary health advisory levels.
The triennial report, required under California Health and Safety Code Section 116470, analyzes water quality against Public Health Goals (PHGs) and Maximum Contaminant Level Goals (MCLGs) — extremely stringent advisory benchmarks set well below enforceable safety limits.
"The City's drinking water supply complies with all Federal and State drinking water standards," said Sunny Wang, Water Resources Manager, in the report presented to council.
While Santa Monica's water exceeded some PHGs during the 2022-2024 reporting period, it remained well within all Maximum Contaminant Levels (MCLs) — the legally enforceable standards that determine whether water is safe to drink. The distinction is critical for public understanding of water safety.
PHGs represent theoretical health risks based on conservative scientific models. For cancer-causing substances, they typically correspond to one additional cancer case per million people drinking two liters of water daily for 70 years — a risk level the state considers negligible.
"PHGs are goals identifying extremely low risks," the report explains. "These risks, when normally assessed, pertain to one in one million persons drinking the water over a seventy-year period who may be at risk from a contaminant based on assumptions and theoretical extrapolations."
The city detected trace amounts of several substances above PHG levels, including uranium, bromate, lead, hexavalent chromium and fluoride. However, all readings remained significantly below MCLs that would trigger regulatory action or pose immediate health concerns.
For example, uranium levels in Santa Monica's treated groundwater averaged 1.2 to 2.0 picoCuries per liter during the reporting period — above the PHG of 0.43 pCi/L but well below the MCL of 20 pCi/L. Similarly, lead levels measured 0.0021 mg/L at household taps, exceeding the PHG of 0.0002 mg/L but remaining below the action level of 0.015 mg/L.
The city's water system serves over 93,000 residents plus businesses and visitors. Staff conducts more than 10,000 laboratory tests annually to monitor water quality, with 24-hour surveillance across the distribution system.
"The water quality of the City's drinking water supply is monitored 24/7 across the water system and over 10,000 tests are conducted annually to ensure its quality and safety," according to Rick Valte, Public Works Director.
Santa Monica sources about 75% of its water from local groundwater wells and 25% from the Metropolitan Water District, which imports water from the Colorado River and California's State Water Project. The city operates several treatment facilities, including the Arcadia Water Treatment Plant that uses reverse osmosis, filtration and disinfection processes.
The report notes that reducing contaminant levels to meet PHGs would require costly additional treatment with uncertain health benefits. "The health protection benefits of these further hypothetical reductions are not clear and may not be quantifiable," staff concluded.
California requires water agencies serving more than 10,000 connections to prepare PHG reports every three years. The reports must include public hearings to accept community input.
"No additional actions are recommended for the treatment of the City's potable water supply," the report states.
The approved report will be available for public review at City Hall, the Main Library, the Water Resources Division office, and online at the city's water information webpage. A public notice about the report was published in the Santa Monica Daily Press on September 30.
The next PHG report will be due in 2028, continuing the city's commitment to transparency about water quality monitoring and public health protection.