Is Fresno, CA Tap Water Safe to Drink?

Where Does Fresno Get Its Water?

Fresno's drinking water comes primarily from groundwater, drawn from a large network of wells spread across the city and surrounding areas. The main public water provider is the City of Fresno, with additional systems serving parts of the metro area including Bakman Water Company, the City of Clovis, Malaga County Water District, and Pinedale County Water District.

The City of Fresno operates two major surface water treatment plants: the Northeast Surface Water Treatment Facility and the Southeast Surface Water Treatment Facility, which process imported surface water alongside the city's groundwater wells. The City of Clovis runs its own surface water treatment plant as well.

Smaller districts like Malaga County Water District and Pinedale County Water District serve specific communities within the Fresno metro area, each drawing from local groundwater sources and maintaining their own treatment operations.

How Is Fresno Tap Water Treated?

Treatment across Fresno's water systems includes a combination of coagulation and flocculation, filtration, granular activated carbon, ion exchange, membrane filtration, and aeration. Many of the city's groundwater wells are equipped with granular activated carbon units specifically to reduce contaminants before the water reaches your tap.

Disinfection relies primarily on free chlorine, with ozone also used at some facilities. Free chlorine kills bacteria and viruses and helps keep the water safe as it travels through distribution pipes to your home. A small residual level of chlorine is normal and expected in finished tap water.

The treatment setup reflects the complexity of managing both surface water and groundwater sources. Surface water plants go through more extensive multi-step treatment, while individual wells typically receive targeted treatment matched to what is detected in that particular source.

What's in Fresno Tap Water?

The most significant finding in recent EPA testing is PFPeA, a type of PFAS chemical, detected at a peak level of 0.031 micrograms per liter. The EPA's federal limit for PFPeA is 0.003 micrograms per liter, meaning the highest detected sample was roughly ten times above that standard. PFPeA was found above the limit in 18 of the ZIP codes mapped to this area.

PFOS, another PFAS compound, was detected at a peak of 0.041 micrograms per liter against an EPA limit of 0.004 micrograms per liter, and was found above that limit in one ZIP code. Both PFPeA and PFOS are covered by federal drinking water rules that took effect in 2024, with utilities required to meet them by 2031. Lithium was detected at up to 9 micrograms per liter but did not exceed any health benchmark.

PFAS chemicals are industrial compounds that do not break down easily in the environment and can accumulate over time. They have been widely used in firefighting foam, food packaging, and many consumer products, which is why they turn up in groundwater in many parts of California's Central Valley.

Health Risk Profile for Fresno

The EPA set its limits for PFAS compounds like PFPeA and PFOS based on evidence that long-term exposure at higher levels may raise the risk of certain cancers, thyroid disease, immune effects, and reproductive harm. The peak levels detected in Fresno testing were above those federal benchmarks, which is the basis for the higher-concern rating in this area.

Infants, young children, pregnant individuals, and people who are immunocompromised face greater risk from PFAS exposure because these chemicals can affect development and immune function. Bottle-fed infants are particularly sensitive since they consume more water relative to their body weight than adults do.

If you want to reduce PFAS in your drinking water, look for a filter certified to NSF/ANSI 58 (reverse osmosis) or NSF/ANSI P473 (pitcher or under-sink filters for PFAS removal). NSF/ANSI is an independent third-party certification you can look for on the box or the manufacturer's website. These filter types are the most effective at removing PFPeA and PFOS. Because chlorine is also used in the distribution system, an NSF/ANSI 42 certified filter or one that covers both PFAS and chlorine reduction can address taste concerns at the same time.

Lithium in Fresno's water was detected but did not exceed any health reference level, so it is not a current concern. The science on PFAS health effects continues to evolve, and the EPA's 2024 limits reflect the most current federal assessment of safe exposure levels.