Is Orange County tap water safe? PFAS and what each water agency says

Who supplies tap water in Orange County?

Three layers. The Orange County Water District (OCWD) manages the Orange County Groundwater Basin, which it says supplies up to 85 percent of the water for 2.5 million people in north and central Orange County. The Municipal Water District of Orange County (MWDOC) is a wholesale provider that works with the Metropolitan Water District of Southern California and 27 member agencies. The water you drink comes from a retail provider: a city utility such as Anaheim, Santa Ana or Huntington Beach, or a district such as Irvine Ranch Water District. Your water bill names yours.

The mix matters because OCWD says its sampling finds no PFAS in the imported water it buys from Metropolitan or in the water its Groundwater Replenishment System makes to refill the basin (OCWD FAQ). MWDOC's supply table for fiscal year 2023/24 shows how much each agency drew from each source. MWDOC says local supplies vary by region and include groundwater, recycled wastewater and surface water. Its table lists recycled water for non-drinking uses separately, and that makes up the rest of each row.

North and central agencies such as Garden Grove and Westminster lean almost entirely on local water, while south county providers such as San Clemente and the Laguna Beach County Water District rely mostly on imported water. Every city is on the Orange County hub.

What are the federal PFAS limits, and what changed?

On April 10, 2024, the EPA announced the first national drinking water limits for six PFAS (EPA PFAS rule):

• PFOA and PFOS: 4.0 parts per trillion (ppt) each.
• PFHxS, PFNA and HFPO-DA (GenX): 10 ppt each.
• Mixtures of two or more of PFHxS, PFNA, HFPO-DA and PFBS: a hazard index of 1.

Compliance is judged on running annual averages. Water systems must finish initial testing and start telling the public their PFAS levels by 2027, and from 2029 a system over a limit must act to reduce PFAS and notify the public of the violation.

In May 2025, the EPA said it would keep the PFOA and PFOS limits and rescind and reconsider the other four. On May 18, 2026, it proposed both changes. The first would let water systems request two more years, to 2031, to meet the PFOA and PFOS limits, with short-term steps required at 12 ppt or more. The second would remove the PFHxS, PFNA, GenX and mixture limits. Comments closed July 20, 2026, and the EPA's pages, last updated October 8, 2026, still list both as proposals, not final rules.

What are California's PFAS notification and response levels?

The State Water Board's Division of Drinking Water sets advisory levels, in ppt (State Water Board PFAS page):

Above a notification level, OCWD explains, a water agency must tell the local governing body, such as the city council, and report the detection to customers through its yearly report, its website or a bill insert. Above a response level, the State Water Board says a system under its monitoring order must take the source out of use, treat the water or notify the public. OCWD describes notification levels as precautionary, health-based advisory levels while the state studies whether to set enforceable limits. The board lists no state PFAS standard yet and calls developing one a priority. It also notes that California adopted public health goals of 0.007 ppt for PFOA and 1 ppt for PFOS on April 5, 2024.

What is OCWD doing about PFAS?

Building treatment plants. OCWD's PFAS page counts more than 100 wells affected, 55 back online, 15 affected water retailers and an expected cost of $1.8 billion over 30 years. It has led a regional treatment program since 2019, paying to design and build the plants and half their operating costs, while the local agencies run them. Two recent plants use ion exchange:

• Tustin: the Main Street plant, dedicated May 22, 2025, treats up to 6,400 gallons a minute from four wells (OCWD and Tustin).
• Orange: Irvine Ranch Water District's Orange Park Acres well treatment, marked complete September 22, 2025, treats up to 3,200 gallons a minute, enough for about 14,000 households (OCWD and IRWD).

More are coming. Santa Ana's 2025 water quality report says the city is working with OCWD on treatment at Wells 31, 38, 27 and 28 and at Garthe Reservoir.

How do I find my water provider's PFAS results?

In its Consumer Confidence Report, also called the water quality report. The EPA says every supplier must send one by July 1 each year, listing its water sources, the regulated contaminants it detected and the health effects of any found in violation of a standard. Call your provider or use the EPA's CCR search tool. Our water hardness by provider guide links the reports for more than a dozen Orange County providers.

Look for rows named perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), in ppt. ND means not detected. Many reports print the notification and response level beside each one; Anaheim's 2026 report, for example, notes that wells above the response level were removed from service. A range shows the lowest and highest result in the report, so ask your provider if a number is unclear.

Do home water filters remove PFAS?

Certified ones can. NSF says a filter certified to NSF/ANSI 53 (drinking water treatment units, health effects) or NSF/ANSI 58 (reverse osmosis systems) is an effective way to limit PFAS exposure, and that a filter must cut PFAS to below 20 ppt to carry a PFAS reduction claim (NSF). NSF also says its committee is updating both standards to line up with the EPA rule. Look up the exact model in NSF's certification listings to see its PFAS claim. NSF adds that boiling water does not reduce PFAS exposure.

As of November 2026. Your provider's latest report and the EPA and State Water Board pages have the final word.