Does Phoenix tap water have PFAS? What filter removes it?

Phoenix tested for PFAS as part of a national EPA program called the fifth Unregulated Contaminant Monitoring Rule, or UCMR 5. The city's report explains that the EPA picked 30 substances for this round, including 29 PFAS and one metal. Phoenix says it monitored from January of 2023 through January of 2024, and that "Any unregulated contaminants detected in 2023 thru 2024 are reported in the following table." The report also notes that no monitoring was required in 2025.

That table lists three substances. Two are PFAS.

The report gives PFAS results in parts per billion. One part per billion equals 1,000 parts per trillion, which is the unit the EPA uses for its PFAS limits. That is why the last column matters. It puts the city's numbers on the same scale as the federal rule.

A few things stand out. First, neither PFBS nor PFBA has its own federal limit. Second, PFOA and PFOS are not in the table. Since the city says the table holds the unregulated substances it detected, their absence means they were not reported as detected during that round. Third, the city lists the MCL column for both PFAS as "None." An MCL, or maximum contaminant level, is the legal limit for a substance in public drinking water.

The report describes PFAS in general terms too. It calls PFAS "a group of synthetic chemicals used in a wide range of consumer products and industrial applications," and its list of examples includes non-stick cookware, water-repellent clothing, stain-resistant carpets, cosmetics and firefighting foams. It adds that they are found in people, animals, water, air, fish and soil across the country and the world.

These results are for City of Phoenix water. Mesa, Chandler, Tempe, Scottsdale and other Valley providers publish their own reports, and our page on what contaminants show up in Arizona tap water covers the wider picture. Check your own provider's report before you buy anything.

On April 10, 2024, the EPA announced its first national drinking water rule for PFAS. It set legal limits for six PFAS, as listed on the EPA's rule page:

• PFOA: 4.0 parts per trillion
• PFOS: 4.0 parts per trillion
• PFHxS: 10 parts per trillion
• PFNA: 10 parts per trillion
• HFPO-DA (known as GenX): 10 parts per trillion
• Mixtures of two or more of PFHxS, PFNA, HFPO-DA and PFBS: a Hazard Index of 1, a formula that adds up the combined risk

PFBS only appears in that last line. It counts as part of a mixture, and only when it shows up with at least one of the other three. PFBA is not on the list at all.

The rule has moved since 2024. On May 18, 2026, the EPA proposed two changes. According to the EPA's page, one proposal keeps the limits for PFOA and PFOS and would give water systems the option to ask for two more years, to 2031, to meet them. The other would rescind the limits for PFHxS, PFNA, GenX and the Hazard Index mixture. Those are proposals, so the final shape can still change.

The monitoring timeline under the 2024 rule matters for your next report. The EPA says water systems must finish initial monitoring by 2027. Systems must also give the public information on the levels of these PFAS in their drinking water starting in 2027. So future Phoenix reports should carry more PFAS detail than the 2025 one. Look for it.

The EPA's own home filter guide answers this better than any sales pitch. It says to contact your water provider first to learn which PFAS, if any, are in your water. Then it says: "If PFAS have not been measured in your water, or if PFAS have been measured but are below federal limits, a filter may not be useful to you."

Phoenix water has been measured. The two PFAS it found have no individual federal limit, and the two that do were not in the detected table. By the EPA's own test, a PFAS filter is not a must for City of Phoenix water based on the 2025 report.

Some people still want one. That's a fair choice. You might be pregnant, feeding an infant formula mixed with tap water, or you might just want your drinking water as low as it can go. You might also be on a private well, where no city report applies at all. The EPA says PFAS in drinking water can be a significant portion of a person's total PFAS exposure, and that reducing exposure lowers the risk of related health problems. If that's you, filter the water you drink and cook with. Nobody needs a PFAS filter on the toilet supply. Just so you know, a filter for PFAS is a separate buy from a softener. A softener deals with hardness, not PFAS.

The EPA names three filter types that "can be effective at reducing PFAS":

1. 1Granular activated carbon (GAC). The EPA says these filters "use carbon to trap chemicals as water passes through them."
2. 2Reverse osmosis (RO). The EPA describes reverse osmosis as "a process that forces water through an extremely thin barrier that separates chemicals from the water."
3. 3Ion exchange resin. The EPA describes resins as "tiny beads that act like powerful magnets that attract and hold the contaminated materials from passing through the water system."

The EPA's research page adds that the GAC, ion exchange and RO point-of-use systems it studied "can greatly reduce PFAS levels." It also lists the catches for RO. The system sends a stream of untreated water down the drain, and the EPA says RO "wastes about one gallon of water per every gallon treated." In a desert city, that's worth knowing before you choose. Our page on whether reverse osmosis is worth it goes deeper on RO trade-offs, and under-sink versus whole-house RO explains why RO usually belongs at one tap.

### How to check the certification

A filter that says "removes chemicals" on the box may not touch PFAS. The EPA's advice is specific. Check the packaging for certification to "NSF/ANSI 53" or "NSF/ANSI 58" for PFAS reduction. The EPA's research page pairs Standard 53 with PFAS reduction claims and Standard 58 with reverse osmosis systems. The EPA also notes that filters come as pitchers, faucet-mounted units or systems for your entire home, at a wide spread of prices. If the box is unclear, the EPA says to check the certification body's product directory. It lists five accredited bodies that certify filters for PFAS: CSA Group, IAPMO R&T, NSF, UL and the WQA.

Two cautions from the EPA are worth reading closely.

• Certifications focus on PFOA and PFOS. The EPA says "As of April 2024, filter certifications focus on removing the chemicals PFOA and PFOS, which are two specific types of PFAS." Phoenix's detected PFAS are PFBS and PFBA, not PFOA or PFOS. The EPA suggests checking the NSF listing to see if a product treats the type of PFAS you're trying to remove. Do that step.
• Certification does not promise the new limits. The EPA notes that the current certification standards "do not yet indicate that a filter will remove PFAS down to the levels EPA has now set for a drinking water standard." Lower is still better, the EPA says, since reducing PFAS levels in your water is an effective way to limit exposure.

### Keep it maintained

A PFAS filter that is past its change date is not doing its job. The EPA says "Filters are only effective if they are maintained according to the manufacturer's instructions." It warns that skipping the replacement schedule can increase your risk of exposure to PFAS. Phoenix's report makes the same point about any home treatment system: not following the maker's operation and maintenance instructions "can result in potentially unsafe water." For RO, that means pre-filters, post-filters and the membrane. Our guide to RO filter replacement and maintenance covers the schedule.

Here's the play. Read your provider's latest report, compare it with the federal list, and only buy a certified filter if the numbers or your household call for one.

If you decide on filtration, HQ Plumbing & Air offers water softening and filtration for Valley homes. We're licensed and insured, and we give free estimates with upfront pricing.