The clearest PFAS story in Arizona plays out beneath Tucson. Aqueous film-forming foam (AFFF) sprayed at the Arizona Air National Guard Base and Tucson International Airport soaked into an aquifer that was already carrying a decades-old trichloroethylene Superfund burden. Monitoring data compiled by ADEQ and reported by AZPM traced a sharp climb in PFAS across parts of the Tucson basin between 2017 and 2021 — roughly a 700% jump in some readings — layering a new contaminant on top of an old one.

Rather than send that water to customers, the utility idled several supply wells once concentrations crossed into unsafe territory. The EPA subsequently directed the Air Force and the Arizona National Guard to shoulder cleanup at the Tucson International Airport Area Superfund site, while the Central Tucson PFAS Project keeps charting how far the underground plume has traveled.

Reading the federal thresholds

The EPA's 2024 rule marked the first time PFAS carried legally binding limits in drinking water anywhere in the country. For PFOA and PFOS, the ceiling is 4 parts per trillion each. PFNA, PFHxS, and GenX are held to 10 ppt apiece, and when several show up at once, compliance is judged through a hazard-index calculation. Arizona has not written a tougher enforceable standard of its own as of 2026, which leaves these federal figures governing every public system in the state.

Start with a test of your own tap

Households pulling from private wells — a common arrangement across the Tucson basin and rural Pima County — sit outside any utility's monitoring program, so nobody is watching those taps but you. A certified-lab analysis run under EPA Method 537.1 or 533 is the one dependable way to learn your actual numbers. Because PFAS can rub off many everyday materials during sampling, follow the lab kit's collection steps to the letter.

Three treatments that hold up

• Granular activated carbon (GAC): a carbon bed that grabs PFAS as water flows through — the everyday backbone of whole-house treatment.
• Anion exchange resin: a strong-base resin drawn to the negative charge on PFAS molecules, frequently pushing short-chain compounds to lower breakthrough.
• Reverse osmosis (RO): a membrane that turns away PFAS alongside a wide span of other dissolved impurities, best deployed at one drinking tap.

A whole-house GAC or anion system covers every fixture, which is the right instinct where PFAS reads across an entire basin. An under-sink RO unit is the budget-friendly way to lock down the water you drink and cook with. A great many Tucson homes end up running both in tandem.

Sizing carries extra weight in the arid Southwest, where household draw and well yield swing widely from property to property. A whole-house unit has to be matched to peak flow so water never outruns the media's ability to adsorb PFAS, and carbon or resin beds need swapping on a cadence tied to your measured levels. That is precisely why a lab number is the starting line and not a guess — it tells you whether to treat, how big a system to buy, and how often to service it. With real figures in hand, the decision stops being speculation and turns into arithmetic.

Systems for Arizona homes

Unsure which fits your test results? Our PFAS water filter removal guide walks through matching treatment to your numbers. Test first, then choose with confidence.