Is there PFAS in Metropolitan Dwid water?
Yes, at low levels. 2 PFAS were detected, all below EPA's 2024 limits.
Metropolitan Dwid
Serves 45,570 people · 42 PFOA samples from 21 sampling points · May 2024 to May 2025
PFAS found, below EPA limits
PFOA Perfluorooctanoic acid
not detected
PFOS Perfluorooctanesulfonic acid
not detected
PFHxS Perfluorohexanesulfonic acid
3.8 ppt avg · max 3.9
Hazard index GenX, PFBS, PFNA, PFHxS combined
0.4 avg · max 0.4
Also detected, no federal limit: PFBS.
Metropolitan Dwid is a public water system drawing on groundwater, based in Tucson, Arizona, serving about 45,570 people. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 42 times across 21 sampling points between May 2024 and May 2025.
Every PFAS detected
Not detected: PFHxA, PFTA, PFEESA, PFMBA, PFPeA, PFMPA, 8:2 FTS, 4:2 FTS, 6:2 FTS, PFBA, HFPO-DA, ADONA, 9Cl-PF3ONS, PFPeS, PFUnA, PFHpS, PFDoA, PFDA, PFOA, PFOS, PFNA, PFHpA, NMeFOSAA, NEtFOSAA, PFTrDA, 11Cl-PF3OUdS, NFDHA.
Lithium, tested in the same program: highest 18.3 ppb, detected in 19 of 42 samples. EPA's health-based screening level is 10 ppb.
What the EPA limits mean here
In April 2024 EPA set enforceable limits of 4 ppt for PFOA and PFOS, 10 ppt each for PFHxS, PFNA and GenX, and a hazard index of 1 for mixtures. Utilities were given until 2029 to comply. In May 2026 EPA proposed keeping only the PFOA and PFOS limits and moving that deadline to 2031. Until that proposal is final, the 2024 limits stand.
Compliance is judged on a running annual average at each entry point, so we show the average at this system's worst sampling point next to its single highest result. UCMR 5 results do not by themselves put a utility in or out of compliance.
What you can do at home
Levels here are under EPA's limits, so no treatment is required. If you want them lower anyway, a certified reverse osmosis system under the sink handles drinking water, and a whole-house carbon filter also takes out the chlorine or chloramine your utility adds.
Other systems in Arizona
All 152 tested systems in Arizona
ZIP codes served
85704 85737 85741 85742
As reported by the utility to EPA. Neighbouring ZIPs are often split between systems; your water bill names yours.
Cite this page
Well & Tap. "PFAS in Metropolitan Dwid water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID AZ0410076. https://wellandtap.com/pfas/arizona/metropolitan-dwid/
About this data
Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID AZ0410076). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.
