We read 18 results from Tucson City of’s 2025 water quality report. No results over a legal limit; 5 above a health goal or guideline.
Serves about 732,906 people · Water system ID AZ0410112 · Read the district’s 2025 report (opens in a new tab)
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Results from the 2025 report
Each number is copied from the district’s report and links to the page it’s printed on. Where the report lists several plants, wells or purchased water, the highest is shown.
| Contaminant | Result | Health goal | Legal limit | What it means |
|---|---|---|---|---|
| Arsenichighest measured · range ND to 8.8 · Entry points · 2025 report, page 16 | 8.8 ppb | 0.004 ppb | 10 ppb | Above the health goal2,200x the health goal |
| Gross alpha (radioactivity)highest measured · range ND to 4.4 · Entry points · 2025 report, page 16 | 4.4 pCi/L | 0 pCi/L | 15 pCi/L | Above the health goalThe health goal is zero |
| Lead90th percentile of homes tested, 0 over the action level · sampled 2023 · Customer taps · 2025 report, page 17 | 0.65 ppb | 0.2 ppb | 15 ppb (action level) | Above the health goal3.3x the health goal |
| Radium (combined 226 + 228)highest measured · range ND to 1.44 · Entry points · 2025 report, page 16 | 1.44 pCi/L | 0 pCi/L | 5 pCi/L | Above the health goalThe health goal is zero |
| Uraniumhighest measured · range ND to 16 · Entry points · 2025 report, page 16 | 16 ppb | 0.6 ppb | 30 ppb | Above the health goal27x the health goal |
| Atrazinehighest measured · range ND to 0.09 · Entry points · 2025 report, page 16 | 0.09 ppb | 0.15 ppb | 3 ppb | Below the health goal |
| Bariumhighest measured · range ND to 0.15 · Entry points · 2025 report, page 16 | 0.15 ppm | 2 ppm | 2 ppm | Below the health goal |
| Chlorineaverage · range 0.94 to 1.07 · Distribution system · 2025 report, page 17 | 1 ppm | None set | 4 ppm | Below the legal limit |
| Copper90th percentile of homes tested, 0 over the action level · sampled 2023 · Customer taps · 2025 report, page 17 | 0.14 ppm | 0.3 ppm | 1.3 ppm (action level) | Below the health goal |
| Disinfection byproducts (HAA5)highest running annual average · range ND to 2.1 · Distribution system · 2025 report, page 15 | 1.3 ppb | None set | 60 ppb | Below the legal limit |
| Disinfection byproducts (TTHM)highest running annual average · range 1.8 to 26.8 · Distribution system · 2025 report, page 15 | 13.6 ppb | None set | 80 ppb | Below the legal limit |
| Fluoridehighest measured · range 0.13 to 0.8 · Entry points · 2025 report, page 16 | 0.8 ppm | 1 ppm | 4 ppm | Below the health goal |
| Nitrate (as N)highest measured · range 0.25 to 6.7 · Entry points · 2025 report, page 16 | 6.7 ppm | 10 ppm | 10 ppm | Below the health goal |
| Seleniumhighest measured · range ND to 4.3 · Entry points · 2025 report, page 16 | 4.3 ppb | 30 ppb | 50 ppb | Below the health goal |
| Simazinehighest measured · range ND to 0.05 · Entry points · 2025 report, page 16 | 0.05 ppb | 4 ppb | 4 ppb | Below the health goal |
| Lithiumaverage · range ND to 63.7 · Wells (UCMR 5) · 2025 report, page 8 | 14.8 ppb | None set | None | No health limit |
| PFBA (a PFAS)average · range ND to 8.1 · Wells (UCMR 5) · 2025 report, page 8 | 0.05 ppt | None set | None | No health limit |
| Sodiumhighest measured · range 22.4 to 70.4 · Entry points · 2025 report, page 16 | 70.4 ppm | None set | None | No health limit |
Utility results describe the whole system, measured where water enters the pipes, not your tap. Your home’s plumbing can add lead or copper. 1 number we weren’t sure about is held back until a person checks.
EPA testing for PFAS and lithium
EPA’s own nationwide testing (UCMR 5) found these in Tucson City of’s water between Jan 2024 and Nov 2025. These are EPA lab results, separate from the district’s report. Anything not listed was not detected.
- Lithium63.7 ppbFound in 112 of 162 samples · highest resultAbove EPA’s health reference level of 10 ppb (a guide, not a legal limit)
Source: EPA UCMR 5 occurrence data. The highest single result is shown; one high sample doesn’t mean every glass is that high.
What you can do
Nothing here is an emergency notice: if the district has a violation, it must tell customers directly. If you’d like to lower these at your tap, these are the treatments that remove them, and the catalog shows the models certified for each. Ranking is by certified removal; commissions never change the order.
Radium and uranium
Found: Gross alpha (radioactivity), Radium (combined 226 + 228), Uranium
What removes it: Reverse osmosis.
Lead
Found: Lead
What removes it: Certified carbon block or RO.
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