Tucson Water · Colorado River water recharged to the local aquifer plus groundwater
Tucson, AZ tap water quality
Tucson's tap water scores 92 out of 100 on published data, which puts it among the better-performing large systems in the country.
Every figure, with its benchmark
Subscores run from 100 at the health benchmark to 0 at the legal limit. The city score is the weighted average of the 4 inputs published for this system.
| Measure | Result | Health benchmark | Legal limit | Subscore | Source |
|---|---|---|---|---|---|
| TTHMs | 26.3 ppb | 15 | 80 | 83 | Utility report |
| HAA5 | 2.2 ppb | 15 | 60 | 100 | Utility report |
| Arsenic | none detected | 1 | 10 | 100 | Utility report |
| Nitrate | none detected | 5 | 10 | 100 | Utility report |
Is there PFAS in Tucson's water?
We don't know. Tucson's system has no UCMR 5 record in EPA's 2026 Q2 snapshot, and no testing is not the same as no PFAS. We won't state a result the data doesn't support.
How much lead is in Tucson's tap water?
Tucson's system has no current lead 90th-percentile figure in the data we collect. Lead sampling runs on a multi-year cycle, so a gap here usually means the most recent round has not been reported yet.
Is Tucson tap water safe to drink?
Tucson's water meets federal legal standards on the measures its utility reports. We score it 92 out of 100 against health-based guidance, which is stricter than the legal minimum by design. Those are two different questions, and most coverage collapses them: a supply can be entirely lawful and still carry readings above the level health researchers would prefer. This score answers the second question, and the table above shows exactly which measure moved it.
Has Tucson's water been in violation?
We found no Safe Drinking Water Act violation records for this system in EPA's compliance data. That is a clean record on the federal register, though absence of a violation is not the same as absence of a contaminant: a system can stay within every legal limit and still carry readings above health-based guidance, which is exactly what the score above measures.
What can you do about it?
If lead is the concern here, the fix is almost never the treatment plant: it's the service line and the plumbing inside the building. Running the tap for thirty seconds after long stagnation, using cold water for drinking and cooking, and asking your utility whether your address has a lead service line are all free. A filter certified to NSF/ANSI 53 for lead is the next step. If PFAS is the concern, NSF/ANSI 53 does not cover it: look for NSF/ANSI 58 reverse osmosis or a filter specifically certified under NSF/ANSI 53 for PFOA and PFOS reduction.
Compare Tucson with the rest
Fifty of the largest US systems, scored the same way, every figure cited.