Compliance record
Formal violations the EPA has on file for this supplier. A health-based violation means a contaminant limit or a required treatment was breached; the rest are monitoring or reporting failures — still violations, but not a measured health risk.
1
health-based violations
2,273
violations on file
0
still open
| Violation | Type | Status | Period |
|---|---|---|---|
| MCL | Health-based | Archived | 1980-11-19 → 1981-03-18 |
| MR | Monitoring | Archived | 2026-01-01 → 2026-03-31 |
| MR | Monitoring | Archived | 2026-01-01 → 2026-03-31 |
| MR | Monitoring | Archived | 2026-01-01 → 2026-03-31 |
| MR | Monitoring | Archived | 2026-01-01 → 2026-03-31 |
| MR | Monitoring | Archived | 2026-01-01 → 2026-03-31 |
| MR | Monitoring | Archived | 2026-01-01 → 2026-03-31 |
| MR | Monitoring | Archived | 2026-01-01 → 2026-03-31 |
| MR | Monitoring | Archived | 2026-01-01 → 2026-03-31 |
| MR | Monitoring | Archived | 2026-01-01 → 2026-03-31 |
PFAS detected
PFAS are industrial “forever chemicals”. These are the EPA's latest
nationwide test results (2023–2025).
| Contaminant | Max | Detection rate | Period |
|---|---|---|---|
| Pfba | 0.0081 µg/L | 1/163 | 2025 |
Other contaminants detected
Each bar shows the measured level as a share of the EPA limit: green is
well under, amber is close to it, red is over. For lead and copper the
limit applies to exactly the 90th-percentile figure shown, so red there
means a real exceedance. For everything else the limit applies to a
running annual average while the figure is the 95th percentile of this
system's samples — over 100% is worth reading, but is not by itself a
violation. Where a single sample came in higher than that percentile, it
is noted under the bar. Formal violations are listed separately.
| Contaminant | Level vs EPA limit | Detection rate | Source | Period |
|---|---|---|---|---|
| Nitrate | 4741.5 µg/L 47% of the EPA limit 10000 µg/L
worst single sample: 7890 µg/L | 1958/1984 | SYR4 | 2012–2019 |
| Fluoride | 626.15 µg/L 16% of the EPA limit 4000 µg/L
worst single sample: 1170 µg/L | 344/354 | SYR4 | 2013–2019 |
| Barium | 110.25 µg/L 5.5% of the EPA limit 2000 µg/L
worst single sample: 157 µg/L | 336/354 | SYR4 | 2013–2019 |
| Arsenic | 6.7335 µg/L 67% of the EPA limit 10 µg/L
worst single sample: 8 µg/L | 278/353 | SYR4 | 2013–2019 |
| TTHM | 22.05 µg/L 28% of the EPA limit 80 µg/L
worst single sample: 48 µg/L | 236/248 | SYR4 | 2012–2019 |
| Total Haloacetic Acids (HAA5) | 2.57 µg/L 4.3% of the EPA limit 60 µg/L
worst single sample: 11 µg/L | 167/248 | SYR4 | 2012–2019 |
| Combined Uranium | 12.92 µg/L 43% of the EPA limit 30 µg/L
worst single sample: 22.648 µg/L | 133/148 | SYR4 | 2013–2019 |
| Nitrate-Nitrite | 4160 µg/L 42% of the EPA limit 10000 µg/L
worst single sample: 6400 µg/L | 129/132 | SYR4 | 2013–2019 |
| Lithium | 63.7 µg/L No EPA limit set | 112/163 | UCMR-5 | 2025 |
| Copper | 197.5 µg/L 15% of the EPA limit 1300 µg/L
worst single sample: 584 µg/L | 110/110 | SYR4 | 2014–2017 |
| Selenium | 2.961 µg/L 5.9% of the EPA limit 50 µg/L
worst single sample: 6.18 µg/L | 107/354 | SYR4 | 2013–2019 |
| Gross Alpha, Excl. Radon And U | 2.69 pCi/L 18% of the EPA limit 15 pCi/L
worst single sample: 3.9 pCi/L | 98/148 | SYR4 | 2013–2019 |
| Lead | 1.4925 µg/L 10% of the EPA limit 15 µg/L
worst single sample: 223 µg/L | 96/110 | SYR4 | 2014–2017 |
| Combined Radium (-226 And -228) | 1.06 pCi/L 21% of the EPA limit 5 pCi/L
worst single sample: 1.3 pCi/L | 13/148 | SYR4 | 2013–2019 |
| Lead | 0.00065 mg/L 4.3% of the EPA limit 0.0150 mg/L | 10/10 | LCR | 2023 |
| Simazine | 0.1100 µg/L 2.8% of the EPA limit 4 µg/L | 8/365 | SYR4 | 2012–2019 |
| Atrazine | 0.1058 µg/L 3.5% of the EPA limit 3 µg/L
worst single sample: 0.1100 µg/L | 7/359 | SYR4 | 2013–2019 |
| Trichloroethylene | 2.05 µg/L 41% of the EPA limit 5 µg/L
worst single sample: 2.5 µg/L | 7/416 | SYR4 | 2012–2019 |
| Di(2-ethylhexyl) Phthalate | 3.72 µg/L 62% of the EPA limit 6 µg/L
worst single sample: 4.4 µg/L | 5/372 | SYR4 | 2012–2019 |
| Xylenes, Total | 7.025 µg/L 0.1% of the EPA limit 10000 µg/L
worst single sample: 8 µg/L | 4/416 | SYR4 | 2012–2019 |
| Cyanide | 9.09 µg/L 4.5% of the EPA limit 200 µg/L
worst single sample: 9.1 µg/L | 3/355 | SYR4 | 2013–2019 |
| 1,1-Dichloroethylene | 1.8 µg/L 26% of the EPA limit 7 µg/L | 1/415 | SYR4 | 2012–2019 |
| Antimony, Total | 1.8 µg/L 30% of the EPA limit 6 µg/L | 1/354 | SYR4 | 2013–2019 |
| Ethylbenzene | 1.1 µg/L 0.2% of the EPA limit 700 µg/L | 1/416 | SYR4 | 2012–2019 |
| Pentachlorophenol | 0.1200 µg/L 12% of the EPA limit 1 µg/L | 1/358 | SYR4 | 2012–2019 |
78 contaminants tested, none detected
1,1,1-Trichloroethane1,1,2-Trichloroethane1,2,4-Trichlorobenzene1,2-DIBROMO-3-CHLOROPROPANE1,2-Dichloroethane1,2-Dichloropropane11Cl-PF3OUdS2,3,7,8-TCDD2,4,5-TP2,4-D4:2 Fts6:2 Fts8:2 Fts9Cl-PF3ONSAdonaAsbestosBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalChlorobenzeneCadmiumCarbofuranCarbon TetrachlorideChlordaneChromiumDichloromethaneDalaponDi(2-ethylhexyl) AdipateDinosebDiquatEthylene DibromideEndothallEndrinGlyphosateHexachlorobenzeneHfpo-DaHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMercuryMethoxychlorNetfosaaNfdhaNmefosaaNitriteOxamylPFBSPfdaPfdoaPfeesaPfhpaPfhpsPfhxaPFHXSPfmbaPfmpaPFNAPFOAPFOSPfpeaPfpesPftaPftrdaPfunaPicloramStyreneTetrachloroethyleneThallium, TotalTolueneTotal Polychlorinated Biphenyls (PCB)ToxapheneVinyl Chloridecis-1,2-DichloroethyleneO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene
Frequently asked questions about Tucson City of
Is Tucson City of tap water safe to drink?
EPA monitoring detected 26 contaminants in Tucson City of's water. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and the utility's annual Consumer Confidence Report for its official compliance status.
What contaminants were detected in Tucson City of's water?
EPA monitoring detected Nitrate, Fluoride, Barium, Arsenic, TTHM, and others. The full list with the level and data source for each is above.
How many people does Tucson City of serve?
Tucson City of reports serving 732,906 people, per its EPA record.
Has Tucson City of had any water quality violations?
The EPA has 2273 violations on file for Tucson City of, of which 1 is health-based (a contaminant limit or required treatment was breached) and 0 remain open. The rest are monitoring or reporting failures.
Where does this data come from?
Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.