What was found in Tucson's water
The highest level seen across the city's suppliers, the EPA limit for each, and where the figure comes from.
| Contaminant | Level vs EPA limit | Suppliers | Source |
|---|---|---|---|
| Nitrate | 13000 µg/L 130% of the EPA limit, in the worst sample — 10000 µg/L | 73/82 | SYR4 |
| Nitrate-Nitrite | 13000 µg/L 130% of the EPA limit, in the worst sample — 10000 µg/L | 62/82 | SYR4 |
| Fluoride | 3400 µg/L 85% of the EPA limit 4000 µg/L | 60/82 | SYR4 |
| Copper | 890 µg/L 68% of the EPA limit 1300 µg/L | 77/82 | SYR4 |
| Nitrite | 400 µg/L 40% of the EPA limit 1000 µg/L | 2/82 | SYR4 |
| Barium | 250 µg/L 13% of the EPA limit 2000 µg/L | 63/82 | SYR4 |
| Lithium | 228 µg/L No EPA limit set | 13/82 | UCMR-5 |
| Lead | 223 µg/L 1487% of the EPA limit, in the worst sample — 15 µg/L | 72/82 | SYR4 |
| Xylenes, Total | 60 µg/L 0.6% of the EPA limit 10000 µg/L | 9/82 | SYR4 |
| Total Haloacetic Acids (HAA5) | 56 µg/L 93% of the EPA limit 60 µg/L | 21/82 | SYR4 |
| TTHM | 52.6 µg/L 66% of the EPA limit 80 µg/L | 43/82 | SYR4 |
| Di(2-ethylhexyl) Phthalate | 28 µg/L 467% of the EPA limit, in the worst sample — 6 µg/L | 9/82 | SYR4 |
| Bromoform | 26 µg/L No EPA limit set | 16/82 | SYR4 |
| Combined Uranium | 22.648 µg/L 75% of the EPA limit 30 µg/L | 8/82 | SYR4 |
| Di(2-ethylhexyl) Adipate | 16 µg/L 4% of the EPA limit 400 µg/L | 1/82 | SYR4 |
| Arsenic | 15 µg/L 150% of the EPA limit, in the worst sample — 10 µg/L | 54/82 | SYR4 |
| Gross Alpha, Excl. Radon And U | 9.62 pCi/L 64% of the EPA limit 15 pCi/L | 8/82 | SYR4 |
| Dibromochloromethane | 9.4 µg/L No EPA limit set | 13/82 | SYR4 |
| Cyanide | 9.1 µg/L 4.6% of the EPA limit 200 µg/L | 1/82 | SYR4 |
| Selenium | 8.9 µg/L 18% of the EPA limit 50 µg/L | 5/82 | SYR4 |
| Chromium | 8 µg/L 8% of the EPA limit 100 µg/L | 33/82 | SYR4 |
| Trichloroethylene | 7.1 µg/L 142% of the EPA limit, in the worst sample — 5 µg/L | 4/82 | SYR4 |
| Ethylbenzene | 5.9 µg/L 0.8% of the EPA limit 700 µg/L | 4/82 | SYR4 |
| Bromodichloromethane | 4.8 µg/L No EPA limit set | 5/82 | SYR4 |
| cis-1,2-Dichloroethylene | 2.8 µg/L 4% of the EPA limit 70 µg/L | 1/82 | SYR4 |
| Tetrachloroethylene | 2.7 µg/L 54% of the EPA limit 5 µg/L | 1/82 | SYR4 |
| Combined Radium (-226 And -228) | 2.5 pCi/L 50% of the EPA limit 5 pCi/L | 24/82 | SYR4 |
| Dibromoacetic Acid | 2.4 µg/L No EPA limit set | 6/82 | SYR4 |
| 1,1-Dichloroethylene | 1.8 µg/L 26% of the EPA limit 7 µg/L | 3/82 | SYR4 |
| Antimony, Total | 1.8 µg/L 30% of the EPA limit 6 µg/L | 2/82 | SYR4 |
| Chloroform | 1.8 µg/L No EPA limit set | 3/82 | SYR4 |
| Dichloroacetic Acid | 1.1 µg/L No EPA limit set | 2/82 | SYR4 |
| P-Dichlorobenzene | 0.7900 µg/L 1.1% of the EPA limit 75 µg/L | 1/82 | SYR4 |
| Styrene | 0.6200 µg/L 0.6% of the EPA limit 100 µg/L | 1/82 | SYR4 |
| Mercury | 0.6100 µg/L 31% of the EPA limit 2 µg/L | 1/82 | SYR4 |
| Toluene | 0.5000 µg/L 0.1% of the EPA limit 1000 µg/L | 1/82 | SYR4 |
| Simazine | 0.1500 µg/L 3.8% of the EPA limit 4 µg/L | 6/82 | SYR4 |
| Pentachlorophenol | 0.1200 µg/L 12% of the EPA limit 1 µg/L | 1/82 | SYR4 |
| Atrazine | 0.1100 µg/L 3.7% of the EPA limit 3 µg/L | 1/82 | SYR4 |
| Lead | 0.0270 mg/L 180% above the EPA limit of 0.0150 mg/L | 82/82 | LCR |
| PFHXS | 0.0090 µg/L No EPA limit set | 2/82 | UCMR-5 |
| Pfba | 0.0081 µg/L No EPA limit set | 1/82 | UCMR-5 |
| PFOS | 0.0060 µg/L No EPA limit set | 1/82 | UCMR-5 |
| PFOA | 0.0050 µg/L No EPA limit set | 1/82 | UCMR-5 |
| PFBS | 0.0048 µg/L No EPA limit set | 2/82 | UCMR-5 |
| Pfpea | 0.0040 µg/L No EPA limit set | 1/82 | UCMR-5 |
| Pfhxa | 0.0030 µg/L No EPA limit set | 1/82 | UCMR-5 |
Water suppliers serving Tucson
The 50 largest of 82 suppliers serving Tucson, by population served.
Frequently asked questions about Tucson tap water
Is Tucson tap water safe to drink?
EPA testing detected 47 contaminants in the water serving Tucson. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.
How many water suppliers serve Tucson?
82 public water suppliers report drinking-water monitoring for Tucson, Arizona to the EPA. Each is listed above with its population served.
What contaminants are in Tucson's water?
The contaminants EPA monitoring detected in Tucson include Nitrate, Nitrate-Nitrite, Fluoride, Copper, Nitrite. The full list, with the highest level found and the data source, is in the table above.
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.