What was found in Tempe's water
The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.
| Contaminant | Level vs EPA limit | Suppliers | Source |
|---|---|---|---|
| Nitrate | 6800 µg/L 68% of the EPA limit 10000 µg/L Main supplier: TEMPE CITY OF · 165,000 people · 2019 | 1/1 | SYR4 |
| Nitrate-Nitrite | 6540 µg/L 65% of the EPA limit 10000 µg/L Main supplier: TEMPE CITY OF · 165,000 people · 2017 | 1/1 | SYR4 |
| Fluoride | 473 µg/L 12% of the EPA limit 4000 µg/L Main supplier: TEMPE CITY OF · 165,000 people · 2019 | 1/1 | SYR4 |
| Copper | 330 µg/L 25% of the EPA limit 1300 µg/L Main supplier: TEMPE CITY OF · 165,000 people · 2019 | 1/1 | SYR4 |
| Lithium | 278 µg/L No EPA limit set Main supplier: TEMPE CITY OF · 165,000 people · 2025 | 1/1 | UCMR-5 |
| Barium | 110 µg/L 5.5% of the EPA limit 2000 µg/L Main supplier: TEMPE CITY OF · 165,000 people · 2019 | 1/1 | SYR4 |
| TTHM | 79 µg/L 99% of the EPA limit 80 µg/L Main supplier: TEMPE CITY OF · 165,000 people · 2019 | 1/1 | SYR4 |
| Total Haloacetic Acids (HAA5) | 26.65 µg/L 44% of the EPA limit 60 µg/L Main supplier: TEMPE CITY OF · 165,000 people · 2019 | 1/1 | SYR4 |
| Lead | 24.6 µg/L 164% of the EPA limit, at the 95th percentile of samples — 15 µg/L Main supplier: TEMPE CITY OF · 165,000 people · 2019 | 1/1 | SYR4 |
| Chromium | 11.3 µg/L 11% of the EPA limit 100 µg/L Main supplier: TEMPE CITY OF · 165,000 people · 2019 | 1/1 | SYR4 |
| Combined Uranium | 11.1682 µg/L 37% of the EPA limit 30 µg/L Main supplier: TEMPE CITY OF · 165,000 people · 2018 | 1/1 | SYR4 |
| Arsenic | 5.73 µg/L 57% of the EPA limit 10 µg/L Main supplier: TEMPE CITY OF · 165,000 people · 2019 | 1/1 | SYR4 |
| Gross Alpha, Excl. Radon And U | 2.58 pCi/L 17% of the EPA limit 15 pCi/L Main supplier: TEMPE CITY OF · 165,000 people · 2018 | 1/1 | SYR4 |
| Selenium | 2.045 µg/L 4.1% of the EPA limit 50 µg/L Main supplier: TEMPE CITY OF · 165,000 people · 2019 | 1/1 | SYR4 |
| Combined Radium (-226 And -228) | 1.14 pCi/L 23% of the EPA limit 5 pCi/L Main supplier: TEMPE CITY OF · 165,000 people · 2018 | 1/1 | SYR4 |
| Thallium, Total | 1 µg/L 50% of the EPA limit 2 µg/L Main supplier: TEMPE CITY OF · 165,000 people · 2019 | 1/1 | SYR4 |
| Trichloroethylene | 0.9780 µg/L 20% of the EPA limit 5 µg/L Main supplier: TEMPE CITY OF · 165,000 people · 2019 | 1/1 | SYR4 |
| Tetrachloroethylene | 0.8400 µg/L 17% of the EPA limit 5 µg/L Main supplier: TEMPE CITY OF · 165,000 people · 2019 | 1/1 | SYR4 |
| Di(2-ethylhexyl) Phthalate | 0.7100 µg/L 12% of the EPA limit 6 µg/L Main supplier: TEMPE CITY OF · 165,000 people · 2019 | 1/1 | SYR4 |
| PFHXS | 0.0705 µg/L No EPA limit set Main supplier: TEMPE CITY OF · 165,000 people · 2025 | 1/1 | UCMR-5 |
| PFOS | 0.0558 µg/L No EPA limit set Main supplier: TEMPE CITY OF · 165,000 people · 2025 | 1/1 | UCMR-5 |
| PFOA | 0.0387 µg/L No EPA limit set Main supplier: TEMPE CITY OF · 165,000 people · 2025 | 1/1 | UCMR-5 |
| PFBS | 0.0257 µg/L No EPA limit set Main supplier: TEMPE CITY OF · 165,000 people · 2025 | 1/1 | UCMR-5 |
| Pfhxa | 0.0225 µg/L No EPA limit set Main supplier: TEMPE CITY OF · 165,000 people · 2025 | 1/1 | UCMR-5 |
| Pfpea | 0.0144 µg/L No EPA limit set Main supplier: TEMPE CITY OF · 165,000 people · 2025 | 1/1 | UCMR-5 |
| Pfba | 0.0099 µg/L No EPA limit set Main supplier: TEMPE CITY OF · 165,000 people · 2025 | 1/1 | UCMR-5 |
| Pfpes | 0.0080 µg/L No EPA limit set Main supplier: TEMPE CITY OF · 165,000 people · 2025 | 1/1 | UCMR-5 |
| Pfhpa | 0.0070 µg/L No EPA limit set Main supplier: TEMPE CITY OF · 165,000 people · 2025 | 1/1 | UCMR-5 |
| Lead | 0.0044 mg/L 29% of the EPA limit 0.0150 mg/L Main supplier: TEMPE CITY OF · 165,000 people · 2024 | 1/1 | LCR |
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 the
system's samples — over 100% is worth reading, but is not by itself a
violation.
Formal violations are listed separately.
These are the utilities' own EPA-reported results, not a city-wide
average. A detection means the lab measured the
substance — it isn't the same as exceeding a legal limit. Hover a source
tag to see the EPA program and years behind each figure.
Water suppliers serving Tempe
| Supplier | Population served |
|---|---|
| TEMPE CITY OF | 165,000 |
Frequently asked questions about Tempe tap water
Is Tempe tap water safe to drink?
EPA testing detected 29 contaminants in the water serving Tempe. 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 Tempe?
1 public water supplier report drinking-water monitoring for Tempe, Arizona to the EPA. Each is listed above with its population served.
What contaminants are in Tempe's water?
The contaminants EPA monitoring detected in Tempe include Nitrate, Nitrate-Nitrite, Fluoride, Copper, Lithium. The full list, with the level at the main supplier 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.