What was found in San Luis'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 | 1037.5 µg/L 10% of the EPA limit 10000 µg/L Main supplier: SAN LUIS CITY OF · 39,705 people · 2019 | 1/1 | SYR4 |
| Copper | 663.15 µg/L 51% of the EPA limit 1300 µg/L Main supplier: SAN LUIS CITY OF · 39,705 people · 2018 | 1/1 | SYR4 |
| Fluoride | 282.5 µg/L 7.1% of the EPA limit 4000 µg/L Main supplier: SAN LUIS CITY OF · 39,705 people · 2018 | 1/1 | SYR4 |
| Nitrate-Nitrite | 188 µg/L 1.9% of the EPA limit 10000 µg/L Main supplier: SAN LUIS CITY OF · 39,705 people · 2015 | 1/1 | SYR4 |
| Barium | 120 µg/L 6% of the EPA limit 2000 µg/L Main supplier: SAN LUIS CITY OF · 39,705 people · 2018 | 1/1 | SYR4 |
| Lithium | 103 µg/L No EPA limit set Main supplier: SAN LUIS CITY OF · 39,705 people · 2025 | 1/1 | UCMR-5 |
| TTHM | 81.585 µg/L 102% of the EPA limit, at the 95th percentile of samples — 80 µg/L Main supplier: SAN LUIS CITY OF · 39,705 people · 2019 | 1/1 | SYR4 |
| Dibromochloromethane | 42.5 µg/L No EPA limit set Main supplier: SAN LUIS CITY OF · 39,705 people · 2017 | 1/1 | SYR4 |
| Total Haloacetic Acids (HAA5) | 18.54 µg/L 31% of the EPA limit 60 µg/L Main supplier: SAN LUIS CITY OF · 39,705 people · 2019 | 1/1 | SYR4 |
| Di(2-ethylhexyl) Phthalate | 13.7 µg/L 228% of the EPA limit, at the 95th percentile of samples — 6 µg/L Main supplier: SAN LUIS CITY OF · 39,705 people · 2019 | 1/1 | SYR4 |
| Dibromoacetic Acid | 9.2 µg/L No EPA limit set Main supplier: SAN LUIS CITY OF · 39,705 people · 2019 | 1/1 | SYR4 |
| Selenium | 5.2 µg/L 10% of the EPA limit 50 µg/L Main supplier: SAN LUIS CITY OF · 39,705 people · 2018 | 1/1 | SYR4 |
| Lead | 4.733 µg/L 32% of the EPA limit 15 µg/L Main supplier: SAN LUIS CITY OF · 39,705 people · 2018 | 1/1 | SYR4 |
| Combined Radium (-226 And -228) | 3.944 pCi/L 79% of the EPA limit 5 pCi/L Main supplier: SAN LUIS CITY OF · 39,705 people · 2018 | 1/1 | SYR4 |
| Arsenic | 2.2835 µg/L 23% of the EPA limit 10 µg/L Main supplier: SAN LUIS CITY OF · 39,705 people · 2018 | 1/1 | SYR4 |
| Gross Alpha, Excl. Radon And U | 2.23 pCi/L 15% of the EPA limit 15 pCi/L Main supplier: SAN LUIS CITY OF · 39,705 people · 2015 | 1/1 | SYR4 |
| Thallium, Total | 0.8005 µg/L 40% of the EPA limit 2 µg/L Main supplier: SAN LUIS CITY OF · 39,705 people · 2018 | 1/1 | SYR4 |
| Beryllium, Total | 0.5300 µg/L 13% of the EPA limit 4 µg/L Main supplier: SAN LUIS CITY OF · 39,705 people · 2018 | 1/1 | SYR4 |
| Antimony, Total | 0.2000 µg/L 3.3% of the EPA limit 6 µg/L Main supplier: SAN LUIS CITY OF · 39,705 people · 2018 | 1/1 | SYR4 |
| Mercury | 0.0700 µg/L 3.5% of the EPA limit 2 µg/L Main supplier: SAN LUIS CITY OF · 39,705 people · 2018 | 1/1 | SYR4 |
| Lead | 0.0010 mg/L 6.7% of the EPA limit 0.0150 mg/L Main supplier: SAN LUIS CITY OF · 39,705 people · 2024 | 1/1 | LCR |
Water suppliers serving San Luis
| Supplier | Population served |
|---|---|
| SAN LUIS CITY OF | 39,705 |
Frequently asked questions about San Luis tap water
Is San Luis tap water safe to drink?
EPA testing detected 21 contaminants in the water serving San Luis. 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 San Luis?
1 public water supplier report drinking-water monitoring for San Luis, Arizona to the EPA. Each is listed above with its population served.
What contaminants are in San Luis's water?
The contaminants EPA monitoring detected in San Luis include Nitrate, Copper, Fluoride, Nitrate-Nitrite, Barium. 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.