What was found in Flagstaff'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 | 1500 µg/L 15% of the EPA limit 10000 µg/L Main supplier: FLAGSTAFF CITY OF · 79,796 people · 2019
Highest in the city: 4200 µg/L — MOUNTAIN DELL WATER INC · 250 people · 2019 | 11/14 | SYR4 |
| Nitrate-Nitrite | 1400 µg/L 14% of the EPA limit 10000 µg/L Main supplier: FLAGSTAFF CITY OF · 79,796 people · 2018
Highest in the city: 2700 µg/L — MOUNTAIN DELL WATER INC · 250 people · 2013 | 11/14 | SYR4 |
| Barium | 709 µg/L 35% of the EPA limit 2000 µg/L Main supplier: FLAGSTAFF CITY OF · 79,796 people · 2019
Highest in the city: 1610 µg/L — DONEY PARK WATER · 8,996 people · 2018 | 11/14 | SYR4 |
| Copper | 300 µg/L 23% of the EPA limit 1300 µg/L Main supplier: FLAGSTAFF CITY OF · 79,796 people · 2017
Highest in the city: 433.4 µg/L — MOUNTAIN DELL WATER INC · 250 people · 2019 | 11/14 | SYR4 |
| Chlorite | 354 µg/L 35% of the EPA limit 1000 µg/L Main supplier: FLAGSTAFF CITY OF · 79,796 people · 2019 | 1/14 | SYR4 |
| Fluoride | 193 µg/L 4.8% of the EPA limit 4000 µg/L Main supplier: FLAGSTAFF CITY OF · 79,796 people · 2019 | 8/14 | SYR4 |
| Lead | 4.64 µg/L 31% of the EPA limit 15 µg/L Main supplier: FLAGSTAFF CITY OF · 79,796 people · 2017
Highest in the city: 136.58 µg/L — FOREST HIGHLANDS WATER COMPANY · 1,668 people · 2017 | 10/14 | SYR4 |
| TTHM | 65.35 µg/L 82% of the EPA limit 80 µg/L Main supplier: FLAGSTAFF CITY OF · 79,796 people · 2019 | 2/14 | SYR4 |
| Total Haloacetic Acids (HAA5) | 55.8 µg/L 93% of the EPA limit 60 µg/L Main supplier: FLAGSTAFF CITY OF · 79,796 people · 2019 | 1/14 | SYR4 |
| Selenium | 31 µg/L 62% of the EPA limit 50 µg/L Highest in the city: DONEY PARK WATER · 8,996 people · 2018 | 1/14 | SYR4 |
| Arsenic | 6.055 µg/L 61% of the EPA limit 10 µg/L Main supplier: FLAGSTAFF CITY OF · 79,796 people · 2019
Highest in the city: 15.425 µg/L — CS FLAGSTAFF RANCH WATER COMPANY · 350 people · 2019 | 11/14 | SYR4 |
| Gross Alpha, Excl. Radon And U | 2.61 pCi/L 17% of the EPA limit 15 pCi/L Main supplier: FLAGSTAFF CITY OF · 79,796 people · 2017
Highest in the city: 14 pCi/L — MOUNTAIN DELL WATER INC · 250 people · 2019 | 2/14 | SYR4 |
| Chromium | 2.465 µg/L 2.5% of the EPA limit 100 µg/L Main supplier: FLAGSTAFF CITY OF · 79,796 people · 2019
Highest in the city: 6.125 µg/L — CS FLAGSTAFF RANCH WATER COMPANY · 350 people · 2019 | 9/14 | SYR4 |
| Toluene | 6.1 µg/L 0.6% of the EPA limit 1000 µg/L Highest in the city: LAKE MARY COUNTRY STORE · 130 people · 2019 | 1/14 | SYR4 |
| Combined Uranium | 2.574 µg/L 8.6% of the EPA limit 30 µg/L Main supplier: FLAGSTAFF CITY OF · 79,796 people · 2017 | 1/14 | SYR4 |
| Combined Radium (-226 And -228) | 1.025 pCi/L 21% of the EPA limit 5 pCi/L Main supplier: FLAGSTAFF CITY OF · 79,796 people · 2017
Highest in the city: 1.6 pCi/L — FOREST HIGHLANDS WATER COMPANY · 1,668 people · 2017 | 5/14 | SYR4 |
| Trichloroethylene | 1.2 µg/L 24% of the EPA limit 5 µg/L Highest in the city: DONEY PARK WATER · 8,996 people · 2019 | 1/14 | SYR4 |
| Pfba | 0.0061 µg/L No EPA limit set Main supplier: FLAGSTAFF CITY OF · 79,796 people · 2025 | 1/14 | UCMR-5 |
| Lead | 0.0036 mg/L 24% of the EPA limit 0.0150 mg/L Main supplier: FLAGSTAFF CITY OF · 79,796 people · 2023 | 13/14 | 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 Flagstaff
| Supplier | Population served |
|---|---|
| FLAGSTAFF CITY OF | 79,796 |
| DONEY PARK WATER | 8,996 |
| KACHINA VILLAGE DWID | 3,500 |
| FOREST HIGHLANDS WATER COMPANY | 1,668 |
| PONDEROSA UTILITY CORP | 1,585 |
| HIDDEN HOLLOW MHC | 400 |
| CS FLAGSTAFF RANCH WATER COMPANY | 350 |
| MOUNTAIN DELL WATER INC | 250 |
| CS WEST VILLAGE WATER COMPANY | 210 |
| LAKE MARY COUNTRY STORE | 130 |
| HECKETHORN WATER COMPANY | 90 |
| A1 RANCH DWID | 45 |
| LOCKETT ESTATES | 30 |
| HUC Regional Water System | 0 |
Frequently asked questions about Flagstaff tap water
Is Flagstaff tap water safe to drink?
EPA testing detected 19 contaminants in the water serving Flagstaff. 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 Flagstaff?
14 public water suppliers report drinking-water monitoring for Flagstaff, Arizona to the EPA. Each is listed above with its population served.
What contaminants are in Flagstaff's water?
The contaminants EPA monitoring detected in Flagstaff include Nitrate, Nitrate-Nitrite, Barium, Copper, Chlorite. 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.