What was found in Casa Grande'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 | 9689.5 µg/L 97% of the EPA limit 10000 µg/L Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2019
Highest in the city: 10585 µg/L — SIERRA VISTA RV PARK · 200 people · 2019 | 6/8 | SYR4 |
| Nitrate-Nitrite | 9536.5 µg/L 95% of the EPA limit 10000 µg/L Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2018 | 6/8 | SYR4 |
| Fluoride | 2155 µg/L 54% of the EPA limit 4000 µg/L Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2017 | 5/8 | SYR4 |
| Lithium | 353 µg/L No EPA limit set Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2025 | 1/8 | UCMR-5 |
| Copper | 192.4 µg/L 15% of the EPA limit 1300 µg/L Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2019
Highest in the city: 290.5 µg/L — ARIZONA WATER CO - TIERRA GRANDE · 1,796 people · 2018 | 7/8 | SYR4 |
| Lead | 128.805 µg/L 859% of the EPA limit, at the 95th percentile of samples — 15 µg/L Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2019 | 7/8 | SYR4 |
| Barium | 79 µg/L 4% of the EPA limit 2000 µg/L Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2017
Highest in the city: 87.5 µg/L — PICACHO WATER COMPANY · 2,440 people · 2019 | 5/8 | SYR4 |
| TTHM | 52.37 µg/L 65% of the EPA limit 80 µg/L Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2019
Highest in the city: 86.63 µg/L — ARIZONA WATER CO - TIERRA GRANDE · 1,796 people · 2019 | 7/8 | SYR4 |
| Total Haloacetic Acids (HAA5) | 10 µg/L 17% of the EPA limit 60 µg/L Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2019
Highest in the city: 63.41 µg/L — AWC - CASA GRANDE WEST WATER COMPANY · 943 people · 2019 | 6/8 | SYR4 |
| Chromium | 34.05 µg/L 34% of the EPA limit 100 µg/L Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2017 | 3/8 | SYR4 |
| Dibromochloromethane | 20.84 µg/L No EPA limit set Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2014 | 2/8 | SYR4 |
| Selenium | 11.1 µg/L 22% of the EPA limit 50 µg/L Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2017 | 2/8 | SYR4 |
| Arsenic | 8.23 µg/L 82% of the EPA limit 10 µg/L Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2019
Highest in the city: 9.31 µg/L — ARIZONA WATER CO - STANFIELD · 639 people · 2019 | 5/8 | SYR4 |
| Bromoform | 9.025 µg/L No EPA limit set Highest in the city: PICACHO WATER COMPANY · 2,440 people · 2019 | 1/8 | SYR4 |
| Bromodichloromethane | 6.01 µg/L No EPA limit set Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2014 | 2/8 | SYR4 |
| Dibromoacetic Acid | 2.98 µg/L No EPA limit set Highest in the city: PICACHO WATER COMPANY · 2,440 people · 2019 | 1/8 | SYR4 |
| Combined Radium (-226 And -228) | 2.14 pCi/L 43% of the EPA limit 5 pCi/L Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2019 | 2/8 | SYR4 |
| Chloroform | 1.4 µg/L No EPA limit set Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2014 | 1/8 | SYR4 |
| Di(2-ethylhexyl) Phthalate | 1.1 µg/L 18% of the EPA limit 6 µg/L Highest in the city: AWC - CASA GRANDE WEST WATER COMPANY · 943 people · 2016 | 3/8 | SYR4 |
| Xylenes, Total | 1.1 µg/L 0% of the EPA limit 10000 µg/L Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2019 | 1/8 | SYR4 |
| PFBS | 0.0911 µg/L No EPA limit set Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2025 | 1/8 | UCMR-5 |
| Pfpea | 0.0208 µg/L No EPA limit set Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2025 | 1/8 | UCMR-5 |
| Pfba | 0.0199 µg/L No EPA limit set Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2025 | 1/8 | UCMR-5 |
| Pfhxa | 0.0186 µg/L No EPA limit set Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2025 | 1/8 | UCMR-5 |
| Pfhpa | 0.0094 µg/L No EPA limit set Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2025 | 1/8 | UCMR-5 |
| PFHXS | 0.0061 µg/L No EPA limit set Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2025 | 1/8 | UCMR-5 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: ARIZONA WATER CO - PINAL VALLEY · 134,432 people · 2025 | 8/8 | 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 Casa Grande
| Supplier | Population served |
|---|---|
| ARIZONA WATER CO - PINAL VALLEY | 134,432 |
| PICACHO WATER COMPANY | 2,440 |
| ARIZONA WATER CO - TIERRA GRANDE | 1,796 |
| AWC - CASA GRANDE WEST WATER COMPANY | 943 |
| ARIZONA WATER CO - STANFIELD | 639 |
| SIERRA VISTA RV PARK | 200 |
| AWC - CASA GRANDE SOUTH WATER COMPANY | 176 |
| GW SANTA CRUZ WATER - CP WATER CO | 37 |
Frequently asked questions about Casa Grande tap water
Is Casa Grande tap water safe to drink?
EPA testing detected 27 contaminants in the water serving Casa Grande. 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 Casa Grande?
8 public water suppliers report drinking-water monitoring for Casa Grande, Arizona to the EPA. Each is listed above with its population served.
What contaminants are in Casa Grande's water?
The contaminants EPA monitoring detected in Casa Grande include Nitrate, Nitrate-Nitrite, Fluoride, Lithium, Copper. 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.