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Not health advice. Contact your local water utility for concerns.
Data from EPA Water Quality Reports. For official information, contact your water utility or health department.
Compare water quality across 11 counties in Arizona
11 counties ranked by average water quality score
| Rank | County | Avg Score | Grade | Cities | Population | Score Range |
|---|---|---|---|---|---|---|
| 1 | Gila County | 98 | A+ | 1 | 15,929 | 98 - 98 |
| 2 | Navajo County | 95 | A+ | 1 | 11,229 | 95 - 95 |
| 3 | Cochise County | 88 | A- | 2 | 59,982 | 82 - 93 |
| 4 | Pinal County | 87 | A- | 6 | 223,228 | 81 - 94 |
| 5 | Yuma County | 87 | A- | 3 | 147,106 | 83 - 95 |
| 6 | Coconino County | 86 | A- | 1 | 76,831 | 86 - 86 |
| 7 | Mohave County | 85 | A- | 3 | 131,181 | 74 - 95 |
| 8 | Maricopa County | 73 | B- | 16 | 4,057,680 | 52 - 95 |
| 9 | Yavapai County | 71 | B- | 3 | 102,445 | 57 - 87 |
| 10 | Pima County | 69 | C+ | 3 | 628,571 | 68 - 71 |
| 11 | Santa Cruz County | 51 | D | 1 | 20,103 | 51 - 51 |
1 cities • 15,929 residents
1 cities • 11,229 residents
2 cities • 59,982 residents
6 cities • 223,228 residents
3 cities • 147,106 residents
1 cities • 76,831 residents
3 cities • 131,181 residents
16 cities • 4,057,680 residents
3 cities • 102,445 residents
3 cities • 628,571 residents
1 cities • 20,103 residents
Our county-level water quality analysis aggregates data from municipal water systems across Arizona. Each county's score represents the average water quality across all analyzed cities within that county, weighted by population served.
With 11 counties and 40 cities analyzed, this data helps residents understand regional water quality patterns in Arizona. County scores range from 51/100 to 98/100, reflecting the diversity of water sources and treatment infrastructure across the state.
Currently, 2 counties in Arizona have average scores below 70, indicating potential water quality concerns. Residents in these areas should review their city's specific report and consider water filtration options.