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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 22 counties in Indiana
22 counties ranked by average water quality score
| Rank | County | Avg Score | Grade | Cities | Population | Score Range |
|---|---|---|---|---|---|---|
| 1 | Johnson County | 100 | A | 1 | 210,510 | 100 - 100 |
| 2 | Vanderburgh County | 100 | A | 1 | 182,444 | 100 - 100 |
| 3 | Delaware County | 100 | A | 1 | 74,030 | 100 - 100 |
| 4 | Howard County | 100 | A | 1 | 59,313 | 100 - 100 |
| 5 | Wayne County | 100 | A | 1 | 41,485 | 100 - 100 |
| 6 | LaPorte County | 100 | A | 1 | 33,996 | 100 - 100 |
| 7 | Grant County | 100 | A | 1 | 28,363 | 100 - 100 |
| 8 | Jackson County | 100 | A | 1 | 20,725 | 100 - 100 |
| 9 | Tippecanoe County | 99 | A | 2 | 106,368 | 97 - 100 |
| 10 | Lake County | 98 | A | 5 | 167,868 | 95 - 100 |
| 11 | Porter County | 97 | A | 1 | 36,000 | 97 - 97 |
| 12 | Clark County | 97 | A | 1 | 15,750 | 97 - 97 |
| 13 | Bartholomew County | 94 | A | 1 | 51,122 | 94 - 94 |
| 14 | Hendricks County | 93 | A | 1 | 34,477 | 93 - 93 |
| 15 | Hamilton County | 91 | A | 3 | 206,995 | 79 - 100 |
| 16 | Elkhart County | 90 | A | 2 | 78,722 | 84 - 95 |
| 17 | Monroe County | 86 | B | 1 | 83,000 | 86 - 86 |
| 18 | Vigo County | 86 | B | 1 | 67,765 | 86 - 86 |
| 19 | Allen County | 84 | B | 1 | 269,994 | 84 - 84 |
| 20 | St. Joseph County | 82 | B | 2 | 164,675 | 81 - 83 |
| 21 | Madison County | 78 | C | 1 | 55,212 | 78 - 78 |
| 22 | Marion County | 75 | C | 2 | 929,345 | 59 - 91 |
5 cities • 167,868 residents
1 cities • 269,994 residents
2 cities • 929,345 residents
See all 22 counties in the ranking table above
Our county-level water quality analysis aggregates data from municipal water systems across Indiana. Each county's score represents the average water quality across all analyzed cities within that county, weighted by population served.
With 22 counties and 32 cities analyzed, this data helps residents understand regional water quality patterns in Indiana. County scores range from 59/100 to 100/100, reflecting the diversity of water sources and treatment infrastructure across the state.
All analyzed counties in Indiana maintain average scores above 70, indicating generally acceptable water quality standards statewide. Individual city scores may vary, so residents should still review their specific city's report.