Illinois vs Iowa: Whose Tap Water Is Cleaner?
Tap Water Quality in Illinois (76.8/100) vs Iowa (81.7/100) — a 6% gap between neighbors, explained with July 2026 data.
Illinois and Iowa share a border, but for tap water quality they don't share much else: Illinois averages 76.8/100 (rank #46 of 51) and Iowa averages 81.7/100 (rank #33) as of July 2026 — a 6% gap between neighbors.
| Illinois | Iowa | U.S. benchmark | |
|---|---|---|---|
| Quality score | 76.8/100 | 81.7/100 | 84.5/100 |
| Violations per water system | 1.9 | 1.5 | 2.5 |
Illinois in context
Illinois ranks near the bottom for tap water quality — its score of 76.8/100 puts it #46 of 51, and its water systems averaged 1.9 health-based violations each in 2024 — better than the U.S. average of 2.5. That average reflects contaminants exceeding EPA limits or health guidelines in a meaningful share of its cities.
Iowa in context
Iowa lands mid-pack for tap water quality: a score of 81.7/100 ranks #33 of 51, and its water systems averaged 1.5 health-based violations each in 2024 — better than the U.S. average of 2.5.
Full local breakdowns: Illinois · Iowa · all states ranked.
Averages describe states, not your faucet. A certified home water test screens for lead, nitrates, bacteria and dozens of other contaminants — the same categories EPA regulates.
Test your water at homeWe may earn a commission if you request quotes through this link. It costs you nothing and never affects the data we publish.