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Iowa Tap Water Quality 2026

EPA drinking water data for 845 cities across Iowa — covering lead levels, violation history, and compliance status.

Systems tracked: 711 Cities covered: 845 Updated: 2026 Q2
A

Iowa earns an A for overall water quality

845 communities across 99 counties and 711 water systems. 99.8% have no open violations.

Median lead where detected: 2.00 ppb
30.3% of systems report lead as not detected — a state filing convention, not a water quality measure
PFAS tested at 20.5% of communities; 1 above the federal limit
Lead reported for 100.0% of communities
99.8% of communities have no open violations
Water Systems
711
Active community systems
Median Lead Level
2 ppb
13% of EPA action level
Fully Compliant
99.8%
of systems — no active violations
How we grade states Grades are based on actual EPA enforcement data — MCL violations and lead levels measured against the 15 ppb federal action level. We do not use MCLG-based detections, which are aspirational zero-tolerance goals that would make nearly every state look dangerous. Read our full methodology →

Best & Worst Cities in Iowa

✓ Cleanest Water
Cedar Rapids
Linn County
1.6 ppb A
Davenport
Scott County
1.0 ppb B
West Des Moines
Polk County
0.0 ppb A
Council Bluffs
Pottawattamie County
2.0 ppb A
Ames
Story County
0.0 ppb A
Bettendorf
Scott County
1.0 ppb B
⚠ Needs Attention
Sioux City
Woodbury County
2.0 ppb D
Livermore
Humboldt County
6.0 ppb D
Victor
Iowa County
18.2 ppb C
Kellerton
Ringgold County
15.0 ppb C
Osceola
Clarke County
6.0 ppb C
Barnes City
Mahaska County
0.0 ppb C

Water Quality by County

99 of 99
Sort:
CountySystemsLead LevelViolationsGrade
Polk County 18 1.0 ppb 0 B
Scott County 17 1.0 ppb 0 A
Linn County 17 1.9 ppb 0 A
Dubuque County 17 2.8 ppb 0 A
Woodbury County 15 2.0 ppb 0 A
Story County 14 1.0 ppb 0 A
Henry County 14 1.1 ppb 0 A
Benton County 14 2.0 ppb 0 A
Dallas County 14 1.4 ppb 0 A
Webster County 14 1.4 ppb 0 A

About Iowa Drinking Water

Iowa is served by 711 community water systems covering 845 communities across 99 counties. 99.8% have no open violation on record.

Lead was detected in 589 communities, with a median of 2.00 ppb — 13% of the federal action level. A further 256 reported none detected. That share is a state reporting convention rather than a measure of water quality, so it is stated separately rather than averaged in.

PFAS has been tested at 20.5% of communities here, and 1 are above the limits EPA set in 2024. Coverage matters: states that test more find more, so this figure is not comparable with a state that has tested less.

Frequently Asked Questions

Is Iowa tap water safe to drink? ▼
99.8% of communities have no open violation on record. 1 have PFAS above the federal limit set in 2024, which is the main open concern.
Does Iowa have a lead problem? ▼
4 water systems report a 90th-percentile lead result at or above the 15 ppb action level. The action level is a treatment trigger, not a legal maximum, and 256 communities report no detection at all.
How complete is the data for Iowa? ▼
Lead results are reported for 100.0% of communities and PFAS for 20.5%. Where a figure is missing it is shown as not reported rather than assumed safe.
How does Iowa compare with other states? ▼
We do not rank states against each other. Lead reporting completeness ranges from under 20% to 100% depending on the state, so a national ranking would compare filing practice rather than water quality.