TapWaterGuide
Worldwide water safety reference
United States Last reviewed:

Iowa Tap Water Quality

about 1,070
Community water systems
1
City reports on this site
3
Tracked contaminants
August 28, 2026
Data reviewed

Check a Iowa ZIP Code

Overview

Iowa's water story is agriculture. Des Moines Water Works runs one of the world's largest nitrate-removal facilities because the Raccoon and Des Moines Rivers drain some of the most intensively farmed land on earth, and it still delivers fully compliant water to half a million people.

Statewide, nitrate and its treatment costs dominate: dozens of small systems have installed removal equipment or drilled new wells, and the state's private wells show frequent nitrate and bacteria exceedances. Atrazine and other herbicides appear seasonally in surface water at levels below federal limits.

Common Contaminants in Iowa

Nitrate

The state's defining contaminant, from fertilizer and drained cropland; utilities treat or blend, and private wells are at highest risk

Herbicides (atrazine)

Spring runoff pulses appear in river-sourced systems, monitored and typically below limits

Bacteria in private wells

Shallow rural wells frequently test positive for coliform; state programs offer free testing

Violations & Compliance

Public systems mostly comply because they invest in treatment: the cost of nitrate removal is the real burden. Small systems account for periodic nitrate exceedances, and Iowa's water-quality debate centers on upstream farm-practice policy.

City Water Reports in Iowa

Frequently Asked Questions

Sources & References

The safety rating and guidance on this page draw on the following sources. See our full methodology.