Iowa Water Quality Report 2026

6 cities676,988 residentsUpdated March 2026

C75.2/100State Average
Iowa has 6 cities in our database, serving approximately 676,988 residents. The average PurityMap score is 75.2/100 (Grade: C), which is 2.7 points below the US average of 77.9/100. Davenport has the cleanest water (78/100) while Sioux City scores lowest (73/100) due to very hard water, high TDS.
Is Iowa Tap Water Safe to Drink?
Safe — Softener May Help

Iowa tap water is safe — softener may help based on our analysis of 6 water systems serving 676,988 residents. The average PurityMap score is 75.2/100 (Grade: C), which is 2.7 points below the national average.

  • 6 cities (100%) have hard or very hard water (7+ GPG) which causes scale buildup and appliance damage.
  • 1 cities exceed the EPA secondary TDS guideline of 500 ppm, which affects taste and may indicate elevated minerals.
  • 6 cities use chloramine or have elevated chlorine residuals. Standard Brita pitchers do not remove chloramine.
Our Recommendation

A water softener is the most impactful investment for Iowa residents in hard water areas. A basic carbon pitcher or faucet filter removes chlorine and improves taste.

All 6 cities in Iowa meet EPA federal drinking water standards as of 2026. However, EPA standards set legal limits — not health goals. Many contaminants are detected at levels that are legal but may still pose long-term health risks according to independent health organizations like the EWG.
Iowa at a Glance
75.2Avg Purity Score
12.7Avg Hardness (GPG)
Very Hard
0Cities with PFAS
6Cities with Hard Water
3Avg Lead (ppb)
434Avg TDS (ppm)

Iowa is 2.7 points below the US average of 77.9/100. Hardness is 6.4 GPG above the US average of 6.3 GPG.

Best & Worst Water in Iowa
Cleanest

Davenport

78/100

Source: Mississippi River

Most Concerns

Sioux City

73/100

very hard water, high TDS

Cities with Most Water Concerns in Iowa

Cities ranked by lowest score. Click any city for the full report and filter recommendations.

RankCityScoreHardnessLeadKey Issues
1Sioux City 73/10015.5 GPG3.0 ppbVery Hard (15.5 GPG), TDS (530 ppm)
2Des Moines 75/10010.8 GPG2.8 ppbVery Hard (10.8 GPG)
3Waterloo 75/10013.5 GPG3.5 ppbVery Hard (13.5 GPG)
4Cedar Rapids 75/10012.5 GPG3.2 ppbVery Hard (12.5 GPG)
5Iowa City 75/10014.0 GPG2.5 ppbVery Hard (14.0 GPG)
6Davenport 78/1009.8 GPG3.0 ppbHard (9.8 GPG)
Score Distribution

How Iowa's 6 cities score on the PurityMap 0–100 scale:

Excellent (85–100)
0 cities
Good (70–84)
6 cities
Moderate (60–69)
0 cities
Poor (below 60)
0 cities
Largest Cities in Iowa — Water Quality

Water quality for the most populated cities. Click any city for details.







CityPopulationScoreHardnessKey Issues
Des Moines214K 75/10010.8 GPGVery Hard
Cedar Rapids134K 75/10012.5 GPGVery Hard
Davenport102K 78/1009.8 GPGHard
Sioux City86K 73/10015.5 GPGVery Hard
Iowa City75K 75/10014.0 GPGVery Hard
Waterloo67K 75/10013.5 GPGVery Hard
Hard Water in Iowa

6 of 6 cities (100%) in Iowa have hard or very hard water (7+ GPG). Sioux City has the hardest at 15.5 GPG. Cities: Sioux City, Iowa City, Waterloo, Cedar Rapids, Des Moines, Davenport. A water softener is recommended.

Hard Water Guide Softener Solutions
PFAS in Iowa Water

Based on EPA UCMR5 data, PFAS have not been detected above advisory levels in any Iowa cities in our database as of 2026.

Lead in Iowa Water

All Iowa cities have lead below 5 ppb. Average: 3.0 ppb. Individual homes with older plumbing may have higher levels.

High TDS in Iowa

1 cities in Iowa have TDS above 500 ppm. Cities: Sioux City. RO effectively reduces TDS.

RO Reduces TDS
Water Sources in Iowa

Where Iowa gets its drinking water, based on 6 water systems.



Source TypeCities% of Total
Surface Water350%
Mixed (Ground + Surface)350%
Recommended Filter for Iowa

Iowa is a hard water state (6/6 cities). A whole-house softener is the best investment.

All Iowa Cities — Ranked
#CityPop.ScoreHardnessLeadPFASTDS
1Sioux City86K 73/10015.5 GPG (Very Hard)3.0 ppb✅ No530 ppm
2Des Moines214K 75/10010.8 GPG (Very Hard)2.8 ppb✅ No370 ppm
3Waterloo67K 75/10013.5 GPG (Very Hard)3.5 ppb✅ No460 ppm
4Cedar Rapids134K 75/10012.5 GPG (Very Hard)3.2 ppb✅ No425 ppm
5Iowa City75K 75/10014.0 GPG (Very Hard)2.5 ppb✅ No480 ppm
6Davenport102K 78/1009.8 GPG (Hard)3.0 ppb✅ No340 ppm
Water Utilities in Iowa

Iowa has 6 utilities. Major: Des Moines Water Works, Cedar Rapids Water Department, Iowa American Water Davenport, City of Waterloo Water Works, Iowa City Water Division.

Sources: Raccoon and Des Moines Rivers, Cedar River, Mississippi River, Cedar River and groundwater, Iowa River and groundwater.

Frequently Asked Questions
Which city has the best water in Iowa?
Davenport scores highest at 78/100. Source: Mississippi River.
Which city has the worst water in Iowa?
Sioux City scores lowest at 73/100 due to very hard water, high TDS.
Is Iowa water hard or soft?
Average hardness: 12.7 GPG (Very Hard). 6.4 GPG above the US average of 6.3 GPG. 6 of 6 cities have hard/very hard water.
Has PFAS been found in Iowa water?
Based on EPA UCMR5 data, PFAS have not been detected above advisory levels in any Iowa cities in our database as of 2026.
What water filter should I use in Iowa?
Iowa is a hard water state (6/6 cities). A whole-house softener is the best investment.
How does Iowa water compare to the US average?
Score: 75.2/100 (2.7 points below US avg 77.9). Hardness: 12.7 GPG (6.4 GPG above US avg 6.3).
Where does Iowa get its drinking water?Where does Iowa get its drinking water?
Iowa water comes from: Surface Water: 3 cities (50%), Mixed (Ground + Surface): 3 cities (50%).
Data Sources & Methodology
  • EPA Safe Drinking Water Information System
  • EWG Tap Water Database
  • State utility Consumer Confidence Reports
  • USGS regional water monitoring data

PurityMap compiles publicly available data and does not perform independent testing.

How we analyze water Data sources
All Iowa Cities with Water Reports

6 city water quality reports available for Iowa.

6 Reports
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Showing all 6 cities
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