State water index

Missouri water hardness

Search 504 indexed communities and 556 ZIP profiles, then compare the underlying utility, source, distance, and reporting context.

Median regional evidence

227PPM

Very Hard

Indexed range 23.8–729.5 PPM

ZIP profiles: 556
Cities: 504
Matched utilities: 722
Counties: 115

Understanding Missouri

Why local comparisons matter here

Missouri spans the carbonate-rich Ozarks, northern plains, and the Missouri and Mississippi river corridors. Major cities and rural systems often use different source types.

In this index, very hard is the largest category, covering 383 of 479 profiles with hardness data. The state median is 227 PPM, but the full indexed range is 23.8–729.5 PPM.

State distribution

Hardness across indexed ZIPs

Counts describe published ZIP profiles, not a population-weighted statewide sample.

Soft · 0–60 PPM6

Moderately hard · 61–120 PPM10

Hard · 121–180 PPM80

Very hard · 181+ PPM383

Evidence coverage

What the current records support

Hardness estimate: 86%
Lead 90th percentile: 100%
Copper 90th percentile: 5%

280

Low-confidence hardness profiles

Research-comparison eligible profiles

Reported source water

Utility source mix

Groundwater: 569
Surface water: 149
Groundwater influenced by surface water: 4

Highest medians

Highest eligible city medians

1. Independence487 PPM

Lowest medians

Lowest eligible city medians

1. Independence487 PPM

City directory

Explore Missouri by city

Search by city or county, then sort by name, hardness, or ZIP coverage.

504 cities · 556 ZIP profiles

Search city or county

County

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504 cities found

Page 1 of 21

Adrian

Bates County · 1 ZIP

219PPM regional

County	Median	Range	ZIP profiles
Atchison County	730 PPM	436–729.5	4
Jackson County	487 PPM	258–488	15
Ray County	487 PPM	441–488	4
Boone County	383 PPM	368.5–383	8
Cole County	377 PPM	371–383	2
Howard County	376 PPM	285–383	4
Clay County	362 PPM	236–486.5	4
Callaway County	352 PPM	328–368.5	5
Moniteau County	349 PPM	274–383	6
Miller County	349 PPM	292–395	6
Osage County	347 PPM	347–371	4
Andrew County	330 PPM	330–330	7

Why local comparisons matter here

Hardness across indexed ZIPs

What the current records support

Utility source mix

Highest eligible city medians

Lowest eligible city medians

Explore Missouri by city

Adrian

Advance

Alba

Albany

Alma

Altenburg

Alton

Amazonia

Amoret

Amsterdam

Anderson

Annapolis

Anniston

Arbyrd

Arcadia

Archie

Arcola

Argyle

Arrow Rock

Asbury

Ash Grove

Ashland

Atlanta

Aurora

Highest regional-evidence county medians