Water Hardness in Hawaii

5 counties — Average 41.5 PPM (Soft)

4
1
Soft (80.0%) Moderate (20.0%) Hard (0.0%) Very Hard (0.0%)

Hawaii Water Hardness Map

Soft   Moderate   Hard   Very Hard

Hawaii

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All 5 Counties — By Water Hardness

CountyClassificationHardness
Hawaii Moderate 68 PPM
Honolulu Soft 54 PPM
Kalawao Soft 36 PPM
Kauai Soft 33 PPM
Maui Soft 16.7 PPM

Source: USGS Water Quality Portal

Frequently Asked Questions

How hard is the water in Hawaii?

Hawaii has an average water hardness of 41.5 PPM, classified as soft. Out of 5 counties, 4 have soft water, 1 moderately hard, 0 hard, and 0 very hard.

Which Hawaii counties have the hardest water?

See the county table above for a complete breakdown by hardness level.

How do I check water hardness for my Hawaii address?

Enter your ZIP code in the search box above to see your area's estimated water hardness, classification, and water utility information.