Water Hardness in Idaho

44 counties — Average 138.3 PPM (Hard)

11
9
9
15
Soft (25.0%) Moderate (20.5%) Hard (20.5%) Very Hard (34.1%)

Idaho Water Hardness Map

Soft   Moderate   Hard   Very Hard

Hardest Water Counties

Bannock280 PPM
Bear Lake260 PPM
Bingham202 PPM
Bonneville200 PPM
Butte188 PPM
Caribou199 PPM
Cassia221.5 PPM
Elmore190 PPM
Franklin290 PPM
Jerome230 PPM
Minidoka240 PPM
Oneida320 PPM
+3 more
Idaho

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All 44 Counties — By Water Hardness

CountyClassificationHardness
Ada Moderate 112 PPM
Adams Soft 54.9 PPM
Bannock Very Hard 280 PPM
Bear Lake Very Hard 260 PPM
Benewah Soft 23 PPM
Bingham Very Hard 202 PPM
Blaine Hard 160 PPM
Boise Soft 28.9 PPM
Bonner Moderate 86.2 PPM
Bonneville Very Hard 200 PPM
Boundary Moderate 110 PPM
Butte Very Hard 188 PPM
Camas Soft 50 PPM
Canyon Hard 150 PPM
Caribou Very Hard 199 PPM
Cassia Very Hard 221.5 PPM
Clark Hard 151 PPM
Clearwater Soft 20 PPM
Custer Soft 54 PPM
Elmore Very Hard 190 PPM
Franklin Very Hard 290 PPM
Fremont Moderate 103.5 PPM
Gem Moderate 78.5 PPM
Gooding Hard 170 PPM
Idaho Moderate 60.2 PPM
Jefferson Hard 160.5 PPM
Jerome Very Hard 230 PPM
Kootenai Soft 22.2 PPM
Latah Moderate 103 PPM
Lemhi Hard 140 PPM
Lewis Hard 127 PPM
Lincoln Hard 143.5 PPM
Madison Moderate 74.3 PPM
Minidoka Very Hard 240 PPM
Nez Perce Soft 39 PPM
Oneida Very Hard 320 PPM
Owyhee Soft 47 PPM
Payette Hard 150 PPM
Power Very Hard 227 PPM
Shoshone Soft 38.4 PPM
Teton Very Hard 186.5 PPM
Twin Falls Very Hard 270 PPM
Valley Soft 25.9 PPM
Washington Moderate 100 PPM

Source: USGS Water Quality Portal

Frequently Asked Questions

How hard is the water in Idaho?

Idaho has an average water hardness of 138.3 PPM, classified as hard. Out of 44 counties, 11 have soft water, 9 moderately hard, 9 hard, and 15 very hard.

Which Idaho counties have the hardest water?

Idaho has 15 counties with very hard water (above 180 mg/L). See the county table above for a complete breakdown by hardness level.

How do I check water hardness for my Idaho address?

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