How hard is the water in Sac County, IA?

23.7 grains per gallon

A softener will pay its way here.

The median hardness measured in Sac County, IA is 405 mg/L as calcium carbonate, which is 23.7 gpg. That is very hard on the USGS scale. It comes from 18 samples at 8 sites between 1991 and 2006, drawn from groundwater wells, which is what most taps and private wells in the county draw on.

How much it varies here

Half the sites came in between 21.9 and 36.4 gpg. The whole middle of that range gives the same answer, so a test of your own tap is unlikely to change it. Confidence in the county figure: medium (how it is measured).

What to do next

At 23.7 gpg a softener pays its way here. Before you buy, check the quoted unit's grain capacity against the sizing table below, and ask whether it regenerates on demand, which uses less salt than a timer. Call your utility for its own report if you are on city water.

More on sizing a softener for your household.

From 18.8 to 99.3 gpg

The softest single sample on record in Sac County was 322 mg/L and the hardest 1,700 mg/L, a 5-fold gap. The top quarter of sites read above 36.4 gpg and the bottom quarter below 21.9 gpg.

What a softener would cost to run

For a household of 3, a 32,000-grain unit covers a week between regenerations. Expect about 517 lb of salt a year (13 bags of 40 lb, about $93), and roughly 2,346 gallons of regeneration water. Installed, most units run $1,000 to $4,500; spread over 15 years with salt, that is about $193 a year.

Sizing at 23.7 gpg

Sac County against the rest of Iowa

Among the 93 Iowa counties with data, Sac County is number 21 of 93 counting from the hardest. Across the whole country it is harder than 90% of counties.

Softest in Iowa: Taylor County at 8.2 gpg. Hardest: Pocahontas County at 45.3 gpg. Closest to Sac County: Ida County (23.7), Audubon County (23.4), Boone County (23.4).