How hard is the water in Marshall County, KS?
15.2 grains per gallon
A softener will pay its way here.
The median hardness measured in Marshall County, KS is 260 mg/L as calcium carbonate, which is 15.2 gpg. That is very hard on the USGS scale. It comes from 864 samples at 23 sites between 1990 and 2016, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 14 and 17.9 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: high (how it is measured).
What to do next
At 15.2 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 8.8 to 31.5 gpg
The softest single sample on record in Marshall County was 150 mg/L and the hardest 540 mg/L, a 4-fold gap. The top quarter of sites read above 17.9 gpg and the bottom quarter below 14 gpg.
Wells 19 gpg, rivers and lakes 14.6 gpg
4 groundwater samples from 4 wells put the median at 324.5 mg/L. 860 surface samples from 19 sites put it at 250 mg/L. In Marshall County the wells come out 4.4 gpg harder. Groundwater sits in contact with rock for years and picks up calcium and magnesium as it goes, so wells usually read harder. A utility here that draws from the river can deliver noticeably different water from a private well next door.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 332 lb of salt a year (9 bags of 40 lb, about $60), 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 $160 a year.
Sizing at 15.2 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 912 | 24,000 | 111 lb |
| 2 | 1,824 | 24,000 | 222 lb |
| 4 | 3,648 | 32,000 | 444 lb |
| 6 | 5,472 | 40,000 | 666 lb |
Marshall County against the rest of Kansas
Among the 105 Kansas counties with data, Marshall County is number 55 of 105 counting from the hardest. Across the whole country it is harder than 70% of counties.
Softest in Kansas: Woodson County at 6.3 gpg. Hardest: Linn County at 114.5 gpg. Closest to Marshall County: Trego County (15.1), Norton County (15.3), Doniphan County (14.9).