How hard is the water in Windham County, VT?
5.2 grains per gallon
Optional: a softener helps, but plenty of homes skip it.
The median hardness measured in Windham County, VT is 90 mg/L as calcium carbonate, which is 5.2 gpg. That is moderately hard on the USGS scale. It comes from 7 samples at 6 sites between 1994 and 2025, 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 5.1 and 5.5 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 5.2 gpg this is your call. Look for white film on glasses and crust on the shower head: if you see little of either, you can live without one. If you do want one, a 24,000-grain unit is enough, so ask for that size rather than a bigger one.
More on when a softener is not worth it.
From 4.0 to 10.0 gpg
The softest single sample on record in Windham County was 68.1 mg/L and the hardest 171 mg/L, a 3-fold gap. The top quarter of sites read above 5.5 gpg and the bottom quarter below 5.1 gpg.
Wells 5.2 gpg, rivers and lakes 1.2 gpg
7 groundwater samples from 6 wells put the median at 89.8 mg/L. 1,007 surface samples from 205 sites put it at 20.7 mg/L. In Windham County the wells come out 4.0 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 115 lb of salt a year (3 bags of 40 lb, about $21), 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 $121 a year.
Sizing at 5.2 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 312 | 24,000 | 38 lb |
| 2 | 624 | 24,000 | 76 lb |
| 4 | 1,248 | 24,000 | 152 lb |
| 6 | 1,872 | 24,000 | 228 lb |
Windham County against the rest of Vermont
Among the 14 Vermont counties with data, Windham County is number 4 of 14 counting from the hardest. Across the whole country it is harder than 32% of counties.
Softest in Vermont: Essex County at 1 gpg. Hardest: Orange County at 7.7 gpg. Closest to Windham County: Windsor County (5.3), Rutland County (5.1), Franklin County (4.9).