How hard is the water in Chittenden County, VT?
3.9 grains per gallon
Optional: a softener helps, but plenty of homes skip it.
The median hardness measured in Chittenden County, VT is 67 mg/L as calcium carbonate, which is 3.9 gpg. That is moderately hard on the USGS scale. It comes from 9 samples at 9 sites between 1996 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 3.4 and 4.7 gpg. That spread crosses a decision line, so some homes here land on a different answer. A $10 test strip on your own tap settles it. Confidence in the county figure: medium (how it is measured).
What to do next
At 3.9 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. Because Chittenden County straddles a decision line, check your own tap with a $10 test strip before you spend anything.
More on when a softener is not worth it.
From 2.3 to 8.1 gpg
The softest single sample on record in Chittenden County was 39.9 mg/L and the hardest 138 mg/L, a 3-fold gap. The top quarter of sites read above 4.7 gpg and the bottom quarter below 3.4 gpg.
Wells 3.9 gpg, rivers and lakes 6.4 gpg
9 groundwater samples from 9 wells put the median at 66.5 mg/L. 833 surface samples from 214 sites put it at 109.8 mg/L. In Chittenden County the rivers and lakes come out 2.5 gpg harder. Here the surface water reads harder than the wells, which often points to streams fed by limestone springs or irrigation return flow. The two sources are close, so the county figure should hold whichever one your tap is on.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 85 lb of salt a year (3 bags of 40 lb, about $15), 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 $115 a year.
Sizing at 3.9 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 234 | 24,000 | 28 lb |
| 2 | 468 | 24,000 | 57 lb |
| 4 | 936 | 24,000 | 114 lb |
| 6 | 1,404 | 24,000 | 171 lb |
Chittenden County against the rest of Vermont
Among the 14 Vermont counties with data, Chittenden County is number 9 of 14 counting from the hardest. Across the whole country it is harder than 26% of counties.
Softest in Vermont: Essex County at 1 gpg. Hardest: Orange County at 7.7 gpg. Closest to Chittenden County: Orleans County (4.3), Grand Isle County (3.5), Washington County (3.5).