How hard is the water in Carroll County, NH?

1.7 grains per gallon

You do not need a softener here.

The median hardness measured in Carroll County, NH is 30 mg/L as calcium carbonate, which is 1.7 gpg. That is soft on the USGS scale. It comes from 104 samples at 94 sites between 1990 and 2021, 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 0.8 and 3 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

You can skip the softener. At 1.7 gpg the most a softener would fix is the odd water spot. If a salesperson in Carroll County says otherwise, ask to see their reading in grains per gallon and compare it with this one.

More on when a softener is not worth it.

From 0.2 to 9.3 gpg

The softest single sample on record in Carroll County was 3.2 mg/L and the hardest 160 mg/L, a 50-fold gap. The top quarter of sites read above 3 gpg and the bottom quarter below 0.8 gpg.

Wells 1.7 gpg, rivers and lakes 0.4 gpg

104 groundwater samples from 94 wells put the median at 29.6 mg/L. 172 surface samples from 38 sites put it at 7.1 mg/L. In Carroll County the wells come out 1.3 gpg harder. Groundwater sits in contact with rock for years and picks up calcium and magnesium as it goes, so wells usually read harder. The two sources are close, so the county figure should hold whichever one your tap is on.

Carroll County against the rest of New Hampshire

Among the 10 New Hampshire counties with data, Carroll County is number 9 of 10 counting from the hardest. Across the whole country it is harder than 14% of counties.

Softest in New Hampshire: Strafford County at 0.8 gpg. Hardest: Rockingham County at 6 gpg. Closest to Carroll County: Strafford County (0.8), Merrimack County (3.1), Coos County (3.4).