How hard is the water in King William County, VA?

0.7 grains per gallon

You do not need a softener here.

The median hardness measured in King William County, VA is 12 mg/L as calcium carbonate, which is 0.7 gpg. That is soft on the USGS scale. It comes from 26 samples at 26 sites between 1990 and 2026, 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 0.3 and 1.2 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

You can skip the softener. At 0.7 gpg the most a softener would fix is the odd water spot. If a salesperson in King William 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 0.1 to 5.4 gpg

The softest single sample on record in King William County was 1 mg/L and the hardest 93 mg/L, a 93-fold gap. The top quarter of sites read above 1.2 gpg and the bottom quarter below 0.3 gpg.

Wells 0.7 gpg, rivers and lakes 1.6 gpg

26 groundwater samples from 26 wells put the median at 11.5 mg/L. 872 surface samples from 15 sites put it at 28 mg/L. In King William County the rivers and lakes come out 0.9 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.

King William County against the rest of Virginia

Among the 126 Virginia counties with data, King William County is number 122 of 126 counting from the hardest. Across the whole country it is harder than 4% of counties.

Softest in Virginia: Isle of Wight County at 0.4 gpg. Hardest: Clarke County at 20.1 gpg. Closest to King William County: Westmoreland County (0.6), Gloucester County (0.8), New Kent County (0.8).