How hard is the water in Lewis County, WA?

0.9 grains per gallon

You do not need a softener here.

The median hardness measured in Lewis County, WA is 15 mg/L as calcium carbonate, which is 0.9 gpg. That is soft on the USGS scale. It comes from 26 samples at 2 sites between 2004 and 2015, drawn from every sampling site in the county, wells and surface water together.

How much it varies here

Half the sites came in between 0.5 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: low (how it is measured).

What to do next

You can skip the softener. At 0.9 gpg the most a softener would fix is the odd water spot. If a salesperson in Lewis 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 1.6 gpg

The softest single sample on record in Lewis County was 2.2 mg/L and the hardest 27.5 mg/L, a 12-fold gap. The top quarter of sites read above 1.2 gpg and the bottom quarter below 0.5 gpg.

Lewis County against the rest of Washington

Among the 38 Washington counties with data, Lewis County is number 37 of 38 counting from the hardest. Across the whole country it is harder than 5% of counties.

Softest in Washington: Chelan County at 0.6 gpg. Hardest: Island County at 20.7 gpg. Closest to Lewis County: Chelan County (0.6), Jefferson County (1.4), Cowlitz County (1.6).