How hard is the water in Cowlitz County, WA?

1.6 grains per gallon

You do not need a softener here.

The median hardness measured in Cowlitz County, WA is 28 mg/L as calcium carbonate, which is 1.6 gpg. That is soft on the USGS scale. It comes from 17 samples at 4 sites between 1997 and 2012, drawn from every sampling site in the county, wells and surface water together.

How much it varies here

Half the sites came in between 0.9 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: medium (how it is measured).

What to do next

You can skip the softener. At 1.6 gpg the most a softener would fix is the odd water spot. If a salesperson in Cowlitz 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 0.8 to 5.2 gpg

The softest single sample on record in Cowlitz County was 13.3 mg/L and the hardest 89 mg/L, a 7-fold gap. The top quarter of sites read above 3 gpg and the bottom quarter below 0.9 gpg.

Wells 5.2 gpg, rivers and lakes 0.9 gpg

4 groundwater samples from 1 wells put the median at 89 mg/L. 13 surface samples from 3 sites put it at 16.1 mg/L. In Cowlitz County the wells come out 4.3 gpg harder. Groundwater sits in contact with rock for years and picks up calcium and magnesium as it goes, so wells usually read harder. A utility here that draws from the river can deliver noticeably different water from a private well next door.

Cowlitz County against the rest of Washington

Among the 38 Washington counties with data, Cowlitz County is number 35 of 38 counting from the hardest. Across the whole country it is harder than 13% of counties.

Softest in Washington: Chelan County at 0.6 gpg. Hardest: Island County at 20.7 gpg. Closest to Cowlitz County: Jefferson County (1.4), Grays Harbor County (1.9), Pacific County (2.3).