How hard is the water in Coos County, OR?
2.9 grains per gallon
You do not need a softener here.
The median hardness measured in Coos County, OR is 50 mg/L as calcium carbonate, which is 2.9 gpg. That is soft on the USGS scale. It comes from 191 samples at 38 sites between 1990 and 2024, 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 1.1 and 7.5 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: high (how it is measured).
What to do next
You can skip the softener. At 2.9 gpg the most a softener would fix is the odd water spot. If a salesperson in Coos County says otherwise, ask to see their reading in grains per gallon and compare it with this one. Because Coos 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 0.2 to 46.7 gpg
The softest single sample on record in Coos County was 4 mg/L and the hardest 800 mg/L, a 200-fold gap. The top quarter of sites read above 7.5 gpg and the bottom quarter below 1.1 gpg. So even in a soft county, a handful of wells here produce water hard enough to scale a heater.
Wells 2.9 gpg, rivers and lakes 2.6 gpg
191 groundwater samples from 38 wells put the median at 50 mg/L. 411 surface samples from 95 sites put it at 45.1 mg/L. In Coos County the wells come out 0.3 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.
Coos County against the rest of Oregon
Among the 36 Oregon counties with data, Coos County is number 28 of 36 counting from the hardest. Across the whole country it is harder than 21% of counties.
Softest in Oregon: Columbia County at 1.4 gpg. Hardest: Malheur County at 17.8 gpg. Closest to Coos County: Deschutes County (2.5), Hood River County (2.5), Lincoln County (2.5).