How hard is the water in Del Norte County, CA?
5.2 grains per gallon
Optional: a softener helps, but plenty of homes skip it.
The median hardness measured in Del Norte County, CA is 88 mg/L as calcium carbonate, which is 5.2 gpg. That is moderately hard on the USGS scale. It comes from 17 samples at 8 sites between 1990 and 2020, 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 4.4 and 6.6 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
At 5.2 gpg this is your call. Look for white film on glasses and crust on the shower head: if you see little of either, you can live without one. If you do want one, a 24,000-grain unit is enough, so ask for that size rather than a bigger one.
More on when a softener is not worth it.
From 1.1 to 12.2 gpg
The softest single sample on record in Del Norte County was 18.8 mg/L and the hardest 208 mg/L, an 11-fold gap. The top quarter of sites read above 6.6 gpg and the bottom quarter below 4.4 gpg.
Wells 5.2 gpg, rivers and lakes 2.7 gpg
17 groundwater samples from 8 wells put the median at 88.4 mg/L. 71 surface samples from 9 sites put it at 46 mg/L. In Del Norte County the wells come out 2.5 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.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 113 lb of salt a year (3 bags of 40 lb, about $20), and roughly 2,346 gallons of regeneration water. Installed, most units run $1,000 to $4,500; spread over 15 years with salt, that is about $120 a year.
Sizing at 5.2 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 312 | 24,000 | 38 lb |
| 2 | 624 | 24,000 | 76 lb |
| 4 | 1,248 | 24,000 | 152 lb |
| 6 | 1,872 | 24,000 | 228 lb |
Del Norte County against the rest of California
Among the 58 California counties with data, Del Norte County is number 43 of 58 counting from the hardest. Across the whole country it is harder than 31% of counties.
Softest in California: Sierra County at 1.7 gpg. Hardest: Calaveras County at 98.3 gpg. Closest to Del Norte County: Napa County (4.9), Alpine County (4.9), Nevada County (4.8).