How hard is the water in North Slope Borough, AK?
10 grains per gallon
A softener is worth it here.
The median hardness measured in North Slope Borough, AK is 172 mg/L as calcium carbonate, which is 10 gpg. That is hard on the USGS scale. It comes from 10 samples at 7 sites between 1996 and 2023, 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 6.2 and 10.8 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: medium (how it is measured).
What to do next
At 10 gpg a softener is worth getting, mainly to protect the water heater and cut soap use. Get at least two quotes, ask each installer what grain capacity they are fitting, and check it against the sizing table below. Because North Slope Borough straddles a decision line, check your own tap with a $10 test strip before you spend anything.
More on sizing a softener for your household.
From 2.1 to 13.2 gpg
The softest single sample on record in North Slope Borough was 35.6 mg/L and the hardest 226 mg/L, a 6-fold gap. The top quarter of sites read above 10.8 gpg and the bottom quarter below 6.2 gpg. So even here some sites draw water soft enough to need nothing at all.
Wells 10 gpg, rivers and lakes 4.5 gpg
10 groundwater samples from 7 wells put the median at 172 mg/L. 70 surface samples from 36 sites put it at 76.2 mg/L. In North Slope Borough the wells come out 5.5 gpg harder. Groundwater sits in contact with rock for years and picks up calcium and magnesium as it goes, so wells usually read harder. A utility here that draws from the river can deliver noticeably different water from a private well next door.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 219 lb of salt a year (6 bags of 40 lb, about $39), 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 $139 a year.
Sizing at 10 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 600 | 24,000 | 73 lb |
| 2 | 1,200 | 24,000 | 146 lb |
| 4 | 2,400 | 24,000 | 292 lb |
| 6 | 3,600 | 32,000 | 438 lb |
North Slope Borough against the rest of Alaska
Among the 22 Alaska counties with data, North Slope Borough is number 4 of 22 counting from the hardest. Across the whole country it is harder than 51% of counties.
Softest in Alaska: Petersburg Borough at 0.3 gpg. Hardest: Southeast Fairbanks Census Area at 16.3 gpg. Closest to North Slope Borough: Denali Borough (10.3), Anchorage Municipality (7.6), Yakutat City and Borough (7.4).