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Well water hardness in Cache County, Utah

15 gpg very hard

Private wells in Cache County typically give very hard water: the median well sampled by the U.S. Geological Survey has 15 gpg (257 mg/L as CaCO₃).

<6060–120120–180>180 mg/L

Wells differ a lot, even next door: one in ten sampled wells had less than 200 mg/L and one in ten more than 338 mg/L. The figure comes from 41 wells and 117 samples taken between 1981 and 2021 (half of them by 2010).

Most samples are older than ten years. Groundwater hardness comes from the rock the well is drilled into and changes slowly, but your own well can be quite different, so treat this as a regional indication and test your water.

What this hardness means for a well household

How to test your well in Utah

Hardness is only one part of a well test. Federal health agencies advise every private well owner to test regularly:

Use a certified laboratory: Utah Public Health Laboratory (UPHL), Private Wells testing.

Utah has no state or federal rule requiring private well testing; requirements are set by local health departments and several counties require none.

What a test costs (Utah Public Health Laboratory (UPHL) service fee schedule)

Total coliforms/E. coli (SM 9223B)$20.90
Nitrate (EPA 353.2)$17.60
Hardness (SM 2340B, requires Ca and Mg tests)$6.05
pH$12
Total dissolved solids$14.03

Prices as printed by the lab (2026-10-29); check the current fee before you send a sample. Utah Public Health Laboratory (UPHL) service fee schedule

If no local lab suits you, mail-in kits from certified labs test a wider panel at home; they cost more than a state or county lab.

Treating hard well water

At this hardness an ion-exchange softener sized for your household is the usual answer. Test iron, manganese and pH first: well water often needs an iron filter or a pH correction in front of the softener.

Nearby counties

Box Elder County19 gpgFranklin County, ID18 gpgWeber County9.3 gpgOneida County, ID19 gpgDavis County13.3 gpgBear Lake County, ID17.2 gpg

FAQ

How hard is well water in Cache County, Utah?

The median well sampled by the USGS in Cache County has 15 gpg (257 mg/L as CaCO₃), which is very hard. One in ten wells had less than 200 mg/L and one in ten more than 338 mg/L.

Is my own well the same?

Not necessarily. Hardness depends on the rock layer your well draws from and on its depth, so neighbouring wells can differ by a factor of two or more. Only a test of your own water tells you.

How often should I test my well in Utah?

Every year for coliform bacteria, nitrate, total dissolved solids and pH (EPA and CDC advice), and after floods, repairs or a change in taste or smell. Hardness, iron and manganese once, and again before you buy a softener.

Do I need a water softener for my well?

Yes, unless you are only passing through: scale damages appliances within a few years.

Where does this figure come from?

From 117 samples of 41 wells measured by the U.S. Geological Survey between 1981 and 2021, retrieved from the Water Quality Portal. We publish a county only when at least 10 wells were sampled.

Source and method

Computed by Water Hardness Atlas from USGS National Water Information System samples (characteristic "Hardness, Ca, Mg", sites of type well, samples since 1980), retrieved 2026-10-29 through the Water Quality Portal. For each well we take the median of its samples, then the median of all wells in the county; wells above 1,000 mg/L (oil, gas or mine brines) are left out. USGS data are in the U.S. public domain. Water Quality Portal query

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