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Well water hardness in Greenlee County, Arizona

8.6 gpg hard

Private wells in Greenlee County typically give hard water: the median well sampled by the U.S. Geological Survey has 8.6 gpg (148 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 43 mg/L and one in ten more than 322 mg/L. The figure comes from 17 wells and 43 samples taken between 1985 and 2007 (half of them by 1989).

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 Arizona

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

Use a certified laboratory: Arizona Department of Health Services, licensed environmental laboratories search (SDW program filter).

Private well water in Arizona is not tested or regulated by any government organization; the owner is responsible for keeping it safe (ADHS).

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

Most households with hard well water install an ion-exchange softener. Test iron and manganese first: above about 0.3 mg/L iron a softener alone is not enough and an iron filter goes in front of it.

Nearby counties

Hidalgo County, NM3.4 gpgGraham County8.4 gpgCochise County8.8 gpgLuna County, NM6.4 gpgSierra County, NM18.1 gpgCatron County, NM6.1 gpg

FAQ

How hard is well water in Greenlee County, Arizona?

The median well sampled by the USGS in Greenlee County has 8.6 gpg (148 mg/L as CaCO₃), which is hard. One in ten wells had less than 43 mg/L and one in ten more than 322 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 Arizona?

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?

Recommended if you have a water heater, boiler or tankless unit: it saves repairs and detergent.

Where does this figure come from?

From 43 samples of 17 wells measured by the U.S. Geological Survey between 1985 and 2007, 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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