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Well water hardness in Litchfield County, Connecticut

4.7 gpg moderately hard

Private wells in Litchfield County typically give moderately hard water: the median well sampled by the U.S. Geological Survey has 4.7 gpg (81 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 35 mg/L and one in ten more than 236 mg/L. The figure comes from 82 wells and 148 samples taken between 1981 and 2017 (half of them by 2003).

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 Connecticut

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

Use a certified laboratory: Connecticut DPH, Environmental Laboratory Certification (in-state labs approved to test drinking water).

Existing private wells need not be tested by law, but newly constructed private wells must be tested (coliform, nitrate, nitrite, sodium, chloride, iron, lead, manganese, hardness, turbidity, pH, sulfate, color, odor, arsenic, uranium) under CGS Sec. 19a-37; tests at a home purchase are usually a lender requirement, not a legal one.

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

A softener is optional at this level. Check iron and manganese in your test as well: staining from them is a more common well problem than hardness.

Nearby counties

New Haven County6.2 gpgFairfield County3 gpgPutnam County, NY8.5 gpgHartford County4.6 gpgWestchester County, NY5.4 gpgDutchess County, NY12.5 gpg

FAQ

How hard is well water in Litchfield County, Connecticut?

The median well sampled by the USGS in Litchfield County has 4.7 gpg (81 mg/L as CaCO₃), which is moderately hard. One in ten wells had less than 35 mg/L and one in ten more than 236 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 Connecticut?

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?

Not essential; a scale inhibitor protects the heater cheaply.

Where does this figure come from?

From 148 samples of 82 wells measured by the U.S. Geological Survey between 1981 and 2017, 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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