Water Hardness Atlas ZIP / postcode

Water hardness in DeForest

16.3 gpg very hard

Tap water in DeForest is very hard: 16.3 gpg (280 mg/L · 15.7 °dH · 27.9 °fH).

<6060–120120–180>180 mg/L

Source: Wisconsin DNR Drinking Water System portal (Deforest Waterworks) (2026) · data checked 2026-10-20

Range across supply zones: 250–366 mg/L.

DeForest Waterworks pumps groundwater from Dane County wells, mostly in the deep sandstone aquifer. Dane County groundwater is typically very hard, and the wells give 279.5 mg/L CaCO₃ (250–366 mg/L). Heavy scale on heaters and fixtures.

USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.

Water data

Total hardness16.3 gpg
UtilityDeforest Waterworks

How DeForest compares

Ranking of the hardest and softest water in the United States →

What it means at home

How much salt will you use for softening?

Yes. At this hardness a softener pays for itself through appliance life and detergent.

Descale a coffee machine or kettle about every 1 months (typical manufacturer guidance for this hardness).

Estimates for planning, not a quote. Check your appliance manual for exact settings.

Dishwasher setting in DeForest

BrandSetting for this water
BoschH04
Miele16 °dH
AEG / Electrolux4
Beko4th
HooverS2
LGH3

From each brand's manual for the model family named in the source; your model may differ, so check its manual. All brands and how to change the setting →

FAQ

Is DeForest water hard or soft?

It is very hard: 280 mg/L as CaCO₃ (16.3 gpg, 15.7 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.

Is tap water in DeForest safe to drink?

Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.

How many grains per gallon is DeForest water?

16.3 gpg, equal to 15.7 °dH, 27.9 °fH or 280 mg/L calcium carbonate.

What dishwasher salt setting should I use in DeForest?

For 280 mg/L (15.7 °dH) check your manufacturer's table: maximum level (5–7).

Do I need a water softener in DeForest?

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

Source

Source: Wisconsin DNR Drinking Water System portal (Deforest Waterworks) (2026). Method: figure published by the water supplier. Wisconsin DNR Drinking Water System portal (Deforest Waterworks) · Outdated figure? Tell us

Nearby cities

Windsor15.5 gpgWaunakee15.2 gpgSun Prairie18.7 gpgArlington19.2 gpgDane14.6 gpgMadison19.9 gpg
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