Water Hardness Atlas ZIP / postcode

Water hardness in Gary

8.2 gpg hard

Tap water in Gary is hard: 8.2 gpg (140 mg/L · 7.8 °dH · 14 °fH).

<6060–120120–180>180 mg/L

Source: Indiana American Water, water quality report (Greater Gary Area) (2025) · data checked 2026-10-20

Range across supply zones: 130–150 mg/L.

Gary lies on the southern shore of Lake Michigan, and Indiana American Water serves the city. Water from the lake basin carries carbonate from limestone and dolomite, giving 140 mg/L CaCO₃ (130–150 mg/L). That is hard water, with scale on kettles and heaters.

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

Water data

Total hardness8.2 gpg
UtilityIndiana American Water

How Gary 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?

Recommended, especially with a heater or boiler: scale cuts efficiency and shortens its life.

Descale a coffee machine or kettle about every 2 months (typical manufacturer guidance for this hardness).

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

Dishwasher setting in Gary

BrandSetting for this water
BoschH01
Miele8 °dH
AEG / Electrolux2
Beko3rd
HooverS1
LGH2

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 Gary water hard or soft?

It is hard: 140 mg/L as CaCO₃ (8.2 gpg, 7.8 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.

Is tap water in Gary 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 Gary water?

8.2 gpg, equal to 7.8 °dH, 14 °fH or 140 mg/L calcium carbonate.

What dishwasher salt setting should I use in Gary?

For 140 mg/L (7.8 °dH) check your manufacturer's table: level 4–5.

Do I need a water softener in Gary?

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

Source

Source: Indiana American Water, water quality report (Greater Gary Area) (2025). Method: figure published by the water supplier. Indiana American Water, water quality report (Greater Gary Area) · Outdated figure? Tell us

Nearby cities

Lowell8.6 gpgChicago7.9 gpgDes Plaines7.9 gpgWheaton7.9 gpgPalatine8 gpgSouth Bend22 gpg
Report an outdated or wrong figure