Water hardness in Elgin
7.5 gpg hard
Tap water in Elgin is hard: 7.5 gpg (128 mg/L · 7.2 °dH · 12.8 °fH).
Source: City of Elgin Water Department FAQ: What is the hardness of City water? (2026) · data checked 2026-10-23
Range across supply zones: 120–137 mg/L.
Elgin's water comes mainly from the Fox River, treated at the Riverside plant, with some groundwater from deep wells. The river drains glacial deposits rich in carbonate, which is why hardness is 128.4 mg/L CaCO₃ (119.8–137 mg/L). Expect scale in kettles and water heaters.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 7.5 gpg |
|---|---|
| Utility | City of Elgin Water Department |
How Elgin compares
- Tap water in Elgin is 17 % softer than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 845 of 1372 in the United States (1 = hardest); 38 % of these cities have softer water.
- In Illinois it is number 11 of 14 cities; the regional median is 8 gpg.
- Nearest city with clearly softer water: Bloomfield, 57 km away (1 gpg).
- Nearest city with clearly harder water: Genoa City, 52 km away (22.6 gpg).
Ranking of the hardest and softest water in the United States →
What it means at home
- Fast scale on taps, shower screens and kettle; white spots on glassware.
- Water heater: efficiency loss and element failures within years if unprotected.
- Dry skin and dull hair after showering are common.
- Softener recommended; jug or reverse osmosis for drinking.
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 Elgin
| Brand | Setting for this water |
|---|---|
| Bosch | H01 |
| Miele | 7 °dH |
| AEG / Electrolux | 2 |
| Beko | 2nd |
| Hoover | S1 |
| LG | H2 |
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 Elgin water hard or soft?
It is hard: 128 mg/L as CaCO₃ (7.5 gpg, 7.2 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Elgin 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 Elgin water?
7.5 gpg, equal to 7.2 °dH, 12.8 °fH or 128 mg/L calcium carbonate.
What dishwasher salt setting should I use in Elgin?
For 128 mg/L (7.2 °dH) check your manufacturer's table: level 4–5.
Do I need a water softener in Elgin?
Recommended if you have a water heater, boiler or tankless unit: it saves repairs and detergent.
Source
Source: City of Elgin Water Department FAQ: What is the hardness of City water? (2026). Method: computed from supplier's calcium and magnesium. City of Elgin Water Department FAQ: What is the hardness of City water? · Outdated figure? Tell us