Water hardness in St. George
18.6 gpg very hard
Tap water in St. George is very hard: 18.6 gpg (319 mg/L · 17.9 °dH · 31.9 °fH).
Source: City of St. George 2023 Water Quality Report (2023 Water Quality Data) (2022) · data checked 2026-10-23
This figure is over 3 years old; hardness may have changed.
St. George buys surface water from the Washington County Water Conservancy District, taken from the Virgin River and stored in Quail Creek and Sand Hollow reservoirs, and blends it with city wells. The Virgin River drains sandstone and limestone country in southwestern Utah, so water is very hard, estimated at 318.8 mg/L CaCO₃. Scale is severe; softeners are common. The figure dates from 2022 and may have changed.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 18.6 gpg |
|---|---|
| Calcium (mg/L) | 65 |
| Magnesium (mg/L) | 38 |
| Utility | City of St. George Water Services (purchased surface water from Washington County Water Conservancy District) |
How St. George compares
- Tap water in St. George is 106 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 201 of 1372 in the United States (1 = hardest); 85 % of these cities have softer water.
- In Utah it is number 2 of 14 cities; the regional median is 10.9 gpg.
Ranking of the hardest and softest water in the United States →
What it means at home
- Severe scale: heater elements and washing-machine heaters fail early.
- Detergent use is very high; taps and screens coat within days.
- Dishwasher at maximum salt setting.
- An ion-exchange softener is practically essential; RO for drinking water.
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 St. George
| Brand | Setting for this water |
|---|---|
| Bosch | H05 |
| Miele | 18 °dH |
| AEG / Electrolux | 4 |
| Beko | 5th |
| Hoover | S3 |
| LG | H3 |
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 St. George water hard or soft?
It is very hard: 319 mg/L as CaCO₃ (18.6 gpg, 17.9 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in St. George 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 St. George water?
18.6 gpg, equal to 17.9 °dH, 31.9 °fH or 319 mg/L calcium carbonate.
What dishwasher salt setting should I use in St. George?
For 319 mg/L (17.9 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in St. George?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: City of St. George 2023 Water Quality Report (2023 Water Quality Data) (2022). Method: computed from supplier's calcium and magnesium. City of St. George 2023 Water Quality Report (2023 Water Quality Data) · Outdated figure? Tell us