Water hardness in Salt Lake City
10.2 gpg hard
Tap water in Salt Lake City is hard: 10.2 gpg (175 mg/L · 9.8 °dH · 17.5 °fH).
Source: Salt Lake City Department of Public Utilities - 2026 Drinking Water Quality Report (2025 data) (2026) · data checked 2026-10-23
Range across supply zones: 136–571 mg/L.
7 supply zones — hardness varies by neighbourhood; the figure above is the median.
Hardness by district / supply zone
| gpg | mg/L | ||
|---|---|---|---|
| Big Cottonwood WTP | 7.9 | 136 | hard |
| City Creek WTP | 12.4 | 212 | very hard |
| Jordan Valley Water Conservancy District (purchased) | 10.8 | 184 | very hard |
| MWDSLS Little Cottonwood WTP (purchased) | 8.9 | 152 | hard |
| MWDSLS Point of the Mountain WTP (purchased) | 9.6 | 164 | hard |
| Parleys WTP | 10.2 | 175 | hard |
| Salt Lake City wells and springs | 21.2 | 363 | very hard |
Salt Lake City Public Utilities draws on mountain streams (City Creek, Parleys, Big and Little Cottonwood), wells and springs, and treated water from a regional wholesaler fed by the Provo, Duchesne and Weber rivers. Snowmelt creeks are soft while valley wells are much harder, which gives 7 zones from 136 to 571 mg/L CaCO₃ with a median of 175 mg/L. Check your zone before choosing a softener.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 10.2 gpg |
|---|---|
| Utility | Salt Lake City Department of Public Utilities |
How Salt Lake City compares
- Tap water in Salt Lake City is 13 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 610 of 1372 in the United States (1 = hardest); 55 % of these cities have softer water.
- In Utah it is number 10 of 14 cities; the regional median is 10.9 gpg.
- Nearest city with clearly harder water: Herriman, 32 km away (37.5 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 Salt Lake City
| Brand | Setting for this water |
|---|---|
| Bosch | H02 |
| Miele | 10 °dH |
| AEG / Electrolux | 2 |
| Beko | 3rd |
| Hoover | S2 |
| 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 Salt Lake City water hard or soft?
It is hard: 175 mg/L as CaCO₃ (10.2 gpg, 9.8 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Salt Lake City 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 Salt Lake City water?
10.2 gpg, equal to 9.8 °dH, 17.5 °fH or 175 mg/L calcium carbonate.
What dishwasher salt setting should I use in Salt Lake City?
For 175 mg/L (9.8 °dH) check your manufacturer's table: level 4–5.
Do I need a water softener in Salt Lake City?
Recommended if you have a water heater, boiler or tankless unit: it saves repairs and detergent.
Source
Source: Salt Lake City Department of Public Utilities - 2026 Drinking Water Quality Report (2025 data) (2026). Method: figure published by the water supplier. Salt Lake City Department of Public Utilities - 2026 Drinking Water Quality Report (2025 data) · Outdated figure? Tell us