Water hardness in Herriman
37.5 gpg very hard
Tap water in Herriman is very hard: 37.5 gpg (642 mg/L · 36 °dH · 64.2 °fH).
Source: Herriman City, Drinking Water Quality Report (CCR) 2021, Herriman City Hardness Test table (2021) · data checked 2026-10-23
Range across supply zones: 171–1027 mg/L.
7 supply zones — hardness varies by neighbourhood; the figure above is the median.
Hardness by district / supply zone
| gpg | mg/L | ||
|---|---|---|---|
| Arnold Hollow Springs | 17.5 | 300 | very hard |
| Hamilton Well | 57.5 | 984 | very hard |
| Jordan Valley Water (JVWCD) | 12.5 | 214 | very hard |
| Stillman Well | 57.5 | 984 | very hard |
| Well #1 | 52.5 | 899 | very hard |
| Well #3 | 37.5 | 642 | very hard |
| Well #4 | 37.5 | 642 | very hard |
This figure is over 3 years old; hardness may have changed.
Herriman's culinary water combines Jordan Valley Water Conservancy District supply with local wells on the southwest edge of the Salt Lake Valley. The sources differ widely, so the 7 zones range from 171.2 to 1027.2 mg/L CaCO₃, with a median of 642 mg/L. Your zone matters far more than the city figure. The figure dates from 2021 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 | 37.5 gpg |
|---|---|
| Utility | Herriman City (culinary water; Jordan Valley Water Conservancy District wholesale plus local wells) |
How Herriman compares
- Tap water in Herriman is 314 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 2 of 1372 in the United States (1 = hardest); 100 % of these cities have softer water.
- In Utah it is number 1 of 14 cities; the regional median is 10.9 gpg.
- Nearest city with clearly softer water: South Jordan, 11 km away (8.5 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 Herriman
| Brand | Setting for this water |
|---|---|
| Bosch | H07 |
| Miele | 36 °dH |
| AEG / Electrolux | 7 |
| Beko | 6th |
| Hoover | S5 |
| LG | H4 |
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 Herriman water hard or soft?
It is very hard: 642 mg/L as CaCO₃ (37.5 gpg, 36 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Herriman 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 Herriman water?
37.5 gpg, equal to 36 °dH, 64.2 °fH or 642 mg/L calcium carbonate.
What dishwasher salt setting should I use in Herriman?
For 642 mg/L (36 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Herriman?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Herriman City, Drinking Water Quality Report (CCR) 2021, Herriman City Hardness Test table (2021). Method: computed from supplier's calcium and magnesium. Herriman City, Drinking Water Quality Report (CCR) 2021, Herriman City Hardness Test table · Outdated figure? Tell us