Utah water is hard. How hard depends on which utility serves your tap, and the spread across the state is wide. The table below pulls hardness and total dissolved solids straight from each provider’s own annual water quality report, so you can look up your city instead of guessing from a state average. Every number links back to the report it came from.
Hardness and TDS by Utah water provider
| Provider | Hardness (grains/gal) | Hardness (mg/L) | TDS (mg/L) | Report |
|---|---|---|---|---|
| Salt Lake City Public Utilities | 8.0 – 12.4 treated surface water; up to 33.4 from wells | 136 – 212; up to 571 | 214 – 292 typical, up to 796 | 2026 |
| Jordan Valley Water Conservancy District | 10.7 average | 182.4 average, 381 highest | 281 average, 652 highest | 2025 |
| West Jordan City | 10.7 average | 182.7 average, 602 highest | 281 average, 960 highest | 2026 |
| Weber Basin WCD (Davis and Weber counties) | 10 – 18 | 171 – 308 | 214 north, 377 central, 738 south | 2025 |
| Orem City | 6.6 – 25 depending on source | 112 – 428 | 112 – 388 | 2026 |
| Provo City | 10 – 15 | 171 – 257 | up to 376 | 2024 |
| Ogden City | not published | not published | 380 average (128 – 380); Weber Basin supply 444 | 2025 |
| St. George City | not published | not published | 552 – 580 average, range 118 – 936 | 2025 |
| Bountiful City | not published | not published | 108 – 1,172 | 2025 |
| Lehi City | not published | not published | 120 – 388 | 2025 |
Checked but not included: Sandy, Layton, Logan, Park City and Draper publish reports that do not give a hardness or TDS figure in a machine-readable form. Draper’s is a scanned image, and Logan and Park City publish theirs only as a linked document. Call the utility if you need a number for one of those.
One thing stood out while compiling this: of the 15 Utah providers checked, only six publish a hardness figure at all. Hardness is unregulated, so no utility has to report it. If your provider is one of the quiet ones, the fastest answer is a $20 test kit or a call to the utility.
How to read these numbers
Two measures matter most for choosing equipment, and they are not the same thing.
- Hardness is calcium and magnesium. It is what scales kettles, shower heads, boilers and RO membranes. Water utilities report it either in grains per gallon (gpg) or in mg/L as calcium carbonate. To convert, multiply grains by 17.1.
- Total dissolved solids (TDS) is everything dissolved in the water, minerals included. It drives taste and the spotting left behind when water dries. The EPA’s secondary guideline is 500 mg/L, which is about taste and appearance rather than safety.
The USGS hardness scale: under 60 mg/L is soft, 61 to 120 moderately hard, 121 to 180 hard, and above 180 very hard. Most of Utah sits in that last band.
What treats what
| Your reading | What you notice | What fixes it |
|---|---|---|
| Hardness above 7 gpg (120 mg/L) | Scale on fixtures and appliances, soap that will not lather | A softener for the building; softener vs RO explained |
| Hardness above 10 gpg (171 mg/L) | Fast scale build-up, shorter appliance and membrane life | Softening plus antiscalant ahead of any RO system |
| TDS above 500 mg/L | Mineral or salty taste, spotting on glassware | Reverse osmosis at the tap, or whole-building RO |
| TDS above 1,000 mg/L | Water is brackish by definition | Brackish water RO |
Where the numbers come from
Every figure is taken from the provider’s own Consumer Confidence Report, the annual water quality report each public system must publish. Federal rules require public systems to test and report, so these are their measurements, not ours, and each row links to the source document and its year.
Three caveats worth knowing before you act on a number:
- These are system-wide figures. Large utilities blend several sources, and a specific neighbourhood can sit well away from the average. Some reports give a range instead of a single value, and where one does, the range is shown.
- Report years differ. Utilities publish on their own schedule, and some tables carry data collected over several years. The year in the table is the report, not necessarily the sampling date.
- A private well is not in here at all. Nobody tests it for you. See how to test your home water quality.
Frequently asked questions
Which Utah city has the hardest water?
Of the providers in the table, Salt Lake City reports the single highest figure, 33.4 grains per gallon from groundwater wells, and Orem’s range tops out at 25. For water that is consistently hard rather than occasionally, Weber Basin’s 10 to 18 grains covers Davis and Weber counties. Hardness varies by source within a single system, so treat this as a comparison between reported averages rather than a fixed ranking.
Is hard water in Utah bad for you?
No. Hardness is a nuisance, not a health risk, and the EPA regulates it as a secondary standard covering taste and appearance. What it does damage is plumbing, water heaters, appliances and RO membranes.
Do I need a softener, a filter, or reverse osmosis?
A softener handles hardness for the whole building. Reverse osmosis lowers TDS for drinking and process water. Many Utah homes end up with both, because they solve different problems. See RO vs water softener.
How do I convert grains per gallon to mg/L?
Multiply by 17.1. So 10 gpg is about 171 mg/L, and 18 gpg is about 308 mg/L.
Where can I get my own water tested?
The Utah Public Health Laboratory tests private wells, and recommends at least once a year for nitrate, pH, total dissolved solids and coliform bacteria. A commercial site needs a full analysis before any system is sized.
Sizing equipment against these numbers
Feed water chemistry sets the pretreatment, the recovery rate and how long membranes last. If you are specifying a system, start with the RO system calculators, then read water treatment in Utah for how local water behaves. AMPAC builds RO systems in Woods Cross, installs and services them on site anywhere in Utah, and ships anywhere. Call (385) 530-1026 or request a quote.