Salt Lake City water hardness: 8 to 12.4 grains per gallon
Salt Lake City tap water is hard to very hard: about 8 to 12.4 grains per gallon (136 to 212 ppm) from the city's treatment plants. Those numbers come from Salt Lake City Public Utilities' 2026 water quality report (PDF, opens in new tab), which covers 2025.
Salt Lake City water hardness
Grains per gallon, from Salt Lake City Public Utilities' 2026 water quality report. Sacramento river water shown for comparison.
Where does Salt Lake City water come from?
The city's report says most of its water comes from mountain streams in the Wasatch Range, including City Creek, Parleys Creek, Big Cottonwood Creek and Little Cottonwood Creek. The city treats it at three plants. It also uses deep wells and springs, and it buys treated water from the Metropolitan Water District of Salt Lake and Sandy and the Jordan Valley Water Conservancy District.
Each stream is a little different. Big Cottonwood water averaged 8 grains per gallon, while City Creek averaged 12.4. In summer, when stream flow drops, the city adds well water. The report shows wells and springs at 9.6 to 33.4 grains per gallon.
What this means at home
- White scale on faucets, shower heads and glass doors
- Spotty dishes and glasses
- Scale inside water heaters, humidifiers and coffee makers
- Water that can get harder in the summer months
Do you need a water softener in Salt Lake City?
Most homes will see a benefit. At 8 to 12 grains per gallon from the plants, and more when well water is mixed in, scale builds up quickly. A softener handles it. Because your number changes with your plant and the season, test your tap before you size a system.
See what a softener costs, or read do I need a water softener with city water?
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Book my free water testCommon questions
Is Salt Lake City water hard?
Yes. Salt Lake City Public Utilities' report lists average total hardness of 136 ppm (8.0 grains per gallon) at Big Cottonwood, 175 ppm (10.2) at Parleys and 212 ppm (12.4) at City Creek. That is hard to very hard.
Why is my water harder in summer?
The city says that when mountain stream runoff drops in summer, it adds groundwater from wells. The report shows city wells and springs at 9.6 to 33.4 grains per gallon, so summer water can be harder.
What softener setting should I use in Salt Lake City?
Test your own tap. Hardness depends on which plant serves you and the time of year, so one number does not fit every home.
Keep reading
DataWater hardness by cityHow hard the tap water is in US cities, from each utility report.
City dataDenver water hardness: about 6 grains per gallonAbout 6.1 grains per gallon. Moderately hard.
GuideHow much does a water softener cost installed?Installed price ranges, running costs, and what drives the price.
GuideDo I need a water softener with city water?It depends on your city. Here is how to decide.