Salt Lake City, Utah Water Hardness & Water Softener Guide
Salt Lake City’s water utility publishes a hardness of 8.0 to 12.4 grains per gallon from the treatment plants. Here is what that means for your plumbing and what it costs to treat.
Where Salt Lake City’s water comes from
Salt Lake City does not spell out its sources alongside the hardness figure it publishes. The report itself is here: slc.gov · 2025
Is Salt Lake City hard water?
At 8.0 to 12.4 grains per gallon from the treatment plants, Salt Lake City sits in the very hard band — above about 10.5 grains per gallon is very hard on the USGS scale. Scale shows up first inside the water heater, then on fixtures and glass. See the hardness scale.
Worth knowing: That is the treated surface water. Salt Lake City's own wells and springs run 9.6 to 33.4, and deep wells are brought online in summer, which raises hardness in the areas they serve.
The first place that shows is the water heater, then the fixtures and the glass.
What Salt Lake City’s hardness means in practice
Sizing is arithmetic once you have a number. At 12.4 grains per gallon — the top of that range, because a softener sized for the soft months lets hardness through in the hard ones — a household using the EPA average of more than 300 gallons a day sends roughly 3,720 grains of hardness through its plumbing every day. Over a year that is about 194 pounds of scale-forming calcium and magnesium passing through the water heater and the fixtures.
Against that load a 32,000-grain softener would regenerate roughly every 8.6 days and a 48,000-grain unit about every 12.9 days. Those are first estimates off the figure Salt Lake City publishes, not a quote: your own use, any iron in the water, and whether you want softened water at the kitchen tap all move the answer, which is why we measure at your tap before sizing anything.
What CASA recommends in Salt Lake City
At the hardness Salt Lake City publishes, a correctly sized softener earns its keep in water heater and fixture life. Reverse osmosis at the kitchen sink handles taste; whole-home carbon takes chlorine out at every tap.
Water hardness in nearby cities
Salt Lake City water hardness FAQ
How hard is the water in Salt Lake City, Utah? Salt Lake City is published at 8.0 to 12.4 grains per gallon from the treatment plants. Source: slc.gov · 2025
Where does Salt Lake City get its drinking water? See the sources listed above.
Do I need a water softener in Salt Lake City? That depends on your measured hardness, not on a citywide average. We test first and size the system to the result.
How do I find my exact hardness? Book a free CASA water test. We measure at your tap and put the number in writing. How the scale works.
Free Salt Lake City water test
We measure your exact hardness and recommend the right system — no pressure, flat written quote.
