Washington County Hard Water Guide: Softeners (2026)

Updated October 22, 2026. This guide is general information, not legal or engineering advice. Rules change, so confirm with the agency listed before you start work.

Quick reference

Topic	What to know	Source
Is it hard?	Most Southern Utah sources are considered hard (calcium and magnesium)	St. George 2024 water quality report
Calcium	18 to 95 ppm across city sources	St. George 2024 water quality report
Total dissolved solids	118 to 936 ppm in city groundwater	St. George 2024 water quality report
Softener setting	About 18 grains, higher only if needed, not over 22	St. George Water Services
Hardness scale	Over 180 mg/L as calcium carbonate is "very hard"	USGS
Who can install	Plumber license exemption only with code-compliant equipment, under a specialty contractor license	Utah Code 58-55-305

Where does the water come from?

The City of St. George draws culinary water from well fields in the Gunlock area and in Snow Canyon State Park, from Mountain Springs on Pine Valley Mountain, and from Virgin River water stored in Quail Creek and Sand Hollow reservoirs and treated at the Quail Creek Water Treatment Plant. That surface water is purchased from the Washington County Water Conservancy District. The city's groundwater comes from the Navajo Sandstone and Kayenta Formation aquifers, and the city reports arsenic removal plants on its Gunlock and Sand Hollow well sources. Washington City, Hurricane, Santa Clara and Ivins residents should read their own provider's annual report.

How hard is the water?

St. George's water quality report says most water sources in Southern Utah are considered hard because of calcium and magnesium, and that many customers use softeners to remove them. The 2024 report lists calcium ranging from 18 to 95 parts per million across sources, magnesium at 38 parts per million at the Quail Creek plant, total dissolved solids in city groundwater from 118 to 936 parts per million, and sodium from 5 to 153 parts per million. The report doesn't publish a single hardness number, which is one more reason to test at your own tap. For context, the U.S. Geological Survey classifies water above 180 milligrams per liter as calcium carbonate as very hard and 121 to 180 as hard.

What softener setting does the city recommend?

St. George Water Services says softeners should generally be set at 18 grains, adjusted higher if needed, with 22 grains as the highest setting. The city's water quality report describes 13 to 24 grains per gallon as the most effective range. The lower the setting, the less salt or potassium the softener uses.

Why does softener salt matter here?

The city explains that the salt or potassium used to regenerate a softener ends up concentrated in wastewater, raising total dissolved solids that treatment doesn't easily remove. Treated wastewater is reused for irrigation, and higher salt levels hurt salt-sensitive plants. The Washington County Water Conservancy District's water conservation plan describes a regional reuse system it is developing to recover water for potable and non-potable uses. We did not find a Washington County rule banning salt-based softeners, but local rules can change, so ask your city or sewer provider whether any discharge requirements apply to your address.

Who can install a water softener in Utah?

Utah's construction trades licensing law exempts installing or repairing a water conditioner or other water treatment apparatus from plumber licensing only when the equipment meets state construction codes or local plumbing standards and the work is done under the direction of someone authorized under an appropriate specialty contractor license. Separately, the handyman exemption covers small jobs under $7,000 but still requires plumbing work on a plumbing system to be done by a licensed plumbing contractor. Ask any company what license it holds and who will handle new plumbing. The statute was renumbered effective January 1, 2027, so the section number may change while the rules stay in place.

Questions to ask a water softener company

Will you test my water at the tap before recommending a size?
What license do you hold, and who does any new plumbing or drain work?
Is the valve metered (demand-initiated) or timer-based?
What setting will you use, and how does it compare with the city's 18 to 22 grain guidance?
What's warrantied, for how long, and who handles service calls?

Before you sign

Get the equipment brand, model, grain capacity and valve type in writing, along with the price, any filter or RO add-ons, the drain plan and the warranty terms. Be wary of free in-home water tests that turn into high-pressure sales visits. A good company explains your test result plainly and lets you take time to decide.

Common questions

Does St. George publish a hardness number?

Its water quality report describes local water as hard and lists calcium, magnesium and total dissolved solids, but not a single hardness value. Test at your tap.

What grain setting should I use in St. George?

The city suggests about 18 grains, higher only if needed, and no more than 22.

Do I need a licensed plumber to install a softener in Utah?

Utah exempts water conditioner installs from plumber licensing only when the equipment meets code and the work is under someone with an appropriate specialty contractor license. New plumbing should be done by a licensed contractor.

Washington County hard water guide (2026)