Herriman moves to Jordan Valley water for the winter, and the water gets softer

HERRIMAN — Herriman City has completed its seasonal water source transition and is now relying on water supplied by the Jordan Valley Water Conservancy District for the fall and winter months, the city said in a notice dated Oct. 27 1. The city said the annual change takes place as outdoor watering decreases and overall demand drops, which allows it to reduce its use of local groundwater wells 1.

The change shows up in the water itself. Herriman's local wells usually run between 25 and 60 grains per gallon of hardness, while district water is usually 10 to 12 grains per gallon, according to the city's water quality page 2. On the city's own scale, water under 4 grains per gallon is soft, 4 to 7 is moderately hard, 7 to 10 is hard and anything at 10 or above is very hard, so both of Herriman's sources are very hard and the district's supply sits at the bottom of that band 2.

Because district water is softer, residents may see less mineral buildup on faucets and fixtures, less spotting on dishes and better performance from soaps and detergents, the city said 1. The city told residents who use water softeners to check and adjust their settings for the change 1.

The switch follows a standing council decision rather than a supply emergency. Three of Herriman's groundwater sources carry total dissolved solids above 1,000 milligrams per liter, above which Utah requires a supplier to show that no better water is available, so that water is blended with district supply, according to the city 2. District water averages about 250 milligrams per liter of total dissolved solids, the city says; the state's maximum is 2,000, and the federal Environmental Protection Agency treats the measure as a secondary standard, recommending treatment above 500 milligrams per liter but not requiring it 2.

The city page gives the reason Herriman does not simply stay on district water year-round: it costs about four times as much, an average of $170 per acre-foot from local sources against $690 per acre-foot from the district 2. Citing the hardness of the local supply and its taste, appearance and smell, the City Council decided to use only district water during the off-peak season, and the city makes the transition each year in mid-October 2.

Both supplies are treated and monitored to meet drinking water safety standards, the city said 1. The city's water quality page says its drinking water meets and exceeds EPA standards and those of the state Division of Drinking Water 2.

The culinary switch is separate from Herriman's secondary water system, the untreated irrigation supply. That system began its seasonal shutdown on Oct. 13, and district service to the Blackridge area had already been discontinued at that point 3. Secondary water is typically available each year from early May to mid-October 3.

The city's notice does not give a date for the return to well water, and the city did not publish a projected cost for the winter's district supply 12. Questions about hardness and softener settings go to Wil Szwarc, the city's water quality and conservation coordinator, at waterquality@herriman.gov 2.