Water is considered "hard" when it contains a high level of dissolved minerals. In the Las Vegas Valley, the two nontoxic minerals that cause our hard water are calcium and magnesium. They're carried into Lake Mead from the mineral-dense Colorado River and do not pose a health risk.
The hardness of Las Vegas Valley Water District water is about 290 parts per million (ppm) or 17 grains per gallon, categorized as "very hard."
The water in Lake Mead, which represents about 90 percent of our water supply, begins as snowmelt in the Rocky Mountains. As it makes its way to the Colorado River channel, it dissolves minerals such as calcium and magnesium from the surrounding rock. While these minerals pose no health risk, the residue can be a nuisance.
Hard water can make it difficult to produce a lather (or suds) while washing. It also can leave a chalky build-up on fixtures and spots on glassware. These effects are solely aesthetic—they don't affect your health—and can be remedied with packaged water softening products and household water softening systems.
Household systems reduce the hardness of the water by replacing calcium and magnesium with sodium or potassium, depending on the type of softener. Installation of a water softener, however, is strictly an issue of personal preference and should be done only out of aesthetic concerns, not because of fears about water quality.
Advantages of water softeners include improved "feel" on skin when bathing, longer life of appliances and reduction of water spots and deposits. Disadvantages include potential health risks from sodium intake, harm to houseplants due to elevated salt content and overload or reduced effectiveness of septic systems.
There are several alternatives to reduce problems associated with hard water. They include laundry detergents that include water-softening agents, dishwasher rinse aids, bath salts and lime- or mineral-dissolving household cleaners.
Deposits on fixtures and countertops can be prevented by wiping surfaces dry. Mineral residue on surfaces only occurs when water is allowed to evaporate.