Water Treatment: Softening Up Hard Water
Joseph F. Harrison, P.E., CWS-VI
According to the U.S. Geological Survey, 85% of the United States has to cope with hard water-water with excessive levels of calcium and magnesium. While hard water is not considered to be unhealthy for people to drink, it can be very unhealthy for household plumbing, cleaning processes and water-using appliances.
The minerals in hard water form a hard scale that can shorten the life of plumbing fixtures and appliances. For example, scale build-up can decrease the life of toilets by 70% and faucets by 40%, according to a report published by the American Water Works Association. Hardness scale can also shorten the life of washing equipment, dishwashers, and washing machines by as much as 30%, according to the AWWA report.
Scale also tends to form on the heating elements and heat-transfer surfaces of water heaters. A New Mexico State University study determined that scale build-up can reduce a gas water heater's efficiency by as much as 29.57%, and an electric water heater's efficiency by as much as 21.68%. Another study conducted by the Office of Saline Water, U.S. Department of the Interior, found that a water heater's useful life can be reduced by as much as 50% through scale build-up
What Is Hard Water?The problems associated with hard water have been known for quite some time. Earlier generations coined the phrase "hard water"
Effects On CleaningAll water-based cleaning and washing is less effective and less efficient with hard water. Cleaning with hard water requires greater physical effort and the use of greater quantities of cleaning agents for surfaces such as floors, sinks and bathtubs. It also leads to spotting on dishes and glassware.
Let's take a further look at one common job around the house: washing clothes.
Hardness minerals affect laundry in a gradual manner that tends to get hidden in today's automated washing process. People accustomed to washing in hard water may not notice the increased detergent use, yet the waste is still there. Soap was the primary cleaning agent for laundry before the development of synthetic detergents. Soap is usually made from natural fatty acids and alkali substances, such as caustic soda, which give it excellent cleaning properties. This is particularly true with vegetable-based fabrics like cotton.
Soap works well to suspend dirt in the wash and helps "lubricate"