Joseph F. Harrison, P.E., CWS-VI, is technical director of the Water Quality Association, Lisle, Ill. He may be reached at 630/505-0160. Prior to joining the WQA in 1990, Harrison was chief, safe drinking water branch for Region V of the EPA for 17 years.
Anyone who has sat through a high school science class may remember the term “osmosis.” This process was first described by a French scientist in 1748, who noted that water spontaneously diffused through a pig bladder into alcohol.
More than 200 years later, a modification of this process known as “reverse osmosis” allows people throughout the world to affordably convert undesirable water into water that is virtually free of health or aesthetic contaminants. Reverse osmosis systems can be found providing treated water from the kitchen counter in a private residence, to installations used in manned spacecraft.
According to the U.S. Geological Survey, 85 percent 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.