In many North American cities, it is naturally occurring ground water sources that supply our households with water. In places where the bedrock is soft limestone, the water dissolves some of this rock creating “hard” water. In some places, the water is so hard that the deposition of this mineral content on household plumbing fixtures, hot water tanks, coffee pots, dishwashers and other places renders many of these devices unusable in short order. Hard water also reacts with soaps and detergents making it very difficult to properly launder clothes. The cost to homeowners in terms of shortened appliance lifespan and increased water heating costs (due to fouling of hot water heater elements) is substantial.
Since the 1950′s the answer to this problem has been the water softener. As with most technology of this vintage, traditional water softeners are grossly inefficient and more alarmingly they represent a significant environmental threat. This environmental threat has been recognized by several cities in the USA and in some places such as California’s Santa Clarita district, these old style softeners have been banned outright.
The problem with water softeners stems from the mechanism by which they operate. Water flows through a tank filled with tiny resin beads. These beads attract calcium and magnesium (the “hardness”) and bind them to their surface. In exchange, the resin releases sodium. Once all the resin in the softener is saturated with hardness, the tank is flushed with concentrated salt brine that recharges the resin. After this process is complete the brine solution is sent down the drain. A water softener for a single home can conservatively discharge 500 pounds of salt directly into the environment each year. In some US cities as much as 42% of homeowners own a water softener. You can begin to understand the quantity of salt being discharged by water softeners and the environmental impact this represents.
