Water re-use

While water is all around us, fresh water suitable for human, agricultural and industrial use is available only in limited supply. Particularly in desert areas supporting large populations such as Arizona and Southern California, there is a pressing need for water conservation and re-use. In some coastal areas, such as Florida, pumping fresh water by drinking water wells has led to saltwater intrusion from the ocean which also increases the need for water conservation and re-use. Unfortunately, in these same areas, groundwater can be exceptionally “hard,” containing very large concentrations of calcium and magnesium which create deposits in pipes and on heating surfaces of industrial boilers and home hot-water-using appliances like water heaters, washing machines and dishwashers. These homes and businesses are prime beneficiaries of ion-exchange water softening, yet the discharge from these units contributes to already-elevated TDS (total dissolved solids) in the receiving waters, impairing that water’s quality for re-use by other communities, farmers and industries. Population growth in these areas exerts a constant and increasing pressure for even more water conservation and re-use.

The water treatment industry has responded by developing salt-efficient technology for ion-exchange water softeners enabling the enjoyment of the benefits of water softeners while lessening the TDS discharge load. Other activities in the home and community contribute TDS and the public policy challenge is to stretch scarce water supplies while allowing those whose property is threatened by hard water to still enjoy its benefits. Hard water, for example, requires the use of greater amounts of detergents and wears out clothing and large home appliances whose replacement creates offsetting social costs. Interested parties, including the salt industry, are grappling with these issues as industry continues to invent innovative technologies to overcome the challenge. Among those developments include development of more energy-efficient desalination technology.