Parts of the U.S. have what is commonly referred to as "hard water," and people who live in these areas battle the problems that hard water creates. The most common defense against hard water, which is a nuisance but not a health hazard, is to install a home water softener.
Water softening involves exchanging calcium and magnesium minerals present in the water – which cause the hardness – with sodium. As the water softener processes gallon after gallon of hard water on a daily basis, the treatment capability of the softener becomes depleted and must be recharged or regenerated. Regenerating the unit uses a large quantity of sodium-rich water, called "brine", that must be disposed of. In homes with onsite septic systems, this brine flows into the septic tank and eventually makes its way to the system's drainfield. People using home water softeners often wonder whether these units might cause problems for their onsite septic systems. Some common questions consumers ask are:
