Even though EPA regulates and sets standards for public drinking water, many Americans use a home water treatment unit to:

• Remove specific contaminants
• Take extra precautions because a household member has a compromised immune system
• Improve the taste of drinking water

Household water treatment systems are composed of two categories: point-of-use and point-of-entryExternal(NSF). Point-of-entry systems are typically installed after the water meter and treat most of the water entering a residence. Point-of-use systems are systems that treat water in batches and deliver water to a tap, such as a kitchen or bathroom sink or an auxiliary faucet mounted next to a tap.

The most common types of household water treatment systems consist of:

• Filtration Systems
  A water filter is a device which removes impurities from water by means of a physical barrier, chemical, and/or biological process.
• Water Softeners
  A water softener is a device that reduces the hardness of the water. A water softener typically uses sodium or potassium ions to replace calcium and magnesium ions, the ions that create “hardness.”
• Distillation Systems
  Distillation is a process in which impure water is boiled and the steam is collected and condensed in a separate container, leaving many of the solid contaminants behind.
• Disinfection
  Disinfection is a physical or chemical process in which pathogenic microorganisms are deactivated or killed. Examples of chemical disinfectants are chlorine, chlorine dioxide, and ozone. Examples of physical disinfectants include ultraviolet light, electronic radiation, and heat.