Water is essential to life. It is a macronutrient required by the body in large amounts each day, although it cannot be stored by the body. Water helps with many bodily functions and is lost daily from the body through functions such as urinating, sweating and breathing. This lost water needs to be regularly replaced.

The appropriate amount of water needed each day may depend on a number of factors, such as age, gender, body composition (amount of lean muscle versus fat tissue) and level of physical activity. Drinking water is the best way to give the body what it needs. Other beverages and foods are important sources of water as well.

Most people get their water from a public drinking water source. It is disinfected and treated to remove detected contaminants that exceed acceptable levels established by the U.S. Environmental Protection Agency (EPA). Some people rely on water from private wells, which are not regulated by the EPA, although most state and local governments have laws that govern the safety of water from private wells.

Bottled water has become increasingly popular. There are many different types of bottled water. Some have been minimally treated to remove possible contaminants, others may have been treated in such a way to eliminate bacteria and viruses. Bottled water is regulated by the U.S. Food and Drug Administration.

Water filters may be used by consumers at home to help remove certain contaminants that may be present in tap water. There are several different types of filters, although no one filter can eliminate or reduce all possible contaminants. Water softeners are sometimes used to reduce the level of hard minerals (e.g., calcium, magnesium) in water. Soft water makes soap lather better and helps dissolve contaminants that may come from old plumbing pipes.