It is estimated that each person in the United States uses about 150 gallons of water a day. Most of this water is used for cooking, bathing, toilet flushing, laundry and landscaping. Surprisingly, out of those 150 gallons of water, only about half a gallon is used for drinking. Although it doesn't sound like much, that half a gallon is extremely vital to your health. This is why the U.S. government has developed strict standards and regulations to make your water safe to drink.

Safe Drinking Water Act
In 1974, Congress passed the Safe Drinking Water Act to ensure safe drinking water throughout the United States. The Act authorized the Environmental Protection Agency to set national drinking water standards for the maximum safe levels of numerous chemicals, metals and bacteria. National drinking water standards were also set for odor, color and turbidity (how clear the water looks). In addition, major requirements of the Safe Drinking Water Act include that all public water systems must provide water treatment, monitor drinking water quality and notify people about water system contamination.

Drinking water comes from surface and groundwater, either of which may contain harmful components of chemicals, bacteria or organisms that can cause disease. Because of possible threat of disease, water must go through an extensive treatment process before it is considered safe to drink. Drinking water treatment processes include:

• Flocculation: a chemical, such as alum or ferric chloride, is added to the water. This causes dirt and other small particles to join together into "floc" or large clumps.

• Sedimentation: Gravity is used to pull floc down to the bottom of a settling basin.

• Filtration: Small particles are separated from the water by using a porous barrier that traps the particles while allowing the water to pass through.

• Disinfection: Chlorine and other chemical disinfectants are added to the water to kill any remaining microorganisms that could be potentially harmful.

Nationally, government agencies such as the Environmental Protection Agency and the U.S. Geological Survey as well as professional associations such as the American Water Works Associations and the American Water Resources Association are active in a variety of drinking water issues. Locally in Southern California, the Metropolitan Water District and its member agencies such as Central Basin Municipal Water District and West Basin Municipal Water District are also actively involved in ensuring that the drinking water that millions of people rely upon is of the highest quality.