The United States Environmental Protection Agency has been working closely with water agencies across the nation to update and improve rules concerning the amount of lead in drinking water.
Since 1945, many American water systems have adjusted the amount of natural fluoride concentration of a community’s water supply to a level that is best for the prevention of dental decay. This process is known as "drinking water fluoridation".
For customers who would like to have the water within their residence tested, the State maintains a list of State-certified commercial laboratories.
If you're thinking of buying a water filter, check out general information from the State Water Resources Control Board on home water treatment devices.