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This legislation resulted in the development of national standards for drinking water quality. The standards establish limits on the amount of various substances in drinking water that can, at certain levels, adversely affect human health. The U.S. Environmental Protection Agency (EPA), after consulting with the National Academy of Science, sets a Maximum Contaminant Level (MCL) for each regulated substance. Periodically, these standards are reviewed and refined based on scientific and technological advancements.

The national regulations apply to all water systems that provide drinking water to at least 25 people or 15 service connections for a minimum of 60 days a year. This includes water utilities that serve about 85 percent of the U.S. population. The remainder receive their drinking water from privately owned and operated sources such as wells and are responsible for regulating their own water quality.

To ensure the highest quality, the SDWA requires each public water utility to implement a regular program of sample collection and laboratory analysis. Contaminants that can cause acute health effects are monitored daily. Others are monitored weekly and still others, monthly. By law, each state must meet the federal standards. Some states have augmented the federal requirements with standards of their own. Local water utilities must meet all the requirements for the state in which they operate. Testing and monitoring results are reported regularly to the state health department and are available to the public. Strict adherence to monitoring and testing are the best guarantees for safe drinking water. The state and EPA work together to see that all requirements are followed. Utilities who fail to comply are fined.

In addition to the SDWA, there are other federal laws that safeguard the quality of drinking water by regulating surface and ground water pollution, management of hazardous substances, and use of chemical pesticides. The effectiveness of the legislation depends on adequate funding, enforcement and agency interaction.

Regulations and standards for drinking water quality like water itself continue to evolve. Health and environmental considerations together with improved science and technology will most likely warrant additional regulations in the future to ensure that the quality of our drinking water remains among the best in the world.

Frequently Asked Questions About Water

Q. How can I find out what's in my water?
A. Call your local water company and ask them to send you a copy of their most recent water quality report. The report should include a list of the contaminants they must monitor and the standards they must meet.

Q. Are there standards for taste, odor and appearance?
A. Yes, public water utilities test and monitor drinking water to meet two types of standards, called MCLs (Maximum Contaminant Levels) are set to protect human health and the secondary standards concern aesthetic considerations such as taste, odor, and appearance. Health and aesthetic aspects are the driving forces behind drinking water regulations.

Q. What should I do if I'm worried about my drinking water?
A. In most cases when there are problems, your water utility will make the correction before you even know there's a problem. Sometimes though, problems do arise in a single house or neighborhood. Many water utilities provide a free or low cost home water analysis if you have good reason to suspect a problem.

Q. Does using a home water treatment device guarantee that my water is safe?
A. No, EPA does not recommend home treatment devices as a substitute for public water treatment because of the difficulty in monitoring their performance. Home treatment devices are not tested or regulated by the federal government. Some, however, are tested by independent laboratories. If you want to use a water treatment device, carefully choose one according to the water conditions in your area. Also, be aware that a device needs to be properly maintained or it could cause water quality problems.

Ask Your Water Utility
The saying "Knowledge is power" certainly applies to drinking water safety. The more you know about your water utility, the better position you will be in to contribute positively to the quality of your drinking water. Begin by asking your utility these questions:

1. What is the source of the drinking water supply (river, lake, aquifer, etc.)?
2. Are state standards stricter or more comprehensive than those at the federal level?
3. Does the utility monitor for unregulated contaminants, particularly those likely to be found in the area?
4. How is the water treated?
5. What is the utility track record for complying with Maximum Contaminant Levels and all monitoring and reporting requirements of the SDWA?