Below are some of the common questions about drinking water that are received by the NSF Consumer Affairs Office. If you do not see your question listed, please contact our Consumer Specialist for assistance.
60 - 70 percent
Public water supply customers can contact their local utility and request a copy of the Annual Water Quality Report (or Consumer Confidence Report). This report is a summary of the water test results obtained by the utility for the previous year. This report lists the following:
The Maximum Contaminant Level (MCL) is the maximum amount of a particular contaminant that is allowed in a public drinking water. Water suppliers must notify their customers if a contaminant exceeds the MCL.
The Maximum Contaminant Level Goal (MCLG) is the level of a contaminant in drinking water at which there is no known or anticipated health threat from that contaminant to a person who consumes the water.
Most lead in drinking water supplies leaches from the plumbing in our homes, including lead service lines, lead-based solder (used to join copper plumbing), and faucets. To reduce your exposure to lead, make sure to flush your pipes for several seconds before using the water for drinking or cooking.
You can contact your local or state public health department, personal physician, or the EPA's safe drinking water hotline at 1-800-426-4791 for further information on the health effects and potential sources of the various contaminants found in drinking water supplies.
NSF International is the leading not-for-profit, nongovernmental organization that tests home water treatment products on the market today. NSF evaluates water treatment devices to ensure the following:
To assist consumers in obtaining a better understanding of these devices, NSF provides online information in the drinking water section of its consumer website. In addition, we provide an online database that the public can use to verify which products carry our certification and to obtain further information about a product's contaminant reduction capabilities as tested. The public can also contact our Consumer Affairs Office for further information on drinking water issues and home water treatment products.
Testing of drinking water supplies is available from many sources. If your water comes from a public water supply and you are experiencing a water quality problem, contact the water utility for assistance. Some utilities will offer testing for common problem contaminants, such as bacteria or lead.
Local public health departments are also another source for information about drinking water, especially for consumers who have their own private well. Many public health departments also offer testing for common contaminants, such as bacteria. If they are not able to perform a test for you, they usually have a list of accredited drinking water labs in your state that you can contact for further water testing.
The land area over which water flows to reach a river, lake, or reservoir from which drinking water is drawn is called the watershed. Any pollution or contamination introduced into the watershed area will ultimately affect the quality of the drinking water supply, so it is important that we protect these areas.