The NSF has developed nationally recognized standards for drinking water treatment products including, carbon filters, reverse osmosis systems, ultraviolet systems, distillers, shower filters, and water softeners. In general, the units help consumers who are concerned about health effects and aesthetics (chlorine, taste and smell), and to make sure the products work as claimed.
Are water treatment systems regulated?
The federal government does not currently require home water treatment systems to be tested or prove effectiveness. A few states have adopted laws to regulate the sale of residential water treatment devices within their borders.
Which drinking water treatment systems are the best?
No systems can protect the user against all contaminants. Even among products that use the same technology, performance capabilities can vary from one unit to the next. As a result, it is important for consumers to identify what contaminants they wish to treat before shopping for a water treatment system.
How can I find out what's in my water?
If your home is on a public water supply, contact the local water utility to request a copy of their annual water quality report. Individuals with private wells may be able to obtain information about local water quality conditions from their local health department. They may also have a list of certified drinking water laboratories in case water testing is needed.
If a product is certified to a NSF/ANSI Standard, does that mean it reduces all contaminants under that standard?
No. Some products may only be tested for material safety, while others may be tested for both material safety and performance. In addition, the number of performance claims validated for each unit can vary.
To view a list of common contaminants that can be found in public and private drinking water supplies, view the contaminant guide.