Whether to improve water’s taste or address specific health concerns, about four in 10 Americans use home water-treatment systems, according to the Water Quality Association. Products vary widely—from $20 in-fridge pitchers to sophisticated whole-house filtration systems—so it’s important to research which, if any, system is right for you. Consider your local water quality; your area’s chemicals of concern; and of course the unit’s costs, maintenance, performance and certifications.
Major contamination sources in drinking water include naturally occurring bacteria and viruses, which cause disease; chemical contamination, usually nitrates, from fertilizers and pesticides, which can cause heart defects in babies; radon, which leads to increased cancer risk; lead, which causes developmental delays; and harmful disinfection byproducts. You can reduce the risks in everyone’s water by never putting toxic chemicals (such as paint, petrochemicals, chlorine or cleaning supplies) down your drain.
To select a filtration system, you need a clear picture of your home’s water quality. If you use the municipal supply, ask your supplier for the annual water quality report (sometimes called the consumer confidence report), which lists contaminant levels, maximum permitted contamination levels, disinfection chemical methods and byproduct concentrations. You can find some of these reports on the Environmental Protection Agency’s website or at the Environmental Working Group’s National Drinking Water Database. If you have a well, get your water tested by a state-certified laboratory. Call your local health department, state water certification officer or go to the EPA website to find a list of certified labs.
Municipal water supplies are typically disinfected with chlorine, ozone, chloramines and/or chlorine dioxide, as well as ultraviolet light, which eliminate most waterborne diseases. When these chemical disinfectants react with organic matter or other compounds present in source water, they form byproducts. Health professionals have concerns about some of the byproducts common chemical disinfectants create: Trihalomethanes may cause liver, kidney or central nervous system problems and increase cancer risk; haloacetic acids and bromate may increase cancer risk; and chlorite may cause anemia and affect infant and fetus nervous systems.
Your water’s contaminants (and their concentrations) will tell you what type of treatment you need and whether to install it at the point of use (to treat water at a single tap) or point of entry (to treat the whole house). Use a whole-house filter for contaminants such as radon and disinfection byproducts, which turn into gases easily and can be inhaled when showering or using steamy water.
ultraviolet and reverse osmosis filters, softeners
home and travel-ready untreated water filters
carbon/ion-exchange pitchers and faucet filters
distillation water purifiers
reverse osmosis, ultraviolet, VOC filters, water softeners
ultraviolet faucet filter
Environmental Protection Agency
EPA list of water-supply contaminants and related health risks
Environmental Working Group National Drinking Water Database
look up water quality by ZIP code
information on disinfection byproducts
Alli Kingfisher, the state of Washington’s Green Building and Sustainability Specialist, is plotting to green her 1906 home in Spokane. Kelly Lerner, a Spokane-based architect specializing in healthy, super energy-efficient homes, is co-author, with Carol Venolia, of Natural Remodeling for the Not-So-Green Home. See her work at One World Design Architecture and Natural Remodeling .