He United States tap water It is generally safe and of high quality. But that doesn’t mean that all glasses taste the same, nor that the pipes in all buildings supply identical water to the tap.
That uncertainty has fueled a booming market for water filters, from simple pitcher models to multi-thousand-dollar reverse osmosis systems. However, experts say that most American homes do not need extensive treatment. The challenge is knowing how to decide if a filter is needed.
Under the Safe Drinking Water Act, the Environmental Protection Agency sets health standards for more than 90 contaminants in public water systems, including chemicals and microbes. Companies treat water with disinfectants such as chlorine to kill harmful germs before it reaches homes. Most public companies follow those standards, and most Americans can safely drink tap water.
“Unless your health is affected, you receive a notice from your water supply system, or there is a credible media story that your water is unsafe to drink, you should not feel the need to purchase a filter,” says Gregory Pierce, director of the Human Right to Water Solutions Lab at the University of California, Los Angeles.. “You’re still welcome because it may make your water taste a little better, but it shouldn’t be considered necessary to have a water filter in more than 90 percent of the United States.”
Below we explain how to check the quality of your local water, when it is appropriate to test it, and how to choose a filter that meets your needs without wasting money.
How to check water quality
Start by reviewing the annual consumer confidence report, which details the contaminants detected and whether the system meets federal standards. These reports are usually available on the city or company website. You can also contact your provider directly if you have questions. Typically, water supply systems are only responsible for water until it reaches private property, which means water quality can vary by building.
For many, these reports may be enough assurance. Still, some consumers want more security, especially in older buildings.
“You should probably test your water to identify if you have a risk that you need to address,” says Jess Goddard, chief scientific officer at environmental testing company SimpleLab.
Private wells have different maintenance and safety needs because they are not regulated by the Drinking Water Law and their control is the responsibility of the owners. The EPA is one of the agencies that offers resources to people with private wells.
Test kits can cost a couple hundred dollars or more, depending on the contaminants they test for.
Here’s how the tests typically work: You order a kit, collect a water sample following the instructions, and mail it to a certified laboratory. The lab analyzes it for specific contaminants, such as a group of chemicals known as PFAS, microplastics, metals and disinfection byproducts, and produces a report.
If testing reveals a serious problem, Pierce recommends contacting your water utility or state environmental agency for guidance. If testing reveals high levels of contaminants, the solution may go beyond installing a home filter. Authorities may recommend temporary alternative water sources, such as bottled water, or infrastructure improvements, such as replacing pipes.
If there is not a problem serious enough to require such measures, a filter can help.
Choose a filter
People need to consider what their filtration goals are and what different filters can do. The EPA warns that many household activities, such as flushing the toilet and doing laundry, do not require treatment, so cooking and drinking are typical uses to consider.
Most filters are classified by the nonprofit organizations NSF and the American National Standards Institute. The most common NSF/ANSI ratings include 42 for taste or odor problems, 53 for health effects, and 401 for emerging compounds. An NSF database allows you to search by the name of the product or compound you want to reduce.
“Not every filter works for everything,” says Sydney Evans, a scientific analyst who led a water filter testing project at the Environmental Working Group. “And even if there is a filter out there that does absolutely everything, maybe you don’t need it.”
Many homes use filters not for safety reasons, but for taste or smell, “which really influences people’s enjoyment or sense of confidence in their drinking water,” Goddard says.
In those cases, a basic charcoal filter, like many common pitcher models, can be effective. Activated carbon reduces chlorine and the byproducts that form when chlorine reacts with natural organic matter in water.
Samantha Bear, a research analyst at SimpleLab, says these byproducts are normal in treated water. Even when levels are below federal limits, she and her colleagues filter tap water, not because the water is unsafe, but to reduce long-term exposure.
Even people who live outside of areas with high levels of PFAS contamination may be concerned about their presence. PFAS is short for perfluoroalkyl and polyfluoroalkyl. The Environmental Protection Agency says filters can reduce PFAS levels, but urges people to contact their local water service provider as an initial step if they have concerns.
Lead is another contaminant that often exceeds the capabilities of filtration systems. However, the EPA notes that no level of lead is safe, so it is advisable to use filters even when alternative water sources or pipe replacement are not recommended.
How treatment systems differ
Pitchers, refrigerator filters, and tap-mounted systems treat water at the point of use, where it is drunk or cooked. Under-sink systems and reverse osmosis units also treat water at the tap, but may require professional installation.
Whole-house systems treat water at the point of entry, meaning they filter it before distributing it throughout the home. These systems are typically more expensive and require professional installation. They are usually used for problems that affect all water in the home, such as hardness, high levels of iron or certain volatile compounds, and not for contaminants that originate in the pipes.
In addition to filtration systems, some homes use softeners to reduce the presence of minerals that can build up and damage pipes, although these systems do not remove most other contaminants. Less common in homes are distillation systems, which boil water and condense steam to remove minerals and some contaminants.
According to experts, most homes do not need whole-house distillation systems unless there is a specific, documented problem.
Maintaining and changing the water filter is also important, because the cartridges can lose effectiveness or allow bacteria to build up if they are not changed according to the manufacturer’s instructions.
“Otherwise, they can do more harm than good,” said Pierce, the UCLA academic.