Do you really need a water filter? Here’s what experts say

U.S. tap water is generally safe and high quality. But that doesn鈥檛 mean every glass tastes the same, or that every building鈥檚 plumbing delivers to the faucet.

That uncertainty has fueled a booming market for water filters, from simple pitcher models to multi-thousand-dollar reverse osmosis systems. Yet experts say most American households don鈥檛 need extensive treatment. The challenge is whether you need a filter.

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. Utilities treat water with disinfectants like chlorine to kill harmful germs before it reaches homes. Most public utilities meet those standards and most Americans can safely drink from the tap.

鈥淯nless you鈥檙e experiencing health impacts, you鈥檝e got a notice from your water system or there鈥檚 a credible media story saying your water is unsafe, you shouldn鈥檛 feel the need to get a filter,鈥� said Gregory Pierce, director of the University of California Los Angeles鈥� Human Right to Water Solutions Lab. 鈥淵ou鈥檙e still welcome to because it might make your water taste a little bit better, but it shouldn鈥檛 be considered necessary to have a water filter in 90-plus percent of the United States.鈥�

Here鈥檚 how to check your local water quality, when water testing makes sense and how to choose a filter that addresses your concerns

How to check your water quality

Start with your utility鈥檚 annual , which details detected contaminants and whether the system meets federal standards. These reports are typically available on a city or utility website. You can also contact your provider directly with questions. Water systems are generally only responsible for the water meaning water quality can vary by building.

For many, those reports may be enough reassurance. Still, some consumers want more certainty, especially in older buildings.

鈥淵ou should probably test your water to identify if you have a risk that you need to treat,鈥� said Jess Goddard, chief science officer at the environmental testing company SimpleLab.

Private wells have different maintenance and safety needs because they are not regulated under the Safe Drinking Water Act and monitoring them is the responsibility of the homeowners. The is among the agencies offering resources for people with private wells.

Testing kits can cost a couple hundred dollars or more, depending on what contaminants they screen.

Here鈥檚 how testing typically works: You order a kit, collect a water sample following the instructions and mail it to a certified lab. The lab analyzes it for specific contaminants, including , microplastics, metals and disinfection byproducts, and provides a report.

If testing reveals a serious issue, 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 household filter. Officials may recommend temporary alternative water sources, like bottled water, or infrastructure upgrades, like pipe replacement.

If there鈥檚 not a problem serious enough to require those measures, a filter may help.

Choosing a filter

People should consider what their filtration goals are and what different filters can do. The that many household activities like flushing toilets and washing clothes don鈥檛 require treatment, so cooking and drinking are typical uses to consider.

Most filters carry ratings by the nonprofit organizations NSF and American National Standards Institute. Common include 42 for taste or smell concerns, 53 for health effects and 401 for emerging compounds. An allows people to search by product name or what compound they want to reduce.

鈥淣ot every filter is good for everything,鈥� said Sydney Evans, a science analyst who led a water filter testing project at the Environmental Working Group. 鈥淎nd even if there鈥檚 a filter out there that does absolutely everything, maybe you don鈥檛 need it.鈥�

Many households use filters not because of safety concerns, but because of taste or odor, 鈥渨hich really do impact people鈥檚 enjoyment or sense of confidence in their drinking water,鈥� Goddard said.

In those cases, a basic carbon filter, like many common pitcher models, can be effective. Activated carbon reduces chlorine and byproducts that form when chlorine reacts with natural organic matter in the water.

Those byproducts are expected in treated water, said Samantha Bear, a senior research analyst at SimpleLab. Even when levels are below federal limits, she said she and her colleagues filter their tap water 鈥� 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 an abbreviation for perfluoroalkyl and polyfluoroalkyl substances. The says that 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 can often be beyond the capabilities of filtration systems. But the that no level of lead is safe, so people may want to use filters even where alternative water sources or pipe replacements aren’t recommended.

How treatment systems differ

Pitchers, refrigerator filters and faucet-mounted systems treat water at the point of use 鈥� where you drink or cook with it. Under-sink systems and reverse osmosis units also treat water at the tap but may require professional installation.

Whole-home systems treat water at the point of entry, meaning water is filtered before it鈥檚 distributed throughout the house. These systems are typically more expensive and often require professional installation. They鈥檙e generally used for issues that affect all household water 鈥� like hardness, high iron levels or certain volatile compounds 鈥� rather than contaminants that originate in plumbing.

Beyond filtration systems, some homes use water softeners to reduce the presence of minerals that can build up and damage plumbing, though these systems don’t remove most other contaminants. Less common in homes are distillation systems, which boil water and condense the steam to remove minerals and some contaminants.

Most households don鈥檛 need whole-home or distillation systems unless they鈥檙e dealing with a specific, documented issue, experts said.

Maintaining and changing your water filter matters, too, because the cartridges can lose effectiveness or allow bacteria to build up if they aren鈥檛 changed according to the manufacturer鈥檚 instructions.

鈥淥therwise they may do more harm than good,鈥� said Pierce, the UCLA scholar.

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