What’s in your water? The best water filters for removing harmful chemicals

Learn about the chemicals that can contaminate drinking water and how to choose a water filter.

Toxic chemicals in your tap

There are thousands of chemicals that can contaminate drinking water. These include:

  • Heavy metals, like lead, arsenic, and mercury. These can leak into water bodies from coal-burning power plants and industrial facilities.
  • Pesticides and fertilizers. Rainwater can carry these chemicals from agricultural fields into our watersheds. 
  • Bacteria. Sewage water can contaminate water supplies and can introduce bacteria.
  • BPA and other harmful chemicals. These everyday chemicals can leak into water supplies. They include plastic chemicals, pharmaceuticals, flame retardants, and detergents.
  • PFAS (Per- and Poly-fluoroalkyl Substances). PFAS are used in stain and water-repellent materials and firefighting foams. They are found in soils, water (including drinking water), animals, and humans. They have been linked to cancer, immune-system problems, and developmental issues in fetuses. 
There is increased interest for filters that remove PFAS from tap water. Recent research shows that the best filters for PFAS removal are reverse osmosis systems. Activated carbon filters were less effective.

Even trace amounts of any of these chemicals can, over time, have serious impacts on human health

Some of these water contaminants are not regulated by the EPA. The EPA regulates chemicals in water under the 1974 Safe Drinking Water Act. Yet, the EPA hasn’t added a new chemical to its list since 1996

Water treatment facilities do not remove all contaminants. Using a home water filtration system ensures that you have toxic-free water.

Here are some tips about how to choose the right filter for you and your family.

How to Choose a Water Filter

1. Find out what is in your water 

You can determine which filter you need by understanding what is in your water.

  • The EPA requires local water utilities to provide water quality reports once a year. These Consumer Confidence Reports are available online.

  • The Water Quality Association (QWA) has developed an interactive map. This map shows water quality from public water systems. 

  • The Water Quality Research Foundation (WQRF) has created a Contaminant Occurrence Map. This map only reports chemicals that are regulated by the government.

  • SimpleLab offers a mail-in home water testing service. Their tests start around $130. Their Tap Score identifies harmful contaminants and rates your water for safety.

2. Check your plumbing

Lead is highly toxic and can affect the brain even at low exposures. Lead in your water comes from service pipes connecting water sources to indoor plumbing. These lead pipes were banned in 1986. But only the public piping was removed. Private plumbing can still contain lead.

Make sure that the water pipes to your house do not contain lead or sediment. Here’s how to check.

3. Consider cost of filter replacement

Water filters need regular maintenance and replacement. When buying a filter, keep in mind this ongoing cost. Some systems may have many stages that need replacement at different times.

Why do I need to replace filters? 
Water filters remove contaminants by trapping them in pores or catching them on the filter surface. Over time, the filter will become clogged, and unable to absorb further contaminants.

When should I change filters? 
Read the manufacturer's instructions for directions on when to change your filters. Some filters have indicator lights, while others recommend time ranges for replacement. This time range is usually an estimate based on how many gallons of water one uses over a certain number of months.

4. Choose a filter from the Million Market Approved Product List

There are no federal regulations for filters, purifiers, and reverse osmosis systems. The National Sanitation Foundation (NSF) developed their own standards for water treatment products. 

NSF tests and certifies drinking water treatment units and filters. Manufacturers must undergo regular certification testing to keep this seal of approval.

We used these stringent standards for our list of approved residential water filters. These filters remove contaminants including plastic chemicals such as BPA. We also make sure the products do not contain any parts with BPA, BPA-alternatives, or phthalates.

Million Marker Approved Water Filters

Water Filters with NSF certifications and high Consumer Report Ratings

  • Multipure Aquaversa MP750SB (NSF/ANSI 42, 53, 401)

  • Kinetico K5 (NSF/ANSI 42, 53, 58, 372)

  • Ecowater ERO-375 (NSF 58)

Water Filters with NSF certifications 

  • ProPur G2.0 series (NSF/ANSI 42 and 53)

  • AO Smith Co. AOW-200 (NSF/ANSI 42, 53, 401, and P473)

  • AO Smith Co. AOW-300 (NSF/ANSI 42, 53, 401, and P473)

  • Aquasana AQ-5300+ (NSF/ANSI 42, 53, 401, and P473)

  • Aquasana AQ-5300A (NSF/ANSI 42, 53, 401, and P473)

  • Aquasana OptimH20 AQ-RO-3 (NSF/ANSI 42, 53, 58, 401, and P473)

  • eSpring 100188 (NSF/ANSI Standards 42, 53, 55B, 401, and P477)

  • eSpring 100189 (NSF/ANSI Standards 42, 53, 55B, 401, and P477)

  • iSpring RCC7 (NSF/ANSI 58)

  • Flexeon LP-700 (Filter parts 200627 and 200659 are NSF/ANSI 42)

Water filters found to remove PFAS

  • Any water filtration system with NSF P473 certification

  • iSpring RCS5T

  • Flexeon LP-700 (Filter parts 200627 and 200659 are NSF/ANSI 42)

NSF Standards for Water Filters and Purifiers 

NSF/ANSI 42 – Removes non-harmful impurities such as chlorine and chloramine. 

NSF/ANSI 53 – Reduces contaminants with health effects, such as cysts (cryptosporidium, giardia), mercury, lead, MTBE (methyl tertiary butyl ether), turbidity, and asbestos. 

NSF/ANSI 55B – Further reduces non-disease causing bacteria, viruses, and cysts in already disinfected drinking water.

NSF/ANSI 58 – Certifies that the water treatment system uses reverse osmosis to filter the water. 

NSF/ANSI 401 – Reduces one or more of the 15 emerging contaminants from drinking water:  atenolol, BPA, carbamazepine, DEET, estrone, ibuprofen, linuron, meprobamate, metolachlor, naproxen, nonylphenol, phenytoin, TCEP, TCPP, and trimethoprim.

NSF/ANSI 372 – Verifies a product’s compliance to minimum lead contaminants. 

NSF P473 – Reduces PFOA and PFOS in drinking water. 

NSF P477 – Reduces microcystin (toxins produced by blue-green algae).

Million Marker Approved Water Filters