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If the water flowing from your tap came out brown, you’d definitely know something was wrong. But what about contaminants you can’t see, smell, or taste? These invisible invaders are more common than you’d think and many of them are linked to chronic health impacts. While the U.S. Environmental Protection Agency (EPA) has set safety standards for over 80 contaminants, there’s a growing list of emerging contaminants that have yet to be addressed. Many people think buying bottled water solves the problem, but bottled water doesn’t have higher safety standards than tap and water bottling companies don’t test their water nearly as much as municipal facilities are required to. What’s a person to do? Filter it. All of it – because you inhale steam while bathing and can absorb contaminants through your skin, too. Here’s how to choose the best whole house water treatment system.


What are common water contaminants?

Different types of filters remove different types of contaminants, so the first step you need to take before finding the best whole house water filtration system is testing your water to identify what’s in it.

According to the Water Quality Association, some common contaminants include:

And don’t forget the emerging contaminants shown in the infographic to the right.

EWG’s Tap Water Database: What’s in Your Drinking Water?

When most Americans drink a glass of tap water, they’re also getting a dose of industrial or agricultural contaminants linked to cancer, brain and nervous system damage, developmental defects, fertility problems, or hormone disruption. That’s the disturbing truth documented by EWG’s Tap Water Database – the most complete source available on the quality of U.S. drinking water, aggregating and analyzing data from almost 50,000 public water utilities nationwide.

What's in your water?

Enter your zipcode into EWG’s Tap Water Database to learn about contaminants found in your municipal water.

Every tap is different

Learning about what’s been found in your municipal water system is the first step in understanding your water. The second is testing the water that comes from your home’s tap because different chemicals and pathogens could be picked up in the pipelines leading to – and within – your home. Oftentimes county health departments will help you test for bacteria or nitrates. You can also test the water yourself using an at-home test kit (available at most home improvement stores) or have your water tested by a state-certified laboratory. Find one in your area by calling the EPA’s Safe Drinking Water Hotline at 800-426-4791 or visiting their Safe Drinking Water website. (NOTE: If you have a private well, you’ll need to test your water at least once a year – twice or more if you live near farms that apply chemicals at certain times of the year. Contact your local public health office to learn about potential groundwater contaminants in your region.)


Shop Drinking Water Quality Test Kits

First Alert WT1 Drinking Water Test Kit

The First Alert WT1 Drinking Water Test Kit contains everything you need to check for eight common contaminants or issues with drinking water that can cause health problems, including bacteria, lead, pesticides, nitrates, chlorine, pH, and hard water.

Watersafe WS425W Well Water Test Kit

Watersafe Well Water Test Kit was specifically designed to help you test quickly and easily for the most common contaminants found in private well water, including: iron, copper, lead, bacteria, pesticides, nitrates, nitrites, chlorine, pH and hardness.

Test Assured Drinking Water Test Kit

This kit contains tests for Lead, Bacteria, Pesticide, Iron, Copper, Alkalinity, pH, Hardness, Chlorine, Nitrates and Nitrites. Calibrated to the EPA standard. Compare your results with EPA recommendations and guidelines for water quality limits.

What Types of Water Treatment Systems Are There?


NSF International, an independent, accredited organization that develops standards, and tests and certifies products and systems, has the following six NSF/ANSI standards that cover home water treatment systems:

  • Filtration (NSF/ANSI 42 and NSF/ANSI 53) — Contaminants are reduced by being trapped in the pores of the filter or by being adsorbed or broken down by the filter media contained in the system. Carbon filters use this technology to filter water.
  • Water softeners (NSF/ANSI 44) — Water softeners covered by this standard use cation exchange resin, regenerated with sodium chloride or potassium chloride, to reduce hardness (e.g. excess calcium and magnesium) from the water. These minerals are replaced with sodium or potassium ions, depending upon the type of softening pellet used.
  • Ultraviolet disinfection (NSF/ANSI 55) – These systems use ultraviolet light to either disinfect water (Class A systems) or to treat heterotrophic (non-disease causing) bacteria in the water (Class B systems).
  • Reverse osmosis systems (NSF/ANSI 58) — RO systems reverse the natural flow of water so that water passes from a more concentrated solution to a more dilute solution through a semi-permeable membrane. Most reverse osmosis systems incorporate pre- and post-filters along with the membrane.
  • Distillers (NSF/ANSI 62) — These systems heat water to the boiling point and then collect the water vapor (steam) as it condenses, leaving many of the contaminants behind, particularly the heavy metals. Some contaminants that convert readily into gasses, such as volatile organic chemicals, can carry over with the water vapor.
  • Treatment Systems for Emerging Contaminants (NSF/ANSI 401) — Systems covered by this standard include several types of systems that have been verified to reduce up to 15 emerging contaminants from drinking water.

The type of system you’ll need is based on what you’re trying to remove from the water. The NSF has a helpful chart outlining which systems will treat which contaminants and if you don’t see your contaminant listed, you can contact the NSF Consumer Office at info@nsf.org for assistance.

Once you know the best whole house water filtration system you need, be sure to find a product that is NSF certified to ensure the system actually removes the contaminants it claims to remove. If you need help getting pointed in the right direction, try using the search feature on the NSF site.


Maintaining Your Whole House Water Treatment System

Just as important as getting your system set up is properly maintaining it. If filters aren’t changed regularly, the water can become even more contaminated. Hang on to your owner’s manual and follow the manufacturer’s recommendations for properly caring for your system.

Don't stop with your water!

Indoor air quality, toxic chemicals to avoid in home decor and renovation products, safer options – we have a wide variety of articles, infographics, videos, and podcasts to help you create a healthy home. Click through to learn more.