Clean drinking water is a fundamental necessity. Still, even properly treated tap water won’t always be completely free from contamination. This is because water utilities rarely have the technology (or the funds) to provide pure water through powerful filtration or distillation.
Instead, the goal is to remove as much contamination as possible to minimize health hazards. Accidents and aging infrastructure also play a role. Fortunately, you can find a wealth of information and resources for home water treatment. So, let’s dig into how to learn about your water supply, a few common contaminants and what you can do for cleaner drinking water at home.
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The importance of water quality reports
It’s essential to review your local water quality report so you can determine if you want to take additional filtration steps at home to further enhance your drinking water.
Before I dive into the most common drinking water contaminants, I want to clarify that this list doesn’t necessarily mean there are unsafe levels of a given contaminant in your area’s drinking water. The easiest way to determine what’s in your water is to review the annual water quality report from your local water utility. Don’t forget to consult the EPA’s handy guide on how to read them (PDF).
One thing you’ll notice in these reports is that regulations set an ideal goal, the maximum contaminant level goal but recognize that water treatment technology can’t always deliver so they provide a realistic standard, the maximum contaminant level.
Similarly, you can find home test kits from Safe Home and Easytest for about $30 or less. Both products can test for lead, bacteria and excess chlorine. (Most people lack the resources for professional water testing services.) If you use well water, it’s a good idea to test it at least once a year.
6 common drinking water contaminants
Pulling back the curtain on what’s in your drinking water might encourage you to invest in a water filter. (Even if it’s mostly for houseplants, like my Typhoon III reverse osmosis system.)
I asked Kyle Postmus, senior manager of the Global Water Division at NSF (formerly the National Sanitation Foundation), about pollutants that could bypass the water treatment process. “While municipal water treatment systems are highly effective at removing many contaminants, certain pollutants can still make it through the treatment process.” Postmus also points out that location, infrastructure age and source water quality all affect the presence of a pollutant.
He notes that the testing and certification work of organizations like NSF helps ensure the efficacy of the water treatment process. “NSF certifies water treatment products against rigorous standards to ensure they perform as claimed, providing consumers with independent assurance of effectiveness.”
1. Lead
Old lead pipes are the most common culprit for the toxic metal leaching into drinking water.
Lead typically sneaks in after the treatment process because some cities still use outdated lead pipes, which can increase contamination. For example, the Utah Lead Inventory notes that some cities where I live have documented lead pipes in their water systems. The ideal solution for removing lead is to replace outdated water pipes but the EPA also suggests a few ways to reduce lead contamination:
- Purchase a water filter certified for lead removal, such as our top pick, the Zero Water filter.
- Regularly clean your faucet’s aerator to remove sediment.
- Drink only cold water — hot tap water can hold more lead than cold water.
- Flush your pipes before drinking water if it has been stagnant for an extended period. The easiest way to do this is to take a shower, wash the dishes or do the laundry.
2. Microorganisms
Storms and flooding can cause dangerous microorganisms to enter drinking water supplies.
Postmus says that some resistant microorganisms may survive standard treatment. However, a more common source of bacterial contamination is an accidental sewage overflow, sometimes after a heavy storm. In most cases, you can remove this kind of contamination by boiling, filtering or disinfecting your water.
In the case of Legionella, one of the most important steps is to set your water heater to at least 140°F to prevent the bacteria from growing in your water heater. This also reduces the likelihood of bacterial growth in places where hot and cold water mix, such as faucets. (Notably, the CDC says that no single method can control Legionella, so you’ll likely need additional disinfectant and flushing steps if it becomes an issue in your home.)
3. Emerging contaminants
Many emerging contaminants originate from the products you use at home and they aren’t yet regulated by water treatment standards.
Emerging Contaminants are a class of contamination that Postmus says includes pharmaceuticals, personal care products and certain industrial chemicals. Per- and polyfluoroalkyl substances (PFAS) are notable recent examples of emerging contaminants.
These kinds of pollutants may not be subject to regulation yet, but the Safe Drinking Water Act requires the EPA to evaluate contaminant candidates every few years. Look for NSF’s water filter certification program for emerging contaminants — NSF/ANSI 401 — if you want to remove them from your drinking water. Water filter brands like Waterdrop and Aquasana are a good starting point.
4. Volatile organic compounds
You can find VOCs in a ton of products like gasoline, adhesives, solvents and cleaning chemicals.
Volatile organic compounds (VOCs) are a type of chemical that easily dissolves in water — hence the word volatile — and are usually the source of the smells (and flavors) we associate with chemicals. The primary source of VOCs, such as trihalomethanes, is the water treatment process itself, as many are minor byproducts of the disinfection process. Fortunately, a properly functioning water treatment facility uses rigorous testing to ensure that VOCs stay out of your tap. Chemical spills are also common sources of VOCs in drinking water, as they can contaminate groundwater.
Activated carbon filters, such as the Rorra countertop filter system used by ‘s Managing Editor David Watsky, are excellent tools for removing VOCs from your water.
5. Chlorine and chloramine
Water that is properly treated is safe for humans but those with pets may want to consider a filter that removes trace amounts of chlorine or chloramines.
These disinfectants (which don’t really fall under the VOC umbrella) aren’t typically harmful to people in properly treated water but they’re not good for pets that live in water, like fish, turtles and frogs. If you have these types of pets, it’s a good idea to treat the water to remove chloramines.
Reverse osmosis filtration is a mainstay for aquarium enthusiasts but you can also find chloramine removal products at the pet store. For chlorine, simply let it sit out for a few days and it will eventually dissipate from the water.
Water purification at home
It’s easy to improve water quality at home with the right kind of water filter.
Postmus recommends that consumers look for an NSF-certified water filter to address specific contaminants. “NSF-certified water filters are rigorously third-party tested to ensure they work according to the manufacturer’s claims and are safe to use and won’t leak. For ease, consumers can check NSF’s Product Listing Page that lists all NSF-certified water filters.”
One reason to check the certification page is to verify the manufacturer’s claims, ensuring the filter will work as intended. “This is a crucial step when it comes to something as important to your health as your water.”
Most of ‘s top tested water filter pitchers and filtered water bottles are NSF/ANSI-certified; however, you can also find fridge filters and whole-home filtration systems that meet the same standards.
