Is Tap Water Safe to Drink or Do You Need a Water Filter?

Is your tap water safe to drink? Should you be using a tap water filter? Gaby Vaca-Flores, RDN, CLE, investigates. Access to clean drinking water is a must for good health. Many people rely on tap water to meet their hydration needs—and for environmental reasons, this is a preferable way to go versus single-use plastic bottles. But how safe is your tap water, really? Before we reveal the truth about tap water, it’s important to keep some things in mind. While most Americans have access to clean drinking water, more than 2 million Americans live without basic access to safe drinking water and sanitation. What’s more, 44 million Americans are served by water systems that violate the Safe Drinking Water Act. While much work is necessary to ensure everyone has rightful access to clean drinking water, the Centers for Disease Control (CDC) shares that the United States still offers one of the safest drinking water systems. Unfortunately, many areas of the world are less fortunate. Over 884 million people lacked safe water to drink in 2019. So although it’s important to know how filtered water stacks up, many Americans are incredibly fortunate to have tap water to fall back on. With that said, let’s get back to the debate: Is your tap water safe?

Where Does Tap Water Come From?

Tap water (aka municipal water) flows out of a water dispenser valve called a tap. This water typically comes from a number of public water systems including wells, lakes, aqueducts, and reservoirs. Its source will largely depend on your location. For instance, cities like Chicago gather their water supply from Lake Michigan. On the other hand, areas like San Francisco get 100 percent of their drinking water from reservoirs. Overhead shot of well water that will end up as tap water in homes

Is Tap Water Safe to Drink?

Before tap water makes it to your faucet, it travels from its source to a treatment facility for processing and sanitation. Water treatment is a four-step process:
  1. Coagulation and flocculation: Chemicals like aluminum salts and activated carbons are added to the water to promote the clumping of unwanted particles.
  2. Sedimentation: Sedimentation occurs when the unwanted particles, called floc, finish clumping and eventually settle to the bottom of the tank.
  3. Filtration: Once settled, the floc is filtered out of the water supply. Floc generally consists of undesirable particles like bacteria, dust, chemicals, and microorganisms.
  4. Sanitation: Finally, the floc-free water supply is disinfected with chemicals such as chlorine. This process helps prevent outbreaks of waterborne infections. At this step, some cities will also add fluoride, a mineral used to prevent tooth decay.
The entire water treatment process is regulated by the Environmental Protection Agency (EPA). The Safe Drinking Water Act (SDWA) requires that the EPA take responsibility for identifying and limiting potential contaminants in drinking water. Over 90 contaminants, including lead and other heavy metals, are actively measured in public drinking water.

Potential for Contamination

Despite treatment, tap water isn’t fully free of contaminants. There are a number of ways that contaminants can infiltrate drinking water, including:
  • sewage leaks
  • natural chemical and mineral runoff
  • agricultural practices (livestock, pesticides, fertilizers)
  • manufacturing practices (heavy metals, cyanide)
  • wastewater treatment malfunctions (septic systems)
  • poor disposal of pharmaceuticals (medical waste, medications)
Exposure to contaminated water can result in a variety of health issues, including: The good news? Over 92 percent of the US population’s water supply is sourced from community water systems, which meet all health-based standards set by the SDWA. So for the majority of Americans, their tap water is highly unlikely to be impacted by dangerous levels of contaminants. Nonetheless, you may still benefit from taking extra steps to purify your drinking water. Pouring filtered tap water into a glass

Do You Need a Tap Water Filter?

Home water filters can provide additional insurance against potential contaminants. While a water filter may not be an absolute necessity for most people, the added protection can provide greater benefits and peace of mind. Keep the following considerations in mind to determine if you need a tap water filter.

Geographic Location

Certain geographical areas—like communities that rely on groundwater—are more vulnerable to contaminants. Groundwater can easily be contaminated by natural and human-driven impurities. The National Resources Defense Council (NRDC) reports that once an aquifer is polluted, it can become unusable for decades and even spread to other nearby sources of water such as streams, lakes, and oceans. Unfortunaely, many rural regions rely exclusively on groundwater for drinking. Also, the SDWA regulates only public water systems that serve over 10,000 people. Water systems serving less than that are regulated only once every five years—plus, they’re tested for only 30 contaminants. Consequently, water systems in small rural communities can be at a higher risk of contamination. Of course, this isn’t to say that all small communities relying on groundwater have polluted tap water. If you have doubts about your water quality, you should reach out to your local county health department who can help you test your tap water for the most common contaminants. Alternatively, you can call the Safe Drinking Water Hotline.

Old Plumbing

The plumbing system in your home or apartment can also influence the quality of your tap water. Pipes make great habitats for waterborne germs to thrive due to moisture. The most common pipe-germ is a slimy substance called biofilm, a glue-like mixture of bacteria, fungi, and amoebas. Biofilm creates a barrier around the pipe, preventing water treatment chemicals from doing their job. Additionally, it allows the germ to multiply and make direct contact with drinking water. In large amounts, waterborne germs can lead to a number of illnesses. Despite a functioning public water system, waterborne germs can exist inside pipes. They usually occur in households where the taps are not turned on for long periods of time or are poorly designed, allowing water to sit still. Additionally, while lead pipes were banned nationwide in 1986, if you live in an older home and the plumbing hasn’t been updated, there’s a risk of lead contaminating water. The EPA recommends considering a few factors before deciding to run a water test. Pertinent questions include:
  • What is the proximity of your nearest water well to your home’s septic system?
  • What is the composition of your home’s plumbing material?
  • Have you felt ill after drinking tap water?
Again, if you suspect that your tap water is compromised, request testing from your county’s health department. You can also call the Safe Drinking Water Hotline. Depending on the test results, you might need to consider investing in a home water filter.

Additional Factors

Certain groups of people can benefit from investing in a water filter regardless of their location or plumbing. These people are usually more vulnerable to the negative effects of contaminants. Examples include: In addition, people who collect their water from a private water supply such as a household well should consider a water filter. Homeowners of privately sourced water are responsible for treating and testing their water supply. Finally, people who simply don’t enjoy the taste of tap water and/or want to limit the use of single-use plastic bottles can benefit from a water filter. Purifying devices can also help ease the taste of chlorine in tap water. Man drinking filtered tap water to stay hydrated and healthy

What to Look for in a Tap Water Filter

According to the EPA, over 40 percent of Americans use a home water treatment unit. With so many options on the market, it can be challenging to narrow down your options. There are a few things to keep in mind when shopping for a water filter, such as performance, cost, maintenance, and certifications. Water filters can range from less than $20 to hundreds depending on the model. Professional installation and annual maintenance are also costs to take into account.

Type and Cost

Simpler devices like point-of-use water filters either attach directly onto the faucet, are installed under the sink, or are built into a pitcher. They’re good options for those looking to filter the water they use for drinking and cooking. Compared to more advanced water filters, they’re relatively less expensive, costing between $20 to $500. On the other hand, point-of-entry water can be more pricey. These filters purify the home’s entire water system by connecting to the primary water line. It’s ideal for homes with more than one water-dispensing location. Being a more advanced model, this water filter is significantly pricier, ranging between $500 to $3,000.


Be sure to look for a tap water filter that’s certified to meet or exceed the EPA’s drinking water standards. There are three certification programs accredited by the American National Standards Institute (ANSI). Be sure to keep an eye out for them on the filter’s label:
  1. NSF Water Treatment Device Certification Program
  2. Underwriters Laboratories
  3. Water Quality Association

The Bottom Line

Ultimately, tap water is considered relatively safe for drinking in many parts of the US, yet its quality can vary depending on where you’re located. While not a necessity for most people, tap water filters do offer many benefits. Additional protection against contaminants and better-tasting H2O can be compelling reasons to invest in a tap water filter.
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