7 Potential Cancer-Causing Contaminants in Tap Water – And How to Remove Them

Being diagnosed with cancer can be terrifying. After receiving the news, one may experience tough times of emotional distress, a range of strong emotions, and other ordeals. Sometimes even the thought of enduring these unpleasant situations can compel us to make significant lifestyle changes to lower our risk of getting the disease. Generally, our cancer prevention plan includes things like:

  • ditching junk food for a healthy diet
  • quitting smoking and drinking (or not starting), and
  • limiting our exposure to the sun and toxic chemicals

However, there’s a precious resource in our homes that may be secretly raising our cancer risk: our tap water.

When we turn on the tap, we often trust that the water that comes out is healthy and contaminant-free. Perhaps that’s because state and local officials are always reassuring us that our tap water is ‘safe’ to drink. Still, even tap water that meets legal standards set by the federal government sometimes contains complex mixtures of contaminants, some of which may create a substantial risk for cancer.

Scientists at the Environmental Working Group (EWG) found that 22 carcinogens commonly found in tap water could cumulatively increase the cancer risk for 100,000 U.S. residents over a lifetime. The analysis concluded that most of the cancer risk is from naturally occurring arsenic, disinfection byproducts, and radioactive contaminants.

While the U.S. is said to have one of the safest public water supplies globally, the fact that Americans can develop cancer from drinking tap water tells us that ‘safe’ water isn’t always safe. With that in mind, let’s determine the specific contaminants in drinking water that may increase the risk of cancer, their potential effects, and how you can remove them from your tap water.

1. Arsenic

Arsenic is a highly toxic chemical element that naturally occurs in rocks and soil. Essentially, it is a byproduct of coal-burning, copper smelting, and mining. The chemical compound is a top driver for cancer in the U.S. and is particularly common in southwestern cities like Scottsdale, Tucson, and Los Angeles, as well as in the Northeastern and Great Lakes areas.

Arsenic can enter our water supply from natural deposits in the earth, or industrial or agricultural pollution. Once it is present on the ground or in surface water, it can slowly enter groundwater used for drinking water. High levels of arsenic in private wells may come from certain arsenic-containing fertilizers that have been used in the past, or industrial waste.

Some industries in the U.S. release thousands of pounds of arsenic into the environment every year. It’s no wonder why arsenic was found in the taps of 107 million Americans from 2015 to 2017. According to a national study of groundwater quality, the compound was also detected in nearly half of the wells sampled in parts of aquifers used for drinking-water supply.

If you’re thinking about switching to bottled water, then you will likely suffer a similar fate. Consumer Reports found that out of 130 bottled water brands tested, 11 contained unsafe arsenic levels, including six with 3 parts per billion (ppb) or more.

Now, the federal standard for arsenic in bottled water is 3 ppb. But despite that, Consumer Reports said current research suggests that arsenic levels over 3 ppb can be dangerous to ingest over an extended period. The Environmental Protection Agency (EPA) has also set an exposure limit of arsenic in public drinking water in the U.S. to 10 ppb. Still, a few public water systems and private wells (which the EPA doesn’t monitor) have detected arsenic levels above this standard.

Arsenic has no color, taste, or smell, so it’s almost impossible to identify it without a test. Exposure to the compound may cause brain development issues in children, congenital disabilities, and an increased risk of cancer, diabetes, and heart disease. The EWG predicts that ingesting arsenic and other carcinogens in tap water may result in 100,000 cancer cases. But don’t worry. We’ll tell you how to remove them from your water later on in this article.

2. Nitrate

Like arsenic, high levels of nitrate in drinking water can be dangerous to health, especially for infants and pregnant women. The chemical occurs naturally in soil and air, but it is also found in many fertilizers used on yards, golf courses, and in agricultural production. Because of its widescale use in farming, the chemical is wreaking havoc on the drinking water quality in many parts of America, mainly in agricultural areas.

Nitrate mainly enters water supply through agricultural and urban runoff, discharges from wastewater treatment plans, and septic systems. Approximately half of all applied nitrogen drains from farms to contaminate surface water and groundwater. Hence, concentrations of nitrate in our water systems have also increased significantly and are expected to continue.

Also, an environmental advocacy group says that millions of tons of nitrates from industrial farming are released into America’s drinking water each year, causing thousands of cancer cases and other health problems. Nitrate is also common in private wells. But since the federal government does not monitor private well water, it falls on the individual homeowner to test the water in their wells.

High levels of nitrate in drinking water has been linked to colon, kidney, ovarian, and bladder cancers. Researchers from the EWG say the chemical is responsible for 12,600 cancer cases a year. Of course, the risk varies from region to region, but many small farming communities have the highest nitrate levels in the water, thus the highest risk.

The EPA suggests a limit of nitrate in drinking water at 10 mg/L. However, the EWG has defined health guidance for the chemical at 5 mg/L, based on studies by scientists at the National Cancer Institute and other independent researchers. These health guidelines are believed to protect against cancer and other health hazards. However, in 2015, 7 million Americans received tap water with levels higher than 5 mg/L.

The odds of having nitrate in your water above the established protective guidelines are high, but it is not a bleak situation. As promised earlier, we’ll tell you how to remove nitrate and other potential cancer-causing contaminants from your water. You’ll certainly want to stick around for that.


If you’ve ever seen the movie, Dark Waters, you’ve likely heard about PFAS, aka, the ‘forever chemicals.’ PFAS, short for per- and poly-fluoroalkyl substances, are a large family of almost 5,000 different types of chemical compounds, all of which are human-made and contain linked chains of carbon and fluorine.

Because of the strong bond between the carbon and fluorine atoms in these chemicals, they don’t break down quickly. Thus, they can stick around in the environment for decades or even centuries, and build up in our bodies.

We come into contact with PFAS through the things we purchase, like stain-proof rugs, paper food packaging (like microwave popcorn bags and pizza boxes), fast-food wrappers, some types of dental floss, non-stick cookware, and more. If a product is waterproof or stain-repellent, like stuff with Gore-Tex, Teflon, or Scotchguard, there’s a good chance that it contains some kind of PFAS.

A report from the EWG found that there are high amounts of PFAS in tap water, much more than the EPA previously reported. Scientists at the EWG believe that some PFAS chemicals are likely present in almost all water supplies in the U.S., especially in areas where facilities handling PFAS, like manufacturing plants and wastewater treatment facilities, are located.

The problem with PFAS is that they exhibit several critical characteristics of carcinogens. That means exposure to these chemicals can increase the risk of cancer in humans. In 2016, the EPA issued Lifetime Health Advisory levels for PFAS in drinking water at 70 parts per trillion (ppt) separately or combined. These advisory levels were developed to protect the most sensitive population groups from the harsh effects of PFAS over a lifetime of daily exposure. However, it’s always best to avoid consuming PFAS altogether.

4. Disinfection Byproducts

Adding chlorine to drinking water helps to kill bacteria and other organisms that cause waterborne diseases, such as cholera and typhoid. While chlorine is practical, affordable, and easy to administer, there have been growing concerns about the safety of adding such a toxic chemical to drinking water in recent years.

The main problem with chlorine is that when added to regular drinking water, it combines with organic compounds in the water, which produce disinfection byproducts (DBPs). High levels of exposure to DBPs have been linked to bladder, liver, kidney, and intestinal cancers.

Studies show that exposure to trihalomethanes (THMs), a significant component of DBPs in chlorine-treated water, can be substantial. Inhaling THMs can be more dangerous than consuming them because they convert to vapor at lower temperatures. That means showering with chlorinated water can also increase your exposure to these toxic byproducts.

Chloroform is the most prevalent among THM compounds in chlorinated water and has been classified as a possibly carcinogenic substance to humans. Some studies revealed that it can damage different cells in the body of laboratory animals and develops cancer in exposed organs. Although it is challenging for scientists to evaluate the effects of THM on humans directly, some studies indicate that THMs are known to increase the risk of bladder cancer, intestinal, anal, esophagus, and some reproductive health complications like abortion and low birth weight.

The Centers for Disease Control and Prevention (CDC) suggests 4 milligrams of chlorine per liter of drinking water as a safe level. The EPA has also established science-based regulations limiting certain DBPs (particularly THMs and haloacetic acids) in drinking water. However, despite these rules and guidelines, scientists discovered that people who drink chlorinated water for 15 years or more had a higher risk of developing colon cancer.

5. Chromium-6

Chromium-6 is a cancer-causing chemical best known for its role in the notorious film “Eric Brockovich,” which documented the poisoning of drinking water in Hinkley, California. Shockingly, nearly 200 million Americans have been exposed to higher-than-recommended levels of this carcinogen through their tap water, according to a new report.

The chemical occurs naturally in the environment, specifically in rocks, plants, soil, etc. However, high quantities are also produced by industrial projects. Pollution can arise when these industrial sites improperly dispose of waste materials, causing the chemical to seep into groundwater and surface water.

Even in small amounts, chromium-6 can cause stomach cancer and other health complications like pneumonia, skin burns, problems during childbirth. While the EPA classifies it as a known carcinogen, there is no federal standard for the maximum amount of the chemicals in the water.

An analysis from EWG found that 1,370 U.S. country water supplies contain chromium-6 levels above California’s benchmark. California was the first state to set a legal limit for chromium-6 in drinking water, but at 10 ppb, which is 500 times the state’s public health goal, it is still insufficient to protect residents against the toxic effects of chromium-6. The good news, however, is that there’s a reliable way to remove the chemical from your drinking water.

6. 1,4-Dioxane

Aside from being a pollutant in drinking water, 1,4-dioxane is also known as a trace contaminant in some chemicals used in cosmetics, bubble baths, detergents, skin cleansers, skin lotions, and shampoos. Foods may also contain small amounts of 1,4-dioxane from some additives and packaging materials.

1,4-Dioxane travels quickly through soils to groundwater and surface water and does not readily degrade. These traits make it difficult to avoid water contamination due to the compound. Because conventional water systems are not effective at removing 1,4-dioxane, there’s a good chance that it may contaminate our drinking water – and so said, so done. The EWG states that 1,4-dioxane is likely a human carcinogen that contaminates drinking water in at least 45 states in the U.S.

In 2013, the EPA reported that 1,4-dioxane is carcinogenic. Low-level exposure to the solvent can over a person’s lifetime increase the risk of cancer. Higher exposures over a shorter time can damage cells in the liver, kidney, and respiratory system.

In response, the EPA defined a concentration level of 0.35 ppb for 1,4-dioxane in tap water as the amount expected to cause no more than one additional cancer case in one million people who drink it for a lifetime. However, samples from water systems serving certain areas in America had average levels of 1,4-dioxane ranging from four times to about 17 times the EPA’S minimal cancer risk level. Because there is no federal regulation limiting the carcinogen in tap water, several states have set their own criteria.

7. Radionuclides

When you hear the term “radioactive elements” or “radionuclides,” the first thing that usually comes to mind is radiation, and ultimately, cancer. Radionuclides are both naturally occurring and human-made. Those that come from naturally occurring sources can get into groundwater and surface water. When they break down, they create radiation.

Radionuclides (such as some forms of uranium and radium) are a natural part of our environment, and small amounts of radiation are frequent in water, air, and soil. However, they can also be concentrated during extraction by mining and other industrial activities. Exposure to too much radiation can cause serious health problems, such as cancer. Yup, you guessed it.

Cancer is considered the primary health effect of radiation exposure. Typically, natural processes control the rate at which cells grow and replace themselves. They also control the body’s processes for repairing or replacing damaged tissue. Damage to these cells and tissues can disrupt the control processes, causing uncontrolled growth of cells, a condition we know as cancer. In addition to causing cancer, uranium in drinking water may cause toxic effects on the kidney.

Maximum contaminant levels (MCLs) in drinking water have been established for a variety of radionuclides. For radium, the MCL has been set at 5 pCi/L (picocuries per liter, a unit of measure for levels of radiation), and for uranium, it’s 30 µg/L.

What can be done to remove potential carcinogens from drinking water?

Generally, tap water is safer than bottled water. That’s because bottled water is less regulated than tap water. Most public water systems meet EPA’s standards for clean water. But since the agency only evaluates one chemical at a time instead of the full combination of contaminants, the 100,000 cancer cases that the EWG predicted could be possible under the EPA standard.

The best way to reduce your risk of cancer from the cancer-causing pollutants in drinking water is to find out where your water comes from, then purchase and install a water filter designed to eliminate those particular types of contaminants in your local water system.

While you may think of bottled water as a cheaper alternative, it’s not. Over time, you’ll likely end up spending more on bottled water than tap water. Plus, researchers have found high levels of arsenic in bottled water sold at Whole Foods and Walmart. That means there’s no guarantee that there aren’t contaminants in bottled water.

Installing a water filter is the first line of defense against carcinogenic pollutants in your drinking water, whether it comes from a private well or a public source. But first, you must find out which specific contaminants are present in your water, if any. That way, you can find a filter that will target and remove them effectively.

The most convenient way to check for contaminants in your drinking water is to use a water testing kit. Alternatively, you can contact your local community water provider and request a copy of their annual water quality report. This report contains information about the levels of certain chemicals and other pollutants in the water. But if you’re looking for a method that produces more accurate results, you can send a water sample from your tap to a local laboratory to be tested.

If your water is found to contain cancer-causing contaminants, your two most effective filter options are:

  • A whole-house filtration system: Whole-house filtration systems, aka “point-of-entry (POE)” filters, treat all the water entering your home. They’re designed to remove all kinds of contaminants and impurities in drinking water so that you and your family can enjoy safe, great-tasting water while reducing or eliminating cancer risk. If you’re looking for an all-round solution like this, then the Springwell whole-house filtration system is your best bet. The CF1 uses carbon filtration and a host of innovative technologies, filter media, and other filtration processes to remove 99.9% of contaminants from drinking water, including chlorine, chloramine, PFAS, pesticides, herbicides, haloacetic acids, THMs, and many more.
  • A reverse osmosis filtration system: Reverse osmosis filters are well-known for eliminating many contaminants from drinking water that many other filters can’t. Typically, reverse osmosis filters treat water at one specific faucet, which is why they’re called “point-of-use (POU)” filters. The Springwell SWRO-Nickel and the Springwell SWRO-Bronze under-sink systems are the most reliable reverse osmosis systems for filtering out cancer-causing contaminants from your drinking water. Both systems use a 4-stage filtration process to remove toxic pollutants from your water, including lead, mercury, arsenic, chlorine, chloramine, chlorine byproducts, pesticides, herbicides, iron, aluminum, and many others.

When you purchase any of these and other Springwell water filtration systems, you get a lifetime warranty, a six-month money-back guarantee, and free shipping. Plus, if you cannot afford the system’s full price upfront, you can finance it with affordable monthly payments up to a year.

Final Thoughts

We often hear about diseases and illnesses caused by water pollution, such as typhoid, cholera, diarrhea, etc. But never would we have imagined that cancer would be a part of that list. Dealing with cancer can be a traumatic experience, so you must try your best to avoid anything that may cause it – like drinking contaminated tap water. The best way to achieve this is to filter your water with a quality water filtration system from Springwell.