What’s in your water?

Even if your tap water is deemed safe to drink by the government standards it can still contain chemicals linked to cancer, brain damage, nervous system problems, fertility problems, and hormone hormone disruption. Some of these chemicals do not even have a legal limit set by the government. 

Common water contaminants


Chlorine is a chemical that is often added to water in municipal water systems for the purpose of controlling microbes; however, it is a powerful oxidant that has led to an increase in heart disease and cancer-related deaths. Chlorine will combine with methane in the water and form chloroform. 


Chloroform is a total trihalomethanes chemical that is formed when chlorine is used to treat drinking water. Chloroform in the water increases the risk of cancer and may cause problems during pregnancy. 


Fluoride is naturally occurring in surface and ground water; however, it is also often added to municipal water. Fluoride is a neurotoxin that affects the function of your thyroid gland.


PFAS is an abbreviation for pre and polyfluoroalkyl substances. These are a group of chemicals that are used to create a fluoropolymer coating in products that resist heat, water, grease, oil, and stains. PFAS can travel through soil and contaminate water sources and do not break down in the environment. 


Uranium is a known carcinogen. The federal legal limit of uranium in drinking water is 30 mcg/liter. Uranium can also be measured and reported in pCi/L which is a measure of radioactivity. The legal limit in pCi/L is 20 pCi/L which is enough uranium to cause more than 4.6 cancer cases per 100,000 people. 

VOCs (volatile organic compounds)

VOCs are chemicals that can evaporate from the water’s surface at room temperature and become a vapor. Not all VOCs are harmful; however, many are hazardous to humans and animals. The EPA (U.S. Environmental Protection Agency) estimates that 1/5th of the nation’s water supply contains VOCs. VOCs are found in degreasers, paint removers, gasoline, and cleaning agents. Overexposure to them can cause respiratory problems, lung damage, and eye, nose, and throat irritation.


 Pharmaceuticals that are ingested by the public are then urinated out and flushed down the toilet and into the water supply. This water is then treated before it renters the municipal water supply; however, the pharmaceuticals are not removed during this process and end up in your drinking water. Some of the common pharmaceuticals that end up in drinking water include aspirin, birth control hormones, blood thinners, cholesterol medication, anxiety and depression medications, caffeine, opiates, and antibiotics 


Nitrate is a chemical in fertilizer that enters the water supply through agricultural and urban runoff as well as discharges from septic tanks and the municipal wastewater treatment plants. Intaking water containing excessive nitrates can increase the risk of cancer and cause oxygen deprivation in infants. 


Arsenic is a highly toxic compound that contaminates the drinking water most commonly from rocks. The flow of water will dissolve the arsenic from the rock formations into water sources that become part of our water supply. This has been increased with humans mining and smelting ores that contain arsenic. This contamination tends to be highest in the water supplies in the western states. Both the environmental protection agency and the world health organization have labeled arsenic to be a “known human carcinogen” that increases the risk of skin, bladder, and lung cancer. Some studies have linked lung cancer risk specifically to drinking water exposures of arsenic. 

How to check your water

At EWG Tap Water Database you can enter in your zip code and see what chemicals are in your water. EWG is a third party that has tested these various water supplies and reported its findings. 

Water filter options

Carbon filtration

 A carbon filtration system has activated carbon in it that will chemically bond with contaminates and remove them from the water as it moves through the filter. The effectiveness of this kind of filter can vary wildly. Some are only able to remove chlorine and focus more on improving the taste and odor of the water. While others can reduce the levels of several contaminants such as lead, mercury, asbestos, and VOCs. This is the least expensive filtration option; however, activated carbon does not filter out inorganic pollutants including fluoride, arsenic, nitrate, hexavalent chromium, and perchlorate. There are two different options for this type of filter, a carbon block or granulated activated carbon. 

Carbon block: A carbon block filter has blocks of activated carbon under high pressure. This option is typically more expensive than granulated activated carbon and is also more effective due to the greater surface area which gives it more contact with the water. The effectiveness of this filter is also affected by how quickly the water moves through the filter. This filter typically needs to be replaced more often than the granulated activated carbon.

Granulated activated carbon: This carbon filter is filled with fine grains of activated carbon. This filter is less effective than the carbon block due to the decreased surface area but is also usually less expensive. The effectiveness of this filter is also affected by how quickly the water flows through the filter. 

A whole house carbon filter can be installed to remove contaminants that could be inhaled through water vapors while showering or washing dishes; however, effectiveness varies widely. 

Reverse osmosis

A reverse osmosis filter contains one or multiple activated carbon and sediment filters as well as a semipermeable membrane that blocks particles that are larger than a water molecule. This type of filter removes all of the contaminants that carbon filters do (chlorine, trihalomethanes, and VOCs) as well as some of the chemicals that carbon filters do not such as fluoride, arsenic, nitrates, hexavalent chromium, and perchlorate. However, this filtration also filters out minerals such as iron, calcium, and magnesium that are essential nutrients for good health. It is an option to remineralize the water with mineral drops. Another downside to this type of filtration is that there is a lot of wasted water because the filter takes in five times more water than it produces and rejects the rest in the filtration process. This option is the most effective filter; however, it is a more expensive option and is wasteful. 

Ion exchange

Ion exchange is the least effective type of filtration. This is the type of filtration that water softeners typically use. The ion exchange process in this filtration reduces the levels of calcium and magnesium in the water by replacing them with sodium. This is done because calcium and magnesium can build up in plumbing. This filtration also removes barium and radium which can be found in tap water; however, other water contaminants are not affected by this type of filtration. Softened water is not recommended for water plants or for individuals on a low-sodium diet due to the sodium content of the water. 


Distillation is a process in which water is heated into a vapor and the steam is collected and condensed back to liquid form. This filtration removes minerals, bacteria, virus, and chemicals that have a higher boiling point than water. This process does not remove chlorine, trihalomethanes, or VOCs. 

Water filters should be changed on time because old filters will harbor bacteria and let contaminants through. 

 Is bottled water better?

Short answer is no.

Most bottled waters do not disclose the water’s source location, treatment, or purity. The EWG conducted an investigation with the top 10 brands of bottled water and found 38 pollutants, including chemicals that are linked to cancer. It is recommended that you drink filtered tap water out of a stainless steel or BPS-free water bottle. This is a purer and more cost effective option that is better for the environment. A plastic water bottle should not be used because it can leach harmful plastic chemicals into the water and can also harbor bacteria. 

Drink safely!