The Five Most Common Contaminants Found in Drinking Water

The Five Most Common Contaminants Found in Drinking Water

9 minute read

When we drink our daily eight glasses of refreshing, nourishing water, how often do we consider the huge host of contaminants living inside our tap water?

Any source of water will by its nature contain some degree of contaminants, some natural and some artificial. As water flows through our streams, lakes, rivers and oceans and filters across various rock formations and soil, it comes into contact with a whole host of substances, all of which will absorb into the water source.

Further, as our water is treated in various facilities by municipalities to become ready to deliver to its residence, a new batch of chemicals and additives are integrated. While this process is regulated by the EPA, the specifics, procedures, and enactments of those regulations vary from municipality to municipality. Currently, the EPA estimated that over 60,000 chemicals are being used within the USA, but the Safe Water Act oversees only 91 contaminants.

tap waterWith regulation and procedures the way they are, it’s quite easy to see why the United States is facing a crisis in regards to the availability of clean, safe drinking water. Tragedies like the presence of lead in Flint Michigan certainly make the headlines, but little is being done to correct the issue. The truth is our water sources are being contaminated by a whole host of dangerous chemicals, and it is up to us as consumers to understand the threat at large so that we may push our leaders to enact comprehensive and effective change.

To understand the situation fully, below are the five most common contaminants in tap water.


Nitrates are chemicals that most often found in fertilizers, manures and liquid waste coming from septic tanks and plumbing systems and therefore are one of the most common forms of water contaminants, especially in rural areas. When nitrogen in fertilizer is either left over by plants or carried off by runoff, it can quickly form with our sources of groundwater and convert into nitrate.

Short term exposure to water with above average nitrate levels can be dangerous, especially to infants as it can lead to methemoglobinemia or the “baby blue” disease, a condition that decreases the blood’s ability to carry oxygen, creating bluish pigmentation. For infants, this condition can be fatal.


Arsenic is a metallic substance found organically in small amounts within nature. Arsenic can find its way into your drinking water in two ways. Mineral deposits found in a very small percentage of regions, such as Illinois, can contain a micro amount of arsenic deposits. More commonly, arsenic can contaminate your water as it comes into contact with hazardous waste produced by arsenic manufacturing industries.

Studies on arsenic have found that the compound can produce a variety of health effects such as thickening and discoloration of the skin, digestive problems, numbness in the feet or hands and has been linked to a variety of skin cancers. Arsenic cannot be detected via sight or smell, and therefore water testing is required to determine whether a water source has been contaminated.

Microorganisms, Bacteria, and Viruses

To some extent, all water hosts some degree of bacteria and protozoans. And while most of these little creatures are harmless, some such as E.Coli and Legionella Pneumophilia can cause quite a lot of damage. These microorganisms and diseases can, in fact, cause severe damage and for infants and the elderly specifically, can in some cases lead to death.


Aluminum is the third most common element present in the earth’s soil, water and air and therefore it can quite easily find its way into our water systems. In recent years, specific attention has been given to the presence of aluminum as a contaminant in our tap water and links to dementia have been made in communities with high traces of aluminum present in their drinking water.

Other aluminum linked health effects include nervous system damage, kidney diseases, and anemia.


Fluoride is a natural mineral found within the earth’s soil and has long been considered a helpful additive for water sources to help combat tooth decay. Since the 1940s, compounds containing fluoride have been added to our water systems. But recently, evidence is beginning to show that fluoride may be doing more harm than good. Extreme levels of fluoride can cause fluorosis, a change in tooth enamel that can lead to white spots and staining. Flouride in high levels can also become concentrated in the bone which can inevitably weaken the skeletal system.

What Can Be Done About Contaminants in Tap Water?

While studies certainly show that our water sources are being flooded by harmful contaminants, in the end, it is up to us to remedy the situation. We must continue to advocate for stronger safety regulations as it pertains to our public health and water. We must also protect our own consumption of water and take filtration of these compounds into our own hands. To ensure that your water is safe to drink, consider procuring your water from outside sources or make consistent use of filtration devices.

Water is a crucial building block for life. But contaminants in tap water stand to hold back our health. It is up to us to ensure that our tap water is safe to drink so that we can continue to lead healthy, safe and hydrated lives.

Frequently Asked Questions

How do I know if my tap water is safe?

The safest way to determine whether your tap water is safe or not is to have the water professionally tested. However, when this is not possible it is advised to visually check if the water appears cloudy. Water that is yellow or brown is never advised to be consumed and water tinged with a blueish or green cue can be a sign of elated levels of copper. If you detect the smell of rotten eggs then that could be a sign that your water contains hydrogen sulfide and water that smells like bleach could contain excessive levels of chlorine. If you detect a metallic taste after consuming water, that could be a sign that your water is contaminated with an excess amount of iron or copper.

Is it safe to drink city tap water?

Tap water is relatively safe in most cities as municipal water is regulated by the Environmental Protection Agency (EPA). However, it is still advised to filter your tap water to ensure optimum purity and safety.

Can you purify tap water?

Yes. Tap water can be purified by boiling, distillation, or chlorination. However, the most effective and safest process for purifying tap water is to use filtration devices to eliminate the molecular compounds that can contaminate tap water.

Where does tap water come from?

Tap water in the United States comes from three main sources; lakes, groundwater, and rivers. Dependent on where you live your tap water can come from any of these source points.

How much chlorine is in tap water?

The EPA has determined a threshold level known as the Maximum Residual Disinfectant Level (MRDL) which sets how much chlorine can be present in drinking water while still benign designated as safe for consumption. Currently, the MRDL is under 4 parts per million (ppm). However, to determine the exact level of chlorination present in your specific water source, it is recommended to check the most up to date water quality report published by your community water supplier.

How much fluoride is in tap water?

As of 2015, the U.S. government has lowered the recommended fluoride level to 0.7 milligrams of fluoride per liter of water to prevent tooth enamel staining.

How to make tap water taste better?

Filtering your tap water and adding flavors such as lemon or lime are the most effective means for removing any bitter or unsavory tastes in tap water.

What chemicals are in tap water?

Dependent on your region, tap water can contain aluminum, ammonia, arsenic, barium, cadmium, chloramine, chromium, copper, fluoride, various bacteria, and viruses, lead, nitrates, mercury, perchlorate, radium, selenium, silver, and uranium.

How to test your tap water?

There is currently on the market a variety of in-home tap water testing kits available for public use. County health departments can assist in testing for bacteria and nitrates in many instances. If county health assistance is not available, you can have your water tested in a state-certified laboratory.

Why is tap water better than bottled water?

Drinking reusable water from the tap is considerably better for the environment as it results in a substantial reduction in harmful plastic. Also, tap water can be filtered to remove the many impurities and chemicals present in tap water and tap water does not contain BPA chemical leaching that is present in bottled water consumption.

How to remove microplastics from tap water?

Microplastics can be removed from tap water by avoiding plastic water bottles and by utilizing water filters to remove the volumes of microplastics present in tap water.

Why does tap water taste bad?

Tap water tastes different than bottled water because it undergoes a different filtering and treatment process. Dependent on how the water is treated in your region, various chemicals may be present in your water which can lead to an undesirable taste and smell.

How to filter tap water?

Tap water can be filtered by boiling or by utilizing iodine solution and tables. However, the most effective way of filtering tap water is by purchasing either an in-house filtration system or a portable filter such as the GOPure Pod.

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