List of Tap Water Contaminants and How to remove them?

Water is the elixir of life. Nothing quenches thirst like water does. Unfortunately, clean water is not available for everyone on the planet. As per the World Health Organization’s statistics in 2019, 785 million people do not have access to a basic drinking water service. 2 billion people worldwide utilize water from a source contaminated with waste matter.

Drinking water can be obtained from two sources; surface water (rivers, lakes, and reservoirs) and groundwater. The water can collect multiple contaminants during its journey towards your household. The Environmental Protection Agency (EPA) and the Food and Drug Administration (FDA) are the regulatory bodies to ensure safe drinking water. The EPA is more concerned with tap water, whereas the FDA supervises bottled water. The tap water obtained from public water systems, undergoes treatment based on the EPA health standards, to ensure removal of contaminants before reaching your home. In this article, we will discuss the common contaminants found in water, their harmful effects, and how you can protect yourself from its dangers.

Common Contaminants in Tap Water

Tap water is treated for more than 90 contaminants that can be found in water. Broad-spectrum water contaminants are listed below:


Tap water contaminants

All microscopic organisms are not harmful. Some are beneficial, while some can be extremely dangerous. These tiny fellows include viruses, bacteria, parasites, protozoan, E. coli, Giardia, Cryptosporidium, and other microorganisms. Microbial contaminants can cause severe gastrointestinal problems, particularly in children. Their immune systems are not as developed as those of adults. Harmful microorganisms can also cause typhoid, diarrhea, cholera, polio, and dysentery. Diarrhea alone causes 485,000 estimated deaths every year, as a result of contaminated water. To eliminate these microbes, water can be disinfected with chemicals such as chlorine, ozone, and iodine. Ultrafiltration or UV light filtration can also be used to kill harmful germs. These methods get rid of about 99% harmful microbial contaminants.

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Aluminum can also get mixed with the water from rocks and soil. Based on the research provided by the Water Quality Association, Aluminum is present in ranges from 0.1 ppm to 8.0 ppm in groundwater. The World Health Organization (WHO) and the EPA recommended level of aluminum is below 0.2 ppm. Some Aluminum salts can be beneficial in coagulation. Reverse osmosis can be an effective method to treat high Aluminum content in water.


Ammonia does not pose a threat to humans, but it is widely known as a toxin for aquatic bodies. Ammonia has been used for chlorine water disinfection processes to increase chlorine’s effectiveness and prevent carcinogenic chlorine by-products from materializing. Although, adding ammonia may also result in the formation of chloramines, which give a bad taste to water. Ion exchange using zeolite can be used to diminish the ammonia effect in the water.


Chlorine is a widely known chemical used to disinfect water from disease-causing microorganisms. However, chlorine can react with the organic substances present in water and develops by-products. This can lead to the formation of trihalomethanes (THMs), haloacetic acids (HAAs), and chloroform. These substances can increase the likelihood of cancer, kidney, and reproductive issues. According to the Water Quality Association (WQA), one in five people uses water infected with chloramines. In the U.S, 2-17% of bladder cancers are caused by THMs every year. Activated Carbon can be used to breakdown chloramines into harmless components.


Arsenic is found naturally in the earth’s crust. Arsenic can seep into the main water supply as a result of erosion or human activity. Industrial and agriculture residue consisting of arsenic-based pesticides, wood preservatives, animal feed, and petroleum waste contribute to arsenic contamination in water. Arsenic is hard to detect in water since it lacks color and taste, but it is highly toxic for humans. Even 100 milligrams of the contaminant can cause poisoning. Prolonged arsenic usage can cause cancer of lungs, kidneys, skin, liver, lungs, nasal passages, and prostate. You may have to contact the local water community to know if arsenic has mixed with your water. You can also visit the Natural Resources Defense Council (NRDC) website to discover traces of arsenic in your region. Treatment methods include iron oxide/hydroxides, activated alumina, anion exchange, and reverse osmosis.


Lead is another dangerous water contaminant that can seep into the water supply through the plumbing system. Before 1986, lead was used in the construction of pipes but was banned later on due to its hazardous health effects. Unfortunately, the ban did not mean that the pipes constructed from the lead material magically became harmless. The households that were built with lead plumbing systems may have lead-contaminated water running through the taps. The water can corrode the pipes, and bits of lead can leach into the water. Lead can cause severe health complications to the nervous system, stomach, brain, kidneys, and bone marrow. Children absorb more lead than adults and, therefore, can be at a higher risk. They may show signs of reduced hearing, growth, and intelligence. Reverse osmosis can prevent lead and remove its particles by about 95% from the water.


The human body needs copper in adequate amounts. However, too much copper can become harmful. Your body cannot develop copper on its own and, therefore, needs it externally. The Water Quality Association (WQA) states that the average human adult needs 2mg of copper per day. However, ingestion of large amounts can cause copper poisoning leading to kidney failure, anemia, and liver problems. If your pipes have turned a bluish shade, it may indicate that the water is corroding the pipes and absorbing copper. Cat-ion exchange and reverse osmosis are the recommended treatments for copper.


Municipal water treatment plants add about one milligram per liter of fluoride in the water to prevent tooth decay. The Safe Drinking Water Act compliance requires public water systems to remove excess fluoride from the water. According to research, elevated levels of fluoride can lead to decreased IQ in children. They may develop permanently discolored teeth. Prolonged use of fluoride can cause bone disorders. To prevent fluoride problems, you can use a strong base anion exchange or reverse osmosis.


Iron is found abundantly on the earth and makes up 5% of the earth’s crust. It is not dangerous to health and helps in the delivery of oxygen throughout the body. Rainwater flows through the ground, can dissolve iron in it, and seep into drinking water. Iron can also seep into drinking water from the corrosion of steel or iron pipes. However, an amount of even 0.3 mg/L can give a rusty color to water. It can also alter the taste of water and leave dark stains on the laundry. Treatment can be done with aeration, iron removal filters, and reverse osmosis.


Chromium, specifically, chromium-6, is a cancerous chemical found naturally but can also seep into drinking water in the form of industrial waste. According to the Environmental Working Group (EWG),  has been associated with an increased risk of stomach cancers and liver damage. Even low concentrations can increase cancer threat. Based on EPA’s national survey, more than half of Americans use water contaminated with chromium-6. Reverse Osmosis and Ion Exchange method can be used to treat the contaminant.


Barium is an alkaline metal found naturally in mineral deposits. It is used in the manufacture of electronic parts, glass, ceramics, dyes, bleaches, and fireworks. It can end up in the main water supply in the form of automobiles, drilling, and industrial discharge. Water-insoluble barium is generally harmless and used in medicinal areas. However, ingesting large amounts of water that has dissolved barium can become a health hazard even in a short duration. Various health conditions such as damage to heart, liver, kidneys, spleen can occur. These problems may lead to blood pressure issues, muscle weakening, brain swelling, and stomach disorders. Barium contaminated water can be made safe for consumption through cat-ion exchange and reverse osmosis.


Cadmium can be found in copper, lead, zinc, coals, and fossil fuels. Volcanic activity can also produce cadmium. Artificially, leaching of the plumbing system, industrial and fertilizer waste, and landfills can contribute to cadmium contamination in water. Some leafy vegetables have cadmium in them and can offer 0.05 to 0.12 mg cadmium/kg. EPA has set the limit for cadmium as 0.005 mg/L in drinking water. Higher concentrations can cause kidney failure, stomach problems, liver damage, salivation, muscle and sensory issues, and convulsions. If it increases the risk of cancer, it is not evidenced and has yet to be determined. Acid cation resin and reverse osmosis can help eliminate the cadmium content in water.


Manganese is a naturally occurring compound that can leach into drinking water from rocks and soil. Human intrusion can also cause manganese to enter drinking water. Manganese is considered safe at low concentrations. It becomes dangerous to the nervous system if consumed too much for long durations. Although there is no confirmation as of now, manganese is considered to affect memory, behavior, motor skills, and intellectual level in children. As per EPA guidelines, manganese is not regulated under health-based standards. However, public water systems are advised to manage manganese levels to avoid any bad odor, taste, or color.


Waste material from agriculture, fertilizers, sewage, septic tanks, and animal manure can cause nitrate contamination in water. The EPA has labeled 10 parts per million as the limit for nitrates. Excess levels can be hazardous for babies and pregnant women. In severe cases, it can be life-threatening for infants who may develop the blue baby syndrome, a condition in which blood is unable to circulate oxygen throughout the body. Nitrate contamination has been considered to cause thyroid issues, neurodevelopmental impairments, and complications in pregnancies. Wells located near septic tanks, and agricultural areas are more prone to nitrate contamination. Treatment methods include chemical reduction, reverse osmosis, ion exchange, and electrodialysis.


Water contaminant

Mercury can be found in the earth as a natural metal. Mercury can enter the atmosphere as a result of industrial waste and fossil fuels burning. From the atmosphere, it can enter oceans and ultimately seeps into rivers and lakes. Mercury is considered dangerous when it is present in the water in excess amounts. Consuming fish that has been contaminated with mercury can cause mercury poisoning. Its vapor form is more lethal and can easily reach the brain in high concentrations. Based on the research, severe and prolonged exposure to mercury can harm the brain and kidneys. It can cause memory, vision, and auditory problems.  Reverse osmosis and activated carbon filtration can be used to remove mercury from water.


Perchlorate is found in both natural and artificial forms. As an oxidizer, it is used to make fireworks, explosives, road flares, and rocket fuel. The soil and water in areas where the manufacturing and storage of these products did take place have become contaminated. Perchlorate can negatively affect the thyroid gland and impede the development and learning of children. Perchlorate concentration increases in the water supply over the years, and the contamination has reached almost 45 states. Perchlorate can be treated with anion exchange and reverse osmosis.


Agricultural pesticides can seep in the groundwater through old wells. In agricultural areas, it can enter into the main water supply along with the crops wastage. Growing usage of pesticides, particularly glyphosate to rid of weeds, has led to an increased risk of pesticide contamination. Atrazine and glyphosate are widely used as pesticides. Glyphosate has been associated with reproduction problems. However, no concrete proof has been found about its adverse effects on human health. NRDC has deemed it harmful and asked the government to prevent its further usage. If you live near an agricultural area and suspect that agricultural waste has seeped into the main water supply, contact your local water community. Reverse osmosis is a reliable method to remove pesticides.


Pharmaceuticals have no EPA standards for potential water contamination. Over time, small concentrations of pharmaceuticals have been detected in the water. These can include cosmetics, fragrances, prescription, and over the counter medicines. Pharmaceuticals can enter into drinking water due to human activities, hospital waste, and manufacturing discharge. The effects of prolonged consumption of pharmaceutical contamination are not entirely known at present.

Radioactive Substances

Radioactive elements can contaminate drinking water as a result of energy and nuclear plant leakage or wastage. However, they can also seep into the water through natural resources. These can include cesium, radon, uranium, and plutonium. Radioactive material can increase the risk of cancer and kidney failure. Reverse osmosis and ion exchange can be effective water treatment methods for radioactive contamination.

How to Remove Contaminants in Water

It is essential to know whether the contamination is because of the plumbing system or the main water supply. Particularly, if you own a private well, you might want to get the water tested for contaminants.

how to test water at home

One way to test your water for the pollutants is to use home-based test water kits. You can also send a sample to licensed water testing laboratories to find the source of the water problem. If many people in the vicinity are also facing issues with the taste or odor of water, you should contact your local water municipality ASAP. There may be a more alarming issue with the water. The local water body can provide you with a Water Quality Report listing the constituents of water. Knowing the water composition can help you better to find a solution to your water problem. Water filtration companies can also analyze your water for you and suggest a suitable filtration system.

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