Whether it is municipally treated or from a private well, your water has no guarantee that it is safe to drink.
After treated water leaves the water treatment plant, the water will carry up various contaminants along the way before reaching your home.
Water from a private well contains even more contaminants.
So how do you know whether your water is safe to drink?
While some contaminants will change the appearance, taste, or smell of water, which is easier to detect, some pollutants are not visible to human eyes, have no taste and no smell, which is hard to detect.
If you live near agricultural areas, your water is more likely to contain pesticides, herbicides, and chemicals from fertilizers.
These chemical contaminants can bring harmful effects to our eyes, kidney, liver, and other body functions and increase the risk of reproductive problems and cancer.
The most effective way to ensure your water is safe to drink is to install a water filtration system or/and water softener that remove what is in your water.
What Are The Common Water Contaminants?

Here is the list of contaminants that may exist in our water:
- Chlorine
- Chloramine
- Sediments
- Lead
- Mercury
- Arsenic
- Iron (ferrous and ferric)
- Hydrogen sulfide
- Manganese
- Pharmaceuticals
- Nitrates
- Microbiological
Categories of Drinking Water Contaminants
Contaminants refer to any other substances in water other than water molecules, including chemical, physical, biological, and radiological substances.
Drinking water is expected to contain at least small amounts of contaminants.
Some contaminants in water may cause harmful effects to humans when taken in a certain amount, either acute or chronic, and some are harmless or even beneficial.
Therefore, drinking water that contains contaminants does not mean it is unsafe to drink. The more important thing is what types of pollutants are in the water.
There are four general categories of contaminants in drinking water:
- Physical
- Chemical
- Biological
- Radiological
Physical Contaminants in Drinking Water
Physical contaminants are substances that may affect the water’s physical property or/and appearance. They can be seen, held, or touched.
Any substances in water that are not purely chemical and not purely microbiological can be categorized as physical contaminants.
Therefore, physical contaminants can be made from chemicals or have harmful microbes due to animals dying in the river.
Physical contaminants can occur naturally in water sources like rivers, lakes, streams, and water.
Examples of Physical Contaminants
- Sediments: soil, sand, dirt
- Organic substance: algae
How to Remove Physical Contaminants from Drinking Water
The most efficient way to remove physical contaminants is through a sediment filter.
Whereas for organic substances like algae, the best way is to use an activated carbon filter.
Chemical Contaminants in Drinking Water
Chemical contaminants are compounds or elements in water that occur naturally or are artificial.
Examples of Chemical Contaminants
- Chlorine
- Chloramine
- Pesticides
- Herbicides
- Toxins
- Metals – lead, mercury, arsenic, copper, chromium, cadmium, nickel.
- Bleach
- Nitrogen
Metal pollution in water is primarily due to mining activities. Long term ingestion can lead to harmful effects on the human body.
How to Remove Chemical Contaminants from Drinking Water
You may use an activated carbon filter or granular activated carbon (GAC) filter to remove chemical contaminants. They are effective, inexpensive, and easy to get.
Biological Contaminants in Drinking Water
Biological contaminants are microbes or organisms in the water. They are harmful and can cause serious illness to the human body.
Examples of Biological Contaminants
- Bacteria – E. coli, Giardia, Cryptosporidium
- Viruses
- Parasites
- Protozoa
How to Remove Biological Contaminants from Drinking Water
The most effective way to remove all biological contaminants is using ultraviolet (UV) light.
For the best effectiveness, the UV filter needs to be used in conjunction with other types of water filters to first remove other contaminants that can scatter the UV ray before reaching the UV filter.
Reverse Osmosis is also an effective filtration technolog98765y that can remove most biological contaminants in water.
Ultrafiltration (UF) is good against biological contaminants of a larger size, such as bacteria.
Radiological Contaminants in Drinking Water
Radiological contaminants are unstable atoms that can emit ionizing radiation. They are chemical elements that have an unbalanced number of protons and neutrons.
Examples of Radiological Contaminants
- Uranium
- Plutonium
- Cesium
Types of Water Contaminants: Effects & How to Remove Them
Sediment
Is your water cloudy? Then your water is likely to contain sediments.
Sediments are inorganic matters or compounds, such as dirt, sand, and silt. They can enter our private well or municipally treated water by runoff.
If you do not get rid of the sediments in your water, they can build up over time, reduce water pressure, and eventually clog the pipes, drains, and water fixtures.
Larger sediments can also damage your water-using appliances and clothes.
How to Remove Sediments from Water
It is easy and inexpensive to remove sediments from water. Just install a sediment filter near the water entrance.
There are mainly two types of sediment filters, flushable and one-time use. You can learn more about the best sediment filter here.
Chlorine & Chloramines
Chlorine is a chemical that has a distinct smell and taste. It is commonly found in municipally treated water and swimming pool water. Many commercial cleaning products also contain chlorine.
Chlorine is a cost-effective solution to kill harmful microorganisms in water and is often used as a disinfectant to treat water on a mass scale.
Some countries or cities use chloramines to treat public water, a disinfectant made of chlorine and ammonia.
While chlorine and chloramines are harmless to humans at an appropriate level, their unpleasant smell and taste turn many people away from drinking the water. These chemicals may also irritate your skin and eyes.
How to Remove Chlorine and Chloramines from Water
The most effective way to remove chlorine or chloramines from water is to use an activated carbon filter.
An activated carbon filter can also remove other chemical contaminants and unpleasant smells and tastes in water.
Iron
Iron is one of the common contaminants found in water as it is widely available on the earth.
In water’s natural cycle, it picks up iron contaminants when it flows over iron-bearing rocks.
There are two types of iron contaminants:
- Ferrous iron (clear-water iron)
- Ferric iron (red-water iron)
Ferrous iron is also known as clear-water iron, and it’s soluble, completely dissolved, and colorless.
The water containing ferrous iron is clear, so you won’t notice it when the water is coming out from the faucet.
However, when the ferrous iron is exposed to air, it will oxidize into the ferric form of iron, a reddish-brown substance that will not dissolve in water, and the water will become cloudy.
Ferric iron is also known as red-water iron, as it will make your water looks yellowish-red right after coming out from the faucet.
How to Know if My Water Contains Iron?
If your water has a metallic smell and taste, it probably contains iron.
If you found rust-like reddish stains on your water fixtures, drains, bathroom floors, or water-using appliances, then most likely there is iron in your water.
Effect of Iron Contaminants in Water
Iron can clog pipes, showerheads, and faucets and stain your water fixtures, bathroom floors, and water-using appliances.
How to Remove Iron Contaminants from Water
You can use an iron removal filter, water softener, or oxidizing filter to remove iron.
Manganese
Manganese occurs naturally in rocks and soils, and it is one of the culprits for hard water. Well water is more likely to contain a higher manganese concentration than city water.
Manganese is beneficial to the human body, but it is a micromineral, which mean our human body only needs a small amount of it and consuming a large amount can bring negative effect to the human body.
The manganese concentration in water is measured in parts per million (ppm).
How to Know If My Water Contains Manganese?
Water containing manganese more than 0.5 ppm may taste metallic and leave brownish stains on your bathroom floor, kitchen sink, water-using appliances, and water fixtures.
A high concentration of manganese will also discolor your water.
How to Remove Manganese from Water?
A water softener is one of the effective ways to remove manganese from the water via an ion exchange process.
If you are using well water, venting air into the water helps reduce manganese as the air bubbles cause manganese to react with oxygen and turn into manganese dioxide, which is insoluble in water, and then remove it via mechanical filtration.
You may also use chlorine dioxide to oxidize the manganese quicker into manganese dioxide. The process is known as chemical oxidation.
Hydrogen Sulfide
Did your water smell like rotten eggs? If yes, then it is likely due to hydrogen sulfide.
The hydrogen sulfide gas comes naturally from decaying organic matter, such as dead animals and plants. It is released once the hydrogen sulfide reaches the liquid state.
Hydrogen sulfide can also come from petroleum products.
Effects of Hydrogen Sulfide in Water
A high concentration of hydrogen sulfide in water (> 0.5 ppm) may corrode steel, brass, and copper fixtures, produce an unpleasant odor, and stain or discolor copperware, silverware, brassware, laundry, and bathroom fixtures.
How to Remove Hydrogen Sulfide from Water?
The hydrogen sulfide can be removed through catalytic carbon filtration, ion exchange, aeration, oxidizing filter, activated carbon filter (for concentration less than 1 mg/L), and chlorination plus filtration.
Lead
Lead contamination is dangerous as lead is a toxic metal that damages our immune system and may cause adverse health effects such as insomnia, loss of appetite, hearing loss, organ failure, and neurological damage.
Besides, intake of lead-contaminated water may slow down childhood development during children’s first six years.
The national plumbing safety codes banned lead piping in 1986 due to the dangers of lead contamination.
How to Know If Your Water Contain Lead
Your water may taste metallic when contaminated by lead. However, the taste may be not significant to notice.
Therefore, the most accurate way is to send the water sample to a certified lab for testing.
How to Remove Lead from Water
The two recommended ways to remove lead from water are Reverse Osmosis (RO) and distillation. The former is more efficient, faster and can remove more than 99% of lead in water.
Arsenic
Arsenic is a tasteless and odorless chemical that is dangerous to humans.
It’s a human carcinogen and could be fatal.
Arsenic exists in air, soil, animals, and plants naturally.
It’s used in drugs, cleaning products, metals, and semiconductors.
Most industrial arsenic is found in wood preservatives.
Arsenic contamination is regularly monitored in water treatment plants, but it is not the case for a private well. So, to know whether your water is contaminated by arsenic, you may send the water sample to a certified lab for testing.
How to Remove Arsenic from Water
There are a few ways to remove arsenic, such as adding coagulants to water, oxidation method, distillation, ion-exchange, adsorptive media, and membrane filtration.
Adsorptive media like activated alumina and membrane filtration like Reverse Osmosis systems are more efficient and cost-effective methods to remove arsenic from water.
Nitrates
Nitrates are commonly used in fertilizers to help recover and replenish the soil after the crop-growing season. They are great for plants but toxic for humans.
Nitrates water contamination is often due to irrigated water containing fertilizer that causes nitrates runoff from agricultural lands and enters our water supply. It is more often in areas near agricultural lands and farms.
Nitrates can adversely affect humans, including reproductive system problems, organ failure, and delayed child development.
How to Remove Nitrates from Water
Nitrates can be removed from water using water treatment systems like Reverse Osmosis (RO), distillation, and ion exchange.
Fluoride
Fluoride is a natural mineral that exists in rock and soils.
Fluoride is commonly added to public drinking water supplies ranging from 0.7 to 1.2 mg/L to prevent tooth decay. The U.S. Department of Health & Human Services recommends an optimal level of 0.7 mg/L of fluoride to prevent tooth decay while minimizing the probability of getting dental fluorosis.
Potential Health Effects of Fluoride
Consuming a high level of fluoride (> 4 mg/L) for an extended period may result in skeletal fluorosis, a severe bone disorder.
It may also cause discoloration of teeth in children under nine years old if consumed for an extended period at a level of more than 2 mg/L.
To prevent the potential health effects of fluoride, keep it at the level below 2 mg/L in drinking water, which is also the secondary maximum contaminants level advised by the U.S. Department of Health & Human Services.
How to Remove Fluoride from Water
Some effective treatment methods against fluoride are Reverse Osmosis, activated alumina, anion exchange, adsorption media, and distillation.
The most common and effective way to reduce fluoride for households is using a fluoride removal filter or point-of-use (POU) Reverse Osmosis system.
Selenium
Selenium is a mineral that is beneficial to humans when ingested in small quantities (around 0.2 mg/day) and may cause selenium toxicity if ingested at 0.7 to 7.0 mg per day.
The Maximum Contaminants Level (MCL) set by USEPA is 0.05 mg/L.
Potential Health Effects of Selenium
EPA has found that exposure to selenium at levels above the MCL may damage the peripheral nervous system, cause hair and fingernail changes, fatigue, and irritability.
Long-term exposure to selenium can damage kidney and liver tissue, cause hair and fingernail loss, and affect nervous and circulatory systems.
How to Remove Selenium from Water
Some of the treatment methods against selenium are distillation (> 98% reduction), Reverse Osmosis (> 90% reduction), activated alumina adsorption (85-95% reduction), and ion-exchange (60-95% reduction).
PHARMACEUTICALS
Pharmaceutical contamination is partly due to improperly disposing of medication.
While pharmaceutical contamination is not directly linked to health risks, drug contaminants could interact with a person’s medicine and result in adverse effects.
Having a sound water filtration system at home can prevent potential harm from pharmaceutical contamination.
How to Remove Pharmaceuticals from Water
The pharmaceuticals can be removed from water by using activated carbon filtration, Reverse Osmosis, and advanced oxidation.
Microbes
Microbes are microorganisms like bacteria, viruses, and cysts.
Microbiological contaminants in water sources are due to the decomposition of organic matter such as waste and dead animals and plants.
Ingesting harmful microbes like E. Coli, Giardia, and Cryptosporidium can cause gastrointestinal problems and other illnesses.
How to Remove Microbes from Water
If you are using municipally treated water, the microbiological contaminants are eliminated in water treatment plants with a disinfectant like chlorine or chloramines before reaching your home.
If you are using private well water, you may remove these microbes using a water treatment system like ultraviolet (UV) filter, Reverse Osmosis, ultrafiltration, and distillation.
Most microbes are not visible to the eyes and with no taste and smell. Some microbes, like algae, may cause your water to smell fishy.
If you want to know whether your water contains microbiological contaminants, you will need to send your water sample to the lab for testing. Alternatively, install a water filtration system that can eliminate the microbes.
Hardness Minerals (Hard Water)
Hard water contains an excess amount of hardness minerals such as calcium and magnesium.
Hard water can be due to naturally carrying up hardness minerals when traveling to your home from the water treatment plant.
If you are using a private well, the hardness minerals can exist naturally in your well water.
How to Know If You Have Hard Water
- There are white deposits (limescale buildup) on your bathroom floor, water appliances, and water fixtures (pipes, faucet).
- You feel something sticky or slimy on your skin or hair after a shower.
- Lower soap lathering.
- Your skin is dry and itchy.
- Your hair is dry and dull.
- Duller clothes.
- Low water pressure.
- Higher energy bills as limescale buildup will decrease appliances’ heating efficiency.
How to Solve Hard Water Issue
The most effective way to solve the hard water issue is to install a water softener at your home.
There are two types of water softeners: salt-based and salt-free.
A salt-based water softener uses ion-exchange technology to remove hardness minerals by exchanging sodium ions with the calcium and magnesium ions in water.
A salt-free water softener (also known as a water conditioner) uses templated-assisted crystallization (TAC) or electromagnetic waves to condition the hardness minerals to prevent them from sticking on the surfaces to form limescale.
Effects of Waterborne Contaminants on Health
Waterborne contaminants can cause two types of effects to your health,
There are two types of impact waterborne contaminants can cause to your health: acute and chronic effects.
Acute effects are temporary and occur within hours or days after a person consumes a high level of contaminant such as microbes.
The acute effect can be dangerous and cause illnesses like diarrhea, vomit, and fever, or even death if serious. Contaminants like microbes can
Chronic effects are long-term and occur after consuming a contaminant at a high level for an extended period. Some of the chronic effects on health are cancer, liver problem, kidney malfunction, reproductive problems.
Conclusion
Contaminants always exist in our water, but fortunately, we have access to water treatment systems that can handle most of them (if not all) to provide our families with a clean water supply.
Therefore, make sure you know what kind of contaminants is in your water or can potentially exist so that you can install the right water treatment systems to deal with them before they could harm your families.
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