Water Contaminants: What's in Your Water?

Water Contaminants: What's in Your Water?

Common Water Contaminants

Ken, the eComfort Product Expert
Product Expert

Previously, you learned where your home's water comes from and how it's treated. However, just because it's treated, doesn't mean it's purified.


There are many different types of contaminants in water. Some of these are beneficial up to a certain point. Others are dangerous even in small amounts. Understanding what the main contaminants are and how to test your tap water for them is important for protecting yourself and your family.


What Are Water Contaminants?

Although water (H2O) typically looks the same from a distance, there is always more floating around in it than just hydrogen and oxygen molecules. There’s a good reason why municipalities take great pains to clean and filter water before sending it to your home, sometimes moving it through five or six levels of purification.


Dirty WaterTo a certain extent, contaminants in water are a good thing. Drinking 100% pure water (only found in the lab) would actually be bad for you because it would sap electrolytes from your body. Water contaminants are not only what give water its taste, but also its nutritional value.


However, many natural and artificial drinking water contaminants pose a major health risk, which is why water quality is important. Ironically, after the water treatment center purifies your water, some of the cleaning additives remain in the water and form new contaminants that can make it into your tap.


Furthermore, after you use the water in your home, it goes down the drain and enters the sewage system. Eventually, some of that water makes it back to the water source (after leaving the sewage treatment plant) and reenters the water supply process.


So, just because you are on treated city water, doesn't mean it's clean or healthy for you!


The U.S. Environmental Protection Agency classifies water contaminants into four categories:

  • Physical contaminants are anything you can see or touch in the water. Sediments, leaves, sewage, and plastic are all examples of physical objects contaminating the water.
  • Chemical contaminants refer to natural or man-made elements or compounds like bleach, arsenic, and chlorine.
  • Biological contaminants are living things in the water like bacteria, viruses, and parasites.
  • Radiological contaminants are unstable elements that give off radiation such as uranium and radium.

All water will have some combination of these contaminants. Ultimately, figuring out the safety of the water you use to drink, shower, and brush your teeth with is your responsibility.


Common Contaminants in Water

There are many different types of specific contaminants in drinking water. The following are some of the most common.


Water Contaminant Type   Description Maximum Allowable Levels
Lead Chemical
A dangerous heavy metal from old pipes and plumbing. Impairs development in children. 0.015 mg/L
Chlorine Chemical   Used in the water treatment process. Can form cancer-causing haloacetic acids. 4.0 mg/L
Chromium Chemical 
Occurs both naturally and as an industrial byproduct. Linked to cancer. 0.1 mg/L
Bacteria/Viruses Chemical    Many different types can exist in water, including salmonella, e.coli, and legionella. Varies
Iron Chemical     A mineral that stains dishes and clothes, creates soap scum, and spoils the taste of water. May cause stomach problems.  0.3 mg/L
Sulfur  Chemical   Causes a strong "rotten egg" smell in the water.  NA
Arsenic Chemical    Found in rocks and soil. Can seep into well water. Extremely toxic and linked to cancer. 0.010 mg/L
Radium  Radiological   A radioactive element that occurs both naturally and as an industrial byproduct. Linked to cancer. 5 pCi/L
Nitrate Chemical     Found in natural sources, agricultural fertilizers and discharges from wastewater treatment plants. Linked to cancer. 10 mg/L
Copper Chemical    Enters the water from pipes and plumbing. Can cause liver and kidney problems. 1.3 mg/L
Manganese Chemical    A naturally-occurring element that is linked to behavioral and developmental problems in large dosages. 0.05 mg/l 

Volatile Organic


Chemical    A broad range of chemicals used in industrial applications. Linked to cancer and other illnesses. Varies


Other Types of Water Contaminants

Besides these, there are other specific drinking water contaminants that have impacted the population. Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) are toxic chemicals used for decades in American consumer goods like non-stick coatings such as Teflon. According to the Natural Resources Defense Council, they can be found in the bodies of 99% of Americans, and drinking water is one way they got there.


Recently, researchers also found high levels of antibiotics in hundreds of the world's rivers, most likely from people flushing medications down the drain. This has helped give rise to increasingly antibiotic-resistant superbugs.


Microplastics are another problem. A recent study by Orb Media tested bottled water from around the world and found that 93 percent of it contained some form of plastic, including nylon and polypropylene. 


What is Water Hardness?

Water hardness refers to the buildup of dissolved calcium and magnesium in the water. Although not necessarily as dangerous as the contaminants listed above, high water hardness can have a number of unpleasant and costly consequences.


For one, hard water makes it tougher to get yourself, your clothing, and your dishes clean because the calcium reacts with the soap to impede lather. You may have noticed this when you wash your hair but are unable to get that thick, bubbly feeling. As a result, you must use more soap to get the job done.

 Hard Water MapWater Hardness Map courtesy of the U.S. Geological Survey


Hard water can also cause scale deposits in your piping and appliances. Water heaters are particularly impacted by hard water, but your coffee maker can also clog up after repeated use. To remove hardness, you need a water softener.


Whether or not you have hard water or any of the water contaminants listed above depends on geography, the industry in your area, and your water and wastewater treatment process.


Private well water is untreated and could contain any of these contaminants. Even municipal water can contain them, despite being treated. In most cases, the water treatment process adds chemicals like chlorine to help purify the water, which can make it to your tap.


Even if the water is clean before it enters your home, it can attract chemicals in your plumbing, such as copper, iron, and even lead. That's why it's wise to learn what's in your water and, ideally, test it yourself.



How to Test Your Water Quality

If you get your water from a private well instead of a municipal system, you will not receive a water quality report. Even if you do get municipal water, your home's water quality may differ depending on the contaminants in your piping.


Water Test KitUnder these circumstances, you will need to test your own water. There are a variety of low-cost kits you can purchase to test your water quality at home. They include strips that change color in the presence of certain contaminants.


For example, some strips test for pH, which is a measure of how acidic a liquid is. A pH level of 7 represents neutral water. Any number lower than 7 indicates acidity, which can mean the presence of certain contaminants. A pH that is higher than 7 indicates alkaline water, which some experts believe has health benefits. 


Other home tests kits can measure hardness, iron, copper, lead, nitrate, chlorine, and more. Some can even detect bacteria such as e. coli. However, these tests aren't always completely accurate, and they won't tell you how much of a contaminant is present. They are an inexpensive way to figure out if you have a problem.


If your water comes back positive for any of these contaminants, you may consider hiring a certified laboratory to do a detailed analysis of your water. For well water testing, you should hire a lab from the start to be safe. These professionals will provide an accurate, detailed report of what's in your water, although they are much more expensive than home test kits.


Once you've identified what's in your water, you can decide what to do about it. If your water is clean, good for you! If not, it's time to start considering water filtration options.


arrow NEXT: How to Filter Water at Home


Ken, the eComfort Product Expert
Product Expert
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