While most Americans are granted the fundamental human right of access to clean water, it’s far from a reality for many towns and cities across the country. But even those with purportedly safe drinking water could be consuming measurable quantities of potentially life-threatening contaminants.

The water crisis in Flint, the arsenic issue in Los Angeles, and the radium problem in Texas might be on the extreme side of the spectrum, but they are telling of a far more widespread and looming concern. The one million miles of pipes that bring us our drinking water today were laid sometime in the early to mid-1900s.

Consequently, they’re outdated and no longer capable of safely serving their purpose. Challenges like external contamination and droughts further complicate the problem, one that the Environmental Protection Agency estimates will cost nearly $400 billion to fix.

But what exactly do we have to watch out for? Here are four contaminants that might be lurking in your tap water.


Described by the Water Quality Association as a colorless, water-soluble gaseous compound, ammonia is commonly used in fertilizer, cleaning products, and manufacturing. It exists in our water supply to prolong the lifespan of chlorine. While safe in small amounts, ammonia can cause poisoning when consumed in higher quantities.


Arsenic is a chemical element that occurs naturally below ground. High levels have been found in drinking water worldwide, including the U.S. This is largely due to industrial and agricultural activities that cause the chemical to spread rapidly. Long-term exposure to tap water contaminated with arsenic can lead to a range of health problems.

This includes skin cancer, stomach pain, nausea, vomiting, paralysis and blindness among numerous other issues. A testing kit can be used to determine the arsenic levels in your home.

Parasitic Cysts

This category of contaminants includes the intestinal parasites cryptosporidium and giardia. They are commonly found in drinking water that hasn’t been properly treated. Giardia cysts are extremely small, as are cryptosporidium. Despite that, they can wreak havoc on the human body, entering the intestine and multiplying by the millions.

When that happens, the development of symptoms such as diarrhea, weight loss, dehydration, pain and fever begins. Medical treatment can usually rid the body of these parasites.

E. Coli

Unbeknownst to most, some forms of E.Coli are actually harmless and essential to the digestive system. But there are other forms that can cause a range of illnesses, including pneumonia, urinary tract infections, diarrhea and more. These microorganisms make their way into our tap water through streams, lakes, and groundwater.

If the water source goes untreated, E.Coli can make their way into your tap and eventually, your digestive system.


This list is by no means extensive, and there could be countless more contaminants in your local water system, waiting to build up in large enough quantities to cause harm. That said, it’s not a major cause for concern, as an affordable filtration system can be installed to ensure that no contaminants enter your body through your tap water.