Is there bacteria in my tap or well water?

May 21, 2024 3 min read

Is there bacteria in my tap or well water?

With the exception of extreme cases, people tend to trust their water. Everyday, people shower, brush their teeth, and cook with water coming straight out of the faucet. Some people will filter their water before drinking it while others drink straight from the tap. Others in more rural areas draw their water from a private well, drinking straight from the source. These practices are commonplace, but is the water we interact with everyday safe?

What is in my water?

Federal and state laws enforce water quality standards that filter out many harmful contaminants and chemicals from our water. However, tap water is not sterile. This means that during the filtration process, a small number of germs can still get into the water. According to the CDC, “These germs can grow and multiply in the pipes inside a home or building if the conditions are right” (1). For example, if water sits in the pipes for a long period of time, the environment is ideal for germs to grow.

Well water, similarly, can harbor many germs due to its exposure to the environment. Damage to the well can make it susceptible to surface contamination, including debris, fertilizers, or animal feces (2). Any of these contaminants can increase germ activity in the water. 


Often, bacteria get into a groundwater supply due to one of the following: feces from infected people or animals enters the water supply from sewage overflows or broken sewage systems, storm water runoff, or agricultural runoff (4). Campylobacter, Salmonella, and Shigella are all bacteria that enter the water supply for these reasons. Ingesting these bacteria, even in small amounts, can result in diarrhea, fever, stomach pain, and stomach cramps. 

Some bacteria are found in nature but can still prove harmful to humans. Legionella, for example, can be found naturally in lakes and streams, but it can find its way into under-maintained water systems. Symptoms of consuming Legionella include coughing, fever, muscle aches, and headaches (4). 

Lastly, E. coli is a bacteria commonly caused by cattle farms, since E. coli lives in the intestines of cattle. It can cause severe stomach cramps, diarrhea, and vomiting (4). 


The most common protozoa found in water are Giardia lamblia and Cryptosporidium, both which can enter a water supply through infected fecal matter. These protozoa can cause  diarrhea, gas, nausea, and dehydration, and they can be passed from person to person through consumption of infected water or washing dishes with infected water. 

Effective removal techniques

Almost all germs can be removed simply by boiling your water for 1-3 minutes (filter for longer at higher altitudes.) However, it is not practical or time-efficient to boil your water every time you need a drink. Additionally, treating the water with ozone, UV light, or reverse osmosis will remove all germs, but these techniques are often expensive (4). One of the most cost-efficient and convenient ways to remove germs from your water is through a water filter that is specifically lab-tested to remove bacteria, and protozoa. For example, the Hollow Fiber Straw by Seychelle is independently lab-tested to remove up to 99.999% of all germs, making it an inexpensive and highly effective removal tactic. 

The Wrap-Up

Bacteria, and protozoa may all be present in both tap and well water, despite public filtration efforts. These germs can cause a variety of illnesses and diseases that can harm you or your family if ingested. To keep you and your family safe, be sure to boil, treat, or filter your water before drinking it. For a cost-efficient filtration system, choose Seychelle.  

Frequently Asked Questions

Does all tap water have bacteria?

While not all water leaves the source contaminated, bacteria can grow in pipes and infect tap water. 

Is tap water 100% safe?

No. Tap water varies in safety level based on your geographic location. Even in areas where tap water is considered safe, it is susceptible to both germs and heavy metals that can stem from your pipes.

Can bacteria in well water make you sick?

Yes. Bacteria in well water can lead to nausea, fever, diarrhea, and stomach cramps.  


  1. Centers for Disease Control and Prevention,,if%20the%20conditions%20are%20right
  2. Minnesota Department of Health, 
  3. Yamini Durani,Kids Health, 
  4. Centers for Disease Control and Prevention,