Bacteria In Well Water? Here’s How You Can Test and Remove Them

The phrase ‘bacteria in well water’ should be alarming for you and your children because of the health issues, drinking contaminated water can lead to. A single glass of which can lead to a number of health concerns, including intestinal infections, cholera, hepatitis, and dysentery to name a few.

Here, we explain the types of bacteria commonly found in well water, the risks they pose, and how to remove them.

Common Bacteria Types in Well Water

Over 2 billion people all over the world use a contaminated drinking water source; with a death toll of almost 502,000 each year due to it. The most common bacteria found in well water are Iron bacteria, Fecal Coliforms, Giardia Lamblia, Salmonella, Cryptosporidium, etc.

All bacteria aren't hazardous to your health, but that is not to say that you shouldn’t be careful.

Following is an introduction to the more common bacteria in well water.

Iron Bacteria

Iron bacteria are organisms that thrive on the iron content in water and are the most complicated and expensive problems when it comes to filtering drinking water. These bacteria are usually found on well pipes, plumbing fixtures, and pumps in the form of a slimy material on top.

Iron Bacteria

If left for long, this biofilm can become the perfect house, especially for iron bacteria, which will leave yellow, orange, red, brown, or rainbow stains on the pipes and in turn stain the water. Also associated with this is a pungent odor and taste in your well water.

Iron bacteria are the most difficult to treat once in well systems. We will discuss the treatment techniques below.

Fecal Coliform

Fecal Coliform bacteria include a collection of bacteria that reside in the intestines of animals and humans. Although helpful in digestions as a colony, some strains of Coliform such as E. Coli are known to cause diseases.

To eliminate Coliform bacteria, especially E. Coli, you can bring the contaminated water to a boil. E Coli can also be removed with the help of UV light, filtration, and other techniques, as explained later on.

Symptoms & Diseases Associated With Drinking Bacteria Contaminated Water?

Some effects of drinking well water contaminated with bacteria may be immediate while others might take a long time before becoming noticeable. These symptoms may include short-term discomfort or long-term diseases.

Short-Term Effects

  • Nausea/Vomiting
  • Cramps
  • Headaches
  • Diarrhea
  • Fever

Long-Term Effects

  • Cholera
  • Hepatitis
  • Legionella
  • Dysentery
  • Typhoid

Testing Bacteria Contaminated Water

It is possible for any of the bacteria mentioned above to be present within your water well. However, it is expensive and impractical to test for all of them. Instead, water is tested only for the presence of Coliform and Iron bacteria – something that you can do easily at home. Following are some of the easier at-home ways of testing well water for bacteria;

Testing For Coliform Bacteria

There are a number of testing kits out there, such as the Innovating Science Qualitative Coliform Test Kit that detects the presence of coliform bacteria with the help of several indicators. All you have to do is pour a vial into unfiltered well water and incubate it for 24 to 48 hours.

The indicators start changing color if coliform bacteria are present. Each box of the kit contains 25 tubes and costs roughly USD 40. Although the results take some time to show, they are accurate in detecting the presence of Coliform Bacteria.

Testing For Iron Bacteria

This is a fairly easy test that you can perform at home. Fill a glass with your well water and let it sit for a while. Wait until all the sediments settle at the bottom. If the sediment layer at the bottom is uniform and there are no clumps, it means there is no Iron Bacteria. If, however, there are clumps, you should call your technician to get your well water or lines checked and get a whole house water filter that effectively rids the water of all bacteria.

How To Treat Bacteria Contaminated Water?

1. Chemical Oxidation

Also known as Advanced Oxidation Processes (AOPs), these processes involve chemical treatment of water to remove organic and inorganic materials. The process uses hydroxyl radicals that react with any impurities and makes it easier to extract.

While the oxidation process is extremely viable when it comes to inorganic impurities (such as Iron – converting Fe to FeOH), the process also disrupts the cell wall of bacteria in your water, effectively stopping their membrane from functioning and thus rendering the bacteria harmless.

2. Filtration (submicron filters)

You can also use submicron filters to ensure consistent, pure water. The process of filtering out bacteria is known as ultrafiltration with holes ranging from 1-200 nm. A very common example of ultrafiltration is Reverse Osmosis (RO), which is not only good for reducing inorganic contaminants but also bacteria, parasites, and viruses.

3. UV Light

UV Light

Using an ultraviolet light for water filtration is a process that you can do easily at home. The process involves screening the water with UV light that kills bacteria and microorganisms in your drinking water.

4. Chlorination (for non-drinking purposes)

You can also chlorinate your water to kill certain types of bacteria. The most common compound used for this purpose is sodium hypochlorite (NaOCl) that gives away its Na+ and OCl- ion in water. The OCl- ion forms Hypochlorous acid (HOCl), which is a weak acid for you but effective against bacteria. However, this process isn’t the best fit for drinking water.

You can consult our in-depth guide about the best whole house filters for well and municipal water for more information about how filters can help you treat bacteria-contaminated water.


Bacteria in well water is an immediate danger for you and your family, and the best way to minimize the risk of disease is to get good filters, especially for drinking water. We hope that this guide was helpful in giving you valuable insight about the dangers bacteria in water pose and how you can test and treat your water.