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My Well Water Tested Positive For Coliform And E.Coli: What Should I Do?

My Well Water Tested Positive For Coliform And E.Coli


If your well water has tested positive for coliform and E. coli bacteria, what should you do? It raises concerns about the safety of your drinking water. 

To solve the problem of E.coli and Coliform bacteria in your water, you can chlorinate your well or use chemical injection. You can also boil your water or install a water filtration system such as distillation, UV purification, or RO filters. Choosing the type of purification is based on the presence of other contaminants along with bacteria.

In this guide, we will explore how coliform and E. coli can enter your well water and what steps you should take to address this issue. We will also discuss the potential health risks associated with these two bacteria.

How Can Coliform And E.Coli Bacteria Enter Your Well Water?

Do you ever wonder how Coliform and E. coli bacteria can enter your well water? 

These bacteria can contaminate your well water by entering through various pathways. We need to know about these routes to take preventive measures. Here are the following:

1. Seepage From The Surface

If your well is not properly sealed or is too shallow, surface water can infiltrate the well. This water can carry coliform and E. coli bacteria from sources like animal waste, sewage, or decaying organic matter.

2. Faulty Well Construction

If the construction of your well isn’t up to standards, there’s a risk of bacterial contamination. Cracks, holes, or damaged well casings can provide a direct entry point for contaminants.

3. Contaminated Runoff

Rainwater and runoff from storms can carry bacteria from the land’s surface into your well. It is particularly concerning if your well is located near septic systems, livestock areas, or land with poor drainage.

4. Nearby Septic Systems

If your well is too close to a septic system, it increases the likelihood of bacteria entering the well. An improperly maintained septic system poses a significant risk.

5. Animal Waste

Another risk of entering bacteria into your well is the animal feeding barns around the well area. Runoff from these areas can carry diseases causing microbes.

How To Get Rid Of Coliform And E. Coli Bacteria From Well Water?

If you want to get rid of Coliform And E.Coli bacteria from your drinking water, follow one of these methods based on the presence of contaminants:

1. Chlorinating Your Well

The most reliable way to remove Coliform and E.coli bacteria from your well water is by Shock chlorination. The process involves a high concentration of chlorine (usually in the form of sodium hypochlorite or calcium hypochlorite) added into the well water. This high dose of chlorine will eliminate pathogens and disinfect the system. It is also beneficial for the removal of iron and sulfur bacteria that cause slime in your pipes and faucets. 

Steps Of Shock Chlorination:

  • Clean all the foreign particles from the well and turn off the pump circuit breaker.
  • Remove the well cap and clean the interior surface with a strong chlorine solution.
  • Calculate the depth and diameter of your well.
  • To treat the water in your well and household plumbing, you should use 3 US pints (1,000 ml) of 5% unscented chlorine bleach for every 100 gallons (378.5 L) of water in your well. Add an extra 3 US pints (1,000 ml) for the treatment of household plumbing.
  • Connect a clean garden hose to the nearest outdoor faucet. Place the hose inside the well and turn on the faucet.
  • Restart the pump and run the water until you detect the smell of chlorine.
  • Use the hose to clean the well casing for about 15 minutes and close the outdoor faucet.
  • Let the chlorine solution circulate throughout every pipe and faucet of your house. Open each faucet one by one until you detect a strong chlorine odor.
  • Turn off the circuit breaker and let the chlorinated water in the pipes and well for about 24 hours.
  • Do not use the shower, and do not drink tap water during this period.
  • Afterward, turn on the pump circuit and on the outside faucets to get rid of the chlorine from your system. 
  • Finally, turn on the inside faucets and until the chlorine smell is gone.
  • Test for chlorine by using a chlorine kit to ensure the safe level of chlorine in your drinking water.

Temporary Elevated Metals Levels:

Research proved that shock chlorination temporarily increases the concentration of arsenic along with lead, zinc, iron, and other metals. It can be solved by purging the well more than 4 well volumes until the metal level returns to normal. If you want to prevent this from happening, you must follow these tips:

  • Make sure to remove chlorinated water after 24 hours.
  • Use chlorine with a balanced pH between 6-7.
  • Flush your tanks and pipes until no sign of chlorine is present.
  • Carefully measure the depth of the well and add the required amount of chlorine.

2. Chemical Injection

Chemical injection is another popular method of removing bacteria from water. It is a broader term that includes various methods of adding chemicals such as chlorine or other disinfectants into a well water supply. Chemical injection involves the continuous addition of disinfectant into a water system to prevent the growth of microorganisms. You can also install a post-carbon filter into the chemical injection water system. It will remove the chlorinated taste of water.

The Chemical Injection water treatment system is typically installed near the point of water entry or the water treatment system. You can also install it before the pressure tank or at the wellhead itself. If you have other water treatment systems (e.g., filtration, softening, or UV disinfection), the chemical injection system can be integrated with them.

3. Boiling Water

Boiling water is an authentic method to kill almost all types of pathogens, including Coliform and E.coli bacteria. You must bring the water up to a rolling boil for one minute to make this process effective. But if you are living at a higher altitude, the recommended time is three minutes. 

This method is a temporary solution because it’s not practical. Your water should be free from pathogens not only for drinking but for other purposes, too. Imagine boiling your water and letting it cool down every time you take a shower. Doesn’t it sound like struggling? So, you must go for alternative solutions.

 In addition, boiling your water will not remove parasites or other toxins such as heavy metals or forever chemicals. Therefore, if your well water has any other contaminants, boiling will not help.

4. UV Purification

UV purification method is highly effective in killing pathogens. Research has shown that when water contaminated with E. coli and fecal coliform bacteria passed through a UV filter, the bacterial concentration became zero. It works by exposing water to ultraviolet light, which kills them by damaging their DNA.

The method of UV disinfection is cost-effective and clean your water without the use of chemical or heat. UV filters will not affect your water taste and maintain its pH. But, if your water has also tested positive for other impurities, such as heavy metals, you must use a granular carbon pre-filter.

5. Water Distillation

When it comes to removing harmful pathogens like E. coli and Coliform bacteria from well water, distillation is a reliable choice. Distillation is a process that boils water, turns it into vapor, and then condenses it back into liquid form. 

According to the Centers for Disease Control and Prevention (CDC), Distillation is one of the most effective methods of removing bacteria from water. This method makes your water safe to drink and use.

If your well water tested positive for other impurities such as chemical contaminants and metals, distillation is not useful. It can also remove beneficial minerals from the water. To install a distillation system, you can set up distillation units or water distillers in your home, office, or laboratory. But keep in mind that distillers can be relatively slow. 

Additionally, they require regular maintenance, making them an expensive investment. That’s why people choose other simple methods of water purification, such as RO filters.

6. Reverse Osmosis Water Filtration

When it comes to pathogens, RO filters are highly effective, and the CDC also promotes them. They can eliminate up to 99% of harmful bacteria, viruses, and parasites in your well water, ensuring that the water you use and drink is safe.  You must wonder if that is possible. The answer is yes because the pore size of this membrane is 0.0001 microns, and bacteria size ranges from 0.4 to 2 microns

However, RO filters have their limitations. They cannot eliminate certain VOCs, pesticides, and hydrogen sulfide heavy metals. Additionally, these systems can be a bit slower in producing purified water and generate some wastewater during the filtration process.

You can usually mount RO filters under your kitchen sink and connect them to your plumbing. It’s a convenient and space-saving solution that provides you with clean, pathogen-free water right from your tap. But, if you want a solution to get rid of bacteria from your whole house, then install it at the point of entry. 

The best solution that can result in 100% removal of E.coli and coliform from your water is to install a UV purification with an RO filter. This combination is ideal for well water with high concentrations of pathogens. However, if you are concerned about VOCs, you can install a carbon pre-filter with an RO system.

Potential Health Risk Of Coliform And E. coli Bacteria

Coliform and E. coli bacteria are harmful to your health. It can cause several mild to severe infections. Children, older people, and those with weakened immune systems are at a higher risk of developing severe symptoms from E. coli contamination. Here are the health risks associated with E.coli and Coliform:

1. Gastrointestinal Distress

If you are drinking E.coli contaminated water, It will lead to gastrointestinal infections. The patient will have stomach cramps, diarrhea, and nausea. The symptoms can range from mild to severe, depending on the individual’s health and the level of contamination.

2. STEC Infection

STEC infection is caused by Shiga-toxin-producing E. coli bacteria, which can lead to severe gastric symptoms. The water contamination has increased, and a study shows that in 2019, 2,000 individuals got infected in California.

3. Acute Kidney Failure

E. coli infection can also lead to Acute Kidney Failure in children. The patient can feel drowsiness and decreased urine output.

4. Urinary Tract Infections

If your well water has E.coli, you can get urine infections such as Cystitis. The condition can lead to several complications, such as if not treated in time.

5. Hemolytic Uremic Syndrome (HUS)

If you have STEC infection or other urine infection by drinking E.coli contaminated water, you can develop a complication, Hemolytic Uremic Syndrome (HUS). It is a curable condition, but some patients may die from this.

6. Inflammatory bowel disease

Consuming water or food with E.coli contamination might result in Inflammatory Bowel Disease (IBD). It can result in abdominal pain, weight loss, and anemia.

7. Meningitis

Meningitis is a condition in which the protective membranes of the brain swell. Drinking water with E.coli can lead to Meningitis, although it’s rare but possible. Research suggests that E.coli causes 20% of neonatal Meningitis.

6. Pneumonia

If you are using E.coli contaminated water to take a shower or drink, it increases the risk of getting Pneumonia. This respiratory infection can inflame your lungs, leading to shortness of breath and cough.


If your well water is tested positive for Coliform and E.coli bacteria, you must take a step immediately. These bacteria pose potential health risks, especially for vulnerable individuals. Many disinfectant methods are available, such as shock chlorination and chemical injection, to get rid of bacteria. 

But, if you want a reliable solution, you should install a water filtration system such as RO filters or UV filters. In addition, Regular testing and well-maintenance are necessary to prevent any risk related to pathogens. 

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