Discovering bacteria in your well water is alarming, but it's more common than you might think—and it's absolutely treatable. Understanding the difference between total coliform bacteria and E. coli, knowing how they enter your well, and taking the right corrective steps can restore your water to safe drinking quality.
What Is Total Coliform?
Total coliform is a broad group of bacteria that are naturally present in soil, surface water, and vegetation. Most coliform bacteria are harmless to humans. However, their presence in well water is a red flag because it indicates that surface water or contaminants have a pathway into your well. If coliform can enter, so can more dangerous pathogens.
Think of total coliform as a warning system. A positive test doesn't mean your water will make you sick, but it means your well's protection has been compromised.
What Is E. coli?
E. coli (Escherichia coli) is a specific type of coliform bacteria found in the intestines of warm-blooded animals, including humans. If E. coli is detected in your well water, it means fecal matter has entered your water supply. This is a serious health hazard and requires immediate action. E. coli contamination can cause severe gastrointestinal illness, particularly in children, elderly individuals, and those with compromised immune systems.
How Bacteria Enter Your Well
Bacteria typically enter wells through several pathways: a cracked or damaged well casing, a loose or missing well cap, a wellhead that sits below ground level or in a depression where water pools, recent flooding or heavy rainfall that overwhelms the well's natural protections, and improper well construction or maintenance. Even a small gap in your well's seal can be enough for bacteria to migrate into the aquifer.
Immediate Steps After a Positive Test
If your water test comes back positive for total coliform or E. coli, take these steps immediately. First, switch to bottled or boiled water for drinking, cooking, and brushing teeth. Boil water for at least one minute at a rolling boil to kill bacteria. Next, call a licensed well professional to inspect your well's physical condition. The source of contamination must be identified and fixed before disinfection will be effective long-term.
Shock Chlorination and Follow-Up Testing
Once any physical problems are corrected, your well should be shock chlorinated. This process introduces a high concentration of chlorine to kill all bacteria in the well and plumbing system. After the required contact time and thorough flushing, wait 7 to 10 days and retest your water. Only when the follow-up test comes back clean can you resume normal water use.
At 77 Water Well Inc., we provide bacteria testing, well inspections, and professional shock chlorination across North Houston. Call (281) 456-4556 if you suspect bacterial contamination.