What Are Bacteria in Water, and How Can They Be Removed?

Water tests often look for total coliform bacteria as an indicator of the sanitary condition of a supply. Most coliforms are not themselves harmful, but their presence can signal a pathway through which disease-causing organisms could enter. E. coli is a more specific warning of possible fecal contamination.

If a water test detects bacteria in your water, follow guidance from the local health department and use a safe alternate water source until the problem is addressed. A well may need repairs and shock disinfection, followed by repeat laboratory testing.