Coliform bacteria are indicators of contamination in water. They enter through sewage or runoff and suggest the presence of harmful pathogens that can cause illness.

Coliform bacteria are widely found in the environment and are used as indicators of water quality. While most coliforms are harmless, their presence suggests that harmful pathogens may also be in the water. Water systems test for coliforms using methods like Most Probable Number (MPN) or membrane filtration. These bacteria can enter water supplies through animal or human waste, soil runoff, or faulty treatment systems. Regular testing for coliforms is crucial to ensure safe drinking water and identify potential contamination issues promptly.