What type of bacteria is an indicator of sewage contamination?

The presence of fecal coliform bacteria serves as a critical indicator of sewage contamination in water sources. Fecal coliform bacteria, which include organisms such as E. coli, are commonly found in the intestines of warm-blooded animals. Their detection in water suggests that sewage or fecal matter has entered the water system, raising health concerns because these bacteria can be associated with pathogens that cause gastrointestinal illnesses.

Fecal coliform testing is widely used in environmental monitoring and public health assessments because the presence of these bacteria implies the potential presence of harmful pathogens. While other types of bacteria mentioned in the options may also indicate contamination or reflect specific health risks, fecal coliform is the standard indicator because it directly correlates with fecal pollution and sewage presence in water bodies, making it essential for evaluating water safety and quality.