What indicator is commonly tested in water supplies to detect potential sewage contamination?

Coliform bacteria are a widely accepted indicator for assessing the safety of water supplies and detecting potential sewage contamination. These bacteria are a group of microorganisms that are found in the intestines of warm-blooded animals, including humans, and their presence in water suggests that there may be fecal contamination.

When coliforms are detected, it raises concerns about the potential presence of harmful pathogens that could pose health risks to humans. Testing for coliform bacteria is relatively straightforward and cost-effective, making it a standard practice in monitoring water quality. While other options like E. coli and Enterococci can also indicate fecal contamination, coliform bacteria are generally the first line of assessment due to their broader presence and significance as a general indicator of water safety.

Thus, the choice of coliform bacteria is logically aligned with standard water quality testing practices aimed at ensuring safety from sewage contamination.