Which of the following is a common indicator of water contamination?

The presence of coliform bacteria is a widely recognized indicator of water contamination. Coliform bacteria are commonly found in the environment, particularly in the intestines of warm-blooded animals. Their presence in water suggests that there may be pathogens or harmful microorganisms present, which can pose a significant health risk.

Testing for coliform bacteria is a standard method in water quality assessments, especially in drinking water. If coliforms are detected, further testing is often warranted to determine the presence of more harmful pathogens, such as E. coli, which can lead to serious health issues. Therefore, understanding that coliform bacteria specifically serve as a proxy for potential contamination helps in monitoring and protecting public health.

Although the presence of microorganisms, unusual odors, and high mineral content can also indicate some form of water quality issue, they do not specifically point to fecal contamination or the potential presence of dangerous pathogens like coliform bacteria do. Hence, coliforms are a more direct and standardized indicator of contamination risk.