Why is it essential to test for coliform bacteria in drinking water?

Testing for coliform bacteria in drinking water is crucial because the presence of these bacteria indicates potential contamination by harmful pathogens. Coliforms are a group of bacteria found in the environment, including soil, vegetation, and the intestines of warm-blooded animals. Their occurrence in drinking water is a key indicator of sanitation quality, as it suggests that the water may have been exposed to fecal material.

If coliform bacteria are detected, it raises alarms about possible contamination from sources like sewage, which can carry infectious diseases. This makes testing for coliform bacteria a primary step in ensuring the safety and quality of drinking water, helping to protect public health by identifying risks before they lead to illness.

In contrast, measuring water hardness, assessing taste, and evaluating chemical balance do not provide insight into the microbiological safety of water. These aspects may affect the overall quality and aesthetic characteristics of water but do not indicate the presence of harmful microorganisms. Thus, drinking water safety relies heavily on the regular monitoring for coliform bacteria as a critical element of public health protection.