What is the main purpose of the presumptive test in coliform analysis?

The main purpose of the presumptive test in coliform analysis is to indicate potential coliform contamination. This test is used as an initial screening method to determine if there are coliform bacteria present in a water sample, which serves as an indicator of possible fecal contamination or problems with the water supply.

Coliform bacteria are commonly found in the environment, but their presence in water indicates a potential pathway for pathogens that may pose health risks. The presumptive test does not quantify the level of contamination or confirm the presence of specific pathogens; instead, it is designed to provide an early indication that the water may not be safe for consumption or other uses, prompting more detailed testing and assessment.

This approach is crucial in water quality monitoring, as it helps identify systems that may require further investigation to ensure public health safety.