What is a common indicator of water contamination?

The presence of coliform bacteria is a widely recognized indicator of water contamination, particularly in drinking water sources. Coliforms are a group of bacteria commonly found in the environment, including in soil and vegetation, and they can also originate from fecal matter. Their presence in water samples indicates that the water may be contaminated with pathogens that can cause disease, as coliforms serve as an indicator of possible fecal contamination. This is significant for assessing the microbial safety of water.

In contrast, high pH levels may indicate certain water quality issues, such as corrosion or alkalinity, but they do not necessarily correlate directly with contamination. Increased water clarity typically suggests fewer suspended particles and may be a sign of cleaner water, whereas low turbidity readings indicate low particle concentration; neither directly indicates contamination. Therefore, testing for coliform bacteria is a standard procedure in water quality assessment, highlighting its importance as an indicator of existing contamination.