What is the primary indicator of fecal contamination in water?

Coliform bacteria levels serve as the primary indicator of fecal contamination in water due to their association with the intestinal tract of warm-blooded animals, including humans. The presence of these bacteria indicates that water has been contaminated with fecal material, which may carry pathogens that can pose health risks.

Monitoring coliform bacteria is essential because it provides a reliable and practical means to assess the microbiological quality of water. While the presence of pH levels, algae, and temperature may indicate other environmental factors or water quality issues, they do not directly relate to the presence of fecal contamination. Therefore, measuring coliform bacteria offers a focused approach to identifying potential sources of pollution and ensuring water safety for consumption and recreational activities.