Fecal coliform is used as an indicator of what in water quality monitoring?

• A. Heavy metal contamination
• B. Temperature
• C. pH
• D. Pathogen or fecal contamination

Answer: (D)

Fecal coliforms signal fecal contamination in water. These bacteria live in the intestines of humans and other warm-blooded animals, so their presence in water suggests that fecal matter has entered the system and may carry pathogens. They’re used as an indicator because they’re relatively easy to test and their presence correlates with the possible presence of disease-causing organisms, helping assess safety and guide treatment or boil-water advisories. This is different from measures of heavy metals, temperature, or pH, which are not indicated by fecal coliform levels.