Which organism is typically used as an indicator of water quality?

Coliform bacteria are utilized as an indicator of water quality because their presence in water suggests potential contamination by fecal matter, which could harbor pathogens harmful to human health. Coliforms are not typically pathogenic themselves, but they are found in the intestines of warm-blooded animals and indicate that other harmful microorganisms may also be present.

Monitoring levels of coliform bacteria is a straightforward and cost-effective method for assessing the safety of drinking water, as their detection triggers further testing for specific pathogens. The use of coliforms aids in evaluating the effectiveness of water treatment processes and helps in ensuring compliance with health regulations to protect public health.

In contrast, while yeast, protozoa, and viruses can also impact water quality, they lack the same reliable correlation with fecal contamination that coliforms have, making coliforms the preferred choice for routine water quality assessment.