If coliform bacteria are present in the water supply, what else may be present?

The presence of coliform bacteria in a water supply is a strong indicator that the water may be contaminated with pathogens. Coliform bacteria, particularly fecal coliforms, are often found in the intestines of warm-blooded animals and can indicate that fecal material has entered the water source. This contamination can carry harmful microorganisms, including viruses, parasites, and bacteria that may pose health risks to humans.

When coliform bacteria are detected, it raises concerns about the overall safety of the water as it suggests that other harmful pathogens might also be present in the same contaminated source. Testing for coliforms serves as a warning signal for potentially more serious pathogens that could be present and thus necessitates further testing and treatment of the water supply to protect public health.

The other options, while potentially related to water quality issues, do not directly correlate with the presence of coliform bacteria. Chlorine is commonly used as a disinfectant and its presence would generally suggest treatment, while heavy metals and organic pollutants would arise from different contamination sources, not necessarily linked to the presence of coliform bacteria.