Question

Which parameter is commonly measured to assess the level of pathogens in wastewater?

• A. pH level
• B. Chlorine concentration
• C. Total coliform count
• D. Dissolved oxygen

Hint:

• Direct detection of all specific pathogens is impractical for routine wastewater monitoring.
• Indicator organisms, like coliform bacteria (total coliforms, fecal coliforms, E. coli), are used instead.
• The presence and count of these indicator organisms suggest the potential presence of fecal contamination and associated pathogens.
• Higher coliform counts indicate a greater risk of pathogen presence.

Answer 1

The Correct Option is C

Assessing the level of specific pathogens in wastewater can be complex, time-consuming, and expensive because many different types of pathogens (bacteria, viruses, protozoa) can be present. Therefore, indicator organisms are commonly used. These are microorganisms whose presence in water suggests the potential presence of fecal contamination and, consequently, pathogenic organisms. Coliform bacteria, particularly fecal coliforms (like Escherichia coli or E. coli), are widely used as indicator organisms.

• Total Coliform Count (option c): This measures the number of coliform bacteria in a water sample. Coliforms are generally found in the intestines of warm-blooded animals and in the environment. While not all coliforms are pathogenic, their presence in high numbers suggests recent fecal contamination and an increased risk that pathogens associated with feces may also be present. Fecal coliform or E. coli counts are more specific indicators of fecal contamination.

Let's look at other options:

• pH level (option a): Measures acidity or alkalinity. While extreme pH can affect pathogen survival, pH itself doesn't quantify pathogen levels.
• Chlorine concentration (option b): This measures the amount of disinfectant (chlorine) present. It's important for ensuring disinfection effectiveness, but it's a measure of the disinfectant, not directly of the pathogen load prior to disinfection or the remaining load.
• Dissolved oxygen (DO) (option d): Important for aquatic life and indicates aerobic conditions. Low DO can be linked to organic pollution (which might be associated with pathogens), but DO itself is not a direct measure of pathogen levels.

Therefore, total coliform count (or more specifically, fecal coliform/E. coli counts) is a standard parameter for assessing potential pathogen contamination in wastewater. \[ \boxed{\text{Total coliform count}} \]