Tennessee Wastewater Operator Practice Exam

As effluent turbidity increases, which microorganism's concentration is likely to increase?

1. Salmonella

2. Legionella

3. E. Coli

4. Cryptosporidium

The correct answer is: E. Coli

As effluent turbidity increases, it creates an environment that can support higher concentrations of certain microorganisms due to factors such as nutrient availability and protection from predation. E. coli is predominantly found in the intestines of warm-blooded organisms and often serves as an indicator of fecal contamination in water. When turbidity rises, suspended solids can provide a habitat where E. coli can cling and thrive, thereby increasing its concentration in the effluent. Moreover, turbidity can originate from organic matter, which can serve as a nutrient source, promoting the growth of bacteria like E. coli. This organism's resilience in varying water conditions makes it more likely to proliferate in turbid environments compared to other microorganisms that may have more specific survival requirements or are affected by competing factors. Therefore, the increase in effluent turbidity correlates with a rise in E. coli concentration due to its adaptability and the favorable conditions created by higher levels of suspended particles in the water.