Tennessee Wastewater Operator Practice Exam

Which of the following is NOT a water quality characteristic that should be measured in the receiving waters and in the plant effluent?

1. Chloride

2. Biochemical oxygen demand

3. pH

4. Temperature

The correct answer is: Chloride

Chloride is often measured in water quality assessments, but it is not universally regarded as a key characteristic that needs to be assessed in every situation for both receiving waters and effluent. While chloride can indicate certain sources of pollution or be significant in specific contexts, such as saltwater intrusion or certain industrial discharges, it is not as commonly monitored as the other options listed. Biochemical oxygen demand, pH, and temperature are fundamental indicators of water quality that reflect the health of aquatic ecosystems and the effectiveness of wastewater treatment processes. Biochemical oxygen demand is critical for understanding the organic pollution load and oxygen depletion potential in both effluent and receiving waters. pH is essential for assessing the acidity or alkalinity of the water, which can significantly impact aquatic life and the efficiency of treatment processes. Temperature is also crucial, as it affects chemical reactions, biological activity, and the solubility of gases like oxygen. In summary, while chloride may be relevant in certain contexts, it isn't as universally critical to overall water quality assessment as the other three parameters.