Tennessee Wastewater Operator Practice Exam

Why is it important for operators to be concerned about the discharge of organic wastes into receiving water?

1. It could increase the water temperature

2. It could cause oxygen depletion

3. It could lead to sediment accumulation

4. It could enhance fish populations

The correct answer is: It could cause oxygen depletion

The discharge of organic wastes into receiving waters is a significant concern for operators primarily because it can cause oxygen depletion. When organic materials are introduced into a body of water, they serve as a food source for bacteria and other microorganisms. As these organisms break down the organic matter through the process of decomposition, they consume dissolved oxygen in the water. This reduction in oxygen levels can lead to a condition known as hypoxia, which can be detrimental to aquatic life. Most aquatic organisms, including fish and invertebrates, require adequate levels of dissolved oxygen to survive. When oxygen levels drop too low, it can result in stress or death for these organisms, disrupting the aquatic ecosystem and potentially leading to larger environmental problems such as fish kills or shifts in species composition. Therefore, managing the discharge of organic wastes is vital to maintaining healthy aquatic ecosystems and ensuring that water quality standards are met.