California Wastewater Treatment Operator Practice Exam

Why is it important to reduce biochemical oxygen demand (BOD) in wastewater?

1. BOD reduction promotes faster evaporation

2. BOD reduction helps maintain aquatic life

3. BOD reduction ensures better filtration

4. BOD reduction increases plant operational costs

The correct answer is: BOD reduction helps maintain aquatic life

Reducing biochemical oxygen demand (BOD) in wastewater is crucial because high levels of BOD can be detrimental to aquatic ecosystems. When wastewater with high BOD is discharged into water bodies, it leads to an increase in microbial activity as these microorganisms consume oxygen to decompose the organic matter present in the wastewater. This process depletes the oxygen available in the water, which is essential for the survival of fish and other aquatic organisms. A reduction in BOD helps maintain the dissolved oxygen levels in water bodies, thereby supporting the health of aquatic life and preventing conditions that could lead to fish kills or other negative impacts on the ecosystem. By minimizing BOD in wastewater treatment, we are ensuring that the effluent released into the environment is less harmful, promoting ecological balance and sustainability. This is why managing BOD levels is a priority in wastewater treatment practices.