Ontario Operator-in-Training (OIT) Practice Exam

What is the main environmental benefit of disinfecting wastewater?

1. It enhances nutrient absorption

2. It prevents disease transmission

3. It increases treatment costs

4. It promotes algae growth

The correct answer is: It prevents disease transmission

The main environmental benefit of disinfecting wastewater is to prevent disease transmission. By effectively eliminating harmful pathogens and microorganisms present in wastewater, disinfection protects public health by reducing the risk of waterborne diseases. This is particularly critical when wastewater is released into the environment, as untreated or inadequately treated wastewater can contaminate surface water bodies and groundwater, posing significant health risks to humans and wildlife. Disinfection processes, such as chlorination, UV treatment, or ozonation, focus on ensuring that any residual pathogens are rendered inactive before the water is returned to the ecosystem or used for irrigation or other purposes. This contributes to a safer environment, safeguarding both human populations and ecosystems that may rely on clean water sources. The other options do not capture the primary environmental benefits associated with wastewater disinfection. For example, enhancing nutrient absorption and promoting algae growth could lead to negative ecological impacts, such as eutrophication. Increasing treatment costs does not represent a benefit but rather a consideration in the planning and budgeting of wastewater treatment systems.