Tennessee Wastewater Operator Practice Exam

How can flies around a trickling filter be effectively controlled?

1. Flooding the filter weekly

2. Regularly applying insecticides

3. Reducing the recirculation rate

4. Cleaning only during winter months

The correct answer is: Regularly applying insecticides

Effectively controlling flies around a trickling filter involves utilizing strategies that target the adult flies and their breeding sites. Regularly applying insecticides is a practical approach as it directly reduces the population of adult flies, thereby diminishing breeding opportunities and ensuring more sanitary conditions around the filter. Insecticides that are safe for use in wastewater treatment settings can help eliminate flies without disrupting the biological processes within the trickling filter. Additionally, this method can be part of a broader integrated pest management strategy, where monitoring and preventive measures are combined with direct treatments to maintain control over pest populations. Other methods, such as flooding the filter, may inadvertently create habitat conditions conducive for breeding. Similarly, reducing the recirculation rate could disrupt the filter's operational efficiency and not necessarily address the fly issue directly. Cleaning only during winter months would limit opportunities for effective control throughout the warmer months when fly populations typically peak.