OPM Termite Practice Exam

What should be avoided to prevent back siphonage during application?

1. Filling the tank indoors

2. Keeping the filling hose above the pesticide mixture

3. Using a vacuum mixer

4. Using a siphon pump

The correct answer is: Keeping the filling hose above the pesticide mixture

To prevent back siphonage during the application of pesticides, it is crucial to keep the filling hose above the pesticide mixture. This practice ensures that any potential negative pressure does not draw the pesticide mixture back into the water supply. When the hose is submerged in the pesticide mixture, if there is a sudden drop in pressure or a siphoning effect occurs, it can lead to contaminants entering the water supply, which poses environmental and health risks. Maintaining the hose above the liquid level effectively creates a physical barrier that prevents backflow. This method is a fundamental safety practice in pesticide application to ensure that chemicals do not contaminate potable water systems. Given the importance of protecting water supplies from pesticides and other chemicals, implementing this measure is both a practical and regulatory requirement in many areas.