Illinois Pesticide Applicator Practice Test

How can you prevent back-siphoning of pesticides into the water supply?

1. By adding vinegar to the water

2. Keeping an air gap or using anti-siphoning devices

3. Always using a garden pump

4. Avoiding the use of any pesticides

The correct answer is: Keeping an air gap or using anti-siphoning devices

Preventing back-siphoning of pesticides into the water supply is crucial for protecting water quality and ensuring safe pesticide application. Maintaining an air gap or utilizing anti-siphoning devices are effective methods to achieve this. An air gap creates a physical distance between the pesticide application equipment and the water supply, which ensures that if a negative pressure occurs in the water line (due to a sudden drop in water pressure), there is no direct path for the contaminated water to be siphoned back into the supply. Anti-siphoning devices, such as backflow preventers, work similarly by providing mechanical barriers that prevent any backflow of liquid. These devices are designed to close off the connection in the event of a pressure loss, thus preventing any hazardous substances, such as pesticides, from entering the potable water system. In contrast, adding vinegar to the water or solely relying on a garden pump does not inherently address the chance of pesticide contamination through back-siphoning. Avoiding the use of pesticides altogether does eliminate the risk of contamination, but it is not a practical solution for individuals who need to apply pesticides for various agricultural or pest control purposes. Therefore, employing air gaps or anti-siphoning devices is the most effective and reliable method to prevent back-siphoning