What is the function of a Back-Flow Preventer?

A Back-Flow Preventer is designed to protect the water supply from contamination. Its primary function is to prevent backflow, which can occur during pressure fluctuations in the water system. When water pressure drops, it can create a vacuum that may cause water (including any unintended contaminants such as pesticides) to flow backward from application equipment into the potable water supply. By installing a Back-Flow Preventer, this reverse flow is effectively stopped, thereby ensuring that pesticides and other hazardous substances do not mix with the drinking water supply. This is crucial for public health and safety, making it vital for anyone involved in the application of pesticides to understand the importance of this device.

The other options, while related to pesticide application, do not capture the critical protective function that a Back-Flow Preventer serves in preventing water contamination.