What is required when drawing water from an open body of water for pesticide application?

• A. Use only municipal water supplies.
• B. Discontinue use if water is contaminated.
• C. No air gap is required.
• D. An air gap must be maintained between the spray mix and intake hose to prevent backflow.

Answer: (D)

When drawing water from an open body of water for pesticide application, preventing backflow into the water source is essential. The best and required measure is to maintain an air gap between the spray mix and the intake hose. This physical separation stops siphoning or backpressure from pulling the pesticide-laden mix back into the water source, protecting the open water and any potable supply downstream. Using only municipal water supplies isn’t a mandate for this situation, and while stopping use if the water is visibly contaminated is sensible, the stated requirement focuses on the air gap. Without an air gap, backflow is possible and contamination can occur.