Which is a recommended best management practice for preventing pesticide contamination of water?

• A. Use pesticides that are highly water soluble
• B. Use grass buffer strips and mulches
• C. Select persistent pesticides
• D. Ensure adequate back-siphoning

Answer: (B)

Keeping pesticides from reaching water relies on creating protective vegetation and ground cover that intercept and slow runoff. Grass buffer strips between fields and water bodies act as a living filter: they reduce the speed of runoff, trap sediment, and promote infiltration, so pesticides are more likely to stay in the soil or be degraded before they reach streams, ponds, or ditches. Mulches and vegetative cover on exposed soil further reduce erosion and splash, lowering the chances of pesticide residues being transported off the field. Together, these practices establish a protective zone that minimizes both surface runoff and movement toward water, which is why they’re recommended for safeguarding water quality during and after pesticide application.

Choosing pesticides that are highly water soluble would make it easier for them to move with water, increasing contamination risk. Selecting persistent pesticides means they linger in the environment longer, raising the chance of long-term water contamination. Ensuring adequate back-siphoning helps protect drinking water supplies but does not directly address contamination of water bodies from field runoff.