A pesticide that is highly soluble in water is very likely to contaminate ground water by leaching.

• A. False
• B. Not sure
• C. True
• D. Sometimes

Answer: (C)

When a pesticide dissolves readily in water, it tends to move with infiltrating water through the soil rather than sticking tightly to soil particles. Groundwater contamination by leaching happens when water moves downward through the soil profile and carries dissolved chemicals with it. If the pesticide remains in solution and isn’t quickly degraded or strongly adsorbed to soil, it can travel deeper with percolating water and reach the groundwater.

This mobility is especially pronounced in soils with coarse textures (like sandy soils) and in situations with substantial rainfall or irrigation, where more water moves downward. While degradation rate and soil adsorption can reduce or slow leaching, high solubility generally means higher vertical mobility, making groundwater contamination by leaching more likely.