Which property makes groundwater leaching more likely?

• A. High volatility
• B. High solubility
• C. Strong adsorption to soil
• D. High photostability

Answer: (B)

Groundwater leaching is driven by how well a chemical can travel with water moving through the soil. The property that makes this most likely is high solubility in water. When a pesticide dissolves readily, infiltrating rain or irrigation water can carry it downward through the soil toward the groundwater, especially in permeable soils and with sufficient moisture.

Other properties don’t promote leaching as directly. High volatility means the compound tends to evaporate into the air rather than move with water, reducing leaching. Strong adsorption to soil keeps the chemical attached to soil particles, hindering its downward movement. High photostability affects how long the substance lasts in illuminated environments, but it doesn’t inherently increase its movement with water toward groundwater.