The only effective method to decontaminate soil saturated with a pesticide is to

• A. Remove top 2-3 inches
• B. Cover area with 2-3 inches of soil
• C. Sprinkle the soil with lime
• D. Flush with water

Answer: (A)

The main idea is physically removing the contaminated layer of soil to eliminate most of the residue. When pesticide contamination is concentrated near the surface, taking out the top 2–3 inches of soil removes the portion that holds the highest concentration and is most likely to contact crops, people, or wildlife. That direct removal is typically the most reliable way to reduce exposure quickly and effectively.

Covering the area with more soil might seem to hide the problem, but it doesn’t remove the pesticide. Residues can still exist beneath the new layer and can be taken up by plants or migrate back to the surface, and it can create ongoing contamination in the longer term. Sprinkling lime changes soil chemistry, which can influence degradation rates for some chemicals, but it does not cleanse the soil of residues. Flushing with water can spread contaminants through the soil and into waterways or groundwater, instead of removing them.

Because the goal is to remove the source of exposure, physically removing the contaminated topsoil, followed by proper disposal in accordance with regulations, is the most direct and effective approach in this scenario.