Pesticides are more likely to reach groundwater in which type of soil?

The correct answer is that pesticides are more likely to reach groundwater in coarse textured soil with low organic material. This type of soil allows for faster drainage and permeation due to its larger particle size and greater void spaces. The coarse texture facilitates the movement of water and, consequently, any dissolved chemicals or pesticides present in the soil.

In contrast, clay-heavy soils, fine-textured soils, and sandy soils with high water retention or organic material generally have more properties that either slow down or filter the movement of water and contaminants. Clay-heavy soils tend to have a compact structure that inhibits water movement, while fine-textured soils retain moisture tightly, making it more difficult for pesticides to leach through. Sandy soils can have high water permeability, but if they also have high organic material, they may adsorb some pesticides, further preventing leaching into groundwater. Therefore, coarse textured soil with low organic material is most conducive to the quick and unfiltered movement of pesticides towards groundwater.