What type of soil has the greatest potential for groundwater contamination when pesticides are applied?

Sand has the greatest potential for groundwater contamination when pesticides are applied due to its coarse texture and larger particle size, which allows for rapid movement of water and, consequently, any dissolved substances, including pesticides. The high permeability of sandy soils facilitates the infiltration of water, which can carry contaminants down to the groundwater table more quickly than soils with finer textures. This rapid movement makes it challenging to mitigate the impact of applied pesticides before they reach groundwater.

In contrast, loam, silt, and clay soils have smaller particle sizes that can retain water and hold pesticides in the upper soil layers for longer periods. Loam has a balanced texture that can absorb water and provide some leaching protection. Silt retains more moisture than sand but does not drain as quickly, while clay has a very fine texture that limits water movement, effectively reducing the risk of contaminants reaching groundwater.