Which item does NOT contribute to groundwater contamination?

Which item does NOT contribute to groundwater contamination?

• A. Using pesticides with short residual action
• B. Improper disposal
• C. Faulty chemigation
• D. Pesticide spills near a well head

Answer: (A)

Groundwater contamination risk hinges on how long a pesticide stays active and how it moves through soil. A pesticide with a short residual action breaks down quickly, so it doesn’t persist long enough to leach through the root zone or reach groundwater, making it less likely to contaminate drinking water sources. The other scenarios create ways for pesticides to reach groundwater: improper disposal can leave residues in places where rain can carry them down into soil and aquifers; faulty chemigation can apply too much pesticide through irrigation, pushing it deeper into the soil and toward groundwater; and spills near a well head provide a direct, concentrated source that can rapidly contaminate the aquifer.

Groundwater contamination risk hinges on how long a pesticide stays active and how it moves through soil. A pesticide with a short residual action breaks down quickly, so it doesn’t persist long enough to leach through the root zone or reach groundwater, making it less likely to contaminate drinking water sources.

The other scenarios create ways for pesticides to reach groundwater: improper disposal can leave residues in places where rain can carry them down into soil and aquifers; faulty chemigation can apply too much pesticide through irrigation, pushing it deeper into the soil and toward groundwater; and spills near a well head provide a direct, concentrated source that can rapidly contaminate the aquifer.