Which statement is true about surface water contamination by pesticides?

• A. Runoff and erosion are sources of surface water contamination
• B. Only atmospheric deposition causes contamination
• C. Groundwater is the only concern
• D. Contamination never occurs with pesticides

Answer: (A)

Pesticides reach surface water primarily through movement from treated land into nearby waterways. Rainfall or irrigation can wash residual chemicals off fields into streams and rivers (runoff), and soil erosion can carry pesticide-laden sediment into water bodies. Atmospheric deposition does contribute some pesticides to surface water, but it isn’t the only or main pathway. Focusing only on groundwater ignores a major route for surface water contamination, and saying contamination never occurs is incorrect because pesticides clearly can contaminate surface water.