Which of the following is an example of point source pollution?

• A. A pest spill entering a storm sewer at mixing and loading sites.
• B. Runoff from a turf area after a broadcast application.
• C. Leaching through soil from an agricultural field.
• D. Wind drift onto off-target property.

Answer: (A)

The concept being tested is the difference between point source and nonpoint source pollution. A point source is a single, identifiable discharge point where pollutants enter a water body. The example of a pest spill entering a storm sewer at mixing and loading sites fits this idea perfectly because the pollution originates from one specific location and enters the water system through that defined outlet. The other scenarios involve pollutants coming from broad, diffuse areas or processes: runoff from a turf area after a broadcast application comes from many spots across the area; leaching through soil from an agricultural field happens as water moves through soil from a large field; wind drift affects off-target properties over a wide area. These are nonpoint sources since there isn’t a single discharge point you can trace.