Which of the following is an example of a nonpoint source?

Which of the following is an example of a nonpoint source?

• A. Agricultural runoff from fields.
• B. A smokestack at a power plant.
• C. Vehicle exhaust from a highway.
• D. A sewer outfall pipe.

Answer: (A)

Nonpoint sources are pollutants that come from many diffuse locations rather than one identifiable discharge. They are carried to water bodies by rainfall, snowmelt, or irrigation across a landscape, so there isn’t a single outlet you can point to. Agricultural runoff from fields fits this pattern perfectly because rain or irrigation can wash nutrients, sediments, and pesticides from numerous fields over a wide area into nearby streams and lakes. There’s no single pipe or outlet to trace, just widespread contamination from a broad land area. In contrast, a smokestack at a power plant represents a defined outlet from a specific facility, and a sewer outfall pipe is a discrete conduit releasing from a known point. Vehicle exhaust on a highway is more diffuse, coming from many vehicles along a road, but the clearest and most classic example among the options is agricultural runoff.

Nonpoint sources are pollutants that come from many diffuse locations rather than one identifiable discharge. They are carried to water bodies by rainfall, snowmelt, or irrigation across a landscape, so there isn’t a single outlet you can point to. Agricultural runoff from fields fits this pattern perfectly because rain or irrigation can wash nutrients, sediments, and pesticides from numerous fields over a wide area into nearby streams and lakes. There’s no single pipe or outlet to trace, just widespread contamination from a broad land area.

In contrast, a smokestack at a power plant represents a defined outlet from a specific facility, and a sewer outfall pipe is a discrete conduit releasing from a known point. Vehicle exhaust on a highway is more diffuse, coming from many vehicles along a road, but the clearest and most classic example among the options is agricultural runoff.