Which scenario is an example of non-point source pollution?

Which scenario is an example of non-point source pollution?

• A. A pipe discharging from a factory
• B. A wastewater treatment plant outlet through a pipe
• C. A smokestack emitting pollutants into the air
• D. Runoff from fields and streets carrying pollutants

Answer: (D)

Non-point source pollution is pollution that enters water from many diffuse sources over a wide area rather than from a single outlet. Runoff from fields and streets fits this because rain picks up pollutants—fertilizers, pesticides, sediment, oil, and other debris—from countless small surfaces and carries them into streams and rivers. There isn’t one identifiable pipe or discharge point responsible; the pollution comes from many locations across the landscape. In contrast, the other scenarios involve a single, identifiable outlet: a factory pipe or a wastewater treatment plant pipe both release pollutants through defined points, which is characteristic of point source pollution. A smokestack emits into the air, which is air pollution rather than water pollution, so it’s not illustrating the water-source distinction.

Non-point source pollution is pollution that enters water from many diffuse sources over a wide area rather than from a single outlet. Runoff from fields and streets fits this because rain picks up pollutants—fertilizers, pesticides, sediment, oil, and other debris—from countless small surfaces and carries them into streams and rivers. There isn’t one identifiable pipe or discharge point responsible; the pollution comes from many locations across the landscape.

In contrast, the other scenarios involve a single, identifiable outlet: a factory pipe or a wastewater treatment plant pipe both release pollutants through defined points, which is characteristic of point source pollution. A smokestack emits into the air, which is air pollution rather than water pollution, so it’s not illustrating the water-source distinction.