Which is an example of point source pollution?

• A. A discharge pipe from a factory
• B. Runoff from farm fields
• C. Agricultural field irrigation
• D. Diffuse road dust

Answer: (A)

Point source pollution comes from a single, identifiable outlet. A discharge pipe from a factory fits this perfectly because pollutants are released through one clearly identifiable point into a body of water. This kind of source is typically regulated with specific permits and monitoring because the contaminant input can be measured and controlled at that one outlet.

The other scenarios describe non-point source pollution, which originates from many diffuse sources rather than a single discharge point. Runoff from farm fields picks up fertilizers, sediments, and other contaminants as it moves across the landscape, coming from numerous locations. Agricultural field irrigation can produce runoff and leaching across a broad area rather than from one spot. Diffuse road dust arises from many small sources along road networks, dispersed by wind and water flow. Because these pollutants originate from multiple places and are hard to link to a single source, they’re classified as non-point.