A specific identifiable source of pollution, such as a factory pipe, is categorized as which?

• A. Point source pollution
• B. Nonpoint source pollution
• C. Residence time
• D. Surface water

Answer: (A)

The key idea is distinguishing pollution sources by identifiability. A single, clearly identifiable outlet—like a factory pipe—points to a defined source entering the water. This is the essence of point source pollution: a discrete source that can be traced to a specific facility or outlet. Nonpoint pollution, in contrast, comes from many diffuse sources over a wide area, making the exact origin hard to pinpoint. Residence time refers to how long a pollutant stays in the system, not where it came from, and surface water is the water body itself, not a description of the pollution source. So the factory pipe fits the label of point source pollution.