Which describes nonpoint source pollution?

• A. A single pipe discharge
• B. Pollution from a large, diffuse area such as urban runoff
• C. Air emissions from a factory chimney
• D. Wastewater treatment plant effluent

Answer: (B)

Nonpoint source pollution is pollution that originates from many diffuse sources across a landscape and is carried into water bodies by runoff, rather than from a single identifiable discharge. That description fits pollution from a large, diffuse area such as urban runoff, where rain washes pollutants like oil, metals, fertilizers, and sediments off streets and into rivers and lakes.

In contrast, a single pipe discharge represents a point source—an identifiable outlet. Wastewater treatment plant effluent is also a point source. Air emissions from a factory chimney involve air pollution, not water pollution, so they’re not nonpoint source pollution. Because nonpoint pollution comes from numerous sources over a wide area, managing it relies on broad strategies such as reducing runoff, increasing permeable surfaces, and promoting better fertilizer and pesticide practices.