Which characteristic best defines non-point source pollution?

Non-point source pollution is best defined by its diffuse nature, which means it originates from multiple sources rather than a single identifiable one. This type of pollution can arise from a variety of activities and can be influenced by environmental factors, making it more challenging to pinpoint and manage effectively.

For example, runoff from agricultural fields, urban areas, and forests can all contribute to the contamination of water bodies, but they do so in a way that is not easily traceable to one specific site. This characteristic complicates efforts to control or mitigate the pollution, as it requires comprehensive approaches that consider an entire watershed rather than targeting a single point of discharge.

In contrast, characteristics such as being localized and easy to control pertain more to point source pollution, where specific measures can be applied to the distinct source of the pollution. Understanding the nature of non-point source pollution is critical for developing effective water quality management strategies, especially in agricultural and urban planning contexts.