What is defined as pollution that comes from multiple, diffuse sources?

Non-point source pollution refers to the type of pollution that originates from multiple and diffuse sources, rather than a single, identifiable point. This means that the pollutants do not come from a specific discharge pipe or outlet but are instead accumulated from various sources over a larger area. Examples of non-point source pollution include runoff from agricultural fields, urban areas, and forests, where rain or snowmelt washes fertilizers, pesticides, sediments, and other contaminants into waterways.

This distinction is critical in environmental engineering and management because it can be much more challenging to control and mitigate non-point source pollution compared to point source pollution, which can be directly attributed to a single source, such as a factory or wastewater treatment plant. Understanding this concept is vital for developing effective strategies for pollution prevention and watershed management.