What is an example of non-point source pollution?

Non-point source pollution refers to contaminants that do not originate from a single, identifiable source. Instead, it occurs when rainfall or snowmelt moves over and through the ground, carrying away natural and human-made pollutants and delivering them to waterways. Runoff from agricultural land is a prime example of this type of pollution.

In agricultural areas, rain can wash fertilizers, pesticides, and sediment off fields and into nearby streams and rivers. Since these pollutants come from widespread areas rather than a single outlet, they fit the definition of non-point source pollution. This type of pollution can be challenging to manage due to its diffuse nature and the various factors that contribute to its presence, including farming practices and land management.

In contrast, the other options present identifiable points of discharge. For instance, wastewater treatment plants, oil spills, and industrial discharges all refer to specific locations where pollution is released into the environment. These represent point sources, as they can be tracked back to specific facilities or incidents.