What defines non-point source pollution?

Non-point source pollution is characterized by its origin from multiple, diffuse sources rather than a single, easily identifiable source. This type of pollution is often related to runoff from agricultural fields, urban areas, and other landscapes where contaminants accumulate and are washed into water bodies after rainstorms or snowmelt. Unlike point source pollution, which can be traced back to a specific outlet (like a factory pipe), non-point source pollution arises from a variety of scattered sources, making it more challenging to regulate and control.

For instance, fertilizers, pesticides, and sediments can runoff from agricultural land, while urban areas might contribute oils, heavy metals, and debris. This broad spectrum of contributors complicates efforts to pinpoint exact sources of pollution and often requires comprehensive strategies to manage and mitigate its effects effectively on aquatic ecosystems.