What type of pollution is difficult to trace back to a single source?

Non-point source pollution is indeed challenging to trace back to a single origin because it arises from multiple, diffuse sources rather than a single, identifiable point. This type of pollution typically accumulates over large areas, making it difficult to determine where the pollutants are coming from. For example, agricultural runoff from fertilizers and pesticides can enter waterways from many different farms within a region, rather than from a specific discharge point. This characteristic of non-point source pollution complicates regulatory and remediation efforts, as it requires addressing multiple contributors rather than targeting a single source of pollution.

In contrast, point source pollution is directly sourced from a single location, such as a factory discharging waste into a river, making it much easier to identify and control.