Nonpoint-source pollution refers to diffuse contamination of air, soil, or water arising from multiple, spatially distributed sources rather than a single, identifiable discharge point, making it ...

Agricultural non-point source (NPS) pollution is a major cause of water quality degradation, with pollutants such as nitrogen and phosphorus carried by farmland surface runoff being important sources.

Concern about polluting water supplies began over 100 years ago when the industrial revolution resulted in noticeable changes in the quality of surface waters. Because groundwater was generally ...