Answer:point source pollution
Pollution of land, water or air can be either caused by the point source pollutants or non-point source pollutants. The point source pollutants are those whose source of origin is known and these pollutants can be traced back to their origin and their further emission can be stopped. For example, the disposal of sewage water in river. The non-point source pollutants are those whose source of origin is unknown and cannot be traced back. These wastes are accumulated from more than one source and get aggregated as land, water or air pollutants. Accumulation of fertilizers in the river by surface runoff is the example of non-point source pollutants.
Stormwater runoffs carry oil leaked by vehicles on a highway into a pond. This is an example of point source pollution because the run off may take away the oils into the pond from originating from the vehicles parked at the highway near the pond. But the source of origin of the oil in the pond can be traced back and the pollution can be prevented.
