"Water pollution come from two different types of sources. A point source is a result of pollutants being emitted directly into a water body, such as a pipe from an industrial facility leaking toxics directly into the water. There is also a non-point source type of polluting that is a result of pollutants being indirectly transported to the water such as run off from fertilizers flowing in to a larger body of water by rain." (Quoted from article)