The two chief sources of water pollution can be seen as Point and Non Point. Point refer to the pollutants that belong to a single source. An example of this would be emissions from factories into the water. Non Point on the other hand means pollutants emitted from multiple sources.he two chief sources of water pollution can be seen as Point and Non Point. Point refer to the pollutants that belong to a single source. An example of this would be emissions from factories into the water. Non Point on the other hand means pollutants emitted from multiple sources.