Water pollution is identified in two categories. Point Source Pollution is contamination that comes from a single, clearly identifiable source, such as a pipe which discharges material from a factory into a lake, stream, river, bay or other body of water.Point source pollution is relatively easy to identify. Non-point Source Pollution is more difficult to identify.ater pollution is identified in two categories. Point Source Pollution is contamination that comes from a single, clearly identifiable source, such as a pipe which discharges material from a factory into a lake, stream, river, bay or other body of water. Point source pollution is relatively easy to identify.