The major objective of this course is to introduce students to various types of wastewater treatment systems viz., conventional wastewater treatment systems, stabilization ponds, constructed wetlands, self-purification systems etc.  On successful completion of the course the students will be able to: identify the various wastewater treatment systems and in depth about activated sludge treatment process, trickling filters, RBC, stabilization ponds and constructed wetlands, and self-purification systems, streeter Phelp‟s oxygen sag model