The intent of this paper is to provide cursory information about coagulation, flocculation and clarification. This knowledge will provide a basis for understanding the needs of the customer wishing to monitor these processes. There is no attempt to provide an exhaustive description of various coagulants, coagulant aids, flocculants, mechanical flocculation techniques, clarification designs or configurations or a comparison of relative merits of the various designs, troubleshooting or operational theories. Consult citations in the list of references if more detailed information is desired. April, 2010.