The various projects reported herein were undertaken to assist in the implementation of the Province of Ontario's phosphorus control program. Under this five-year program, phosphorus removal was to be initiated on the discharges of more than 170 existing wastewater treatment plants serving some five million persons. In order to implement this program, a methodology to predict the coagulant best suited for phosphorus removal at any particular treatment facility was required. It was also necessary to determine whether the chemicals used for phosphorus removal would have any physical or process effects on present wastewater treatment processes, facilities, methods of sludge treatment, and subsequent sludge disposal practices. This report discusses coagulation prediction and prime coagulant selection, and the operational results, problems and design considerations derived from a series of full scale studies. The study concluded that phosphorus removal may be readily implemented with minimal capital expenditure at operating municipal wastewater treatment facilities of all designs currently in use in Ontario.