The results of a field demonstration project to investigate the removal of BOD, suspended solids and nutrients from a secondary effluent flowstream by the foam flotation process are presented. Two major tasks were accomplished: (1) operation of and the accumulation of data from a 0-10 gpm foam flotation pilot plant using secondary effluent from the San Jose-Santa Clara Water Pollution Control Plant, and (2) economic evaluation of the foam flotation process. It was found that efficient phosphorus and suspended solids removals and an improved effluent saturated with oxygen could be effected by the foam flotation process. Based on a 10 MGD plant, the projected costs for the foam flotation process were shown to be 5.76 cents/1000 gallons for chemicals and power.