Abstract: A wastewater treatment process is provided that entails both a biological or activated sludge process and a ballasted flocculation process. A first stream of wastewater is directed to a biological system for biologically treating the wastewater. The biological treatment process produces a first effluent and a first sludge. In cases where the biological system is an activated sludge process, the first sludge is recycled. A second stream of wastewater is directed to a ballasted flocculation system. The second stream of wastewater can be a stream independent of the first stream of wastewater or can be derived from the wastewater passing through the biological system. Sludge in the form of activated sludge or mixed liquor from the biological system is mixed with a second stream of wastewater in the ballasted flocculation system for the purpose of biologically treating the second stream of wastewater.