NOVELTY - Treatment of wastewater comprising combining the wastewater with activated sludge in an activated sludge tank to form a mixed liquor; transferring the mixed liquor to a solid-liquid separator; transferring a portion(s) of the sludge stream to a bioreactor; converting phosphorus in the sludge stream into soluble phosphates in the bioreactor; transferring a portion(s) of the sludge stream from the bioreactor to a sidestream reactor; and adding a source of multivalent metal ions to the sludge stream in the sidestream reactor to precipitate phosphate solids.    USE - The method (i.e. a batch or a continuous process) is for treatment of wastewater (claimed) comprising biochemical oxygen demand, nitrogen, and phosphorus, such as from municipal, commercial, and industrial sources.    ADVANTAGE - The method reduces or eliminates the waste activated sludge within a sludge stream.    DETAILED DESCRIPTION - Treatment of wastewater comprises:    (a) combining the wastewater with activated sludge in an activated sludge tank to form a mixed liquor;    (b) transferring the mixed liquor to a solid-liquid separator to separate the mixed liquor into a clear effluent and a sludge stream;    (c) transferring a portion(s) of the sludge stream to a bioreactor;    (d) converting phosphorus in the sludge stream into soluble phosphates in the bioreactor;    (e) transferring a portion(s) of the sludge stream from the bioreactor to a sidestream reactor;    (f) adding a source of multivalent metal ions to the sludge stream in the sidestream reactor to precipitate phosphate solids;    (g) separating and removing the phosphate solids from the sludge stream; and    (h) returning the sludge stream to the activated sludge tank for further treatment with the mixed liquor.    An INDEPENDENT CLAIM is also included for a method of removing phosphorus from a low waste activated sludge treatment process, comprising:    (a) transferring a sludge stream comprising ammonia and soluble phosphates to a sidestream reactor;    (b) adding base to the sidestream reactor until the sludge stream has a pH of 8-10;    (c) adding a source of multivalent metal ions to the sidestream reactor;    (d) mixing the sludge stream in the sidestream reactor to precipitate phosphate solids; and    (e) transferring the sludge stream to a separator to remove the phosphate solids from the sludge stream.    DESCRIPTION OF DRAWING(S) - The figure is a schematic view of wastewater treatment system.