upstream of a digester 105 and downstream from a sludge thickening station 25 and a sludge storage tank 20 disposing the pathogen reduction system 35 upstream with respect to the digester is generally preferred however it should be pointed out that the pathogen reduction system 35 could be employed downstream from the digester 105 pathogen reduction system 35 is designed to treat sludge and to remove pathogens such as bacteria viruses etc from the sludge generally the sludge being treated by the pathogen reduction system 35 constitutes either primary or secondary sludge or both those skilled in the art will appreciate that primary sludge is typically separated from influent wastewater during the course of primary treatment secondary sludge on the other hand is separated from the wastewater during the course of secondary treatment in conventional sludge treatment both the primary and secondary sludge is combined and after being combined is directed to a digester such as anaerobic or aerobic digester once in the digester the sludge is held for an extended time sometimes on the order of approximately 30 days and at a selected temperature level which is typically about 30 35 u00b0 c during the process the digester performs two important functions first the digester rids the sludge of pathogens such as bacteria viruses etc secondly the digester removes or at least substantially reduces volatile solids found in the sludge in the sludge treatment process of the present invention pathogen reduction is separated from the treatment for volatile solids in fact pathogen reduction occurs outside of the digester in the preferred process illustrated and discussed herein the pathogen reduction system 35 removes the pathogens from the sludge prior to the sludge being admitted to the digester 105 but after.