The anoxic biological reduction system and method for treating wastewater may be an anoxic biological reduction element disposed in a membrane anaerobic stabilization system. The wastewater may be treated to produce an effluent suitable for membrane filtration with the treating incorporating processes substantially free of aerobic biological treatment. The effluent may be filtered through a membrane element selected from the group consisting of a microfiltration system and an ultrafiltration system or a combination thereof. The membrane effluent may then be treated in an anoxic biological reduction element to produce a process effluent stream.