NOVELTY - The method comprises recirculating leachate between a leachate bay reactor and a leachate storage tank, cycling leachate from the leachate storage tank to a fixed film environment in a high rate reactor for methogenesis (130), processing multiple substrates with varying solids content, co-digestion of substrate, digesting leachate in a dual mode using separate aerobic and anaerobic phases, maintaining inorganic material in the leachate bay reactor, separating the inorganic material from the leachate digested, and producing a soil amendment from waste material in the leachate bay reactor.    USE - The method is useful for hydrolysis and methanogenesis in separate stages for digesting organic waste material.    ADVANTAGE - The method allows effective, rapid and economic hydrolysis and methanogenesis with separate stages in an environmentally friendly manner with improved hydrolysis rates and increased total gas production.    DETAILED DESCRIPTION - The method comprises recirculating leachate between a leachate bay reactor and a leachate storage tank, cycling leachate from the leachate storage tank to a fixed film environment in a high rate reactor for methogenesis (130), processing multiple substrates with varying solids content, co-digestion of substrate, digesting leachate in a dual mode using separate aerobic and anaerobic phases, maintaining inorganic material in the leachate bay reactor, separating the inorganic material from the leachate digested, producing a soil amendment from waste material in the leachate bay reactor, slowing leachate flow when gas production drops, and reducing ammonium and phosphate accumulation in the leachate. An operation is under anaerobic conditions until organic material sollubilization into a liquid phase is maximized then operation under anaerobic conditions is terminated. The operations include aerating to compost recalcitrant materials. An INDEPENDENT CLAIM is included for a digester system with separate stages for hydrolysis and methanpgenesis.    DESCRIPTION OF DRAWING(S) - The figure shows a flowchart of a biological process.    Organic waste material (105)    Hydrolysis (110)    Acidogenesis (120)    Acetogenisis (125)    Methanogenesis (130)    Biogas. (140)