The project consisted of removal of a steel dome on the existing 40′ diameter Digester #1 and then installing an inflatable diaphragm dome with associated structure supports. Hydraulic Mixers were installed in Digester #1 to increase the mixing action of the digested sludge. Adjacent to Digester #1, a concrete containment area approximately 51′ x 28′ was constructed with a 12,000 gallon fuel, oil and grease storage tank and pump to discharge to the retrofitted Digester #1. A concrete pad approximately 16′ x 10′ was constructed to mount the Sludge Thickener and pumping appurtenances. Above ground piping and valves, along with pipe insulation and heat trace completed this project. The project was funded by the California Energy Commission and was constructed for Anaergia.