WITH INCREASING SEWER CHARGES AND FUEL COSTS, AN INVESTIGATION WAS INITIATED TO REVIEW AN ANAEROBIC PRETREATMENT ALTERNATIVE IN 1981. AFTER EXTENSIVE EVALUATION, IT WAS DECIDED THAT THE UPFLOW ANAEROBIC SLUDGE BLANKET PROCESS SHOWED THE GREATEST POTENTIAL FOR SUCCESSFUL APPLICATION. A PILOT STUDY WAS CONDUCTED IN 1982 TO DETERMINE THE LOADINGS, WASTE CHARACTERISTICS, REMOVAL EFFICIENCIES, GAS QUANTITY AND QUALITY, AND OTHER REQUIREMENTS. BASED ON THE SUCCESSFUL OPERATION OF THE PILOT STUDY, A FULL SCALE SYSTEM WAS DESIGNED AND BUILT AND BEGAN OPERATION IN MARCH 1985. THIS PLANT, WITH SOME MINOR MODIFICATIONS, IS STILL IN OPERATION TODAY AND IS THE FOCUS OF THIS PAPER.