As the basis of the economic evaluation, the conventional process stream at NWWTW was considered. A total solids inflow was 1.5 times that of the current maximum capacity of the NWWTW plat. The cost of the conventional process and the coupled CFMF/digestor process were determined from data supplied by NWWTW personnel. Over a project life of 20 years, the total cost of the coupled procedure including labour, electricity, capital redemption and maintenance, is 11/240% less than that of the conventional process stream. Thus, the economic evaluation indicates that the coupled CFMF/digestor system is economically feasible.