A microcomputer simulation model was developed to compare sludge disposal alternatives for an urban region. The model calculates both capital and operation costs for sludge treatment and disposal operations. For a study of an urban region with an equilibrium wastewater generation rate of 44.74 million m³/yr, the optimum sludge disposal alternative was dedicated land disposal for a baseline analysis of wastewater sludge treated by gravity thickening and anaerobic digestion. The capital cost at system equilibrium is $6.09 million and the total cumulative operation and maintenance cost over 100 years is $103.2 million. The operation and maintenance cost is 94% of the total capital and cumulative operation and maintenance cost. A description of the investigation and the criteria used for selection of this sludge disposal alternative ls included / Master of Science