Process for treating and disposing of sewage sludges of a region

The invention relates to a process for treating and disposing of sewage sludges in a region having a plurality of sewage treatment plants. Preferably, the process is useful starting from a total disposal throughput of more than 100,000 population equivalents. A central sewage sludge disposal is provided with mobile sludge dewatering units which, after on-site dewatering, transport the sewage sludge concentrate to a central sewage sludge disposal plant where they are then subjected to composting or mechanical secondary dewatering with or without subsequent drying and combustion. The content of heavy metals is determined before or after sludge preliminary dewatering by analyses to establish which contaminated sludge volumes, depending on the landfill requirement, are subjected to secondary dewatering, and then are dried and/or incinerated.