|| Within a series of processes, slaughterhouses produce large amounts of different wastes and wastewaters. The problems are complex: many slaughterhouses are located in the centres of the cities, traditional ways to make use of the wastes such as application to agricultural land are not applicable because transport distances have become too long. Direct disposal of highly polluted wastewater and organic residues into the sewerage system without prior treatment on the other hand is mostly not acceptable due to resulting environmental and ecological problems and the risk of clogging in the wastewater piping systems. An estimated 20% to 30% of the slaughtering costs are generated by the costs for water, waste treatment and energy. Here, anaerobic processes can contribute in an interesting way to improve the situation.