The Department of Urban Water Management has a long experience with wastewater disposal in rural areas. Many projects and publications have been made (http://www.siwawi.tu-berlin.de/) Different researches on the comparison of small scale wastewater treatment plants have been carried out especially regarding nutrient removal. Already in the early 90s Prof. Barjenbruch was responsible for the test procedure for the permission to sell small treatment plants in Germany. His special engagment in the DWA (German Association for Water, Wastewater and Waste) in various working groups for wastewater treatment and operation brought much benefit to practice and research. He was leading the work of the DWA working paper DWA-A 202 for P-removal. He is also a member of the DWA Board of advanced wastewater treatment including nutrient removal. The Baltic sea is always in the focus. The department took an important part in the Project on Reduction of Eutrophication of the Sea TOday PRESTO together with the Union of the Baltic Cities (UBC) and partners in Belarus, founded by EU. The gained results of special projects for small and rural watewater treatment like „Comparative study of small wastewater treatment technologies under special operation conditions at BDZ test field in Leipzig (COMPAS)” and „Efficiency of multi-chamber systems” can offer much input into this project.