The Emschergenossenschaft plans to improve the Emscher drainage system by separating sewage and clean water. 6 or 7 subcatchment areas will be created and served by separate wastewater treatment plants. The Bottrop WWTP has been planned for 1.3 million population equivalents. It is scheduled to start operation in 1995 and its costs are estimated as totalling 820 million DM in total. Biological treatment will be effected by a low-loaded, single-stage activated sludge system with cascade denitrification and modified UCT process.
