Realisation of the EU Directive 91/271/EWG in Germany technical and economic effects from the perspective of an operator of large wastewater treatment plants

In the Federal Republic of Germany, the requirements on the effluent quality which wastewater treatment plants (WWTPs) with a design value larger than 100,000 PE must achieve in regard to the parameter Nanorg were increased by a national regulation on 01/08/2002. The reason for this action was a pending threat of the European Court because of the insufficient realisation of the EU Municipal Wastewater Directive (91/271/EWG). The report at hand describes the consequences of such an increase of the requirements for operators of WWTPs, using the example of Emschergenossenschaft and Lippeverband. The currently applicable demands in Germany are compared to those valid on a European level, and the current construction and performance state of the WWTPs operated by Emschergenossenschaft and Lippeverband is presented. The secure compliance with the increased requirements necessitates optimisation measures, but also construction measures; these are described in regard to their technical realisation and the prospective costs.