River basin management, described for the example of the Emschergenossenschaft.

Considerable problems concerning drainage capacity made it necessary, at the beginning of the 20th Century, to make a joint public-private effort, because the existence of the Ruhr Area as an industrial location was endangered. By Prussian law a co-operative was established for wastewater and drainage-management of the entire Emscher river system. In the past the Emscher Association and the later founded Lippe Association have proved to be the best instrument to cope with the wastewater problems of a densely-populated industrial area. In recent time, the Emscher area is undergoing fundamental structural changes. To increase its attractiveness increased efforts are needed for a modernisation of the wastewater transport and treatment system. To deal with the various and complex tasks to reshape the Emscher system, the joint association again provides a highly efficient and competent instrument.

Benchmarking--an approach to efficiency enhancement in planning, construction and operation of wastewater treatment plants.

In the following paper the technique of benchmarking was transferred to the field of wastewater treatment. The method was developed within a pilot project, in which 4 wastewater treatment plants (WVTP) (size category: 10,000-100,000 p. e.) of the Emschergenossenschaft/Lippeverband and the Aggerverband were involved. Meanwhile this method is applied to more than 100 WWTP. Specific technical and economic parameters were determined for the whole treatment plant and afterwards assigned to the different treatment steps. With these numbers differences between the examined plants and the respective benchmarks were visible. On the basis of the following cause analysis a schedule could be developed containing at first measures, which could be translated into action immediately. The less obvious reasons for differences between individual numbers required a deeper cause analysis. Because of external influences not all the plants can reach the benchmarks.