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 pro ject, in which 4 wastewater treatment plants (WWTP) (size category: 10,000- 100,000 p. e.) of the Emschergenossenschaft/Lippeverband and the Aggerverba nd were involved. Meanwhile this method is applied to more than 100 WWTP. S pecific technical and economic parameters were determined for the whole tre atment plant and afterwards assigned to the different treatment steps. With these numbers differences between the examined plants and the respective b enchmarks were visible. On the basis of the following cause analysis a sche dule could be developed containing at first measures, which could be transl ated into action immediately. The less obvious reasons for differences betw een individual numbers required a deeper cause analysis. Because of externa l influences not all the plants can reach the benchmarks.