3.1.01 Learning from the best – benchmarking in the field of wastewater disposal

3.1.01 Learning from the best – benchmarking in the field of wastewater disposal

In 2002, the German Bundestag initiated a modernisation strategy for the German water industry in the form of its resolution “Sustainable water management in Germany”. This also includes the development of modern procedures for comparing the performance of different operations (benchmarking). In its corresponding project, the water board Emschergenossenschaft/Lippeverband (EG/LV) – in conjunction with its partners Aggerverband, RINKE Unternehmensberatung and the Universität der Bundeswehr München (Bundeswehr University Munich) – adapted this method to the field of wastewater treatment and devised strategies for its application in other areas of the water industry. The project thus became a building block of the modernisation strategy and set the tone for the successful development of the benchmarking instrument.

The boundary conditions for the water economy have changed significantly: demands for efficiency have risen and fees are now only accepted if the underlying costs are sufficiently transparent. To be able to perform their duties in a reliable and economical manner, companies must devise methods for efficient wastewater disposal without losing sight of other important requirements. Launched by EG/LV in 1999, the aim of the project “Benchmarking in wastewater disposal on the basis of techno-economic indicator systems” was to improve the operational processes in sewage plants. Since benchmarking was an entirely new concept in the water industry at the time, its implementation required a significant amount of development work. One particular challenge facing the project partners was to ensure the comparability of the various technical solutions and their costs despite the differing boundary conditions. This required the development of standardised assessment criteria. The partners compared over 100 sewage plants with population equivalents (PE) of 420 to 2,400,000. The project consisted of four parts:

1. Application of the methodology to all plants
The results of a precursor project concerning the benchmarking of sewage plants with a PE of 10,000 to 100,000 were applied to all EG/LV and Aggerverband plants. The experts defined the technical and economic parameters to be determined, collected the data, calculated the performance indicators, analysed the reasons for deviations from the optimum values and identified improvement measures. To compare the “wastewater treatment” process across multiple plants, six sub-processes were Learning from the best – benchmarking in the field of wastewater disposal examined: mechanical, biological and advanced purification, sludge stabilisation, sludge recycling and disposal as well as miscellaneous facilities (e.g. external plants, labs and workshops).

2. Creation of strategies for the inclusion of other operators
The experts also succeeded in including other operators of treatment plants with different databases in the benchmarking process. The parameters were adjusted according to the requirements of small and medium-sized enterprises.

3. Generation of techno-economic assessment criteria for planning
The benchmarking not only relates to plant operation but also to planning. EG/LV has documented the investment costs for all its plants, sub-divided into the cost types structural engineering and mechanical/electrical engineering. Based on the established data, the experts are able to assess the economic efficiency of structural solutions and process combinations in terms of investment costs and operational expenditure.

4. Development of the methodology for other areas of wastewater disposal
The project partners also applied the benchmarking process to other areas, such as wastewater discharge. For this purpose, they created survey forms, which were tested with other local authorities along with the system itself. The benchmarking of rain overflow basins and pump stations of the sewage network was also examined.

Practical benefits

The venture succeeded in establishing a solid foundation for benchmarking in the water industry. The method is now used throughout the world and is helping to reduce annual operating costs by 3 to 12%. Furthermore, sewage plants of all sizes can be compared using a techno-economic indicator grid. Since the performance indicator system presents all wastewater disposal sub-processes in a uniform manner, comparisons of individual process steps are also possible. Targeted improvements can thus be made on a structural and selective basis.

The experts enhanced the system to be able to implement the requirements of the EU Water Framework Directive. The results of the project served as the basis for the benchmarking organisation aquabench GmbH, which is made up of Emscher Wassertechnik GmbH and Aggerwasser GmbH, the cities of Hamburg, Bremen, Dresden, Zurich, Cologne, Düsseldorf, Munich and Berlin – or their corresponding water companies – as well as the consulting firm on.valco. aquabench provides online access to a wide range of benchmarking products, which relate to different processes and enable comparisons at company level.

The experts continuously presented the results of their research project and experiences gained from follow-up projects to the relevant trade associations. A uniform, quality-assured process is supported by a leaflet and guidelines published by the German Association for Water, Wastewater and Waste (DWA) and the German Technical and Scientific Association for Gas and Water (DVGW) as well as an example indicator system of the DWA. Since 2005, the associations have also been informing politicians, the public and companies about the industry’s performance via their “Profile of the German water sector”. Benchmarking projects are now conducted and corresponding reports published in virtually all German states (e.g. www.abwasserbenchmarking-nrw.de; only in German).

The aim is to continue the proliferation of benchmarking and to establish an international performance indicator basis to enable comparisons between different projects. In accordance with the Water Framework Directive, means of extending the observation period beyond company boundaries must also be examined. An initial investigation of this subject was performed by EG/LV, aquabench, the Universität der Bundeswehr München (Bundeswehr University Munich) and the University of Duisburg-Essen in their pilot project “Benchmarking the management of river basins◄”.

Project website http://www.aquabench.de/index_1__1_gb.html