Planning and operation of drinking water distribution systems with regard to the avoidance of regrowth occurences< Back

DVGW project W 6/01/05

In some regions of Germany, the trend of declining water consumption will go on. Thus, water companies have to cope with the question what kind of action has to be taken in order to assure bacteriological water quality. This affects the operation of existent networks as well as the planning of new pipelines.

A process model was developed at TZW Dresden by which we were able to explain the bacteriological processes in several drinking water networks in Germany. However, it is necessary to clarify the extent of disturbances in connection with regrowth ocurrences.

The objectives of this study are
1.) to develop recommendations for operation and planning of distribution systems with regard to the avoidance of regrowth within the distribution network
2.) to verify a mathematical water quality model simulating the bacteriological situation for the applicability in existing networks.

Studies are performed with a test rig varying the different biofilm situations, organic nutrients, temperature, and disinfection residuals. Besides standard microbiological methods, the characterisation of biofilms includes possible shifts in populations which are detected by T-RFLP analysis in cooperation with Dresden University of Technology.