On the set-up of field research in sumps of wastewater pumping stations

Alex Duinmeijer, Francois Clemens, Ivo Pothof, Femke Verhaart

Thursday 2 july 2015

9:30 - 9:45h at South America (level 0)

Themes: (T) Water engineering, (ST) Experimental facilities and instrumentation

Parallel session: 10C. Engineering - Industrial

On the set-up of field research in sumps of wastewater pumping stations Alex Duinmeijer (a,b), Ivo Pothof (a,c), Francois Clemens (a,c) & Femke Verhaart (c) (a) Water Management Department, Faculty of Civil Engineering and Geosciences, Delft University of Technology, PO Box 5048, 2600 GA, Delft, The Netherlands E-mail (Corresponding author) (e) Engineering Agency Municipality of Rotterdam, PO Box 6633, 3072 AB, Rotterdam, The Netherlands (c) Deltares, PO Box 177, 2600 MH, Delft, The Netherlands Abstract A large number of sumps of wastewater pumping stations experiences problems due to the presence of sewer sludge, floating fat, scum and other floating debris (hereafter referred to as ‘pollution’). This pollution can result in pump failures. It has been shown that the occurrence of pump failures has a significant impact on the serviceability of sewer systems such as a 16% increase of the yearly volume of CSO’s. In the current guidelines (e.g. ANSI/HI 9.8-2012) for sump design, guidelines with respect to pollution is only dealt with, in a superficial manner, for a limited number of sump geometries (i.e. trench type and circular sumps). Basically there is a need for a more generic formulation of guidelines. The current guidelines provide optimal hydraulic conditions in the sump and are, to the knowledge of the authors, only verified for clean water sumps. Applying measures to prevent vortices and air entrainment may even result in an increase of the pollution. Therefore, future guidelines should seek for a balanced compromise between avoiding poor flow conditions and air-entrainment on one hand and avoiding the development of pollution on the other hand. Furthermore, experimental data from real wastewater sumps is considered essential for science-based optimised design of wastewater pumping stations. Three classes of experimental parameters have been identified: _ sump geometry; _ pump operation, including capacity and suction level; _ sewage composition. The proposed paper will address all relevant issues and limitations for the set-up of an experimental field campaign. This reflection will result in a comprehensive description of the experimental set-up and possibly an analysis of the first results.