NEAR BED SOLIDS TRANSPORT IN SEWERS

This paper describes the results of three sewer sediment studies, carr ied out in Dundee, financed by the Engineering and Physical Sciences R esearch Council (EPSRC) and the Water Research centre (WRc). The work was carried out by the University of Abertay Dundee (Wastewater Techno logy Centre) as pan of a collaborative research project undertaken wit h the University of Newcastle and the University of Sheffield. In Dund ee, through collaboration with the sewerage system operator (Tayside R egional Council Water Services Department), three field sites have bee n established in interceptor and trunk sewer sires, since 1992, to mon itor, as closely as possible, sediment and other pollutant erosion, th eir transport and the effects of first flushes. The physical and bioch emical nature of the material being transported near the bed of real s ewers has been measured. The importance of this mode of transport, in terms of mass transported and pollutant potential, is demonstrated bas ed on data collected from the Dundee system sites. Comparisons are mad e between measured transport rates at the bed, at sites with and witho ut deposited beds, with results obtained by applying empirical relatio nships developed to predict near bed transport in laboratory studies. A modified relationship is proposed which best fits the Dundee system data. Copyright (C) 1996 IAWQ. Published by Elsevier Science Ltd.