The management of sediment in combined sewers

Sediments in sewers are ubiquitous because of the diverse nature of the inputs. Over the past decade or so, new understanding of the provenance, behaviour and nature of sewer solids is now allowing more effective means for solids management. Whilst current computer models are good at representing the hydraulic performance of sewer systems, their handling of sewer solids and associated processes is still embryonic. Hence any attempts to manage in-sewer solids more effectively require a diversity of approaches, both for any modelling studies and for the selection of the most appropriate option. Little information currently exists on which to draw to determine cost-effective or wholelife solutions. Nonetheless significant advances have been made in enhancing the traditional approaches to sewer solids management which have been in use for more than a century.