Authors

M. G. Faram, J. M. Saker & V. M. Story

Abstract

This paper presents a study of UK water industry capital equipment selection, focusing in particular on behaviour in relation to sewerage/combined sewer overflow (CSO) and wastewater-associated investment activities. Valuable new insights into the perspectives of different parties, including water service providers (WSPs), design consultants and construction companies, are provided. Through analysis of over 200 questionnaires, equipment selection is confirmed to be multi-organisational, with different parties dominating different roles. Among the selection criteria, service and quality are found to be valued as parameters worth paying for. Relationships and sustainability considerations are also found to be important, although views on whether sustainability benefits will be paid for are divided. While interparty alignment of views is generally good, there are occasional discrepancies at the individual water region level. It is suggested that optimisation might derive from recognising the significance of intangible components of the supplier offering, and managing relationships to allow these to be capitalised upon.

Authors

S.P. Hides, R.Y.G. Andoh and P. Carroll

Abstract

Sewer systems evolved as part of the human development process to meet the challenges of effectual draining of urbanizing areas. In the recent history of human development, following the implementation of wastewater treatment plants to control point sources, a shift occurred with wet-weather induced overflows from sanitary sewer systems (SSOs) and combined sewer systems (CSOs) being deemed to be a major cause of water quality impairment in urban streams, rivers and other receiving waters. The general move was towards separate sewers, one to convey foul water (sewage) and the other to convey the supposedly cleaner stormwater runoff to the nearest watercourse.

With the increased awareness, in more recent times, of the adverse environmental impacts of stormwater runoff and other diffuse wet-weather discharge sources, the need has arisen for stormwater control and treatment systems. There is a need now for a more holistic approach to be adopted in the development of solutions to wet-weather induced problems in the drainage of urban catchments. This paper reviews approaches to the management of urban wet-weather such as stormwater runoff, premature overflows, basement backups and flooding; outlining case examples of the successful application of non-conventional, innovative, novel and emerging approaches, techniques and devices that assist in the better management and control of inflow sources and water quality. This involves the seeking of solutions within the upstream portions of drainage and sewer systems by intercepting, containing, controlling and treating excess wet-weather flows before they cause hydraulic and water quality problems in downstream areas / sections of drainage systems.

Authors

LeCornu, J.P. and Faram, M.G.

Abstract

The ability to accurately and reliably control flows in drainage and sewerage systems is critical for the effective operation of such systems. The use of inaccurate or unreliable flow controls can lead to adverse effects including flooding. Conventional methods for the calibration of flow controls are time consuming and can suffer from poor repeatability.

This paper describes work carried out with the aim of developing new, improved methods, to both enhance accuracy and improve repeatability, while also reducing test times. In order to achieve the objectives, a PROFIBUS based instrumentation and control system was fitted to existing hydraulic test facilities, operated by Hydro International. The new methods, applied to the calibration of vortex flow controls and orifice plates, show potential to reduce test times by a factor of more than ten, while also increasing the accuracy and repeatability of results.

Authors

D.A. Egarr, M.G. Faram, I. Guymer, T. O’Doherty, N.Syred

Abstract

The fluid residence time characterisation of a 3.4m diameter Hydrodynamic Vortex Separator (HDVS) has been carried out over a range of flowrates. Computational Fluid Dynamic (CFD) modelling has also been undertaken for the same conditions and validated against the experimental results, for which reasonable correspondence has been found. Using the results from the CFD modelling and batch inactivation results from the disinfection of secondary treated wastewater, it is shown that the theoretical performance of a HDVS as a contact vessel for disinfection can be predicted.

Authors

R.Y.G. Andoh, A.J. Stephenson and P. Collins

Abstract

The need for a more holistic approach in the development of solutions to wet-weather induced problems in urban drainage systems is advocated. A review of current approaches to resolving problems of premature overflows and flooding is presented outlining a case example of the successful application of non-conventional approaches, techniques and devices that assist in the better management and control of wet-weather flow sources. This involves the seeking of solutions within the upstream portions of drainage systems by intercepting, containing, controlling and treating excess wet-weather flows before they cause hydraulic and water quality problems in downstream areas (sections of the drainage system). These approaches have been found to be more cost-effective than conventional solutions and involve the implementation of distributed/decentralised schemes which in turn offer improved opportunities for wider community and other stakeholder involvement leading to the realisation of amenity and other non-structural benefits.