Author

A.G.Stephenson

The problems surrounding how we deal with stormwater run-off and issues such as drought, flooding and water pollution have been well publicised in recent years fuelled, to great extent, by the growing consciousness of climate change. The summer floods of 2007 throughout the UK also led to the publication of several reports such as Sir Michael Pitt’s Interim Review and the more recent Flooding report from the House of Commons Environment Food and Rural Affairs Committee. DEFRA have also published Future Water, the Government’s water strategy for England and all of these documents have heightened awareness of the benefits of sustainable drainage and the contribution that can be made to reduction of flood risk. There are many methods available and approaches in the SUDS ‘toolbox’ but all too often designers are restricted to ‘soft’ or natural options or what have become known as traditional SUDS, failing to consider some of the innovative proprietary solutions that have been used for many years which have provided very robust, cost effective and reliable answers. This paper will use an interesting case study to demonstrate how these systems have been used in conjunction with traditional SUDS options resulting in a complimentary, holistic solution helping create a whole sustainable community.

Authors

D.A. Phipps, R.M. Alkhaddar and M.G. Faram

Abstract

In recent years, various proprietary treatment technologies have evolved to reduce the polluting impact of urban run-off on receiving watercourses. The majority are ‘flow-through’ devices, designed to intercept and store pollutants in submerged chambers for later removal and safe disposal. Frequently, the performance of such systems is described solely in terms of ‘ability to remove pollutants from the inflow’, usually at specified discrete flowrates. However, it is suggested that this is insufficient to give a true assessment of performance and a critical parameter that is often overlooked is chamber ‘retention efficiency’, the ability of a chamber to retain stored pollutants once collected. In the current study, this parameter is investigated experimentally for a range of chamber configurations. Cylindrical chambers with different inlet orientations, internal components and hence flow dynamics are considered. The study identifies retention efficiency as being a major differentiator between designs, and concludes that chambers in which captured pollutants are stored in regions that are hydraulically isolated from the main treatment area are likely to be the most effective in practice.

Authors

David A. Phipps, PhD, Rafid M. Alkhaddar, PhD, James Dodd, Michael G. Faram, PhD, Pamela J. Deahl, P.E.

Abstract

With the objective of reducing the polluting impact of urban run-off on receiving watercourses, various proprietary treatment technologies have evolved, including ‘flow-through’ devices that are designed to intercept and store pollutants such as sediments and floatables for later removal and safe disposal. Frequently, the performance of chambers is stated in terms of ‘ability to remove pollutants from the inflow’, often at discrete flowrates. However, a parameter that is often overlooked is chamber ‘retention efficiency’, the ability of chambers to retain stored pollutants once collected. The paper presents the findings of both simulation and experimental studies of different designs of treatment chamber, focussing in particular on the ‘retention efficiency’ parameter. It is concluded that chambers in which the pollutants storage region is isolated from the main treatment area are likely to be most effective.

Authors

Robert Andoh, Robert Pitt and Lisa Glennon

Abstract

An advanced novel stormwater filtration system utilizing the upflow mode of filtration as opposed to the conventional down flow or radial flow filtration is described. The technology developed under the US EPA’s Small Business Innovative Research (SBIR) program, incorporates elements of a treatment train approach including screening, sedimentation and high-rate filtration in a compact modular device designed to treat different classifications of stormwater.