Authors

Lisa Glennon, Marcus Mumford, Uday Khambhammettu, Robert Pitt

Abstract

Runoff from urban drainage areas is a major source of diffuse pollution containing high concentrations of pollutants such as phosphorus and silts (sediments in the 3.9 to 62.5 μm range). Urban drainage areas such as parking lots, vehicle fueling and maintenance stations, and public works storage areas have been dubbed critical source areas due to the observation that runoff from these areas may contain high pollutant loadings of varying diffuse pollutant classifications, including trash and other debris, coarse and fine sediment, hydrocarbons, toxic trace metals, nutrients such as phosphorus and nitrogen, pathogens, and/or other toxicants (Bannerman, et al. 1993; Pitt, et al. 1995; Claytor and Scheuler 1996). One approach to stormwater treatment is to treat urban runoff at end-of-pipe, once runoff from critical source areas has mixed with runoff from less polluted areas. An alternative approach is to use small-footprint treatment devices upstream at critical source areas before the runoff mixes with larger volumes of less polluted runoff. Treatment devices installed at critical source areas need to incorporate several treatment processes, such as sedimentation, screening, and filtration, to target the different classifications of pollutants and respond to the inherent variability of runoff quality from different types of critical source areas (Pitt, et al. 1999). An upflow filter device equipped with a pre-settling sump and a coarse screening system has undergone a full-scale field evaluation at a site near the City Hall in Tuscaloosa, Alabama as part of a Small Business Innovative Research (SBIR) project funded by the United States Environmental Protection Agency (US EPA). This paper presents results of ongoing comprehensive characterization and performance evaluation of the upflow filtration unit tested under controlled laboratory conditions at Hydro International's hydraulics facility in Portland, ME, and compares the results to the field data collected by the University of Alabama (Pitt, et al. 2005; Khambhammeettu 2006).

Authors

Amos Kabo-Bah, Robert Andoh, Samuel Nii Odai and Kwabena Osei

Abstract

Rainwater Harvesting, a traditional practice in parts of Ghana many centuries ago, has received very little attention in recent times. The paper describes a collaborative research effort aimed at the adaptation and development of affordable technologies for capturing and retaining rainwater runoff including that from roof tops; and using this as a valuable source of water to supplement the water needs of households in Northern Ghana. The project also ultimately seeks to address issues of flooding and erosion caused by the lack of adequate drainage through the effective capturing, retention and controlled release of rainwater. The Project will verify the extent to which adoption of the adapted technologies could help greatly in conserving water resources in the Sahel and other semi-arid regions in developing countries and at the same time helping to alleviate poverty by improving the quality of life of women and children in these regions. The rainwater harvesting systems will be designed and implemented adopting an integrated approach utilizing expertise from a collaborating team comprising engineers, agriculturists, economists, sociologists and a practitioner of rainwater harvesting (and other water conservation technologies). It is envisaged that the systems would enable poor households in the community to supplement their water supply needs as well as engage in small scale backyard gardening; extend their cropping seasons through improved security of water resources, ultimately enhancing food security and contributing to poverty reduction.

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.

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

Michael G. Faram, Kenneth O. Iwugo and Robert Y. G. Andoh

Abstract

Sediment entrained in urban run-off is acknowledged as being an important carrier of pollutants. The paper reports on the physical and chemical characteristics of sediments captured by six installations of a proprietary interceptor device. The sites, located in the United Kingdom and the Republic of Ireland, were selected to represent a range of urban contexts. Particle D50 values were found to range from 7 to 112 microns, corresponding with ranges reported for stormwater ponds. Heavy metal and hydrocarbon concentrations were also found to vary, with the highest corresponding to the most established and heavily trafficked sites. Further to confirming the ability of the interceptor to remove contaminated sediments, useful insights are provided into the interrelation between sediment characteristics and site conditions.