An Initial Screening Tool for water resource contamination due to development in the Olympic Park 2012 site, London

Abstract

Groundwater is the primary source of potable water in southeast England. Its protection in urban environments is of paramount importance. Following a scoping study the British Geological Survey (BGS) established a project to develop an initial screening tool (IST) to assist the planning community in the assessment of the potential risk to ground and surface waters from contaminants mobilised as a consequence of redevelopment. The tool has been designed in the context of the source-pathway-receptor paradigm that informs Part IIa of the UK Environmental Protection Act (1990). Building on the work of previous screening tools and in particular ConSEPT, a BGS contaminated site evaluation and prioritisation tool, the IST incorporates significant refinements to scoring methodologies and takes the prioritisation approach into the 3-D environment. Implemented as a customised GIS application and utilising surfaces extracted from 3-D geological modelling, the tool collates and interrogates a range of geoscientific information, including: contaminant scale, geological, historic land use, groundwater level and hydrogeological domain data. The IST facilitates the ranking of various proposed development scenarios through a semi-quantitative assessment of contamination potential, via a number of pollutant linkages, providing planners with reports on the type, spatial distribution and hazards associated with potential contaminant sources within their area. To achieve this, a range of evaluation factors applied to the sources, pathways and receptors are scored through a combination of spatial and attribute queries, then assessed on the basis of potential linkages. The initial research area selected for the application of the IST was the Olympic Park site, London