The impact of urban groundwater upon surface water - eTheses ...

1.1 Project outline
CHAPTER 1. INTRODUCTION
INTRODUCTION
The development of conurbations in the vicinity of river systems is common. Such
urbanisation may cause contamination of land and underlying groundwater by a wide range of
substances (Lerner et al, 1996), with the attendant risk of contamination of urban surface
waters. Also, any improvements achieved in the quality of surface water, as a result of better
control of industrial effluent discharges and industry closures, may be limited by the long-
term release of pollutants from contaminated land to the underlying groundwater that
subsequently discharges to urban river systems. Poor quality surface water will have a
negative impact on the local ecology, on the potential for potable supply and on the amenity
value of the river, both locally and perhaps for a considerable distance downstream.
Impetus for the study of the impact of contaminated land on baseflow and urban surface water
quality is driven by several factors. These include UK legislation covering the regulatory
assessment of liability with respect to local surface water receptors (Environmental Protection
Act, 1990); and the new European Commission Water Framework Directive (Council of
Europe, 2000). The latter provides for integrated catchment management of both groundwater
and surface water. In addition, the processes occurring in the groundwater/surface-water
interface (the hyporheic zone) merit study as they may reveal ‘natural attenuation’ of
contaminants which could limit the impact of the contaminants on the surface-water quality
(Environmental Protection Agency, 2000). The above considerations have provided the
underlying rationale for the current research.
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