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

REVIEW
and under conditions of non-uniform recharge adjacent to a surface water body (Winter, 1983,
Cooley 1983). Models have been used to evaluate the effect of groundwater pumping on
stream flow for water resources and environmental impact purposes (Sophocleous, 2000,
Eberts and Blair, 1990). Flow and transport modelling has been used to investigate solute
(contaminant) transfer between groundwater and surface water on the regional scale (Duffy
and Lee, 1992, Jakeman et al., 1989). Geochemical models such as the USGS model
PHREEQC have been used to simulate solute fate and transport across the
groundwater/surface water interface (Van Breukelen et al., 1998).
2.6 Conclusions
Groundwater/surface water quality and flow interactions are complex and variable between
and within catchments. Further work is required to better understand the link between quality
and flow processes, particularly in an urban setting where research to date has been limited.
The groundwater/surface water interface is ecologically important and is a major pathway for
mass transfer between the subsurface and surface. Contaminant and nutrient concentrations
within both the groundwater and surface water may be altered significantly during their
passage through the groundwater/surface water interface. The interface often shows high
environmental and concentration gradients. Significant processes that occur across this zone
that may affect contaminant fate and transport include; sorption and precipitation reactions
and bacterial activity which may mediate chemical reactions and degrade organic
contaminants. The key references identified in the review of groundwater-surface interactions
were, Sophocleous (2002), Winter et al. (1998), EPA (2000), and Woessner (2000). Useful
case studies of groundwater quality and flow interactions were Cey et al. (1998) and Gburek
et al. (1999).
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