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

4.4 Surface water quality sampling.
MONITORING NETWORKS AND METHODS
Surface water samples were obtained along the 23.8 km section of the River Tame between
Bescot and Water Orton gauging stations (Figure 4.1, Appendix 10). A series of ~40 samples
were taken to form a longitudinal profile along the river, and this was repeated four times
during the project. Daily variations in water quality were examined at one site by repeat
sampling through the course of a day. On four occasions surface water samples were taken in
conjunction with river discharge measurements to enable estimates of total mass flux within
the river to be made. Surface water sampling was conducted only during periods of dry
weather flow with no rainfall having occurred within the preceding three days. A sampling
device was constructed to allow representative samples to be collected from the approximate
mid-depth of the river. A weighted ceramic jar with a cork seal was lowered on a string into
the river and the seal removed only when the required depth was attained to prevent sample
bias (e.g. volatilisation) which may occur close to the river surface. Samples for volatile
organic compound (VOC) analyses were placed directly into the sample vial without
filtration. A series of samples were taken from different positions in the river channel at the
same time to determine the degree of variation in concentration across the channel. As part of
a comparative study a total of three surface water samples and two samples of spring water
were taken from Sutton Park.
4.5 Groundwater quality sampling.
4.5.1 Riverbed piezometers
Several methods were considered for assessing groundwater quality and flow through the bed
of the Tame. Both seepage meters and mini drive point piezometers have been used by
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