Advances in Water Treatment and Enviromental Management

GROUNDWATER POLLUTION BY VOLATILE ORGANIC SOLVENTS 203ResultsThe results of the Phase I investigation showed the chalk aquifer to be widely contaminatedwith TCE, PCE and TCA. Although the concentrations within the main chalk aquifer weregenerally moderate (10 to 100 µg/1), very high levels of TCE were measured in the upper, lowpermeability weathered putty chalk at one site (Borehole 6–19,850 µg/1) and in the permeabledrift above this putty chalk at a second site (Borehole 1–25,300 µg/1). Localised pollution byCTC was also detected at two other boreholes. The extent of the main areas of contaminationis shown in Fig. 2. The distribution of the pollutants suggested that there have been multipleslugs of organic solvents entering the groundwater system at a number of sources over severalyears.Fig 3 Example of Contaminant Profiles with DepthCase Study ‘A’