Assessing urban groundwater quality using biological and chemical methods

Groundwater is an important resource in the UK, with 45% of potable water in the Thames region being derived from subterranean sources. In urban areas, such as the west of London, groundwater has been contaminated with pollutants over a long period. With the introduction of new legislation to protect groundwater, the rapid assessment of groundwater quality has become increasingly important. Groundwater quality is currently assessed using a range of chemical species to determine the extent of contamination. Analysing a complex mixture of chemicals is both time consuming and expensive, whereas using an ecotoxicity test (bioassay) provides information both on the degree of contamination present in the groundwater, and the potential effect of that contamination on surface water bodies with which the groundwater is in continuity. Microtox (TM), Eclox (TM), and Daphnia magna microtests, were used to assess the contamination of groundwaters from sites throughout the west London area.