Sustainabilitylive! 2012 Seminar Programme - Chlorofluorocarbons as tracers of landfill leachate in surface and groundwater.

The widespread use of chlorofluorocarbons (CFCs) as refrigerants, aerosols and foam insulation gases has led to their ubiquitous presence in modern landfills. Landfill leachates may have concentrations of CFC11, CFC12 and CFC113 thousands of times higher than in uncontaminated surface and groundwaters. Such great disparity offers a means of using CFCs as tracers of environmental contamination by landfill leachate. The threshold at which diluted leachate can be detected is around 0.1 to 1%, compared with 10 to 50% for conventional indicators such as COD, Cl- or NH4+. A single, systematic survey may establish the extent and pattern of a leachate plume, whereas conventional indicators must rely on monitoring continued over many years to establish trends rising above background. This paper presents results from several such surveys of UK landfills. This presentation is for anyone interested in landfill monitoring and hydrology, and is of broader interest to hydrogeologists, environmental scientists and anyone else interested in environmental tracers. Delegates will learn a new method for rapidly identifying leachate impacts to surface and ground waters in the vicinity of landfills.