Fluorescence of dissolved organic matter as a natural tracer of ground water

The fluorescence properties of dissolved organic matter (DOM) in ground water in the Permian limestone of northeast England determined from six monitoring boreholes, a private water supply well and from a natural resurgence in a Hooded collapse doline the environs of Darlington, County Durham, northeast England. Measurements of both protein and fulvic-like fluorescence is undertaken from January to December 1999. The wavelengths of fulvic-like fluorescence excitation and emission and of protein fluorescence emission were all determined to be sensitive fingerprints of organic matter fluxes through the ground water, with iter within the till and within both gypsum and limestone strata deep inside the Magnesian Limestone being differentiated by these parameters. Previous research has suggested that proteins in waters are young in age, hence our seasonal variations suggest that we are sampling recently formed DOM. The rapid response of all deep borehole samples suggests relatively rapid ground iter flow, probably through karstic cave systems developed in the gypsum and solution widened features in the dolomitic lime)ne. Our results suggest that use of both protein and fulvic-like fluorescence wavelength variations provides a DOM signature at can be used as a natural tracer.