Application of strontium isotopes for tracing landfill leachate plumes in groundwater

AMBROSI (J. P.) / ANGELETTI (B.) / BOTTERO (J. Y.) / CHATELET-SNIDARO (L.) / MOUSTIER (S.) / VILOMET (J. D.) / WIESNER (M.) - ARTICLE DE PERIODIQUE - 2001

We are evaluating strontium isotopes as alternative tracers of landfill leachate in groundwater. The municipal landfill studied here is located in southeastern France. This landfill has no bottom liner, and wastes are placed directly on the ground. Based on the evaluation of chloride concentration, the plume extends a maximum of 4600 m. Strontium isotopic composition characterizes two sources: natural groundwater (87Sr/86Sr = 0.708175) and landfill leachate contamination (87Sr/86Sr = 0.708457). The evolution of mixing ratios obtained with strontium reveals a second source of groundwater contamination: fertilizers (87Sr/ 86Sr = 0.707859). These results suggest that isotopic signatures can be used to provide useful information on sources of groundwater contamination where convention- al water quality parameters may yield ambiguous results.