Natural attenuation of contaminants in groundwater depends on an adequate supply of electron acceptors to stimulate biodegradation. In an alluvial aquifer contaminated with leachate from an unlined municipal landfill, the mechanism of recharge infiltration was investigated as a source of electron acceptors. Water samples were collected monthly at closely spaced intervals in the top 2 m of the saturated zone from a leachate-contaminated well and an uncontaminated well, and analyzed for δ18O, δ2H, non-volatile dissolved organic carbon (NVDOC), SO42−, NO3− and Cl−. Monthly recharge amounts were quantified using the offset of the δ18O or δ2H from the local meteoric water line as a parameter to distinguish water types, as evaporation and [...]
