Identifying Landfill Leachate in Environmental Samples Using a Triple Isotope Approach - δ13C, δ11B and 87/86Sr in Norwegian Landfill Leachate

Leachate from industrial and municipal solid waste landfills is a complex and unique fluid usually subject to regulatory regimes for characterization and treatment. Due to increasing urbanization and the location of many landfill sites near other industrial sources, it is not always trivial to trace downstream pollution back to a landfill source. In addition, many landfills have insufficient control over the water flowing into and out of the waste body, complicating mass balance calculations. The aim of this contribution is to demonstrate the effectiveness of the isotope systems of boron (δ¹¹B), strontium (^87/86Sr), and dissolved inorganic carbon (δ¹³C-DIC) as tracers of Norwegian landfill leachate.

 

The studied isotopic systems were selected based on parameters including types of waste and composition of leachate, local geology, local hydrology, and the presence and type of other nearby pollution sources. In this study, we present the results of more than 15 years of δ¹³C-DIC measurements at selected Norwegian landfills. We combine these data with δ¹¹B and ^87/86Sr measurements of landfill leachate from Norwegian landfills, in combination with measurements from groundwater and freshwater bodies near the landfill sites. We discuss challenges in δ¹¹B determination as well as evaluate the utility of δ¹¹B and ^87/86Sr as leachate tracers at the studied sites as supplements to δ¹³C-DIC. Increased understanding of the behavior of landfill leachate can lead to more targeted remediation measures and a benefit for landfill operators, local communities, and the environment.