Landfill leachate can contain thousands of contaminants that may pose risks to human health and the environment if transported offsite. A barrier to remediating leachate contamination has been the lack of a comprehensive (and affordable) approach to identifying and selecting leachate contaminants to target with remediation activities. A team led by the Northern Research Station developed a systematic pollutant prioritization tool that can be used anywhere in the United States to increase the efficiency of landfill remediation efforts.

Landfills in the United States generate thousands of gallons of leachate every day. The composition of landfill leachate is dynamic over time and space and can vary due to factors such as landfill age, waste characteristics, and site hydrogeology.  

Many classes of pollutants can exist in landfill leachate, including solvents, herbicides and pesticides, industrial byproducts, and flame retardants. Regulatory lists of monitored landfill leachate compounds may not cover the complete spectrum of landfill pollutants, particularly newer classes of pollutants, such as perfluorinated chemicals (PFAS), pharmaceuticals, or personal care products. This knowledge gap results in traditional methods of contaminant monitoring and remediation being unable to comprehensively address the potential human and environmental impacts of landfill leachate pollutants. To fill this need, Northern Research Station scientists and University of Missouri collaborators developed a tool for systematically prioritizing the pollutants in landfill leachate. The tool uses toxicity data from three publicly available toxicity databases; communities that have specific concerns about contamination can easily customize it for local priorities. Further, the tool offers a cost-effective approach for identifying pollutants to target with remediation efforts. For example, the tool can be integrated with phytoremediation, the use of trees to clean up contaminated soils and waters, to match specific tree species to the identified pollutants.