Project activities Activity 1: Field quantification of methane flux from cover soils This activity aims to identify and quantify methane emission hot-spots associated with landfill infrastructure and quantify emission levels from cover soils. Activity 2: Field sampling for soil microbiota This activity will measure geochemical conditions across each landfill’s survey sites and between landfill locations, and will determine the soil microbial community composition. Activity 3: Hyperspectral imaging of methane hotspots This activity will assess the capacity for hyperspectral infrared emissions imaging to distinguish methane emission hot-spots. Activity 4: Multi-omic analyses of cover soil microbiota This activity will conduct in-depth microbial community analyses to generate predictions of microbial activity and interactions in landfill cover soils. Activity 5: Methane emission model development This activity will develop a detailed reactive transport model of hot-spot methane emission dynamics from active and closed municipal landfills. Activity 6: Landfill cover soil methanotrophic enrichments This activity will conduct methane-amended enrichment culture experiments to quantify cultures' methane oxidation capacity for use in landfill cover soils. Activity 7: Isotopic modeling of microbial methane oxidation This activity will assess isotope fractionation patterns to quantify the role of microbial oxidation in controlling methane emissions in landfill cover soils. Activity 8: Knowledge mobilization and communication We will work with end users to ensure that our research is needed, relevant, and actively used.