A Comparison of the Efficacy of Methane-Oxidizing Alternative Daily Landfill Covers and Policy Recommendations for Landfill Regulatory Agencies

Methane (CH4) is a potent greenhouse gas (GHG) that has 28-36 times the greenhouse effect of carbon dioxide (CO2) over a 100-year timespan. Recent remote sensing research conducted by NASA Jet Propulsion Laboratory and Scientific Aviation has indicated that the working face of landfills are sectors of much higher methane emissions than previously considered. A working face location, which is the area of the landfill where daily waste is deposited, lacks the engineering controls present on the rest of the landfill. Controls such as gas collection and extraction wells and substantial covers to ensure surface integrity for methane leaks are missing at the working face. While a layer of alternative daily cover (ADC) is required over the working face location to ensure that wind blown debris, disease vectors, fires, and odors are abated when the working face is not in use at the end of the working day, that layer of ADC does not address GHG emissions. Current state regulations and industry management practices fail to address this specific aspect of landfill management. Biochar, basic oxygen furnace (BOF) slag, and biotarping (methanotroph-embedded geomembrane covers) were assessed for their efficacy of oxidizing CH4 at the working face when used as ADC. Biochar and biotarping showed the best CH4 oxidizing potential, while a combination of biochar and BOF slag could also prove an optimal solution at reducing both CH4 and CO2 emissions