||Environmental Quality Management, Inc., Durham, NC.;Environmental Protection Agency, Research Triangle Park, NC.;Environmental Protection Agency, Washington, DC. Office of Research and Development.
This report describes a case study that applies EPA-600/R-05/123Cthe guidance for conducting air pathway analyses of landfill gas emissions that are of interest to superfund remedial project managers, on-scene coordinators, facility owners, and potentially responsible parties. The particular site examined for this case study was the Bush Valley Landfill in Harford County, MD. This site has a flexible membrane liner, 5 passive vents, and 17 monitoring probes. The case study exemplifies the use of the procedures and tools described in the guidance for evaluating LFG emissions to ambient air. The air pathway analysis is used to evaluate the inhalation risks to offsite receptors as well as the hazards of both onsite and offsite methane explosions and landfill fires. Landfill gases detected at the site were methane and chemicals of particular concern (COPCs) that encompassed 1,1,1trichloroethane, 1,1-dichloroethene, 1,2-dichloroethane, benzene, chlorobenzene, 1,4-dichlorobenzene, chloroethane, dichlorobenzene, methylene chloride, toluene, trichloroethene, vinyl chloride, and xylenes. The report includes values of 90th percentile concentration of COPCs and isopleths of the COPC concentrations overlaid on an aerial photograph of the site.