Quantifying Uncontrolled Landfill Gas Emissions from Two Florida ...

1.7 Calculation of NMOC Fluxes
As described previously, concentrations of NMOC were determined from samples of landfill gas
collected at the gas header pipe at each site. The samples were analyzed for the target
compounds listed in Table 1-1. Upon completion of the sample analysis, the concentration of the
detected target compounds (obtained from the EPA Method TO-15 data) was ratioed to the
concentration of the methane in the landfill gas samples (obtained from the EPA Method 25-C
data). This ratio was used with the methane emissions data collected with the ORS
instrumentation to calculate an estimated emissions flux value, from the top of the landfill cell
for each of the target VOC compounds, using the following formula:
Where
Ft = [(Ct * Fo)/Co] [Mt/Mo] (1)
Ft is the flux of the target compound (VOC)
Ct is the measured concentration of the target compound
Fo is the calculated methane flux
Co is the measured methane concentration
Mt is the molecular weight of the target compound
Mo is the molecular weight of methane
1.8 Field Schedule
Two field campaigns were completed for this study at two separate sites during February and
October 2007. During the February 2007 field campaign, methane concentration data were
collected using the ORS instrumentation, and gas and mercury samples were collected near the
landfill header pipes. Due to questionable gas and mercury data from the February 2007
campaign, additional gas and mercury samples were collected during a second campaign
conducted in October 2007. Table 1-2 presents the schedule of work that was performed.
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