Quantifying Uncontrolled Landfill Gas Emissions from Two Florida ...

Table 3-34. Results for C1 to C6 and Permanent Gases by GC/FID/TCD from Site #2
Sample
ID
Methane
(%)
Ethane
(ppmv)
Propane
(ppmv)
Butane
(ppmv)
Pentane
(ppmv)
Hexane
(ppmv)
Oxygen
(%)
Nitrogen
(%)
Carbon Dioxide
(%)
Landfill Gas G-1 15.0 6.7 9.7 4.6 7.4 ND 13.3 57.7 19
Landfill Gas G-2 15.2 5.9 10.6 4.4 7.0 11.8 13.8 60.0 18.9
Landfill Gas G-3 15.6 6.0 9.8 4.5 7.2 ND 14.2 61.5 18.9
Nitrogen Blank G-4 0.0238 ND 2.0 ND ND ND 2.5 97.1 ND
Table 3-35. Results for Method 25-C Analysis from Site #2
Sample
ID
Methane
(%)
CO2
(%)
NMOC
ppmv
Mass Conc
mg/m 3
Landfill Gas G-1 45.7 39.5 1922 960
Landfill Gas G-2 42.4 36.5 1897 947
Landfill Gas G-3 41.5 36.3 1891 944
Nitrogen Blank G-4 ND ND 17.0 9.0
The results presented in Table 3-34 show a possible leak during the analysis, and should be
considered as suspect data. Concentrations of O2, methane, and CO2, are not typical of a mature
gas producing landfill, as O2 concentrations should be less than 2 percent, methane greater than
50 percent, and CO2 greater than 35 percent. In response to these questionable results, additional
landfill gas measurements were taken during the October 2007 field campaign. These results are
presented in Section 3.3 of this document.
The results shown in Table 3-35 appear to be the most valid results for methane and CO2.
3.2.5 Total Mercury Measurements
Total mercury concentrations in the landfill gas at Site #2 ranged from 36 to 47 ng/m 3 , with an
average of 43 ng/m 3 for all of the samples. Spike recoveries for the total mercury samples were
89.9 and 97.6 percent. Table 3-36 presents the total mercury concentration data from Site #2.
3-36