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} <br /> 8 LFR <br /> EquipCo, prior to each sampling event. At each probe, a reading of ambient air in the vicinity of <br /> the probe being tested was recorded before soil gas was monitored within the probe. Initially, the <br /> GEM was attached to the soil gas probe, the valve was opened, and the initial soil gas probe <br /> pressure was monitored and recorded. Then the GEM's internal pump was activated to extract soil <br /> gas from the probe. Readings for methane, oxygen, and carbon dioxide were monitored until the <br /> readings stabilized. After the readings were recorded, the internal pump was deactivated and the <br /> post reading soil gas probe pressure was monitored and recorded. The soil gas probe valve was <br /> then closed, and the GEM was disconnected. <br /> Results. As shown in Table 1, methane was detected above its LEL in SGP-2A at a concentration <br /> of 19.6 percent by volume during the second quarter of 2002. The GEM displayed 1.0 percent by <br /> volume for methane at SGP-3B. The other soil gas probes at the Austin Road landfill displayed no <br /> methane during the second quarter of 2002. The monitoring results at the scale house indicated <br /> methane was not present in the building. <br /> Oxygen readings in soil gas probes ranged from 1.0 percent by volume in SGP-2A to 20.4 percent <br /> by volume in SGP-9A. Carbon dioxide readings ranged from 0.4 percent by volume in SGP-9A to <br /> 8.4 percent by volume in SGP-2A. With the exception of SGP-2A results, these data are generally <br /> consistent with previous soil gas data at this site. The relative air pressure of the probes ranged <br /> from -0.10 to 0.10 inches of water, indicating that the pressure within the soil gas probes is at or <br /> near equilibrium with atmospheric pressure. <br /> Soil gas monitoring will be conducted again during the third quarter of 2002. If you have any <br /> questions, please call me at (916) 786-0320. <br /> Sincerely, <br /> 2/ es E. Eisert, R.G. <br /> Senior Project Hydrogeologist <br /> Enclosures: Figure 1, Table 1 <br /> cc: Ross Atkinson, RWQCB <br /> Butch Stefan, Forward Landfill <br /> Lochlin Caffey, Allied Waste Industries <br /> Project File, LFR-Granite Bay <br />