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� r Ms. Christina Carbajal June 6, 2006 Page 3 up to 12.4 percent by volume (see Table 1). By May 23, 2006, methane gas concentrations detected at Monitoring Probe Nos. GP-11 and GP-12 had decreased to below the LEL in response to system adjustments and collection system expansion. SCS will continue to monitor Probe Nos. GP-9, GP-11 and GP-12 weekly as directed by the client. The next complete quarterly probe monitoring is due by the end of June 2006. Also, on May 5, 8, 15 and 23, 2006, SCS performed testing of subsurface evaluation monitoring point ETGP-09 as requested by the Client(see Table 5). These test results are intended for evaluation purposes to assist in LFG extraction well adjustments. Finally, on May 15, 2006, SCS performed monthly monitoring of Temporary Gas Probes, defined as TGP-O 1 through TGP-39, as directed by the Client. Results of this monitoring indicated that methane gas concentrations in excess of the LEL were detected at several locations tested (up to 60.4 percent by volume). However, during their reporting period, SCS has continued to observe a fluctuating trend in the detected methane gas concentration. Note, that these probes are intended for evaluation purposes only and are not compliance locations (see Table 1). On-Site Structure onitoring In accordance with the approved testing schedule, the interior of the on-site structures are to be tested quarterly. The next quarterly interior structure monitoring is due by the end of June 2006. LFG Extraction Well Testing System adjustments are required whenever an extraction well exhibits an unacceptable change in methane and/or oxygen gas concentration (which could be due to an overpull or underpull condition). Overpull occurs when the extraction rate of a particular extraction well exceeds that of the LFG generation rate within the radius of influence of the well. During this overpull condition, air can be drawn through the ground surface to the extraction well and then ultimately be injected into the flare. If an excessive overpull condition is allowed to continue for a long period, a significant drop in the methane gas content of the LFG and/or a subsurface landfill fire could occur. Underpull occurs when the extraction rate of a particular extraction well is less than the generation rate within the radius of influence of the well. This condition could result in off-site subsurface LFG migration and/or surface emissions. Results of monthly testing of LFG extraction wells performed on May 5, 8, 13 and 23, 2006 (see Table 2) indicate that several extraction wells exhibited an overpull and/or underpull condition. These conditions are necessary to maintain operational criteria (e.g. maintain a minimum 1400