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Mr. Dan Johnson February 11, 2009 ! Page 2 concentrations, methane gas is flammable. However, the presence of methane gas in site soil does not mean there is an immediate threat of explosion because flames cannot typically propagate through soil. OPERATION CRITERIA ! The current Authority to Construct (issue date November 17, 2005) issued by the San Joaquin Valley Air Pollution Control District (SJVAPCD) delineates the equipment description and operating criteria for the subject system. All LFG extraction wells will be operated under negative pressure with the g oxygen as ! g concentration less than five (5) percent by volume and wellhead temperature less than 131 degrees Fahrenheit unless disconnected for landfilling activities. In addition, the extraction wells and flare are being operated under adjustment parameters established by the County Additionally, the gas collection system shall be operated in accordance with all applicable provisions of 40 CFR 60 Subpart WWW at all times except during periods of startup, shutdown, or malfunction, such that the surface emissions, measured as methane, do not exceed 500 ppmv at any point on the surface of the landfill or along the transfer path of the gas collection system. State California Code of Regulations (CCR Title 27) requires that solid waste disposal site owners/operators implement LFG control or monitoring provisions to ensure that methane gas concentrations in soil at the property line do not exceed the lower explosive limit (LEL, or 5 percent by volume) and that interiors of on-site structures do not exceed 1.25 percent methane by volume in air. Instrument calibration logs are attached to this report. GAS TESTING Testing for methane gas (the combustible component of LFG), oxygen gas, carbon dioxide gas, pressure, and temperature were performed using a Landtec GEM -2000 Gas Analyzer or comparable unit. This instrument measures combustible gas concentrations in air directly on either of two scales: the first as percent by volume of the lower explosive limit (LEL) of methane gas in air (5 percent); the second as percent by volume (0 to 100 percent) in the gas sampled. An instrument calibration form is provided with this report. LFG MONITORING PROBES In accordance with the approved schedule, all perimeter monitoring probes are to be tested on a ! quarterly basis. On January 22 and 23, 2009, as requested by site personnel, SCS performed testing of LFG Monitoring Probe Nos. SG -01 through SG -10 and SG -12. Test results indicated that LFG Monitoring Probe No. SG -04 exhibited methane gas concentrations above the LEL (5 % by volume) up to 8.4 % (see Table 1), and immediately notified County Personnel. The next required complete quarterly testing of all compliance probes is to be performed by the end of June 2009, as directed by the County. ! C G'