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Mr. Don Litchfield April 9, 2010 Page 2 If the methane gas component of LFG is allowed to accumulate in a confined area(i.e., utility lines, irrigation valve boxes, vaults, basements,wall spaces,etc.) and is exposed to an ignition source, it can be explosive at concentrations between 5 and 15 percent by volume. At higher 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 most current Title V(effective December 13,2006), issued by the San Joaquin Valley Unified Air Pollution Control District(SJVUAPCD)delineates several main operational criteria for the subject system. • When the flare is in operation,the exit gas will be maintained at a minimum of 50 degrees below latest source test temperature in Fahrenheit. • All LFG extraction wells will be operated under a negative pressure, oxygen content below 5 percent by volume,temperature below 131 degrees Fahrenheit and landfill surface emissions will not exceed 500 parts per million(ppm) methane in air. Note that the Extraction Wells that are closed are exempt from these requirements. 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. 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. Instrument calibration forms are attached to this report. LFG MONITORING PROBES In accordance with the approved testing schedule, LFG Monitoring Probes (GP)are to be tested quarterly or when methane gas concentrations detected exceed 5 percent by volume. On March 5, 12, 16 and 22, 2010, Perimeter Monitoring Probes defined as Nos. GP-09, GP-11 and GP-12 were tested for the presence of LFG to verify that no migration was occurring as requested by Republic personnel. Results indicated that no methane gas concentrations in excess of 5 percent by volume were detected at any location tested(Table 1),with the exceptions of