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c T Mr. Loehhu Caffey July 19,2006 Page 2 Gas Testing Instrumentation and Methods Testing for methane gas, oxygen,gas,carbon di.oxid.e gas and pressure was performed using a Landtcc Gem-2000 or Gast--ch GT-302 Gas Analyzer calibrated to methane gas. These instruments measure combustible gas concentrations in air directly on either of two scales, tl,e first as percent by volume of the lower explosive limit(LEL) of methane gas in air (0 to 5 percent); the other as percent by volume (0 to 100 percent) in the gas sampled. The detection limit for both instruments is approximately 0.1.0 percent by volume. Gas monitoring well testing procedures are as follows: • Connect sample tubing, open test valve; observe pressure and.record data. • 1~or. probes 20 feet deep or less,tura on sample pump, observe and record methane, oxygen, and carbon dioxide gas concentrations, when readings have stabilized for 30 seconds. • For probes more than 20 feet deep, turn on sample pump, extract a minimum of one probe volume, observed and record methaT.)e, oxygen, and carbon dioxide gas concentrations, when,readings have stabilized for 30 seconds. ® Close test valve, disconnect sample instruments and secure sample location. SCS monitored structures by testing random selected locations where methane gas would most likely accumulate(e.g., electric outlets and junction boxes, conduits, drains, cabinets and closets). Other required monitoring documentation (e.g., sampling personnel, date, time and meteorological conditions) is shown on the attached testing data. tables. Gas Monitoring Well Testing Tn,accordance with the approved testing schedule, all.perimeter GP probes are to be tested at a -minimum, on a quarterly basis. During this reporting period, all accessible perimeter Gas Monitoring Probes defined as GP-Nos. 1 through GP-25 were tested for the presence of LFG_ Test results (,shown on Table 1) indicated that a1 l GP probes tested exhibited methane gas concentrations below the LEL (5 percent by volume) or no methane gas was detected with the exception of GP-11. and GP-12 (up to 60.0 percent by volume), By May 23, 2006, methane gas concentrations detected at both probes bad decreased to below the LEL in response to system adjustments and expansion. These results indicated that the subject site perimeter probes are in compliance with the requirements of Title 27 CCR Sections 2091.9.5 and 30931 through 20934.