ARCHIVED REPORTS_TEMPORARY SOIL GAS PROBE PERMIT APPLICATION PACKAGE

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SOP TO-14A/15 ' Rev 4 December 2007 ' syringes, Tedlar bags or other vessels designed to prevent the loss of volatile compounds. Holding times for the various sample vessels should be observed. H&P will observe maximum holding times of 72 hours for Tedlar bags and 2 hours for syringe samples and 30 days for Summa and other passivated canisters. ' Once vapor samples have been collected, they should immediately be placed on the purge and trap autosampler or in an appropriate container away from sunlight. 11.0 Sample Preparation Sections 11.1 through 11.5 describe the steps for sample preparation for vapor samples. ' 11.1 Dilution Factor Calculation The calibration curve assumes a standard volume of sample is introduced into the analytical instrument. ' Calculations for sample concentrations must take into account the actual volume of sample analyzed. To achieve lower detection limits or to analyze higher level samples, other sample volumes are required. The factor by which the current sample size differs from the expected sample size of 50 mL is called the ' "dilution"factor. Dilution factors less than one (or perhaps more precisely "concentration factors) are possible and mean that more than 50 mL was analyzed. ' 11.2 Laboratory Blank Preparation Place a cleaned minican or other appropriate sample container on then autosampler. Laboratory blanks are prepared from zero grade air or nitrogen in the appropriate container 11.3 Soil Vapor/Air Sample Preparation ' Prepare soil vapor/air samples using the following steps: If the sample is contained within a Summa or other pasivated canister, it may be directly placed on the autosampler using the quick connect fittings. Always measure the vacuum of the sample before analysis. ' If the vacuum is too high , sampling errors may have occurred. Screen can for water by pulling out 1 cc of sample while holding can tip down. If water is present the syringe will show signs of water. If water is present use an adapter to keep water from entering the Entech sampler. Only vapor samples known to be dry ' may be placed on the autosampler upside down. 12.0 Troubleshooting. If there are problems with instrumentation refer to the appropriate manual for troubleshooting options. t12.1 Preventive Maintenance Preventive Maintenance(PM) is that set of procedures taken in an effort to assure that sample throughput is ' continued and that data quality is not degraded by system malfunctions. Although failure to perform Page 10 of 24