ARCHIVED REPORTS_GROUNDWATER MONITORING REPORT - THIRD QUARTER 2014

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CRA MEMORANDUM Paget The samples were properly preserved and delivered on ice and stored by the laboratory at the required temperature (0-60C). 3.0 Gas Chromatography/Mass Spectrometer (GC/MS)—Tuning and Mass Calibration (Instrument Performance Check)—Volatile Organic Compounds (VOCs) Prior to analysis, GC/MS instrumentation is tuned to ensure optimization over the mass range of interest. To evaluate instrument tuning, the volatile method requires the analysis of the specific tuning compound bromofluorobenzene (BFB). The resulting spectra must meet the criteria cited in the methods before analysis is initiated. Analysis of the tuning compound must then be repeated every 12 hours throughout sample analysis to ensure the continued optimization of the instrument. Tuning compounds were analyzed at the required frequency throughout the volatile analysis periods. All tuning criteria were met; indicating that proper optimization of the instrumentation was achieved. 4.0 Initial Calibration - Organic Analyses GC/MS To quantify VOC compounds of interest in samples, calibration of the GC/MS over a specific concentration range must be performed. Initially, a five-point calibration curve containing all compounds of interest is analyzed to characterize instrument response for each analyte over a specific concentration range. Linearity of the calibration curve and instrument sensitivity are evaluated against the following criteria: i) All relative response factors (RRFs) must be greater than or equal to 0.05 ii) The percent relative standard deviation (RSD)values must not exceed 30.0 percent ora minimum correlation coefficient (R) of 0.995 and minimum coefficient of determination (R2) of 0.99 if linear and quadratic equation calibration curves, respectively, are used The initial calibration data for VOCs were reviewed. All compounds met the above criteria for sensitivity and linearity. GC In order to quantify organic compounds of interest by GC, calibration of the gas chromatograph over a specific concentration range must be performed. Initially, a calibration curve consisting of a minimum of five concentration levels is analyzed for all single component compounds of interest. Linearity of the calibration curve is acceptable if all RSD values are less than or equal to 20.0 percent or if the correlation coefficient(R) is 0.995 or greater for linear regression curves. Retention time windows are also calculated from the initial calibration analyses. These windows are then used to identify all compounds of interest in subsequent analyses. EW&EMPIOVMENICPPoPiUNT'EMRMEP