ARCHIVED REPORTS_TEMPORARY SOIL GAS PROBE PERMIT APPLICATION PACKAGE

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4 DATA QUALITY OBJECTIVES (DQO) ' The data quality objectives (DQOs) described below determine the type, quantity, and quality of data needed to support the scope of work for the soil gas sampling event for the RAW. Specific requirements for each DQO are described in further detail in Section 4 of Appendix J ' (QAPP) of the RAW and data validation procedures are further described in Section 8 of Appendix J of the RAW. Lab specific standard operating procedures (SOPS) for the soil gas sampling activities are provided in Appendix A of this Workplan. ' 4.1.1 PRECISION ' Precision is the ability of a measurement to be consistently reproduced. Analytical precision is associated with the variability between one measurement and its duplicate analysis. Analytical precision will be evaluated by the analysis of field duplicates, matrix spike duplicates, and ' laboratory control sample duplicates. Both field and analytical precision will be evaluated by the analysis of field duplicate samples as discussed in Section 4.1.2 of RAW Appendix J (QAPP). ' If the recoveries of the applicable control samples are within the established control limits, then the precision is within limits. Duplicate results are evaluated by comparing the relative percent difference (RPD) between duplicate measurements. If the RPD is not within or exceeds the established criteria, the data will be identified with a data quality flag (DQF) during the data validation procedure. ' 4.1.2 ACCURACY Accuracy is the ability of a measurement to match the actual value from a known ' concentration (e.g. spike or standard). Accuracy in the laboratory will be evaluated by using matrix spikes, laboratory control samples, and surrogates. Statistically derived laboratory accuracy limits, percent recovery (%R), are included with the laboratory Standard Operating Procedures (SOPS) provided in Appendix A. If the percent recovery is not within the established acceptance limits, the data will be identified with a DQF during the data validation procedure. Accuracy in the field will be evaluated using the analysis of field equipment blanks. The results from field blank samples should be less than the laboratory detection limit for each target constituent. If contamination is reported in the equipment blank the data will be identified with ' a DQF during the data validation procedure. 4.1.3 REPRESENTATIVENESS ' Representativeness will be defined by the sampling rationale established for both the soil and groundwater sampling activities. This will include the appropriate number of samples to be ' collected, location of samples, sampling methodologies, laboratory analyses, field quality assurance/quality control (QA/QC), and laboratory QA/QC procedures. 1 4 MF M/LLER BROOKS arc.