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3.5 GROUNDWATER MONITORING WELL SURVEY The top of casing elevation for each of the proposed monitoring wells will be surveyed by GHD's California State licensed land surveyor to within 0.01-foot vertical elevation relative to mean sea level, and will be referenced to a permanent datum. The soil borings will also be surveyed for their horizontal components. The well casing elevations, and new well horizontal locations (monitoring wells and soil borings)will be surveyed in accordance with State requirements for electronic data submittal, and survey data will be submitted to the State GeoTracker database once the stamped surveyors report is received. Soil gas probe horizontal locations will also be surveyed and uploaded to GeoTracker. 3.6 QUARTERLY GROUNDWATER MONITORING,SAMPLING,AND REPORTING After well development, the newly installed monitoring wells will be added to the existing monitoring program. GHD will visit the site on a quarterly basis through one hydrologic cycle(four quarters)for the collection of depth-to-groundwater data and groundwater samples for laboratory analysis. Groundwater samples will be collected from each of the six(6) groundwater monitoring wells during each of the four (4) sampling events following GHD's SOP for Groundwater Sampling (Appendix A). Groundwater samples will be analyzed for the full suite of analytes discussed above in Section 3.3. Following receipt of laboratory analytical reports from each sampling event, GHD will prepare a quarterly monitoring report, which presents the findings of each sampling event. A total of four(4) monitoring reports will be prepared. The fourth quarterly report will be an annual summary report, which will also evaluate the findings of the previous three (3) quarters and provide recommendations for further action, as appropriate, to proceed towards regulatory case closure. 3.7 INVESTIGATION DERIVED RESIDUALS Investigation derived residuals (IDRs) generated from the boring and monitoring well drilling activities and the quarterly monitoring and sampling activities will be stored on site in labeled DOT approved 55- gallon drums pending disposal arrangements. 4.0 REPORT PREPARATION A Subsurface Investigation Report of Findings will be completed within 60 calendar days after the receipt of final analytical reports. The report of findings will include a description of the field activities performed, a discussion of the findings, tabulated data, an updated map from field measurements and observations, a map showing the sample locations, laboratory data reports, boring logs, well construction details, and conclusions with recommendations as appropriate for this site. 4.1 QUALITY ASSURANCE/QUALITY CONTROL QA/QC for field work shall be provided by adherence to this Workplan. Laboratory QA/QC shall include the use of a"method blank" sample analysis for each analyte to avoid false positive results and the analysis of"Laboratory Control Spike" samples to evaluate the"percent recovery" for each analyte. The director of the laboratory shall sign each laboratory report. 5.0 SITE-SPECIFIC SAFETY PLAN Field activities will be performed in accordance with this Workplan. A Site-Specific Safety Plan has been prepared and is included in Appendix B. 03009-10017-37110 5 of 6 March 2014