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1 Well Installation and Quarterly Groundwater Monitoring Report <br /> Second Quarter 2008 <br /> 1950 West Fremont Street, Stockton, California <br /> 1.2 INVESTIGATION PURPOSE AND OBJECTIVES <br /> ' The purpose of the investigation was to further evaluate the quality of the groundwater at the site, where <br /> chemicals have been previously found at concentrations exceeding regulatory criteria. The groundwater <br /> monitoring program was designed to meet the following primary objectives: <br /> • Verify that groundwater with nickel, MDMA and MTBE at concentrations exceeding regulatory <br /> ' criteria is not migrating off-site; and <br /> • Evaluate the trend of nickel, NDMA and MTBE concentrations in groundwater over a period of <br /> four consecutive quarters to assist with evaluating site closure. <br /> ' 2.0 WELL INSTALLATION AND GROUNDWATER MONITORING <br /> In order to further evaluate the quality of groundwater at the site, three groundwater monitoring wells <br /> ' (MW-1 through MW-3) were installed, developed and sampled in accordance with the approved Work <br /> Plan. As outlined in the Work Plan, one monitoring well (MW-1) was installed outside of the building, <br /> upgradient of the former chemical storage and wastewater treatment area, while two monitoring wells <br /> (MW-2 and MW-3) were installed directly outside the building footprint in the down-gradient direction <br /> (towards the north),just outside of the former plating shop area. It should be noted that the location of <br /> MW-1 had to be slightly moved approximately 25-30 ft to the west to avoid a newly-installed concrete <br /> pad(18 inches thick). The locations of the three monitoring wells are shown on Figure 2. <br /> 2.1 PRE-FIELD ACTIVITIES <br /> 2.1.1 Permitting <br /> Prior to installation of the monitoring wells, Earth Tech obtained a well permit for installation of the <br /> wells from the San Joaquin County Environmental Health Department. A copy of the permit is presented <br /> ' in Appendix A. <br /> 2.1.2 Utility Clearance <br /> Earth Tech employed the services of Cruz Brothers Locators (Cruz Brothers) of Scotts Valley, <br /> California, to verify the drilling locations were clear of underground utilities or obstructions using visual, <br /> magnetic and radio-detection techniques. Underground Service Alert (USA) was notified at least 48 <br /> hours prior to the commencement of any intrusive activities,as required by law. <br /> Project 102790 3 July 2008 <br />