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f <br />• MW4, MW5 and MW6 were available for groundwater monitoring The static groundwater level <br /> has continued to fluctuate between 1992 and the present Results of quarterly monitoring show a <br /> steady rise of the water table through 1993 and 1994 The hydraulic gradient has generally been <br /> 0 001 - 0 003 to the east throughout this period <br /> During drilling in June 1995, groundwater was encountered at about 60 feet below grade The <br /> hydraulic gradient was measured to be about 0 003 to the northeast on June 6, 1995 Figure 4 <br /> shows this most recent groundwater measurement Appendix B contains the survey data <br /> including depth to water measurements, relative well head elevations, and groundwater elevations <br /> SITE INVESTIGATION <br /> The drilling program for the proposed scope of work was scheduled to begin in December 1994 <br /> On December 20, 1994, Thrifty installed two vadose wells (TB4 and TB6), and three soil borings <br /> (TB3, TB 13, and TB 14) at the site in conjunction with the scope of work presented in the <br /> Workplan The monitoring wells were installed along the west margin of the site adjacent to the <br /> western pump island Well TB4 is located near the northern end of the dispenser island and <br /> extends to a depth of 50 feet bgs This well is intended as a potential vapor extraction point to <br /> access the contaminated soils noted in the area during site reconstruction Accordingly, the well <br /> is screened from total depth to 5 feet below grade Well TB6 is located south of TB4 and extends <br /> to about 25 feet bgs This well is screened from total depth to 5 feet and will be used to <br /> complement nearby well MW5 in a remediation program <br /> Borings TB3, TB 13, and TB 14 were installed to 15 feet below grade and are located in the pump <br /> dispenser island area The locations were intended to investigate suspect areas that were <br /> identified by PHS/EHD based on observations made during site reconstruction activities <br /> Additional drilling could not be performed at this time due to obstructions and access problems <br /> related to the site reconstruction effort However, underground piping was installed to many of <br /> Page 4 <br />