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<br /> 13• July 2001
<br /> AGE-NC Project No 96-0232
<br />' Page 7 of 15
<br />' pounds of extracted MTBE-impacted ground water yields approximately 0 22 pounds of MTBE
<br /> removed from MTBE-impacted ground water between 04 June and 02 July 2001(Appendix D)
<br />' During the second quarter 2001, an estimated 142 pounds of MTBE was extracted from ground
<br /> water,to date,the ground water treatment system has removed a total of approximately 8 76 pounds
<br /> of MTBE from extracted ground water(Table 8) Second quarter 2001 mass-volume calculations
<br />' of MTBE-impacted ground water extracted from the ground water pump-and-treat system are
<br /> presented in Appendix D Plots of cumulative ground water pump and treat mass removal trends and
<br /> Iinfluent ground water MTBE concentrations versus time are in Appendix E
<br />' 3.0. QUARTERLY GROUND WATER MONITORING AND SAMPLING EVENT
<br /> On 13 and 14 June 2001,ground water monitoring and sampling were performed on 30 ground water
<br /> monitoring wells (MW-1, MW-2, MW-4, MW-5, MW-6A, MW-6B, MW-7, MW-8A, MW-8B,
<br /> MW-8C, MW-9A, MW-9B, MW-9C, MW-10A, MW-1013, MW-10C, MW-IOD, MW-10E,
<br /> MW-11A, MW-11B, MW-11C, MW-11D, MW-12A, MW-12B, MW-12C, MW12D, MW-13A,
<br /> MW-13B, MW-13C and MW-13D) As-built monitoring well construction details are summarized
<br /> in Table 9
<br /> I In addition, ground water samples were collected from 9 extraction wells (EW-2, EW-3, EW-4,
<br /> EW-5,EW-6,EW-7,EW-8,EW-9 and EW-10),two domestic drinking water wells located at 14659
<br /> Thornton Road(RDW-1)and at 14749 Thornton Road(DW-1),and two San Joaquin County service
<br /> area No 31 municipal water wells (CSA-1 and CSA-2) Quarterly ground water monitoring
<br /> procedures for the site were outlined in the Work Plan Addendum, dated 28 January 1998, and
<br /> approved by the PHS-EHD by letter dated 24 February 1998 A coordinated effort was made with
<br /> Three B's Truck Plaza (14749 Thornton Road, Lodi CA) to conduct ground water monitoring
<br /> activities concurrently, the Three B's Truck Plaza tabulated ground water elevation results are in
<br />' Appendix F
<br /> 3 1 MONITORING WELL PURGE PROCEDURES
<br /> I
<br /> Depths to ground water were measured in the ground water monitoring wells from the tops of the
<br /> well casings to the nearest 0 01-foot utilizing a Solinst water level meter Ground water elevations
<br /> in each monitoring well at the site were calculated by subtracting the measured depth to ground
<br /> water from the surveyed well casing elevations(Table 4) Ground water elevations were plotted for
<br /> I the informal First Zone, Second Zone, Secondary Aquifer Zone and Primary Aquifer Zone
<br /> hydrogeologic flow units as defined in Final Remediation Plan,dated 31 August 2000 Ground water
<br /> elevation data was contoured on scaled site maps (Figures 3, 4, 5 and 6, respectively)
<br /> Advanced GeoEnvironmental,Inc
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