ARCHIVED REPORTS XR0000669 - Laserfiche WebLink

Home Browse Search

i 1 1 � i 4i 4 y r 3 31 January 2003 AGE-NC Project No 96-0232 Page 2 of 17 r ' pump-and-treat remediation system • 04, 05 & 06,December 2002 - AGE performed a quarterly ground water monitoring event ' (fourth quarter 2002) at wells MW-1 through MW-18, EW-1 through EW-10, CSA-1 and CSA-2 2.0 GROUND WATER PUMP AND TREAT REMEDIATION SYSTEM i ' Between 05 September and 25 September 2002, and between 29 October and 05 December 2002 (fourth quarter 2002), a ground water pump-and-treat remediation system was in continuous operation at the site The pump-and-treat system was suspended at the site between 25 September 4 ' and 29 October 2002 due to a detection of hexavalent chromium in the effluent grab water sample at a concentration of 30µg11 The pump-and-treat system effluent was re-sampled on 25 September ' 2002,and the laboratory reported non-detectable levels of hexavalent chromium(less than 0 5 µg/1) Following concurrence with the RWQCB,the Flag City Chevron pump-and-treat remediation system was restarted on 29 October 2002 Ground water pump-and-treat operation and maintenance 10 procedures for the site were outlined in AGE's Final Remediation Plan r 2 1 GROUND WATER PUMP AND TREAT OPERATION The Flag City Chevron ground water pump-and-treat system was designed to operate at a maximum flow rate of 25 gallons per minute(GPM) On-site extraction wells EW-4, EW-5,EW-8, EW,9 and EW-10 were adjusted at each well-head to;continuously extract ground water during the fourth quarter at a flow rate of approximately 5 to 6 GPM, previously, extraction well EW-8 was I substituted for well EW-9 on 08 August 2002 due to a pump malfunction, extraction well EW-9 was repaired on 13 November 2002 and substituted,for well EW-8 r During the fourth quarter 2002, all extracted ground water was routed through a ground water treatment system consisting of granular activated carbon (GAC) and Sunsolve® Following treatment,water was discharged to a conveyance ditch(located approximately 450 feet south of the Isite) at a flow rate of approximately 24 GPM Field notes of ground water pump and treat operation and maintenance activities are in Appendix A Based on effluent flow meter readings (Appendix A, Table 8), a grand total of approximately 1,169,835 gallons of Flag City Chevron treated ground water were discharged to the conveyance ditch during the fourth quarter 2002 under RWQCB.General Order 5-00-119 for discharge to surface waters ofgroundwater from cleanup of petroleum fuel pollution Since initiation of the groundwater -• pump-and-treat remediation system on 20 November 2000, a total volume of approximately i Advanced GeoEnvironmental,Inc