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I 1 _ _ ti 15 October 2000 1 AGE-NC Project No 96-0232, Page 9oflS , 1 t water wells located approximately 700 feet southeast(CSA-2) and 1,700 feet southeast (CSA-1) of the Flag City Chevron Ground water monitoring procedures for the site were outlined in the Work Plan Addendum dated 28 January 1998 and approved by the PHS-EHD by letter dated 24 February ' 1998 , f ' A coordinated effort was made between Three B's Truck Plaza and Flag City Chevron(6421 Capitol Avenue) to conduct ground water monitoring activities concurrently, the Three B's Truck Plaza tabulated ground water elevation results are included with Appendix I 5 1 MONITORING WELL,PURGE PROCEDURES ` Depths to ground water were measured in each well from the tops of the well casings to the nearest 0 01 foot utilizing a Sohnst water level meter Ground water elevations in each monitoring well at the site were calculated by subtractmg the measured depth to ground water from the surveyed well casing elevations(Table 2) Ground water elevations were plotted and contoured on a scaled site map (Figure 5) After water levels were measured,approximately 6 to 8 gallons of ground water(a mmunum of three casing-water volumes per well) were removed from wells MW-1, MW-2, MW-4, MW-5, MW-6A, ' MW-6B and MW-7 utilizing a two-stage submersible pump, ground water pumping was initiated at the top of the water column and the pump was slowly lowered to total depth to purge ground water within the entire well casing Approximately 6 gallons of ground water were removed from well MW-6B before being pumped "dry" Temperature, pH and conductivity were measured for stabilization at regular purge-volume intervals from each well using a Hydac water analyzer Field ` data and logs are included with Appendix J Purged ground water was containerized in 55-gallon ' drums and was stored on-site in ari area lacking general public access The multi-level momtoring wells MW-8 through MW-13 were purged by lowering and raising a 3/8- inch outer diameter, length-discrete polyethylene hose equipped with a ball-valve water tip through the top chambers'mto the specific water-charged screened section Field data logs are included with Appendix J ! 5 2 GROUNDWATER SAMPLING � 1 Following well piirging, ground water levels in all of the above mentioned,monitoring wells ' achieved a rm-m,rmum of 80 percent recharge prior to sample collection Ground water samples were r • " collected from the purged wells MW-1 through MW-7 utnhzmg new,disposable polyethylene bailers and polyethylene tubmg and were transferred into one-liter amber bottles without a preservative and 1 � ' Advanced GeuEnvereumesstni,Ina 1 a r �