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1 <br /> 4 <br /> 5 3 v <br /> . 17 June 1996 w <br /> AGE-NC Project No 95-0121 <br /> Page 3 of 6 <br />' 3.0. QUARTERLY MONITORING PROCEDURES <br /> 4 <br /> 311 MONITORING WELL PURGE PROCEDURES <br />' On 22 May 1996, the depth to ground water in each monitoring well was measured to the nearest <br />' 0 01 foot utilizing a Solist water level meter The relative ground water elevations were calculated <br /> by subtracting the depth to ground water from the relative casing elevations surveyed from a <br /> temporary benchmark (Table 1 - Relative Ground Water Elevations) Relative ground water <br />' elevations were plotted and contoured on a scaled site map (Figure 3 - Relative Elevation Ground <br /> Water Map) <br /> After water levels were measured, approximately 12 to 14 gallons (minimum of three well volumes) <br /> I of ground water were purged from wells MW-1 through MW-9 utilizing a two-stage submersible <br /> pump Temperature, pH and conductivity were measured at regular intervals from each well using <br /> an ICM model 52200 water analyzer Stabilization data and field logs are in Appendix A Purged <br /> water was stored in'55-gallon drums on-site in an area inaccessible to the general public <br /> 3 2 GROUND WATER SAMPLING <br /> Monitoring wells MW-1 through MW-9 were allowed to recover for a minimum of one hour prior <br /> to sample collection Water samples were collected from wells MW-1 through MW-9 utilizing <br /> dedicated,disposable polyethylene bailers and new nylon rope Sufficient sample was collected from <br /> each well to fill three 40-m1 EPA vials containing hydrochloric acid as a preservative for the <br /> samples,and a one-liter amber bottle lacking hydrochloric acid Care was taken to ensure that visible <br />' air bubbles were not present in the VOAs after filling and capping Ground-water sample containers <br /> were labeled with the well designation, date, time, and samplers initials <br /> 3 3 LABORATORY ANALYSIS OF GROUND WATER SAMPLES <br /> IEach ground water sample was logged on a chain-of-custody form, placed in a chilled container and <br /> transported to a Castle Analytical Laboratories (CAL), a California state-certified laboratory for <br /> analysis of hazardous materials Each sample was analyzed for Total Petroieum Hydrocarbons <br /> quantified as gasoline and diesel (TPH-g and TPH-d), volatile aromatics (benzene, toluene, ethyl <br /> ' benzene and xylenes BTE&X), and methyl-tertiary-butyl ether'(MTBE) in accordance with EPA <br /> methods,respectively The laboratory report(CAL Laboratory No 764)and chain-of-custody forms <br /> are presented in Appendix B, <br /> { <br />