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28 <br /> July 1995 <br /> AGE-NC-95-0134 <br /> Page 3 of 6 <br /> Isamples were also analyzed for total lead Lead was detected in samples CB1-15 and CB 1-20 at <br /> concentrations of 12 ppm and 9 ppm, respectively <br /> Ground water morntonng was conducted on four occasions between June and December 1994 by <br /> GeoAudit The depth-to-water was measured in MW-8, MW-9 and EW-I The wells were purged <br /> and sampled on three occasions The ground water gradient range from 0 00048 ft/ft to 0 0029 ft/ft <br /> The flow direction ranged from N 80° E to N 56° E on three occasions An anomalous flow <br /> direction of due south was observed in October 1994 Toluene and xylenes were detected in the <br />' sample from MW-9 at concentrations of 0 52 ppb and 2 9 ppb respectively in June 1994 No other <br /> petroleum hydrocarbons were detected in any of the samples during the three quarterly monitoring <br /> events <br /> 3.0. PROCEDURES <br /> 3 1 MONITORING WELL PURGE PROCEDURES <br /> On 10 May 1995, a Solinst water level meter was used to measure the depth to ground water ;n <br /> monitoring wells MW-8, MW-9 and EW-1 relative to the top of the casing The relative ground water <br /> elevations and hydraulic gradient were determined from these data(Table 1) <br /> Monitoring wells MW-8, MW-9 and EW-1 were then purged using precleaned PVC bailers <br /> Approximately 6 to 7 gallons (minimum of three well volumes) of water were removed from <br /> Imonitoring wells MW-8, MW-9 and EW-I Temperature, pH and conductivity were measured at one- <br /> gallon intervals using an ICM water analyzer The purge water was stored in 55-gallon DOT- <br /> approved drums and stored on-site Field data sheets are included in Appendix A <br /> I3 2 GROUND WATER SAMPLE COLLECTION AND ANALYSES <br /> Water samples were collected from MW-8, MW-9 and EW-1 using new disposable bailers <br /> I Immediately upon retrieval, the samples were transferred into 40-m1 VOA vials preserved with <br /> hydrochloric acid The samples were transported in a chilled container to Alpha Analytical <br /> Laboratories in Ukiah Each sample was analyzed for total petroleum hydrocarbons as gasoline (TPH- <br /> I g)and volatile aromatics (benzene, toluene, ethylbenzene and xylenes BTE&X) in accordance with <br /> EPA methods 5030 and 602, respectively <br />