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r <br /> from this value. <br /> 3.4 Well Konitoring and Sampling <br /> A Solinist water meter was used to measure water depth in all wells <br /> except MW-3 on 27 April 1993 . After measurements were made, all <br /> wells were purged of between 4 and 14 gallons of standing water, <br /> using a PVC bailer. Temperature, pH, and conductivity were measured <br /> at one-gallon intervals using a Hydac water analyzer (Table 1) . <br /> Purge water was stored in a 55-gallon DOT drum on the site. <br /> Water samples were collected after temperature and other parameters <br /> stabilized. Water samples were collected using a disposable plastic <br /> bailer. Three 40 ml EPA vials were collected from each well and <br /> transmitted in a chilled container to Alpha Analytical Laboratories <br /> in Ukiah, California. <br /> 3.5 Soil and Groundwater Analysis <br /> Soil samples were analyzed by EPA methods 8015m and 8020 for <br />' total petroleum hydrocarbons in the gasoline range (TPH-g) and for <br /> volatile aromatic hydrocarbons (BTE&X) . Water samples were analyzed <br /> for the same components by EPA methods 8015m and 601. Laboratory <br /> reports and chains of custody are included in Appendix B. <br /> 4 .0 FINDINGS <br /> 4=z Soil Sample Pial.;e;s <br />' No volatile organic vapors were detected during drilling and no <br /> petroleum hydrocarbons were detected in any of the analyzed samples <br /> (Table 2) . All three wells are beyond the lateral limits of the <br /> plume of soil contamination. <br /> 4.2 Groundwater Sample Analysis <br /> TPH as gasoline was detected in both MW-1 and MW-4, but not in MW-5 <br /> through MW-8 . BTE&X compounds were also detected in MW-1 and MW-4 , <br /> and as in October of 1992, toluene was detected in MW-5 (Table 3) . <br /> Concentrations have declined in MW-1, but have remained relatively <br /> unchanged in MW-4 since the October 1992 sampling event. <br />' 4.3 Groundwater Elevation and Gradient <br /> The relative elevation of the water table in each well was <br /> calculated by subtracting the water depth from the casing elevation <br /> lT�1,3e A_1 Thn n I n x r iiv% MTA1._7 anA MW-R tahirnh Gra within a_ fow <br /> feetofeach other, should +be+ about the same. The higher elevation <br /> in MW-2 appears to be spurious, but the source of error is <br /> uncertain. The value from this well is not used in subsequent <br /> calculations of the groundwater gradient. <br /> 3 <br />