ARCHIVED REPORTS XR0001925 - Laserfiche WebLink

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CECCULNI. CECCWNI, AND GIOVANNONI, FULLING ISLAND 3.(D FINDIN(GS 3.1 1P SL LID OBSER A lY RO S , On December 12, 1944 ESE observed That the well box for well Si-1 was still broken and in need of repair The remaining ground water monitoring wells, SI-2, SI-3, and UST-1 appeared in good condition ESE noted that the interior of well UST-1 was clean and free of surface leakage 3.2 (GROUND WATER MO`NIT(DI18E`l(G On December 121994 the ground water levels in wells 1-1, SI-2, SI-3, and UST-1 were approximately 76 feet below the top of casing No free product was observed in any of the wells Table 1 tabulates water level measurements and elevation calculations for these wells, and Figure 2 shows these data in map view The groundwater flow direction beneath the site at the time of measurement appears to be toward the northeain the area of the fueling island The calculated ground water gradient was approximately 0005eet/foot or 2 9 feet per mile Analytical results for well UST-1 are shown on Table 2 - Analytical Results of Ground Water Samples and on the enclosed laboratory certificates of analysis (Appendix A) Ground water from UST-1 contained toluene, ethylbenzene and total xylenes at a maximum concentration of 25 micrograms per liter (µg11) TPH as diesel was reported at a maximum concentration of 5 8 �5 TO o P0- I milligrams per Liter (mglL or parts per million in the initial sample and quality control duplicate Analysis of the trip blank accompanying the UST-1 sample reported/nondetectable concentrations of BTEX analytes 3.2.1 DISCUSSION The ground water elevation calculated for well UST-1 has increased approximately 2 34 feet relative to that reported for September 1994 (Third Quarter 1994) This increase is likely due to seasonal precipitation Ground water flow direction at the site has generally been to the northeast in recent quarters This flow direction is similar to regional flow direction interpreted from San Joaquin County Spring 1994 Ground Water Report Maps (San Joaquin County Flood, 1994) I� TPH,as gasoline was not measured this quarter in the ground water sample, however, it will be next quarter Benzene remained at nondetectable concentrations Toluene, ethylbenzene and 69454W\4QM94 RPT 3 EnnronmenW Science h Engmeenng, Inc