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Ms Marla Guensler Exxon Company, U S A January 12, 1996 Page 2 Analytical Results Ground water samples collected from each of the eight monitoring wells on October 5, 1995, were submitted to Sequoia Analytical (a California-certified laboratory) for analysis of benzene, toluene, ethylbenzene, total xylenes (BTEX), and total petroleum hydrocarbons (TPH) as gasoline using EPA Methods 602 and 8015 Modified, respectively Analytical test results are summarized in Table 2 The ground water samples collected from monitoring wells MW-3 through MW-6 reported benzene at concentrations of 13 micrograms per liter (µg/L), 1 9 jcg/L, 2 6µg/L, and 7 7 µg/L, respectively A dissolved benzene concentration map based on analytical results for ground water samples collected on October 5, 1995, is included as Figure 4 Copies of the laboratory analytical reports are presented in Enclosure B On November 29, 1995, ground water samples were collected from monitoring wells MW-4 through MW-6 and were submitted to Sequoia Analytical for analysis of BTEX and TPH as gasoline using previously mentioned EPA methods Previous analytical results have shown these wells to be below laboratory's limits of detection for petroleum hydrocarbon constituents Analytical results indicate benzene was detected in the samples collected from MW-5 with a reported concentration of 0 54µg/L and MW-6 with a reported concentration of 0 86 ug/L These results, although above detection were considerably lower than the results reported from the October 5, 1995, sampling event Analytical results are summarized in Table 2 and copies of the laboratory analytical reports are presented in Enclosure B Future Work The next quarterly monitoring event for this site is scheduled for January 1996 Delta and Exxon are currently negotiating with the property owners to the north of the site for placement of proposed ground water monitoring well MW-9 which is illustrated on Figure 2 r-- Remarks/Signatures The interpretations contained in this report represent our professional opinions, and are based in part on information supplied by the client These opinions are based on currently available information and are arrived at in accordance with currently accepted hydrogeologic and engineering practices at this time and location Other than this, no warranty is implied or intended