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RESULTS OF INVESTIGATION: SSI - PHASE TWO SUBSURFACE CONDITIONS , SOIL for fuel oxygenates and I, 2-DCA indicated that PROFILE none of these analytes were detected above normal reporting limits in either of the samples submitted The soil profile at the site was summarized in the Based on these results, HLA scheduled the final ' Site Conditions Section, and additional sampling round for July 19, 1999 Observations information was presented above the Results of made during the development, purging and Investigation SSI—Phase Two Section above sampling of these two and the final round of ' Monitoring well boring MW-7 was drilled as close sampling(see below) indicate that free product as possible to the location of boring HP-2 and the was not present in well MW-7 soil types encountered were very similar The boring log for well MW-7 is included in Appendix FINAL MONITORING ROUND RESULTS t A Within boring MW-7, subjective hydrocarbon odors were only encountered in the 15-foot sample Based on the depth to groundwater measurements and PID readings were encountered in the 15, 20, on July 19, 1999 and TOC elevations, a ' and 30-foot samples groundwater contour map was produced for Third Quarter 1999 The Groundwater Contour Map is ANALYTICAL RESULTS - SOIL SAMPLES included as Plate 7 The groundwater flow ' direction was southerly but quite variable, ranging Analytical results from two soil samples are listed from southwesterly to southeasterly The in Table 5 and TPHg concentrations are plotted on groundwater gradient was determined to be Plates 4 and 6 Copies of the laboratory analytical approximately 0 005 feet per foot reports and chain of custody forms are included in Appendix D In accordance with a request from Table 1 lists the results from TPHg and BTEX ' PHS/EHD, samples from 25 and 30 feet bgs were analyses of groundwater samples collected during submitted for analyses TPHg and BTEX the final sampling round of all seven site wells constituents were not detected in either sample The results of the EPA 8260B analyses for fuel above normal method reporting limits oxygenates and 1,2-DCA are listed in Table 5 and ' the result from both analyses are plotted on PIate ANALYTICAL RESULTS— MONITORING 8 Copies of the chain of custody forms and the WELL MW-7 laboratory analytical report are included in ' Appendix D Analytical results from the final Analytical results for TPHg and BTEX analyses of sampling round indicated that concentrations of groundwater samples collected from well MW-7 TPHg, BTEX, MTBE,DIPE, ETBE, TBA, and on May 5, 1999 and on June 8, 1999 are listed in 1,2-DCA were not detectable at normal reporting Table 2 and the results of the EPA 8260B analyses limits in any of the groundwater samples from any for fuel oxygenates and 1,2-DCA are listed in of the seven wells ' Table 5 Copies of the chain of custody forms and the laboratory analytical report are included in LOPEZ IRRIGATION WELL SAMPLING Appendix D The analytical results indicated that the groundwater sample collected on May 5, 1999 At the request of PHS/EHD, HLA sampled the ' contained a TPHg concentration of 620 ug/L and a irrigation well on the adjacent Lopez property on benzene concentration of 1 9 ug/L Following the July 29, 1999 The analytical results for TPHg aggressive re-development and re-sampling of and BTEX are listed in Table 2 and the results of well MW-7 on June 8, 1999,the TPHg the EPA 8260B analyses for fuel oxygenates and concentration was reduced to 160 ug/L and the 1,2-DCA are listed in Table 5 and are also shown benzene concentration fell below detection limits on Plate 8 Copies of the chain of custody forms ' of 0 5 ug/L The analytical results of the analyses and the laboratory analytical report are included in ' L\300001387371WP138737N19 Harding Lawson A'ssoclates 17