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( Ms. Linda Turkatte
<br /> June 11, 1996
<br /> Page 6
<br /> Soil Analytical Results
<br /> Chemical analytical results for soil samples are presented on Table 2.. Figures 6 and 7present TPHg
<br /> contours for two depth intervals within the vadose zone below the base of the former USTs. Results of the
<br /> soil field screening for VOCs using the PID are displayed on the boring logs included with Attachment A.
<br /> In general, the field screening results corresponded with the reported laboratory analytical data: Soil
<br /> laboratory analytical data reports and chain-of-custody records are provided with Attachment C.
<br /> TPHg results for soil samples from 13 to 21.5 feet.bgs are contoured and displayed on Figure 6. Soil.
<br /> sampling results from the UST removal activities conducted in February 1994 are included in this depth'
<br /> interval. Within this depth•interval, soil sample VE-1-21 collected from'a depth of 21. to 2i.5 feet bgs
<br /> directly beneath the west and the former USTs was reported to contain the maximum TPHg and BTEX
<br /> concentrations at 13,000 mg/kg and 44 mg/kg,4.80 mg/kg; 180 mg/kg, and 910 mg/kg, respectively. Soil
<br /> samples analyzed from the MW-1, S13-1, and SB-2 locations and the two samples (TKIE and TK2E)
<br /> collected from the east end of the UST excavation contained no detectable concentrations of TPHg and low
<br /> to nondetectable concentrations of BTEX.
<br /> TPHg results for soil samples from 26 to 26,5 feet bgs are contoured•and displayed as Figure 7. Thesex6sults
<br /> f` indicate that the maximum petroleum hydrocarbon concentrations at this depth interval are also directly
<br /> below the west end of the former USTs; however, at lower concentrations. Soil sample VE-1-26 was
<br /> reported to.contain TPHg and BTEX at maximum respective concentrations of 4,900 mg/kg and.25mg/kg;
<br /> 220 mg/kg, 70 mg/kg,and 360 mg/kg. Additionally,.the lateral extent of petroleum hydrocarbons for this
<br /> depth interval appears larger than the 13-to 2L5-foot interval.
<br /> Soil samples results from depths of 35 to 36.5 feet bgs.represent petroleum hydrocarbon concentrations
<br /> below the potentiometric surface but above the contined'or semi-confined lower sand-d6minated interval.
<br /> Soil sample VE-1-36, located directly below the former USTs, reported the maximum TPHg and BTEX
<br /> concentrations in the capillary fringe at 1,400 mg/kg, and I l mg/kg, 63 mg/kg, 20 mg/kg,and 100 mg/kg,
<br /> respectively.
<br /> Groundwater Analytical Results
<br /> Groundwater chemical results are presented on Table 3 and shown graphically on Figure 8. Chemical results
<br /> from well MW-1 and grab groundwater sampling locations SB-I and SB-2 were similar. Samples collected
<br /> from well MW-1, and soil borings SB-1, and SB-2 were reported to contain TPHg at respective
<br /> concentrations of 160,000 gg/e, 180,000 gg/P,and 190,000 gg/P. The samples collected from the SB-i and
<br /> S13-2 locations reported the maximum BTEX concentrations at 32,000 Vg/P,41,000 gg/P, 4,500'gg/P, and
<br /> 23,000 gg/P, respectively.
<br /> Groundwater monitoring wells MW-6, MW-8, and MW-14 were sampled by Blaine Tech, on behalf of
<br /> Texaco, on February 27, 1996. Samples analyzed from wells MW-8 and MW-14 were reported to contain
<br /> TPHg, benzene,and xylenes at concentrations ranging from 200 to 550 gg/P; 19 to 23 gg/P, and 0.54 to 1.1
<br /> gg/P, respectively. The sample collected from well MW-6 contained no detectable concentrations of TPHg
<br /> and BTEX.
<br /> f-f:SUMDR]LL.RPT
<br /> 50090-011-02
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