ARCHIVED REPORTS_ROY'S AUTO - HISTORICAL (2)

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The septic tank samples (water and sludge) did not contain detectable VOCs, except for minor concentrations of TEX. TPHg was detected at concentrations of 0.62 and 10 ppm, respectively. TPHd was detected at concentrations of 27 and 4,400 ppm, respectively. TRPH was detected at concentrations of 20 and 370 ppm, respectively. Lead in the water sample was detected at 2.6 ppm. Total lead in the sludge sample was detected at a concentration of 120 ppm, and the STLC lead was detected at 0.6 ppm. Laboratory data are summarized in Table 2. The results of septic sampling were included in the Soil Sampling Report-Results of Investigation (4/18/97). Field notes and laboratory data sheets were included in the report. 6.3 Additional Soil Sampling--July 1997 The rationale and proposed methods for additional soil investigation were presented to PHS/EHD in the Preliminary Soil Remediation Plan dated June 19, 1997. The additional work was designed to provide better constraints on the lateral and vertical extent of soil contamination, to evaluate the solubility of the lead under more representative conditions and evaluate the amenability of the soil to treatment. On July 28, 1997, under the supervision of PHS/EHD, a backhoe was used to open small test holes at the locations indicated on Figure 2. Soil samples (SS-1 through SS-6) were collected from a depth of approximately 1 foot from all locations except proposed location SS-4, which was inaccessible. The bulk sample collected from location BSS at a depth of 1 foot was split into a number of duplicates for potential treatment testing. In addition, samples were collected from location BSS at depths of 2, 3 and 4 feet. The samples were submitted to APPL where all, except for SS-1-1', BSS-2' and BSS-4', were analyzed for soluble lead (these three samples were held by the lab for possible analyses depending upon the results of the other samples). In addition, the control split of sample BSS-1' was analyzed for total lead, soluble lead using deionized water (as opposed to citric acid) as the extraction fluid, soluble lead using the federal method (TCLP) and pH. None.of the soluble lead concentrations exceeded the STLC limit of 5 mg/1 (most were non- detect at a practical quantitation limit of 0.5 mg/f). These results establish the lateral limits of soil contamination in excess of the STLC limit for lead. The sample collected from a depth of 3 feet at location BSS did not contain a detectable concentration of soluble lead. In this situation, it was anticipated that the sample collected at 2' (BSS-2') would be analyzed. However, although adjacent to previous sampling locations A/AA, the sample from the depth of 1 foot at BSS only contained 0.62 mg/f soluble lead by STLC. For this reason, the sample from the depth of 2 feet was not analyzed. Laboratory results of supplemental soil samples are summarized in Table 3. The TCLP and deionized water STLC results from sample BSS-1' establish the low solubility and leachability of lead under less rigorous extraction procedures than the standard STLC using citric acid. These are more indicative of the solubility of the lead contaminant under actual environmental conditions. -ysrepwU\summuy 5