Laserfiche WebLink
respectively. <br /> I4.0 FINDINGS <br /> Laboratory results and chain-of-custody forms for all soil and <br /> water samples are contained in Appendix A. TPH as gasoline was <br /> detected in the sample from the west sidewall of the excavation at <br /> a concentration of 1 . 7 ppm. No other contaminants were detected in <br />' the samples collected from the excavation. <br /> Low to moderate concentrations of TPH as gasoline were detected in <br /> I five of six samples from the stockpiled soil (Table 4) . Toluene and <br /> xylene were detected at concentrations slightly above detection <br /> limits in three samples. <br /> The groundwater gradient was calculated to be 0. 0031 ft/ft, <br /> oriented N470E (Figure 3) . This result is similar to the gradient <br /> in April 1993 and confirms that MW-3 is the most down-gradient <br /> well. No contamination was detected in the June and July water <br /> samples from this well, or from the samples collected from MW-1 and <br /> MW--2 in July. <br /> 5. 0 CONCLUSIONS & RECOMMENDATIONB <br /> Two rounds of groundwater monitoring have been completed at this <br /> site. A consistent groundwater flow direction to the northeast has <br /> been established. Water samples from MW-1 and MW-2 have been <br /> uncontaminated in both monitoring events. Toluene was reported in <br /> the first sample from MW-3 , but this result appears to be due to <br /> laboratory error. Re-sampling in June and July detected no <br /> I contamination in this well. Therefore, GeoAudit concludes that <br /> groundwater has not been impacted. We recommend that groundwater <br /> monitoring be discontinued and the wells destroyed. <br /> Soil samples collected from the excavation indicate that the <br /> contaminated soil has been removed from the area of the former <br /> underground storage tank. We recommend that the excavation be <br /> backfilled to grade with clean fill. <br /> Laboratory analysis revealed that approximately 150 cubic yards of <br /> stockpiled soil are contaminated with petroleum hydrocarbons. <br /> Several remediation techniques are available to mitigate this <br /> contamination. We recommend that a Soil Remediation Plan be <br /> prepared and submitted to PHS/EHD for approval. <br /> I <br /> 6. 0 LIMITATIONS <br /> Our professional services were performed using that degree of care <br /> and skill ordinarily exercised by environmental consultants <br /> I 4 <br />