Laserfiche WebLink
N 1 <br /> Uppermost groundwater samples were collected at 12 and 13 feet bgs in borings B3-3 (sample <br /> W-014) and B3-2 (sample W-015), respectively Sample W-015 contained trace amounts of <br /> PHCs (0 00042 mg/1 benzene), while no PHCs were detected in sample W-014 (Table 3) <br /> Groundwater sampled from boring B3-1 at 22 feet bgs, within the zone of strong petroleum ' <br /> product odor, contained the highest concentrations of PHCs in groundwater samples, with <br /> 1,600 mg/1 TPHg The depth-discrete groundwater sample collected from 31 to 35 feet bgs <br /> in boring B3-2 contained 2 7 mg/f TPHg and 0 060 mg/1 benzene, indicating that dissolved <br /> phase PHCs are present in the coarser-grained sediments below the zone of PHC impacted soils <br /> (Figure 4). <br /> 5,0 CONCLUSIONS AND RECOMMENDATIONS ' <br /> Conclusions and recommendations for Sites 2 and 3 are presented in the following sections , <br /> 5.1 SITE 2 ' <br /> No indications of PHCs in soils or groundwater were found at this site The total lead ' <br /> concentrations found in sods are within the range of background levels for the area and well <br /> below the TTLC values set by the State and the preliminary remediation goals set by the US <br /> EPA Based on the results of this investigation, there is no recognized environmental condition <br /> which might constitute a threat to human health and safety It is therefore recommended that <br /> the Port request from PHS/EHD that no further site investigation or remedial action be ' <br /> required at this site. <br /> 5.2 SITE 3 <br /> The analytical results for soil samples at Site 3 generally corroborate the field observations of ' <br /> soil discoloration and petroleum product odor in soils, and indicate that the upper boundary of <br /> PHC impacted soils occurs between about 10 to 15 fest bgs, while the maximum vertical extent ' <br /> of PHCs in soils occurs between 20 to 30 feet bgs (Figure 4). Concentrations of dissolved <br /> phase PHCs in groundwater are highest within the zone of impacted soils, and attenuate <br /> substantially below about 25 feet bgs. Dissolved phase PHCs are present in groundwater to <br /> a depth of at least 35 feet bgs. <br /> It appears that much of petroleum product infiltrating into soils beneath the former tanks was ' <br /> trapped in the layers of silt, clayey silt, and clay identified from about 13 to 23 feet bgs. <br /> Based on the results of this investigation, the vertical extent of PHCs in soils beneath the <br /> 10 98117UNVRrrs%=USTW RPS' <br /> 1 <br />