ARCHIVED REPORTS XR0013118 - Laserfiche WebLink

Home Browse Search

samples. The PAHs pyrene and chrysene(PAHs)were detected in the soil sample collected from GMX-32 at concentrations of 57 and 79 mg/kg,respectively. Petroleum constituents were detected in the grab groundwater sample from boring GMX-29,which was advanced on site within the area of affected soil. Constituents quantified as TPHd were reported at 660 4g/1 in the sample when a silica gel preparation procedure was not performed and TPHd was detected at 160µg/1 following the silica gel preparation procedure). TPHd was reported at 360 WA in the aliquot that was filtered prior to extraction and analysis. These collective results indicate that much of the original TPHd quantification(660µg/t)is due to polar biogenic byproducts resulting -from intrinsic bioremediation and non-dissolved constituents adhered to particulates in the sample. TPHg was detected at a concentration of 140µg/l,benzene was detected at 0.6µgd,and TEX were detected at concentrations up to 4µg/1. Fluorene and phenanthrene were the only PAHs detected, both at concentrations of 0.1 µg/l. Grab groundwater samples from borings GMX 25,GMX-30,GMX-31 and GMX-33 were collected from locations approximately 10 to 100 feet downgradient of affected soil. Material quantified as TPHd was detected in all samples analyzed without a silica gel preparation procedure,at concentrations ranging from 86 to 560µg/1. However,TPHd was not detected in any of these samples following a silica gel Preparation procedure, indicating that the constituents detected without the silica gel preparation are polar biodegradation byproducts resulting from in situ biodegradation of the residual petroleum in soil. TPHg,benzene,ethylbenzene and PAHs were not detected in any of these samples. Low concentrations of toluene(0.8µg/1 in GMX-30)and xylenes(1.1 and 1.9 WA in GMX-30 and GMX-31,respectively)were detected. Grab groundwater analytical results are summarized in Table 2 and presented on Figure 3. The analytical laboratory reports for the sod and grab groundwater samples are presented in Appendix C. 6.0 CONCLUSIONS Based on the results of this and previous investigations,Geomatnx has developed the following conclusions about site conditions. Two areas of petroleum hydrocarbon affected soil have been identified at the site,one on the eastern portion of the property and one on the western portion of the property. Based on the results of a forensic evaluation(Geomatrix,2000), some of the soil on the castem portion of the property may be affected by degraded low-boiling-range compounds(such w gasoline)as well as high-boiling-range compounds(such as crude oil). The degraded low-boiling-range compounds may be associated with the former Mohawk gasoline station at the site. \ASF DUTDATA\nOC_WE\60DOSW 17ANT0M80SOTWWRM10VW .DOC 6