ARCHIVED REPORTS XR0000632 - Laserfiche WebLink

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Parsons Engineering Science, Inc 0 600 mg/kg, respectively] In addition, total xylenes were detected in the sample collected from MW-3 (0 010 mg/kg) Benzene and toluene were not detected in any of the samples TPH-G, TPH-D and BTEX were not detected in any of the groundwater samples submitted for analysis InJune 1992 Greyhound initiated a monthly monitoring and quarterly groundwater b in sampling program Monthly monitoring reports and quarterly status reports were submitted to the PHS-EHD and the California Regional Water Quality Control Board - Central Valley 4 Region (RWQCB) for a period of one year In January 1993, Greyhound implemented a Supplemental Site Assessment A total of four soil borings (13-3 through B-6 in Figure 2) were advanced to characterize the vertical and r: horizontal extent of soil contamination at the site Soil borings were advanced to a maximum depth of 46 feet Samples were field-screened at five-foot intervals using a photoionization detector (PID) and analyzed for total petroleum hydrocarbons (TPH) using an immunoassay technique All samples tested in the field indicated TPH concentrations less than 100 parts per million (ppm) Selected soil samples collected during the supplemental site assessment were subnutted to a California-certified laboratory for analysis of TPH-D and BTEX Toluene was the only BTEX compound detected in the samples Concentrations ranged from 0 0007 to 0 0034 mg/kg TPH-D was not detected in any of the soil samples tested (Parsons ES 1994) After meeting with PHS-EHD in June of 1993, Greyhound requested that PHS-EHD consider a semi-annual rather than monthly monitoring program PHS-EHD approved the semi-annual monitoring and groundwater sampling program in a faxed transmission to Parsons ES on July 22, 1993 On January 26, 1994, PHS-EHD provided a letter to Greyhound with comments on the December 1993 seine-annual groundwater monitoring report In this letter, PHS-EHD directed Greyhound to continue serru-annual groundwater monitoring and reporting, and to further investigate the extent of soil contamination of the site In August 1994, a total of eight exploratory soil borings (SB-l through SB-8 on Figure 2) were advanced by Parsons ES to characterize the lateral and vertical extent of hydrocarbon contamination at the site The soil borings were drilled in accordance with the PHS-EHD letter dated January 26, 1994, in which further investigation of soil contar enation at the site was requested The soil borings were advanced to depths between 45 and 51 5 feet below ground surface (bgs) with sample collection at five-foot intervals All soil samples collected during the investigation were submitted for analysis of TPH-D and BTEX TPH-D was detected in 21 of the 71 samples and BTEX was detected 27 of the 71 samples submitted for analysis TPH-D concentrations ranged from non-detect to 16,000 mg/kg, while BTEX concentrations ranged from non-detect to 3 91 mg/kg The highest TPH-D and BTEX concentrations occurred in the area of borings SB-2, SB-7, and SB-8 at a depth of 15 to 30 PARESSYR01 VOLIR IWM27607 80969127607803 WW6 4