WORK PLANS - Laserfiche WebLink

Home Browse Search

ARCADIS GERAGHTY&MILLER these soil samples (detection limit <5 mg/Kg), associated concentrations of TEX were detected. TPHg and BTEX were nondetect in soil samples collected from all other borings during this field investigation with one exception. Xylenes were detected at 4.5 feet bgs in boring U-B at a concentration of.017 mg/Kg. . In July 1994, GSI drilled five additional on-site soil borings (U-I through U- M) and installed three on-site groundwater monitoring wells (U-1 through U-3); (Well Installation And Exploratory Soil Boring Report(No. 4827703-5); GSI, September 21, 1994). This work was performed to assess the extent of impacted soil in the southeast corner of the site, in the vicinity of the former 1967 UST pit, and to evaluate whether groundwater beneath the site had been impacted by petroleum hydrocarbons. TPHg were detected in soil samples analyzed from borings U-J (1.7 mg/Kg at 26.5 feet bgs) and U-K (130 mg/Kg at 41.5 feet bgs). TPHg were detected in soil samples analyzed from borings U-3 (330 mg/Kg at 46.5 feet bgs), U-L (19,000 mg/Kg at 45.5 feet bgs), and U-M (510 mg/Kg at 45.5 feet bgs). GSI performed a limited environmental site assessment (ESA) of the properties in the vicinity of the subject site (Limited Phase I Environmental Site Assessment(No.4827.04-1);GSI,May 11, 1995). The ESA identified a former station located at 448 East Miner Avenue, south of the subject site. GSI reported that historical groundwater data indicated that this former station is upgradient of the subject site. Environmental information related to the soil and groundwater conditions beneath this former service station were not obtained during the ESA. To further assess on-site and off-site subsurface conditions, GSI installed three additional on-site groundwater monitoring wells (U-4 through U-6) and two off-site groundwater monitoring wells (U-7 and U-8), drilled two additional on-site exploratory soil borings(U-N and U-O),and installed one on-site vapor extraction well (UV-1) in August 1995. TPHg or benzene were not detected in soil samples collected from borings U-5 through U-7 or U-O. TPHg was detected in the soil sample collected from boring U-N at 25 feet bgs (1.7 mg/Kg). TPHg and benzene were detected in the soil sample collected from well boring U-4 at 10 feet bgs (41 and 0.011 mg/Kg, respectively). TPHg was detected in the three soil samples collected from well boring UV-1 at 25,35, and 40 feet bgs at concentrations ranging from 3,400 to 20,000 mg/Kg. Benzene was detected in the soil samples collected at 35 feet (99 mg/Kg) and 40 feet bgs (15 mg/Kg) in boring UV-1. Drilling and well installation data are presented in GSI's Well Installation And Soil Boring Report (No. 4827.04-3), dated October 9, 1995. Based on the subsurface data gathered to date, a Soil Remediation Feasibility Study Work Plan (GSI Report No. 4827.05-1, April 30, 1996) was prepared that proposed a vapor extraction test(VET)to evaluate whether soil vapor extraction was a possible remedial alternative at this site. This Work Plan has not been implemented