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Report of Secondary Investigation 5 Prepared for Barbara Drake 26485 Thornton Rd, Thornton GA May 4 1995 Samples were transported under chain-of-custody manifest to MBT Laboratories, a state-certified laboratory located in Rancho Cordova, CA Soil and groundwater samples were analyzed for benzene, toluene, ethylbenzene and xylenes (BTEX) and total petroleum hydrocarbons-as-gasoline (TPH-G) by Environmental Protection Agency(EPA) methods 50301802018015 modified After water sampling,the temporary well casing was removed from each boring The borings were backfilled on February 17, 1995 by Groundwater Technology field personnel using a bentonite/cement grout placed into the borehole using a tremae pipe Less than 2 cubic feet of soil cuttings were generated from the borings The small volume of cuttings was placed on the soil pile that currently exists to the north of the former UST pd Rinse water used in decontamination of drilling and sampling equipment was stored on site in a Department of Transportation (DOT)-approved 55-gallon drum so RESULTS OF FIELD ACTIVITIES Summarized below are the results of field activities conducted at the site by Groundwater Technology between January and February 1995 . 51 Geology The site is located at approximately 8-9 feet above mean sea level and the site topography is flat The site is bordered to the east by an open field,to the south by a large truck stop (BP fueling facility),to the north by residential property, and to the west by Interstate 5 A drainage ditch (appro)amately 3-4 feet deep) runs east/west on the south side of Walnut Grove Road During site reconnaissance on February 9, 1995,the ditch was empty Sod logged in bonngs at the site consisted of silty clays and clayey silts with occasional thin, fine sand layers Groundwater was encountered at depths ranging from 6-15 feet BGS in bonngs 131-610 As noted in the tank pit during site reconnaissance,the soils appear to be alternating clayey silts and silty clays 5.2 Analytical Results of Soil Samples Table 2 summarizes the laboratory analytical results for sod samples collected on February 16, 1995 All of the soil samples submitted to the laboratory for analysis were below laboratory reporting limits for BTEX and TPH-G with the exception of the 6 feet BGS sample from B3 which contained 5 3 pg/L ethylbenzene It should be noted that Qualify Assurance/Quality Control (QA/QC)standards were beyond acceptable limits for surrogate recovery due to the presence of a matrix interferant Laboratory personnel confirmed that the data are valid since surrogate recovery represents only one of many • 0053EAR RPT GROUNDWATER ❑D❑ TECHNOLOGY ,.