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l) A Mr Jeffrey Wong Page 6 of 10 • cross contamination to occur, however, due to refusal at a depth of 85 feet bgs and subsequent malfunctioning of the Simulprobeo tool boring S137 was terminated In an attempt to obtain the desired depth subsequent samples were collected with conventional groundwater sampling methods utilizing a Hydropunch° type groundwater sampler in boring SB6 Borings S136 and SB7 are twinned borings (Figure 2) After collection, the samples were transferred into pre- cooled 40-mL vials with hydrochloric acid preservative, sealed, labeled, and immediately placed in an iced cooler for transport and submittal to Argon under chain of custody protocol Analysis consisted of TPHg, BTEX, gasoline oxygenate additives, 1,2 DCA, EDB, methanol and ethanol 4.0 DECONTAMINATION PROCEDURES All downhole drilling and sampling equipment was decontaminated by steam cleaning and/or washing with laboratory-grade detergent during all drilling and sampling activities Decontamination water and soil cuttings produced was placed into properly labeled DOT approved 55 gallon drums The drums are being stored on site pending disposal options No soil cuttings were generated from either CPT or direct push drilling 5.0 RESULTS OF INVESTIGATION 5.1 Subsurface Conditions CPT and traditional AST Designation soil the soil, however, CPT data wasgused eDlusiBvely)to desocgbiegthe methods ndein the used classify units following Unit A 0 to 15 feet bgs, silt and clay Unit B 15 to 24 feet bgs, sand Unit C 24 to 32 feet bgs, clay Unit D 32 to 65 feet bgs, alternating sand and clay Unit E 65 to 77 feet bgs, sand and silt Unit F 77 to 103 feet bgs, sand Unit G 103 to 110 feet bgs, clay with minor sand interbeds Depth to groundwater was approximately 45-47 feet bgs during field activities Soil boring locations are shown on Figure 2 Soil boring logs are included in Attachment A The CPT log and raw data is included in Attachment C 5.2 Soil Analytical Results Borings MW2 and MW3 had non-detectable levels for all analytes of concern In bonng MW4, TPHg was detected at 20 feet bgs and 30 feet bgs at low levels, and benzene was not detected In boring SB6, TPHg was detected at concentrations of 27 parts per million (ppm), and 16 ppm and • benzene was detected at concentrations of 0 33 ppm and 0 02 ppm at depths of 100 and 110 feet bgs, respectively Neither TPHg nor benzene were detected at 90 feet bgs or 105 feet bgs in boring dallgrounzelliarryslwellreporl doc