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rl . <br /> S ECOR <br /> Circle K Store 1205 <br /> September 7, 2004 <br /> Page 3 <br /> analyzed for TPHg, BTEX, and fuel oxygenates by EPA Method 82608. TPHg, xylenes, and ethanol <br /> were reported in soil sample GP-13@10 at concentrations of 1.2 mg/kg, 0.0095 mg/kg, and 0.65 <br /> mg/kg, respectively. No detectable concentrations of petroleum hydrocarbons were reported in the <br /> soil samples from GP-10, GP-11, GP-12, and GP-14. Groundwater "grab" samples collected from <br /> each of the geoprobe boring locations were analyzed for TPHg, BTEX, and fuel oxygenates by EPA <br /> Method 8260B. MtBE was reported at a concentration of 0.88 ug/L in boring location GP-12 and <br /> ethanol was reported at a concentration of 610 ug/L in boring location GP-13 <br /> SCOPE OF WORK <br /> The scope of work for this site assessment includes the drilling and installation of three groundwater <br /> monitoring wells and two soil borings. The specific scope of work is discussed below: <br /> • Health and Safety Plan. As required by the Occupational Health and Safety <br /> Administration (OSHA) Standard "Hazardous Waste Operations and Emergency <br /> Response" guidelines (29 CFR 1910.120), and by California Occupational Health <br /> and Safety Administration (Cal-OSHA) "Hazardous Waste Operations and <br /> Emergency Response" guidelines (CCR Title 8, Section 5192), SECOR will prepare <br /> a site-specific Health and Safety Plan (HASP). Field staff and contractors will review <br /> the HASP before beginning field operations at the site. ; <br /> • Permitting. The applicable permits for monitoring well installation and soil borings `- <br /> will be obtained from San Joaquin County, encroachment permits from the City of <br /> Lathrop, and access to private property prior to beginning work. <br /> • Groundwater Monitor Well Installation. Soil borings will be drilled using 8-inch <br /> diameter hollow stem auger equipment to a depth of 25 feet below ground surface <br /> (bgs). Groundwater monitoring wells will be constructed of 2-inch diameter schedule <br /> 40 PVC pipe and will be screened from 5 to 25 feet bgs. _ <br /> • Vertical Site Assessment. Two (dual-hole) direct push soil borings will be drilled at <br /> the locations shown on Figure 1. Soil borings will be drilled to an approximate depth <br /> of 70 feet bgs. Soil samples will be collected continuously for logging. Upon <br /> determination of lithology, grab groundwater samples will be collected. SECOR <br /> anticipates collecting groundwater samples at depths of approximately 50 and 70 <br /> feet bgs at each location. Groundwater samples will be collected using a <br /> hydropunch" or similar sampling device. Field procedures for direct push drilling are,, <br /> provided as Attachment A. 7 <br /> • Soil Selection and Analysis. No soil samples will be collected during the <br /> installation of wells MW-17 through MW-19 because of their proximity to previous t <br /> geoprobe borings and existing soil data. Soil samples from the vertical delineations j <br /> borings will be field screened with a PID. Soil samples exhibiting positive detections <br /> or a minimum for three samples from each boring (including the deepest sample) will <br /> be analyzed for TPHg, BTEX, and fuel oxygenates (MtBE, EtBE, DIPE, TAME, TBA, e:=. <br /> EDB, 1,2-DCA, and ethanol) by EPA Method 82606 and total lead. <br /> • Monitor Well Development, Sampling, and Analysis. Following installation, <br /> • monitoring wells will be developed by rigorously surging the well over the length of <br /> .;r <br /> ,�A <br /> I:IConocoPhillips112051Work Pian For Weil Installation 9-04.Doc <br />