SITE HISTORY - Laserfiche WebLink

Home Browse Search

GEOMATRIX Ms. Katie Hower Chevron Pipe Line Company February 17, 1999 Page 2 collected at depths of 7.0 feet bgs and 9.0 feet bgs in borings B-2 and B-3, respectively. Soil samples were collected in brass liners and sealed with Teflon sheets, plastic caps, and silicon tape. A grab groundwater sample was collected from boring B-1 following installation of 1-inch- diameter PVC blank casing and 0.020-inch slot well screen from approximately 3 to 15 feet bgs. Groundwater was collected in a new disposable polyethylene bailer and decanted into acidified 40-milliliter volatile organic analysis vials and 1-liter amber bottles provided by an EPA approved analytical laboratory. Soil and groundwater samples were labeled,placed in an ice-cooled chest, and submitted for chemical analyses to Friedman&Bruya, Inc.,of Seattle,Washington(Friedman&Bruya), under Geomatrix chain-of-custody control. Soil samples were analyzed for total petroleum hydrocarbons as crude oil(TPHc; C,, - C36 carbon range)by EPA Method 8015 Modified; for polynuclear aromatic hydrocarbons(PAHs)by EPA Method 8270C SIM; and, for benzene, toluene, ethylbenzene, and xylenes(BTEX)by EPA Method 8260. Silica gel clean-up was performed on soil sample extracts prior to being analyzed for TPHc. Groundwater samples were analyzed for TPH quantified as gasoline(TPHg; C6 to C12 carbon range) using EPA Method 8015; TPH quantified as diesel(TPHd; C,o to C24carbonrange) using EPA Method 8015 Modified; BTEX using EPA Method 8020A; and PAHs using EPA Method 8270C SIM. Groundwater samples were passed through a glass fiber filter prior to extraction and the extracts were cleaned up with silica gel prior to TPHd analysis. Following collection of soil and groundwater samples,boreholes were backfilled with Type I-II cement grout. RESULTS Analytical results are included as Appendix B and presented in Tables 1 and 2. No TPHc, BTEX, or PAHs were detected in soil samples collected from borings B-2 and B-3. TPHc (2,100 milligrams per kilogram [mg/kg]) and two PNA's (pyrene at 0.035 mg/kg, and chrysene at 0.053 mg/kg)were detected in the soil sample collected from B-1; BTEX was not detected. No TPHg, TPHd,BTEX, or PAHs were detected in the groundwater sample collected from boring B-1. DISCUSSION AND RECOMMENDATIONS Based on the results of this soil and groundwater investigation,petroleum hydrocarbon affected soil is very limited at the site. A thin lense of petroleum hydrocarbon-affected soil was encountered in boring B-1 at a depth between approximately 8.5 to 9.5 feet bgs; petroleum-affected soil was not encountered in adjacent boring B-3. The potential health risk posed by the petroleum constituents detected in soil at the site was evaluated based on a