ARCHIVED REPORTS XR0000379 - Laserfiche WebLink

Home Browse Search

ATTACHMENTC FIELD AND LABORATORY PROCEDURES Chevron 9-4275, 2905 Benjamin Holt Drive, Stockton, CA • CPT INVESTIGATION Health and Safety As required by the Occupational Health and Safety Administration (OSHA) Standard "Hazardous Waste Operations and Emergency Response" guidelines (29 CFR 1910 120), and by California Occupational Health and Safety Administration (Cal-OSHA) "Hazardous Waste Operations and Emergency Response" guidelines (CCR Title 8, Section 5192), SECOR prepared a Site-Specific Health and Safety Plan for use during fieldwork The field staff and contractors reviewed the Site-Specific Health and Safety Plan before beginning field operations at the site Exploratory Drilling and Soil and Groundwater Sampling The CPT soil borings were advanced using a direct push cone penetrometer testing (CPT) ng to log soil stratigraphy Immediately adjacent to each CPT borehole, a second direct-push borehole was advanced to collect discrete groundwater samples Groundwater samples were collected using a hydropunch, or similar technology, by lowering a stainless steel or Teflon bailer into accumulated groundwater in the borehole, then retrieving and transferring the water into laboratory supplied containers The groundwater sample containers were placed on ice for transport to the laboratory accompanied by chain-of-custody documentation Down-hole boring and sampling equipment was steam-cleaned prior to and following the completion of each soil boring Down-hole sampling equipment was washed in a tri-sodium phosphate or AlconoxTM solution between samples Organic Vapor Procedures Soil samples collected continuously during drilling were analyzed in the field for ionizable organic compounds using a photo-ionization detector (PID) with a 10 2 eV lamp or a flame ionization detector(FID) The test procedure involved measuring approximately 30 grams from an undisturbed soil sample, placing this sub-sample in a sealed container (either a zip-lock bag or a mason far) The container was warmed for approximately 20 minutes (in the sun), then the head-space within was tested for total organic vapor, measured in parts per million as benzene (ppmv, volume/volume) The instrument was calibrated prior to drilling using a 100-ppm isobutylene standard (in air) and a sensitivity factor of 55, which relates the photo-ionization potential of benzene to that of isobutylene at 100 ppm The results of the field-testing was noted on the boring logs PID and FID readings are useful for indicating relative levels of contamination, but cannot be used to evaluate hydrocarbon levels with the confidence of laboratory analyses