ARCHIVED REPORTS XR0000217 - Laserfiche WebLink

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FIELD ACTIVITIES Depth to Groundwater Measurements ' On May 9, 2002, a representative of Geocon measured the depth to groundwater in monitoring wells MW-9, MW-11 through MW-14, MW-16, MW-19, MW-20, MW-24, MW-25, VM-1 and VM-2 ' using a battery operated water level meter The measurements were obtained from surveyed reference points at the top of the well casing (TOC) The approximate well locations and site features are depicted on Figure 2, Groundwater Elevation Map-May 2002 ' During the First Quarter - 2002, the depth to groundwater in the twelve existing wells was recorded between 48 05 and 49 01 feet below TOC Based on the May 2002 groundwater elevation data, the ' groundwater beneath the Site appears to be directed toward the east-northeast at an approximate gradient of 0 005 which is consistent with historical groundwater flow A summary of the TOC elevations, depth to groundwater measurements and Mean Sea Level groundwater elevations is presented on Table 1 Well Purem and Sampling ' Approximately three well volumes of water (5 5 to 83 gallons) were extracted from each well utilizing a 2-mch diameter submersible pump During the well purging activities, the groundwater was monitored for pH, electrical conductivity, temperature and turbidity This information is ' included on the Monitoring Well Sampling Data Sheets presented in Appendix B Following the purging activities, groundwater samples were collected from the wells and decanted into four 40-milliliter volatile organic analysis vials and one one-liter amber glass bottle The samples were sealed, labeled, placed in an ice chest containing ice, and subsequently transported to the laboratory using standard chain-of-custody protocol The extracted groundwater was placed into twelve Department of Transportation-approved, 17-H, 55-gallon drums and temporarily stored onsite pending receipt of laboratory analysis The drums are ' scheduled to be transported by ABCO Environmental Services to an appropriate disposal facility in June 2002 ANALYTICAL METHODS AND RESULTS Laboratory Analyses ' Groundwater samples were delivered to Creek Environmental Laboratories, Inc , a Caltrans-approved and California-certified analytical laboratory, for the analyses of TPHg and TPHd following EPA Test Method 8015 and benzene, toluene, ethylbenzene and total xylenes(BTEX) following EPA Test ' Method 8020, fuel oxygenate compounds (FOCs) including MTBE, tert-amyl methyl ether (TAME), ethyl tert-butyl ether (ETBE), di-isopropyl ether (DIPE) and tert-butanol (TBA) following EPA Test Method 8260 Groundwater analytical results are summarized on Table 1 Laboratory reports and ' chain-of-custody documentation are presented in Appendix C Groundwater Analytical Results TPHg was not detected above its laboratory method detection limits for the twelve groundwater samples collected at the Site TPHd was detected in the groundwater samples collected from wells MW-14, VM-1 and VM-2 at concentrations of 1,800, 520 and 5,300 µg11, respectively Benzene was ' Project No 58475-06-24 -2- June 21,2002