ARCHIVED REPORTS XR0009906 - Laserfiche WebLink

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I March 12, 1993 Working To Restore Nature ARCO Service Station No 2130, Stockton, California C F' I INSTALLATION OF MONITORING WELD On November 16 and 17, 1992, a geolo 1st from RESNA observed Westex' rllhng of West Sacramento, California, drill twyi soil on gs (B-21 and B-22) and construct two ground- water monitoring wells (MW-6✓and MW- ) adjacent to the site The location of the two I new wells are sh9wn on the Area Map, Plate 3 The borings were terminated at crl approximately 74/feet below grade. Soil samples were collected from the borings for possible laboratory analyses and to evaluate the geology beneath the site I The geologist logged the samples using visual and manual methods and classified the samples according to the Unified Soil Classification System (Plate 4) Sediments encountered during drilling are shown on the Logs of Boring (Plates 5 through 10) The geologist also collected soil samples from the stockpiled drill cuttings for analyses to evaluate disposal options Our field methods are described in an attachment to this report I Soil samples were submitted to Sequoia Analytical Laboratories in Sacramento, California, which is certified by the State of California for the requested analyses (Hazardous Waste Testing Laboratory Certificate No 1624) The samples were analyzed for total petroleum hydrocarbons as gasoline (TPHg) and benzene, toluene, ethylbenzene, and total xylene isomers (BTEX) using Environmental Protection Agency (EPA) Methods 5030/8015/8020 1'• Results of analyses are shown in Table 1 and indicate TPHg and BTEX were not detected in the samples collected from the borings The soil samples collected from the drill cuttings were composited into one sample at the laboratory, this sample was analyzed for reactivity, corrosivity, ignitability, STLC lead, and TCLP BTEX Analytical results indicate TPHg, BTEX and lead were not detected, corrosivity was 8 3, ignitability was greater than 100 r degrees Centigrade and was not reactive with sulfide, cyanide, or water Dillard disposed the drill cuttings at BFI GROUND-WATER MONITORING r Field work was conducted by RESNA and Emcon Associates (Emcon) of Sacramento, California Emcon was contracted by ARCO, Emcon subsequently forwarded their field notes and the laboratory reports to RESNA Data obtained from Emcon is presented in the Appendix to this report r Subjective Analysis and Water-Level Measurements r October 6992, a technician from Emcon measured depths to water, performed �. On ' , 1subjective analyses of ground water, and collected ground-water samples from the wells for laboratory analyses A technician from RESNA was onsite on November 11, 1992, to take 1105kchr 2 30003-6 r