ARCHIVED REPORTS XR0006986 - Laserfiche WebLink

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1 ' SITE BACKGROUND • On October 30 1991, Warren I Gorses I xcavating, Inc. , of Rio Vista, California, excavated and removed three ' LJSTs (TKI 1K2 and TK3) from the site fhe USrs contained gasoline and diesel fuel A Condor representative was on site during the UST removal to collect soil samples The field activities were observed by Carol Oz of thL PIIS/I;HD A small hole was found on the lower fill end of rK3 (diesel tank) Petroleum ' staining and odors were noted in the soil beneath the former locations of the US 1's Groundwater was not encountered during the UST removal Six soil Samples were collected by Condor from the UST excavation at depths of 9 to 12 Feet below the ground surface l'he samples were analyzed for TPH-G (gasoline), BTEX, TEPH ' (diesel), LDB (t,thylerlL dibromide), and total lead Laboratory analyses indicated elevated concentrations of TPH-G, TEP11, and BTEX Lonstitur.nts in the soil samples 1 or additional information, refer to Tank Pull Testing Results prepared by Condor, dated November 18, 1991 ' At the direction of the PHS/EHD, Condor prepared a work plan to investigate the gasoline and diesel contamination associated with the former USTs (,Soil and(-rroundwater lizvestigation Woj k Plan, dated May 30, ' 1995) rhe work plan was approved by the PHS/l-HD and the Reclamation District#2029 On August 22, 1995, three hydropunch boreholes (HP-1, HP-2, and HP-3) were drilled at the site (see the figure ' attached to the back of Appendix B for borehole locations) Ronald Rowe of the P11S/EI1D was on site periodically to observe the fieldwork Gilbert Cosio of Murray, Burns, and Kienlen Engineering was on site to observe the drilling activities as a Reclamation District representative Two of the hydropunch boreholes (11P-1 ' and 11P-2) were located on the levee and were drilled to depths of approximately 16 and 11 feet below the top of the levee (btl), respectively The third hydropunch borehole (HP-3) was Iocated below the levee and was drilled to a depth of approximately 6 feet below ground surface (bgs) Soil samples were collected at five foot intervals ' Groundwater samples were collected using a Hydropunch II groundwater sampler Gasoline odors were noted in each borehole Laboratory analyses indicated concentrations of TP11-G and BTEX in the soil and groundwater samples analyzed from each borehole (see Tables B I and B 2, below) ' TABLE B.1 Laboratory Results (Soil- August 1995) ' a T E X TPH-G TEPH ' Detection 50 50 50 50 10 10-10 Sample I D Limits mglkg mg/kg mg/kg mg/kg mg/kg mg/kg 1432-14P1-11 (#} 1 200 3 100 5 500 22 000 300 190(diesel) ' 1432-IIP2-11 (#} ND ND 130 2 800 22 ND 1432-HP3-5 5 61 68 52 91 7 5 16(diesel) INote The last number in each sample ID indicates the depth at which the sample was collected Unit Conversions Analytical mg/kg parts per million(ppm) BTEX=benzene toluene ethyl benzene and total xylenes TAH-G--total petroleum hydrocarbons,quantified as gasoline TEPH total extractable petroleum hydrocarbons quantified as diesel motor oil, and kerosene 'SID—none detected at or above laboratory detection limits # detection limits raised due to gasoline interference • r