Laserfiche WebLink
1 2005 3"d Quarter Groundwater Report <br /> iFrontier Transportation,Inc. <br />' December 5,2005 <br /> Page 1 <br /> 1.0) INTRODUCTION <br /> Biophysics Environmental Assessments, Inc (BEA)was contracted by Frontier <br />' Transportation, Inc to report the 2005 third quarter groundwater monitoring results at the <br /> Frontier Transport facility,425 Larch Road, Tracy, California(See Figure 1, Site Location Map) <br /> The 2005 third quarter groundwater monitoring episode was performed on September 26,2005 <br /> by Del-Tech Geotechnical Support Services The San Joaquin County Public Health Services, <br /> Environmental Health Division (PHS/EHD), Carrol Oz, Senior REHS requested quarterly <br /> groundwater monitoring on September 8, 1999. <br />' 2.0) SITE LOCATION AND HISTORY <br /> The site is located in Tracy, California at 425 Larch Road in the northwest quarter of <br /> section. 16, Township 2 South, Range 5 East, Mount Diablo Baseline at Meridian. The site <br /> consists of a trucking facility with one metal frame building and all parking and work areas <br />' capped by cement and/or asphalt The site is located in an industrial park <br /> Six (6)underground fuel storage tanks(USTs),three diesel tanks located northeast of the <br />' • terminal and three gasoline tanks located southeast of the terminal,were removed from the site <br /> on July 21, 1995 Soil sample analysis identified total petroleum hydrocarbons as gasoline <br /> (TPH-g)and total petroleum hydrocarbons as diesel (TPH-d) m the gasoline tank excavation at <br />' maximum concentrations of 9,800 mg/kg and 120 mg/kg,respectively. Groundwater sample <br /> analysis identified dissolved phase TPH-d in the diesel excavation pit at a maximum <br />' concentration of 1,200 µg/L <br /> In August of 1996, Twinning Laboratories, Inc (Twinning)advanced six vertical soil <br />' bonngs (B-1, B-2 B-3, MW-IRA, MW-IRB,and MW-2RA)and one angle boring(B-4)to <br /> depths between 1 and 1-Y5'-below grade surface(bgs)to assess subsurface conditions near <br /> the northeastern excavation In addition,two hand augers (S-1 and S-2)were advanced to 3'bgs <br />' to assess subsurface conditions beneath the dispenser and product lanes and three groundwater <br /> monitoring wells, MW-1 through MW-3,were drilled to approximately 25'bgs to assess the <br /> subsurface water beneath the site initial subsurface water was encountered at 10 5'bgs Boring <br />' B-4 located northwest of the former USTs identified maximum TPH-g, BTEX(Benzene, <br /> Toluene, Ethylbenzene, and Xylene), and MTBE (Methyl-tert Butyl Ether) as 1,300 mg/kg, 180 7 <br /> mg/kg, and 110 mg/kg,respectively at 10 2' bgs <br />' Groundwater samples were collected from monitoring wells MW-1, MW-2, and MW-3 <br /> on August 30, 1996 and April 21, 1997 by Twinning. Results are presented in Table 1 <br /> 1 <br />