Laserfiche WebLink
'Executive Summary <br /> On behalf of the California Department of Transportation (Caltrans), IT Corporation (IT) <br /> conducted a groundwater investigation at the Stockton Yard Maintenance Station, in the city of <br /> Stockton, California (Figure 1) The site is located at 1604 South B Street,just south of <br /> Charter Way The property is an active maintenance yard and is owned by Caltrans The <br /> objective of this investigation was to determine the extent of hydrocarbon contamination in <br /> groundwater at the site and to calculate the estimated contaminant mass for the encountered <br /> water bearing zones <br /> On February 11, 2002, an underground utility location survey was conducted to assess the <br /> absence or presence of unreported underground utilities at the site The utility survey cleared <br /> utilities for the proposed boring locations The boring locations were found to be free of <br /> anomalies <br /> On February 13 and 14, 2002, IT conducted an investigation that consisted of the advancement <br /> of two borings using Cone Penetrometer Testing (CPT) methods for lithologic evaluation and <br /> groundwater sample collection The CPT log indicated that potential water bearing zones were <br /> located at 19 8 meters (65 feet) below ground surface (BGS), 27 4 meters (90 feet) BGS, and <br /> 30 5 meters (100 feet) BGS Groundwater samples were collected from each of these zones <br /> Total Petroleum Hydrocarbons as gas (TPHg), toluene, ethylbenzene, total xylenes, <br /> n-Propylbenzene, tert-Butylbenzene, and 1,2,4-Tnmethylbenzene were detected in groundwater <br /> samples collected from the boring SC-1 None of these contaminants were detected at <br /> concentrations exceeding their respective State of California Primary Maximum Contaminant <br /> Levels (MCLs) Benzene was detected in groundwater samples SC-1-90' and SC-1-100' at <br /> concentrations exceeding the primary MCL of 1 microgram per liter <br /> Local regulatory ry agencies may require further investigation of the presence and concentration of <br /> petroleum hydrocarbons within the soil and groundwater Based on results from this <br /> investigation, IT recommends that a Remedial Action Plan be prepared in order to perform <br /> remedial activities to clean up the site <br /> i <br /> I <br /> 6��0++�6w1Tgp�gyll$ACAFPTICOMMCl1M1s9eDP420024PAJWRB18318352772aadx ES-1 <br /> 4/41V2 <br />