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Phase II Environmental Site Assessment Manteca Multimodal Station Project,Southeast of Moffat Boulevard and Main Street,Manteca, California • Soil Sampling-Historic Railroad Spurs-Using a Geoprobe direct push rig, 16 soil borings (RB 1 through RB 17)were advanced in the locations where railroad spurs were formerly located on the subject property. The soil borings were advanced to a maximum depth of 2 feet below grade. Soil samples were obtained from depths of 0.5 and 2 feet below existing grades. Select soil samples were analyzed for TPH,total metals, VOCs and herbicides. • Soil Sampling Beneath Stained Pavement-Using a Geoprobe direct push rig, one soil boring was advanced to 5 feet below grade beneath the stained pavement. Soil samples were collected at 1 and 5 feet below grade. The one-foot deep soil sample was analyzed for VOCs, SVOCs, TPH,total metals, PCBs,pesticides and herbicides. • Reporting-After receiving the analytical results from the laboratory,we compared the concentrations of detected constituents in the soil and groundwater samples to one or more of the following: USEPA Regional Screening Levels (SLs), California Human Health Screening Levels (CHHSLs), soluble and total threshold limit concentrations (STLCs and TTLCs),Environmental Screening Levels (ESLs) established by the San Francisco Bay Regional Water Quality Control Board(RWQCB) and Maximum Contaminant Levels (MCLs) established by the State of California Department of Public Health(DPH). Following completion of the sampling program,we prepared this report that presents the findings of the assessment. During the Phase I ESA, an unlabeled 55-gallon drum was observed on the site. The drum appeared to be half full of a liquid substance,however,the type of liquid was unknown. During the Phase I ESA site reconnaissance, Rincon did not observe any indication of a potential release from the drum on the site. Because the contents of the drum were unknown,Rincon recommended that a sample of the contents of the drum be collected and analyzed for various chemical contaminants. The results of the drum sampling would be used to determine how to properly dispose of the contents of the drum. However, during the Phase II ESA conducted at the site,the 55-gallon drum was no longer present on the site. Therefore, sampling of the contents of the drum was not conducted as part of this Phase II ESA. GEOLOGIC AND HYDROGEOLOGIC SETTING Topography The current USGS topographic map (Manteca Quadrangle, 1952,photorevised 1994) indicates that the site is situated at an elevation of between about 30 and 35 feet above mean sea level with relatively flat topography. Southern Pacific railroad tracks are depicted bordering the southern property line,with a railroad spur depicted on the site. Moffat Boulevard and S. Main Street are depicted north and west of the site, respectively. The subject site and surrounding properties are depicted as developed areas in the City of Manteca. Highway 99 is depicted approximately 1.5 miles to the northeast and east of the site.- Geology ite:Geology and Hydrogeology The site is situated within the Great Valley Geomorphic Province of California, a large, elongate northwest tending, asymmetric structural trough. The Great Valley Province has been filled with thick sequences of sediment ranging in age from Jurassic to Recent, creating a nearly flat lying alluvial plain extending from the Tehachapi Mountains in the south to the Klamath Mountains in the north. The western and eastern boundaries of this province are comprised of the California r Rincon Consultants 5