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Phase II Environmental Site Assessment Report 324 East 11th Street Tracy,CA July 23,2013 INTRODUCTION On behalf of Tracy Office Plaza,LLC,Pangea Environmental Services,Inc.(Pangea)prepared this Phase II Environmental Site Assessment Report(report)for the subject site. Phase II work was completed to address concerns identified in your Phase I Environmental Site Assessment dated April 2, 2013. The Phase II assessment identified petroleum hydrocarbons near former fueling facilities, and involved six borings to delineate the extent of hydrocarbons. Consistent with boring permit requirements,this report will be submitted to the San Joaquin County Environmental Health Department(SJCEHD).The SJCEHD and Regional Water Quality Control Board will determine if additional action is required. SITE BACKGROUND The subject site is an office building operated by Tracy Office Plaza, LLC (Figure 1). The site consists of offices and a large parking lot. Land use surrounding the site is predominantly commercial with residential land use present 275 ft southwest of the site(upgradient). Additional site background information is provided in the Phase I Environmental Site Assessment report. The Phase I identified concerns regarding the property being the location of a truck/auto station from the 1950s until 1973. In 1973, a permit was obtained to demolish the station and remove six USTs.No documents confirming the removal of the USTs have been found to date at the San Joaquin County Environmental Health Department or the Central Valley Water Quality Control Board. The Phase I also identified petroleum hydrocarbons north of the site at Tracy High School. The estimated groundwater direction at the Tracy High School site was northerly,indicated the subject property is upgradient of Tracy High. The Tracy High School case was closed in March 2009. The Phase I also recommended a subsurface investigation to determine if the source of hydrocarbons at Tracy High is the subject property. SITE ASSESSMENT PROCEDURES Geophysical Survey and Potential UST Evaluation To help determine if potential USTs were present,Pangea contracted Geotech Utility Locating of El Cerrito, California to survey the site on June 28, 2013. Ground penetrating radar (GPR), electromagnetic utility locating methods and a metal detector were used to survey the area where USTs were potentially located. No USTs were identified during geophysical surveying.This suggests that any USTs installed at the site have been removed. Geophysical surveying did identify a potential 20-ft long underground pipe anomaly near the 1