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ARCADIS Site Investigation Work Plan 401 Norlh San Jose Street,Stockton,Callfomla 3.1 Geophysical Survey A geophysical survey is proposed to Investigate for possible USTs, utilities, and other miscellaneous debris. A magnetic(MAG)and electromagnetic terrain conductivity(EM)survey will be performed on a 10-ft.grid to define locallzed magnetic and conductivity variations(anomalies)that may be caused by subsurface metallic and non-metallic sources. The recorded data will be uploaded to a laptop computer and processed in the field to generate preliminary MAG and EM contour maps, Used on these results,ground penetrating radar (GPR)will be focally operated over defined anomalies to further define the nature of the subsurface sources In terms of approximate size,configuration,and/or depth. Additionally EM will systematically be used to locate potential utility alignments and other features.The locations of all detected subsurface features will be marked on the ground surface and documented on a scaled site plan. The field survey will be performed by a 2-person crew headed by a CA Professional Geophysicist. 3.2 Cone Penetrometer Testing with Laser Induced Fluorescence Ten CPTILIF borings(CPT-1 through CPT-10).will be advanced at the Site(Figure 2).The locations of the CPT,-Ortngs may be modified fused on the results of the geophysical survey. CPT technology provides detailed Iltholog-fc data that can be used to Identify permeable zones.The CPT borings will be conducted using a plezocone attached by stainless steel rods to a hydraulic system that pushes the plezocone through the soil. The plezocone will continuously measure the friction,tip resistance and pore pressure which will be used to evaluate soil types on a geologic log. Laser Induced Fluorescence(LIF)testing, using an Ultra-Violet Optical Screening Tool(UVOS7)Installed on a cone penetrometer tool(CPT),can provide detailed stratigraphic logging and simultaneous hydrocarbon contaminant screening. CPT/LIF data can be used to select appropriate boring, sampling,and monitoring well locations and allowfor a rapid,accurate,and cost-effective site assessment. A CPT/LIF survey, consisting of approximately 10 borings distributed throughout the Site,will be used to semi-quantitatively evaluate the lateral and vertical distribution of TPH. The depth of the borings cannot be defined a priori;rather,the CPT will be driven to a depth at which the LIF Indicates the absence of TPH. Upon completion of the CPTs,the boreholes will be brought to grade with neat cement grout The CPT borings will be performed In accordance with the revised(2002)American Society for Testing Materials (ASTM)standards(D 5778-95). 4