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Kennedy/Jenks Consultants 2 FIELD INVESTIGATION The field investigation will include the following activities. 2.1 Prefield Activities Kennedy/Jenks has prepared a site-specific Health and Safety Plan for the activities proposed in this Work Plan. In addition, the City of Stockton has obtained access agreements with the appropriate property owners at the subject site. For the proposed activities to be performed in the street, the City of Stockton has obtained an encroachment permit. Underground Services Alert (USA) will be contacted prior to the start of work to mark the locations of subsurface utilities adjacent to the property, however USA does not typically locate onsite utilities or privately owned utilities. Therefore, a utility locating firm will also be contracted to search for buried utilities or obstacles at the proposed sampling locations. The utility locating firm will also perform geophysical surveys in the vicinity of each of the former UST systems and sumps. Kennedy/Jenks will retain a licensed driller who is authorized to drill soil borings and obtain soil samples within San Joaquin County. If necessary, a concrete cutting contractor will be retained by Kennedy/Jenks prior to the start of drilling activities to allow drilling access to the subsurface. 2.2 Field Investigation 2.2.1 Geophysical Survey Kennedy/Jenks will employ a geophysical exploration subcontractor to attempt to confirm or deny the presence of the subsurface piping and USTs identified in the Phase I ESA. The geophysical survey will use magnetics and induced electromagnetics, as appropriate, to attempt to locate the USTs and piping. Survey grid patterns appropriate to the size and shape of the objects will be used in the locating attempts. Because of the uncertain subsurface conditions, and the likely presence of interfering metallic objects, it is possible that the results of the survey may be inconclusive. 2.2.2 Subsurface Soil Sampling Kennedy/Jenks proposes to advance seven borings (SB-1 through SB-7) to an approximate depth of 20 feet below ground surface (bgs) in the locations shown on Figure 1 to assess the potential source areas identified above. A combination direct push sampling/drilling rig will be used to advance the borings and collect soil samples for laboratory analysis. The rig will be converted to auger drilling if the soils cannot be penetrated or a target depth cannot be achieved using the direct push method. The direct push sampling techniques are presented in Appendix A. The hollow-stem auger sampling techniques are presented in Appendix B. Soil samples will be collected for potential chemical analysis approximately every 5 feet using a split-spoon sampler lined with either brass or stainless steel liners (6 inches long by 7/8-inch diameter) or a single butyrate liner(24 inches by 7/8 inches). Sample collection and preservation procedures are contained in Appendices A and B. Subsurface soils will is%job\96\966070.00\workp lan\text.doc 3