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Subsurface Investigation Report 216 N.California St. March 24,2008 Page 2 In a letter dated December 22, 2004, Margaret Lagorio of the SJCEHD directed the Property Owner to submit a work plan to investigate the lateral and vertical extent of contamination at the Site. The purpose of the work described herein was to comply with the above SJCEHD directive. PREPARATION ACTIVITIES Condor obtained an encroachment permit from the City of Stockton, which included street and sidewalk closure and a traffic control plan. Condor obtained a soil boring installation permit from the SJCEHD. The proposed boring locations were marked with white paint and Underground Service Alert (USA) was notified 72 hours in advance of the fieldwork to locate and identify underground utilities in and near the work area. Prior to initiating fieldwork at the Site, a tailgate safety meeting was held, and all Site personnel reviewed and signed the Site-Specific Health and Safety Plan (HASP). A section of the concrete sidewalk was removed prior to advancement of boring SB 1. DRILLING AND SAMPLING PROCEDURES Condor completed one boring on February 19, 2008. The direct push boring was hydraulically advanced using a 2-inch-diameter conical bit. The bit and associated push rods were thoroughly cleaned before the boring was advanced using a laboratory-grade, non-phosphate detergent and deionized water and double- rinsing with deionized water. Upon completion of the boring and sampling, the boring was grouted with neat cement to surface. Continuous core soil samples were collected from the boring with a 1.75-inch outside diameter(O.D.), 4-foot-long core barrel fitted with a clean, single use, polyethylene liner. During the sampling, the core barrel was driven in 4-foot intervals, however, due to saturated conditions, only two-foot intervals were possible once groundwater was encountered. The sample liner was extracted from the core barrel and used for geological logging and field observations. The soil samples were logged according to the Unified Soil Classification System (USCS). Portions of the soil samples were checked with a photoionization detector(PID) for the presence of volatile hydrocarbons. Geologic conditions were logged to document field observations including soil type, PID measurements, and the presence of staining or odor(see Field Observations,below, and Attachment C). Soil samples were collected from the borings for laboratory analyses based on field observations and PID measurements. Soil samples were collected from selected intervals for laboratory analyses. The soil cuttings were placed in a 55-gallon drum, sealed, labeled, and removed from the Site to await disposal pending results of the laboratory analyses. Each soil sample collected for laboratory analyses was retained, undisturbed, and cut from the liners. The liners were sealed at the ends with Teflon® sheeting, capped, and labeled. The samples were placed in a cooler chilled with Blue Ice® and delivered under chain-of-custody procedures to Argon Laboratories, Inc. (DHS#2359)for analyses. The groundwater sample was collected using a push-type groundwater sampler. The sampler has a sealed, retrievable stainless steel screen, pushed in a closed position to the desired sampling interval, and the sampler push rod was retracted at the target depth, exposing the inlet screen. A groundwater sample was collected from within the screen with a length of clean, 3/8-inch diameter polyethylene tubing equipped with a check valve at the bottom. The tubing was moved up and down by hand to draw groundwater up inside the tubing. The groundwater sample was discharged directly from the tubing into laboratory- supplied sample containers. The sample containers were sealed, labeled, placed in a cooler chilled with Blue Ice®, and delivered under chain-of-custody procedures to Argon Labs along with the soil samples. conrnaR