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L' PHASE II ENVIRONMENTAL SITE ASSESSMENT REPORT Heritage Square 640 N. San Joaquin Street Stockton, California 1.0 INTRODUCTION This report was prepared by Condor Earth Technologies, Inc. (Condor) to describe the limited Phase II Environmental Site Assessment (ESA) conducted on May 29, June 10, and June 11, 2002 at the Heritage Square property (site). The site is located at 640 N. San Joaquin Street, Stockton, San Joaquin County, California (Figures 1, 2, and 3 Appendix A). The purpose of the work was to evaluate the site for �+ potential subsurface hydrocarbon contamination associated with previously unidentified USTs and related piping. The work included the advancement of eight direct push borings and four hand auger borings to collect soil and groundwater samples. This report w-as prepared at the request of David and Marianne i. Warwick in cooperation with Stockton Unified School District(SUSD). ' All work conducted by Condor was performed cinder the supervision of a California Registered Geologist. This report includes project background information, a description of the fieldwork and laboratory analytical results, conclusions, and recommendations. v 2.0 PROJECT BACKGROUND The site is located in a commercial area in downtown Stockton and is currently known as Heritage Square. The existing structure at the site is an unreinforced concrete and masonry building constructed in �.. 1916 that SUSD has recently purchased for use as a charter school. Prior to purchasing the site, SUSD retained Condor to perform a geotechnical investigation at the site to evaluate subsurface conditions based on the age of the structure and its proposed use. A geotechnical borehole was drilled east of the building on February 6, 2002 in the parking lot (APN 139-161-11, see Figure 2)jointly owned at the time by the Warwicks and the Women's Center of San Joaquin County (Women's Center). The borehole location is shown on Figure 3. This borehole pierced a metal pipe not identified by Underground Service Alert (USA), as locators do not generally mark utilities on private property. A viscous black bunker oil-like fluid seeped from the pipe onto the soil. One sample of the fluid and underlying soil was collected for laboratory analyses before the pipe was repaired to prevent further leaking. The sample was nearly a raw product sample and was analyzed for total petroleum hydrocarbons quantified as gasoline (TPH-G), and for total extractable petroleum hydrocarbons quantified as kerosene (TEPH-K), diesel (TEPH-D), and motor oil (TEPH-MO) by EPA Method 8015m; for volatile organic compounds (VOCs) by EPA Method 8260$; and for California Administrative Manual (CAM) metals by EPA Methods 7471A/601013. The hydrocarbons detected in the extractable range were primarily TEPH-D ' and TEPH-MO. TPH-G was also detected; however, the chromatogram did not match a typical gasoline La pattern. The detection of gasoline-range hydrocarbons may result from weathering of heavier hydrocarbons. No CAM metals were detected at or above the U.S. EPA Region IX Preliminary Remediation Goal (PRG) values for residential sites or Total Threshold Limit Concentrations (TTLC). L. On May 7, 2002, following evaluation of the laboratory analyses, the extent of the pierced fuel line was investigated using a backhoe and Cruz Brothers line locating service. During the backhoe work, additional fuel lines were located south of the geotechnical borehole. These lines were traced to a fuel 1.+ CONDOR to