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Apache Plastics 4Q 2001 QMR Page 2 Petroleum hydrocarbons were detected in soil samples collected from borings B-1, VEW-1, MP-1, and MP-2 Dissolved petroleum hydrocarbons were detected in samples collected from monitoring wells MW-1 and MW-5, and in vapor extraction well VEW-1 In June 1994, a soil vapor extraction (SVE) remediation system was installed The system is comprised of an internal combustion engine with catalytic converter and associated filters, controls, and piping Vapor extraction wells VEW-1 and VEW-2 are inamfolded to the SVE system The system operated continuously from July 1994 to December 1996 The system operated intermittently during the first quarter 1997 due to mechanical problems EMCON submitted a Case Closure Report (July 17, 1997) that included estimates of remaining petroleum hydrocarbon mass in soil and groundwater, and recommended case closure under the low risk criteria After reviewing the report, San Joaquin County PHS/EHD requested additional vertical assessment of soil and groundwater In February 1999, EMCON directed the installation of onsite monitoring wells MW-8 and MW-9 to a depth of approximately 105 feet bgs Dissolved petroleum hydrocarbons were detected in groundwater samples collected from monitoring wells MW-8 and MW-9 First encountered groundwater beneath the site has ranged from 68 to 44 feet bgs Previous consultants have calculated groundwater flaw directions to be south and east, with the predominate flow direction toward the southeast It is our understanding, based on j conversations with San Joaquin County PHS/EHD, that first encountered groundwater in the • area of the site was recorded as low as 110 feet bgs in 1979 A work plan to conduct additional soil and groundwater assessment activities was submitted to San Joaquin County PHS/EHD on December 3, 1999 The work plan was subsequently approved Stratus obtained one onsite and two offsite access agreements and a revocable encroachment permit from the City of Stockton prior to initiating field work Between February 5 and March 12, 2001, Stratus oversaw Gregg Drilling and Testing, Inc of Martinez advance 13 cone penetration test (CPT) and direct push soil borings and drill and install 3 groundwater monitoring wells (MW-10 through MW-12) A report documenting the findings of this investigation was submitted on July 27, 2001 GROUNDWATER GRADIENT AND DIRECTION Fourth quarter 2001 groundwater levels were measured on November 5, 2001 using an electronic sounding device, and recorded on the field data sheets presented in Appendix A Table 1 presents historic and fourth quarter 2001 groundwater elevation data Figure 2 presents groundwater elevation contours (corrected to mean sea level [msl]) for monitoring wells with total depths of less than 75 feet bgs (shallow wells) Figure 3 shows groundwater elevation contours for wells with total depths ranging from 105 to 115 feet bgs (deep wells) At the time of the fourth quarter monitoring event, groundwater was encountered in the monitoring wells at depths ranging from 46 65 to 49 10 feet bgs The groundwater flow direction in the upper water bearing zone was calculated to be towards the east-northeast at an average gradient of 0 00048 ft/ft The groundwater flow direction in the lower water . bearing zone was calculated to be towards the southeast at an average gradient of 0 0064 ft/ft P\Apache Plastics\Quarterly reports1200I\Apache_4Q01 doe