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Stantec Work Plan for Feasibility Study BP Stockton Terminal No. 40T June 17, 2009 Site Health and Safety Plan As required by the Occupational Health and Safety Administration "Hazardous Waste Operations and Emergency Response" guidelines (29 CFR 1910.120) and by California Occupational Health and Safety Administration "Hazardous Waste Operations and Emergency Response" guidelines (CCR Title 8, Section 5192), the contractor will prepare a site specific Health and Safety Plan (HASP). At a minimum, the HASP will define the proposed subsurface investigation activities, describe physical and chemical hazards that may be associated with the work, provide a map to the nearest emergency medical facility, and include material safety data sheets for any hazardous chemicals that will be used or produced during the work. A copy of the HASP will be available on-site at all times during field work. The field staff and subcontractors performing field activities will review the HASP prior to beginning field operations at the site. Permitting and Clearance Activities Any necessary permits will be obtained from the San Joaquin County Environmental Health Department (SJCEHD) prior to field activities. Bio Sparge Feasibility Study Stantec proposes to perform a one to three-day (eight-hour days) biosparge feasibility study near monitoring wells with elevated levels of contamination to target petroleum hydrocarbon impacts in the A-zone (Tables 1 and 2) using an air compressor (ten to 15 psi), a regulator, a generator, an inline helium tank, two existing injection points (IS-1 and IS-2), and two existing groundwater monitoring wells (MW-5A and MW-50 are to be used as observation wells) to evaluate the feasibility of this remedial technique. During first quarter 2009, A-zone depths to groundwater ranged between 1.08 and 7.08 ft bgs, with a general flow towards the southeast (Tables 3 through 5). Well construction details for the current network are summarized in Table 6. Stantec will evaluate whether communication between the injection points and the observation wells is present. To achieve this, a mixture of air and helium (90/10 ratio) will be injected into IS-1 and IS-2 and will be evaluated using both field measurements and water samples from MW-5A and MW-50. Field measurements include: pressure differential (using well caps); down hole VOC, carbon dioxide (CO2), and helium (He) concentrations (using a PID, FID, or equivalent device) in vadose zone; and dissolved oxygen (DO) concentration, temperature, pH, oxygen reduction potential, conductivity, and CO2 and He concentrations (to be determined by a State-certified laboratory) in the water-bearing zone. Vadose-zone measurements will be taken prior to the start of the feasibility study, every 15 minutes for the first hour, every 30 minutes for the next three hours, and every hour for the remainder of the study. Water-bearing zone measurements and/or sampling will be collected prior to the start of the feasibility study and every two hours for the remainder of the study. Following the feasibility study, all field measurements and sampling data will be evaluated. If the evaluation finds no evidence of increased DO concentrations in wells MW-5A and/or MW-50 and no He in the samples, communication between the injection points and the observation wells will be determined to be inadequate. 0040T Work Plan for Feasibility Study.doc 2