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0 ground obstructions that were not noted on the site plan Underground Service Alert was . notified to clear each probe location for underground utilities Field Data Collection The level of volatile organic vapors were measured from beneath product dispensers and within turbine manways using a H13U PI-101 photo-ionization detector (PID) A PACIFIC field technician opened each product dispenser and turbine manway and collected a PID measurement from soil immediately below each dispenser or turbine at a height of approxi- mately 112-inch above the exposed soil If native soil was not exposed,then this observation was recorded on the Field Data Sheet and PID measurements were not collected PID measurements and field observations are recorded on the attached Field Data Sheet The location of each PID reading is shown on the attached site plan Soil Gas Survey On September 19, 1997, a PACIFIC staff technician directed the installation of 4 soil gas probes in the vicinity of USTs, product islands, and product lines at the site referenced above The approximate location and designation of each soil gas probe is shown on the attached Site Plan Sample collection depths are noted on the attached Field Data Sheet Two samples were collected from the area of the UST complex at depths ranging from 3 feet to 15 feet Two soil gas samples were collected adjacent to the product dispenser islands at depths of approximately 3 feet. Soil gas samples were not collected along the product tines because either line locations could not be field verified, or less than 20 linear feet of product exists between the UST complex and product island The soil gas survey consisted of driving a 1/2-inch diameter hollow steel probe into unsatu- rated soils at each sampling location The end of the driven probe was fitted with a small screened interval with protective cover The probes were driven into the soil with pneumatic equipment Upon reaching the desired depth the outer protective casing was retracted to allow the screened interval to be exposed to the soils Soil gas samples were drawn from the probe by means of a vacuum pump through a probe head fitting and a silastic tubing sample line The soil gas probe was purged of vapors for approximately 3 minutes prior to sample collection A soil gas sample was then collected into a clean I-liter Tedlar bag ,Each Tedlar bag was labeled with the appropriate sample designation, date of sample, and UNOCAL station number and stored in a cool dark box The samples were submitted to Sequoia Analytical Laboratories within 24 hours of sample collection Upon completion of the sampling procedures the probes were removed and the probe holes were backfilled to the surface with a neat cement seal 3111631A15417 2 October 29, 1997