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Stantec 76(Former BP)Service Station No. 11192 March 10, 2011 Page 1 STANTEC'S FIELD AND LABORATORY PROCEDURES Utility Locating Prior to drilling, boring locations are marked with white paint or other discernible marking and cleared for underground utilities through Underground Service Alert (USA). In addition, the first five feet of each borehole are air-knifed, or carefully advanced with a hand, to help evaluate the borehole location for underground structures or utilities. Cone Penetrometer Testing (CPT) and Groundwater Sampling The CPT method consists of advancing a cone-tipped cylindrical probe (1.7 inches-in- diameter) into the ground while simultaneously measuring resistance to the penetration. The CPT method evaluates soil stratigraphy/lithology by comparing the force (cone bearing pressure) required to advance the probe (Qt)to the friction ration (Rf). The Rf equals sleeve friction [Fs] divided by the probe tip load, times the penetration pore pressure [Ud]. Computer generated CPT logs are plotted in the field to provide a graphical log of subsurface soil stratigraphy/lithology. A CPT test data report, including logs of the CPT technique, is submitted with the final report. CPT testing is performed in accordance with American Society of Testing and Materials (ASTM) Method D 5778-95(Reapproved 2000). Groundwater sampling depths are selected based on the computer generated CPT logs (I.e. from areas identified to be coarse-grained material and with a high permeability). A separate companion boring is advanced for each groundwater sampling depth. A Hydropunch tip is affixed to the head of the CPT rods in place of the CPT cone. The Hydropunch tip is advanced approximately 2 feet to be within the desired groundwater sampling zone (effort is made to emplace the Hydropunch screen across the center of the water table surface, if appropriate), and retracted to expose the Hydropunch screen. Grab groundwater samples are collected by lowering a pre-cleaned, single-sample polypropylene, disposable bailer down the annulus of the sampler rod. The groundwater sample is discharged from the bailer to the sample container through a bottom emptying flow control valve to minimize volatilization. Collected water samples are discharged directly into laboratory provided, pre-cleaned, vials or containers and sealed with Teflon-lined septum, screw-on lids. Labels documenting sample number, well identification, collection date, and type of preservative (if applicable, i.e. HCI for TPPH, BTEX, and fuel oxygenates) are affixed to each sample. The samples are then placed into an ice-filled cooler for delivery under chain-of-custody to a laboratory certified by the State of California to perform the specified tests. The CPT is performed inside a grout collar installed at the ground surface. The grout collar allows the CPT contractor to backfill the boring as the steel rods are retracted from the hole to help prevent cross-contamination of water bearing zones through an open borehole. Each boring is backfilled to surface grade. Grout mix used to backfill the boring is Portland cement, mixed at a ratio of 6 gallons of water per 94 pounds of cement. A concrete or asphalt patch is placed over the borehole where applicable.