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Limited Environmental InvestigationSorral Hollow,Tracy,California ground surface (bgs). Additionally,the Underground Service Alert of Northern California (800-227-2600) will be notified at least 72-hours prior to drilling. Utilities notifications will be renewed as necessary during the course of the field investigation. Soil boring permits will be obtained from San Joaquin County. Permit applications must be submitted at least 5 days prior to beginning of drilling. Terraphase will retain a drilling contractor to perform the soil sampling and an analytical laboratory to perform chemical analysis of soil samples. Field work planning will include contractor scheduling and procurement of equipment and supplies. Task 2—Soil Sampling Activities The background documents indicate the primary contaminants of concern are total petroleum hydrocarbon as crude oil (TPH-cr) and polycyclic aromatic hydrocarbons (PAHs). Based on the proximity to the Orchard Supply Hardware store front, sampling will occur at night from 10PM to 6AM in order to minimize the impacts on the store operations. Task 2.1—Soil Sampline Soil samples will be collected from four depths nominal depths (1-1.5, 3-3.5,5.5-6, and 7.5-8 ft bgs).The samples from 1-1.5 and 3-3.5 will be analyzed for TPH-cr at the locations shown on Figure 2.The remaining samples will be held pending analytical results.Additional samples below these depths will be collected if visual observation indicates potential impacts from petroleum contamination. Samples will be held for PAHs also and will be analyzed for PAHs upon the client request. A continuous soil core will be collected from each sample location using a hydraulic direct-push drill rig to minimize the amount of investigation-derived waste (IDW). Borings will be advanced by a California- licensed drilling contractor under the supervision of field staff working under the direction of a California Professional Geologist.The core barrel will be lined with a clear plastic liner to facilitate lithologic logging.The core will be examined and the lithology will be logged by a field geologist using the Unified Soil Classification System. Borings will be advanced to a maximum of 12 ft bgs. Boring logs will be prepared in the field and completed under the direction of a California Professional Geologist. In addition to standard descriptors(e.g., soil types, moisture,grain size) other pertinent field observations will be recorded including organic vapor field readings (using a photoionization detector[PID]), colors, odors encountered and visual observations of unusual conditions.The sampling depths may be adjusted in the field based on the results of PID screening, and visual/olfactory observations.A global positioning system unit will be used to survey sampling locations. We estimate that soil sampling will be completed in one 10-hour work day completed at night. Terraphase Engineering Inc. Page 2 of 3