SITE INFORMATION AND CORRESPONDENCE

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M. Scott Mansholt - 2 - 8 September 2008 990 Beechnut-Tracy • • Excavation Workplan In accordance with the 2008 ESLs, Aand use for the Site will beort stated that the as follows: lowsosed cavation remedial goals for commercial/industrial Direct exposure 1. carcinogenic PAHs (as BaP Toxic Equivalency Factor) - 0.13 mg/kg; 2. naphthalene - 2.8 mg/kg; and, Gross contamination 3. TPH as crude oil - 2,500 mg/kg. According to the workplan, AMEC proposed the following tasks: • AMEC will distribute notification regarding the excavation process to nearby residents at least: one week prior to start of the Site activities. • Maximum excavation depth will be approximately 6 feet with a contingency to 10 feet for focused excavation of areas where affected soil may be observed. Laterally, the extent of affected soil has been determined and excavation will not extend offsite. • Approximately 1,350 cubic yards of potentially affected soil in the vicinity of GMX-09 will be excavated and temporarily stored onsite pending appropriate disposal profiling. If the profiling results are determined acceptable, the stockpiled soil will be transported to Forward Landfill for disposal. • Once the excavation is complete, bottom and side-wall confirmation samples will be collected and submitted for analysis. The excavation will be secured with fencing but remain open until results of analysis are received after a 24-hour turnaround time. • Results of a Site topographic survey determined that an adequate volume of excess soil is available onsite for backfill. Previous analytical sampling results indicated the excess soil did not contain TPH compounds at concentrations that exceeded environmental screening levels for residential or commercial/industrial uses. Backfill and compaction will follow once acceptable confirmation laboratory results are received. • Dust conditions will be monitored using water for necessary dust suppression. Since the area to be excavated is less than 5 acres, no permits or dust control plans are required by the San Joaquin Valley Air Pollution Control District. But, they will be notified at least 48 hours prior to startup. • Implement the Site cleanup before the end of the year prior to the start of the rainy season. Regional Water Board staff has the following comment: • It would be advisable to allow a two-week notification period for the local residents. Notifications should be in dual language and a copy provided to this office.