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- REMEDIAL AtrnON WORK PLAN, 1645 CHEROKEE ROOD, STOCKTON, CA This section presents the tasks and methods proposed to remediate the affected soil and/or groundwater. 2.2 Groundwater Monitoring Well Abandonment In a letter dated November 9, 2004,the SJCDEH suggested that all of the current on site groundwater monitoring wells were dysfunctional and requested that they be permanently abandoned. Furthermore, the proposed excavation will encroach upon some of the well locations. Therefore, upon approval, BES proposes to destroy the on site wells by drilling out the entirety of casing depth and pressure grouting the wells with a mixture of neat Portland cement and 5% bentonite material. Any and all soil cuttings and waste material generated during destruction activities will be stockpiled on site and off-hauled and disposed of with the excavated materials. All well locations will then be resurfaced to match existing surface material. 2.3 Excavation Previous assessments of the subject property have concluded that the gross impact to the native surface soils exists primarily within the B-1 and B-5 locations (Figure 3). Therefore, excavation activities will be initiated at the B-I (MW-4) location and will extend laterally toward the boring B- 11 and B-5 locations. The depth of the excavation is not expected to exceed 45 feet bgs and completed at an average depth of 26 feet bgs. Figures 6 and 7 attached as Appendix A, present the proposed location and boundaries of the remedial target area. All impacted soil targeted for removal will be excavated using an excavator. Excavation of impacted soil will proceed laterally and - vertically as field screening indicates the necessity. Field screening will be conducted using a Flame Ionization Detector(FID). All soil removed will be segregated and the materials deemed necessary for disposal will be immediately loaded for transport and disposal. Overburden soils which do not meet the prerequisites for off-haul will be re-used as backfill 2.4 Confirmation Sampling Upon completion of excavation activities, one confirmation and verification soil sample will be collected per 20 lineal feet of excavated area and submitted for chemical analysis. Each sample submitted will be evaluated for the presence of Total Petroleum Hydrocarbons calculated as diesel (TPH-d), using EPA method 8015 and/or Total Petroleum Hydrocarbons calculated as gasoline(TPH- g), Benzene, Toluene, Ethyl-benzene, and Xylene (BTEX), Fuel Oxygenates, EDB and 1,2-DCA using EPA method 8260B. The samples will be collected manually in 2-inch x 6-inch brass sleeves. Upon sample retrieval, each tube will be capped with polyethylene sheeting and a plastic cap and labeled with the client's name and sample identification number. The samples will then be placed in a pre-cooled container for transportation under chain of custody to a state certified laboratory for chemical testing. 2.5 Groundwater The groundwater beneath the subject property has been established to be impacted by elevated concentrations of residual petroleum hydrocarbons. The depth to water at the site has been encountered at depths greater than 40 feet bgs. Therefore, it is not anticipated that this groundwater will be encountered during soil removal activities. However, should water be encountered, in order to dewater the excavation as well as provide a supplementary remedial action to the affected groundwater, a slotted Polyvinyl Chloride (PVC) sump will be constructed with the excavation and 3 Bohm Environrrmerita? SOIL16011S