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monitoring wells have indicated positive for BTEX and TPHg The last quarterly sample for monitoring well 8S for TPHg was 305 ug/L and 8D was 18500 ug/L for TPHg This has a history of large variation in groundwater elevation between quarter This variation is much greater than what is considered normal for the Stockton area This work plan will propose a receptor survey covering a 2000 foot radius of the site Historically the groundwater gradient has been down slope to the northeast SCOPE OF WORK Item L Conduct a standard of the industry receptor survey of all commercial,industrial,agricultural and residual water wells within the 2000' radius of the site Item 2 Dnll an eight-inch soil bore with depth of+/-ninety feet below the surface This soil bore will terminate five feet into the permeable layer that lies about ninety feet below the surface A deep monitoring well with a one-inch PVC casing is to be installed at the bottom of the soil bore with five feet of screen A shallow monitoring well with a two-inch PVC case is to be installed with the bottom of the casing sixty feet below the surface This shallow monitoring well will have twenty feet of screen A typical groundwater surface is forty to fifty feet below the surface Soil Boring Location and Restrictions The proposed location of this bore hole is thirty feet west of the existing monitoring wells MW#8S & MW#813 This location may be modified slightly to fit the building conditions This location is limited . by a sixteen-foot height restriction on a drill ng Sampling of Soil Boring Existing soil borings have shown contamination starting at twenty-five below the surface It is proposed that sampling begin at twenty feet below the surface Samples will be extracted with a split spoon sampler at five foot intervals to the bottom of the soil boring Soil Sample Transportation and Analysis Soil samples will be extracted with a metal liner that will be covered at the ends with a Teflon sheet and secured with a standard plastic cap The cap will be secured with duct tape and the sample stored on ice for transport under a chain of custody to a state certified laboratory The samples will be analyzed by EPA methods 8015, 8020, and 8260 and the findings presented in a standard engineering report • Monitoring Well Construction Monitoring well MW#9S will be constructed with a two-inch PVC casing The bottom twenty feet of casing shall be slotted with 0 010 slots Filter sand for the slotted portions of monitoring wells shall be #2x#16 sand A two-foot plug of bentonite shall cover the filter section and cement grout will be pumped from the bentonite seal to the surface A well box with locking caps shall cover the monitoring wells(see monitoring well detail attached) Monitoring well MW#9D will be installed in the bottom the soil boring and contain five feet of 0 10" slotted screen with 42 x#16 sand filter A bentonite plug will be installed from two feet above the screen 2