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Mr. Jeffery Wong Page 3 WORKPLAN To further evaluate the nature and extent of soil and groundwater impact on the property the following workscope is proposed: Monitoring Well Drilling and Construction Three additional groundwater monitoring wells will be constructed at the site. Groundwater information from the U-Haul site at 2701 N. Wilson Way indicates many instances of gradient and flow direction fluctuation, which has varied from northeasterly to southwesterly. In order to optimize well placement, the work will be completed in two phases. Phase 1: Two wells will be constructed southwest and southeast of the former tank pit (Figure 3). Phase 2: The two new wells will be surveyed and tied in to the existing monitoring well at the site. Water levels will be measured and groundwater gradient and flow direction will be calculated. Based on that data, the location for the third, northerly, well will be determined and the well installed. The following drilling procedures and construction specifications will be used for all three wells. All work will be performed by a C-57 licensed drilling contractor under the supervision of an experienced geologist. The contractor will advance soil borings using a rig equipped with 8" diameter hollow stem augers and convert them into groundwater monitoring wells. The wells will be completed at depths of approximately 60 feet below ground surface (bgs), and constructed with 2-inch diameter, Schedule 40 PVC casing and 0.020" slotted screen. The screen interval will be from approximately 35 feet to 60 feet bgs to accommodate water level fluctuations. Filter pack will consist of No. 3 Monterey sand from the bottom of the wells to approximately 2 feet above the top of the screens. The remaining annulus will be completed with 2 feet of hydrated bentonite overlain by neat cement grout tremied to the surface. At the surface each well will be fitted with a locking cap and water tight, traffic rated well box. �he borings to be converted into monitoring wells will be sampled at 5-foot intervals for stratigraphic and field screening concerns. All soil samples will be classified in accordance with ASTM Designation D2488-90, which is equivalent to the Unified Soil Classification System. Selected soil samples will be submitted for laboratory analysis. At a minimum these will include samples collected from the capillary fringe. Samples selected for analysis will be immediately capped, labeled and placed in an ice chest at a temperature of 4 degrees Centigrade for shipment to the laboratory under chain of custody protocol. The samples will be analyzed for total petroleum hydrocarbons as gasoline(TPHg)using EPA Method 8015, and BTEX using EPA method 8020. Gasoline oxygenate additives, 1,2 dichloroethane (DCA) and EDB will be analyzed using EPA Method 8260. �-- Well Development, Surveying and Groundwater Sampling The elevations of the casing collars of the wells will be surveyed to an accuracy of 0.01 feet. After a minimum of 48 hrs from completion, an experienced field technician will measure static depth to water and then develop the wells by pumping and surging until turbidity is minimized. A minimum of three casing volumes will be purged from each well. Harrys\reports\workplan3mws