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1 * Aril 21,2,006 Beacon Station No. 3641 P Stockton.California WorkPlan To evaluate groundwater conditions at approximately 95 to 100 feet depth, Horizon proposes installation of a groundwater monitoring well to a depth of approximate 100 feet below surface grade (bsg) in the vicinity of soil boring B-5. The proposed monitoring well MW-14 location is approximately 5 feet northeast of boring B-5 as shown on the attached Figure 2. All fieldwork shall be conducted in general accordance with the Horizon Field Methods and Procedures (Attachment B). The work shall be accomplished by performing the following tasks: Task 1 Select and schedule a C57-licensed drilling contractor; obtain drilling permits from the SJCEHD; update the site-specific health and safety plan; notify Underground Service AIert (USA) to identify underground utility locations. Task 2 Advance soil boring MW-14 using hollow-stem auger equipment to approximately 100 feet bsg; record pertinent data on soil boring logs including soil descriptions, soil sampling intervals and well construction details; describe sediments according to the Unified Soil Classification System (USCS); collect soil samples at 5-foot intervals from the soil boring; field screen soil samples with a photo-ionization detector (PID) for volatile petroleum hydrocarbons; stockpile drill cuttings at the site on, and cover with, plastic; collect four representative samples of the drill cuttings stockpile for disposal characterization. Construct a groundwater monitoring well in soil boring MW-14 as shown on the typical well construction diagram (Attachment C); construct the screen interval at approximately 95 to 100 feet bsg on the basis of field stratigraphy. Task 3 Submit soil samples collected under chain-of-custody (COC) documentation, to a state-certified analytical laboratory; analyze selected boring samples for total petroleum hydrocarbons as gasoline (TPHg), the volatile aromatic compounds benzene, toluene, ethylbenzene, and xylenes (BTEX), the seven fuel oxygenates methyl-t-butyl ether (MTBE), diisopropyl ether (DIPS), ethyl tertiary-butyl ether (ETBE), tert-amyl methyl ether (TAME), tert-butanol (TBA), ethanol and methanol, and for the lead scavenger compounds 1,2- dichloroethane (DCA) and 1,2-dibromoethane (EDB); combine the four stockpile soil samples into one composite sample and analyze for TPHg, BTEX, and MTBE by EPA Method 8260B and for total lead by EPA Method 6010. Task 4 Develop and sample the monitoring well; submit groundwater samples, under COC documentation, to a state-certified analytical laboratory; analyze groundwater samples for TPHg, BTEX, seven oxygenates, DCA and EDB by EPA Method 8260B. 641wp4-06 Project No. 1641.19 2 HORIZON ENVIRONMENTAL INC.