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i ** Mr.James Barton,RWQCB May 14,2008 Work Plan for Additional Site Assessment Former Dolly Madison Bakery;Stockton,California Page 10 of damaging underground utilities. Details regarding exploratory boring procedures are included in Appendix A. Soil samples will be collected at 5-foot intervals from borings MW-17, MW-18, MW-19 AS-2, AS-3, and AS-4 using a California-type, split-spoon sampler equipped with three pre- cleaned brass or stainless steel sleeves. Additional soil samples may be collected within the saturated zone of these soil borings to provide additional information regarding lithologic conditions. Soil samples will not be collected during the advancement of borings VW-4, VW-5, VW-6, MW-15, and MW-16 due to the close proximity of borings AS-1, AS-3, MW-5, MW-19, and MW-17, respectively. The ends of the bottom-most, intact tube from each sample interval will be lined with TeflonTm sheets, capped, and sealed. Each sample will then be labeled, placed in a resealable plastic bag, and stored in an ice-chilled cooler. Strict chain-of-custody procedures will be followed from the time the samples are collected until the time the samples are relinquished to the laboratory. Additional samples from the soil core will be screened for volatile organic compounds using a photoionization detector (PID). Stratus will record PID readings, soil types, and other pertinent geologic data on a borehole log. A minimum of two soil samples from each boring will be submitted for chemical analysis. Additional samples may be selected for chemical analysis based on soil type and field observations. Task 2B: Monitoring Well Installation Monitoring wells MW-15 through MW-19 will be installed through 8-inch diameter hollow stem augers using 2-inch diameter schedule 40 PVC well casing and 0.02-inch diameter factory slotted well screen. Well MW-15 will be screened from approximately 10 to 35 feet bgs,well MW-16 will be screened from approximately 15 to 35 feet bgs, and wells MW-17 through MW-19 will be screened from approximately 58 to 68 feet bgs. A filter pack of#3 Lonestar�m sand will be placed in the annular space around the well casing from the bottom of the well screen to approximately 2 feet above the top of the well screen. Prior to installing the well seal, each well will be surged with a surge block to "seat"the filter pack around the well screen. Approximately 2 feet of bentonite chips (MW-15 and MW-16), or four feet of coated bentonite pellets (MW-17 through MW-19) will be placed on top of the filter pack to provide a transition seal for the well. Neat cement will be used to backfill the remaining annular space around the well casing. A watertight locking cap will be placed over the top of the well casing, and a traffic rated vault box will be installed around the top of the well. Diagrams illustrating the proposed construction of each monitoring well are provided in Appendix B. The actual well construction may be modified in the field based on conditions encountered at the time of the investigation. KATimothy Kong Property\Work Plans\Kong-may08workplan.doc