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Ms. Vera Fischer, P.G., RWQCB April 24, 2017 Work Plan for Additional Site Assessment Project No. 2154-1817-01 1817 South Fresno Avenue, Stockton, CA Page 6 supplied glass vials, properly labeled, and placed in an ice-chilled cooler. The groundwater samples will be transported under strict chain-of-custody protocol to a California-certified analytical laboratory for chemical analysis. Upon completion of groundwater sampling, the sampling borehole will be pressure grouted from the bottom of the borehole up to surface grade. Well Boring Advancement A licensed well driller will advance the soil borings using a truck mounted or limited access drill rig equipped with 8-inch diameter hollow stem augers, in the presence of a Stratus Geologist. Each boring will be completed as a groundwater monitoring well, as described below. The initial 5 feet of each boring will be advanced with hand tools, or an air knife, to reduce the possibility of damaging underground utilities. Soil samples will be collected in 5-foot intervals from borings MW-12 and MW-13 using a California-type, split-spoon sampler. The recovered soil will be logged in the field using the Unified Soil Classification System. Given the distance of the well borings from the Site, no soil samples will be retained for submittal to a laboratory for chemical analyses. Monitoring Well Installation Monitoring wells MW-12 and MW-13 will be constructed through 8-inch diameter augers using 2-inch diameter schedule 40 PVC casing and 15 feet of 0.02-inch diameter factory slotted well screen. An approximate well depth of 30 to 35 feet is proposed, with the exact well depth and screening interval to be determined at the time of the investigation. Our intention is to screen wells MW-12 and MW-13 within sandy strata typically observed between about 20 to 25 feet bgs and 36 feet bgs (discussed above), as these sandy strata could potentially allow for preferential lateral migration of fuel contaminants away from the Site in the downgradient direction. A filter pack of #3 sand will be placed in the annular space around the well casing from the bottom of the well screen to approximately two feet above the top of the well screen. Approximately two to three feet of bentonite chips will be placed on top of the filter pack and hydrated with clean water 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. The actual well construction may be modified in the field based on conditions encountered at the time of the investigation. Well Development and Sampling A minimum of 72 hours following installation, Stratus will develop wells MW-12 and MW-13 by surging and bailing, followed by groundwater pumping. Approximately 10 well casing volumes will be removed from each well during development; however, removal of groundwater will continue until the water appears free of suspended sediment. KABames Trucking\ Work Plans\ barnes trucking work plan 2017.doc STRATUS