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the adjacent Taco Bell facility to the southeast (SB-6). The SJCEHD provided a technical response to the Workplan in correspondence dated June 5, 2009, outlining the following comments. Included below is ATC's proposed action to address each point: v Proposed Action 1 SJCEHD: The site map illustrating the proposed location for SB-4 does not include the approximate location where soil sample QS-2 was collected. Based on information on file at the SJCEHD, the proposed location for SB-4 is not where soil sample QS-2 was collected; �. therefore, you must provide technical justification for the proposed sampling point for SB-4, collection of a grab groundwater sample at approximately fifteen feet bgs, and collection of a soil sample at the capillary fringe. V ATC: Based on the November 1990 RESNA Plate 4 obtained from SJCEHD(attached), ATC will re-locate proposed boring SB-4 to an area that approximates where QS-2 was collected. Proposed Action 2 SJCEHD: ATC proposes to advance the boring (SB-5) to approximately forty feet bgs and collect a grab groundwater sample. Instead of the proposed boring, the SJCEHD believes a monitoring well should be installed adjacent to soil boring ATC-5, and screened between w approximately twenty and twenty-five feet bgs. Noting that MTBE was detected at 2,900 pg/L in a grab groundwater sample collected at twenty feet bgs from A TC-5, the EHD believes a monitoring well will better address the possible plume migration down gradient of the source e. area. ATC: ATC will complete a groundwater monitoring well within proposed soil boring SB-5 ` (proposed well MW-11)adjacent to previous soil boring ATC-5.Additional discussion regarding methodology for installation, development, and sampling of the proposed groundwater monitoring well is outlined below. Monitoring Well Installation Development and Sampling ATC will utilize hand-auger techniques to clear the proposed monitoring well location to approximately 5 feet bgs. All drilling and sampling activities will beperformed consistent with ATC's standard operating. A soil boring will be drilled using a Combination Drill Rig_ hich is equipped with 8zjg�h outer diameter(OD) hollow stem augers and direct push technology. Drilling will be conducted by a California C57-licensed drilling company. An ATC field scientist, under the responsible charge of a California registered professional engineer or geologist, will log the boring,and.collect soil samples. During drilling, an approximately 1.5-inch diameter borehole will be advanced and logged, where applicable, to an approximate depth of 20 to 25 feet,bgsSoil samples will be collected just above the, water table (i.e., at approximately 10 feet bgs) or where elevated PID readings indicate the presence of impact. �. Soil samples will be collected from the boring for lithologic logging and field screening. The samples will be collected in a 5-foot by 1.5-inch O.D. core sampler equipped with an acetateliner. Soil samples will be s.. (IM ,e<TC T Additional Investigation Workplan 2'"Addendum V Quik Stop No. 132,Stockton,CA November 03,2009