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Site Inspection UFP-QAPP Addendum Stockton AASF, Stockton, California 834 Table 17-2: Soil Sample Rationale and Target Depths for Borings 835 Notes: 836 A01= area of interest 837 bgs = below ground surface 838 DPT = direct push technology 839 840 The soil cores will be continuously logged for lithological descriptions by a field geologist using 841 the Unified Soil Classification System (USCS) per SOP 3-16. A photoionization detector (PID) will 842 be used to screen the breathing zone during boring activities. Observations and measurements 843 will be recorded on field forms and in a non -treated field logbook. Photographs of the boring cores 844 will also be taken. At a minimum, depth interval, recovery thickness, PID concentrations, moisture, 845 relative density, color (using a Munsell soil color chart), and texture (using the USCS) will be 846 recorded. Additional observations to be recorded may include groundwater or perched water 847 depth, organic material, or cultural debris. If a clay layer is observed in a boring with a thickness 848 in excess of 3 feet with groundwater encountered above the layer, boring activities will be 849 terminated in order to avoid completely penetrating a competent clay layer. If the clay layer and 850 overburden is unsaturated, then boring activities will continue as planned. 851 It is anticipated that all borings will be advanced in areas without surface cover; however, if a 852 boring is required in asphalt, it will be abandoned by backfilling with bentonite chips to 853 approximately 6 inches bgs, and the remainder of the borehole will be patched with an asphalt 854 cold patch. Borings into concrete will be avoided, if possible; however, if borings are advanced 855 into concrete, the borings will be abandoned by backfilling with bentonite chips to approximately 856 6 inches bgs, and the remainder of the borehole will be filled with concrete to provide as flush a 857 surface as possible. The surface at each location will be restored to match the surrounding area. 858 QC samples will be collected in accordance with Worksheet #20. Field duplicate samples will be 859 collected at a rate of 10 percent and analyzed for the same parameters as the accompanying 860 samples. Matrix spikes/ matrix spike duplicates (MS/MSDs) will be collected at the rate of 5 861 percent and analyzed for the same parameters as the accompanying samples. One Field Reagent 862 Blank (FRB) will be collected per sampling event and will be analyzed for PFAS. Equipment 863 rinsate blanks (ERBs) will not be prepared or analyzed unless a deviation from this plan requires 864 sample handling using non -dedicated equipment. If non -dedicated sampling equipment is used, 865 ERBs will be collected and will be analyzed for the same analytes as the associated samples. A AECOM QAPP Worksheet #17 Page 5 of 10 Mill— Rationale Five borings proposed adjacent to potential or 5 DPT 35 suspected release areas. AOI 1 Four locations (two on each side of the airfield) 4 Hand Auger 2 proposed for hand auger samples to determine potential release to surface soil through runoff. One boring proposed downgradient of suspected AOI 2 2 DPT 35 release area close to facility's northern boundary to avoid drilling on the ramp and hangar area. One boring proposed within suspected release area. Two borings proposed immediately downgradient of 3 DPT 35 the suspected release area. One boring proposed AOI 3 within the area where potentially contaminated soil 2 Hand Auger 2 backfill occurred. Two locations proposed within the soil backfill area for hand auger samples. 835 Notes: 836 A01= area of interest 837 bgs = below ground surface 838 DPT = direct push technology 839 840 The soil cores will be continuously logged for lithological descriptions by a field geologist using 841 the Unified Soil Classification System (USCS) per SOP 3-16. A photoionization detector (PID) will 842 be used to screen the breathing zone during boring activities. Observations and measurements 843 will be recorded on field forms and in a non -treated field logbook. Photographs of the boring cores 844 will also be taken. At a minimum, depth interval, recovery thickness, PID concentrations, moisture, 845 relative density, color (using a Munsell soil color chart), and texture (using the USCS) will be 846 recorded. Additional observations to be recorded may include groundwater or perched water 847 depth, organic material, or cultural debris. If a clay layer is observed in a boring with a thickness 848 in excess of 3 feet with groundwater encountered above the layer, boring activities will be 849 terminated in order to avoid completely penetrating a competent clay layer. If the clay layer and 850 overburden is unsaturated, then boring activities will continue as planned. 851 It is anticipated that all borings will be advanced in areas without surface cover; however, if a 852 boring is required in asphalt, it will be abandoned by backfilling with bentonite chips to 853 approximately 6 inches bgs, and the remainder of the borehole will be patched with an asphalt 854 cold patch. Borings into concrete will be avoided, if possible; however, if borings are advanced 855 into concrete, the borings will be abandoned by backfilling with bentonite chips to approximately 856 6 inches bgs, and the remainder of the borehole will be filled with concrete to provide as flush a 857 surface as possible. The surface at each location will be restored to match the surrounding area. 858 QC samples will be collected in accordance with Worksheet #20. Field duplicate samples will be 859 collected at a rate of 10 percent and analyzed for the same parameters as the accompanying 860 samples. Matrix spikes/ matrix spike duplicates (MS/MSDs) will be collected at the rate of 5 861 percent and analyzed for the same parameters as the accompanying samples. One Field Reagent 862 Blank (FRB) will be collected per sampling event and will be analyzed for PFAS. Equipment 863 rinsate blanks (ERBs) will not be prepared or analyzed unless a deviation from this plan requires 864 sample handling using non -dedicated equipment. If non -dedicated sampling equipment is used, 865 ERBs will be collected and will be analyzed for the same analytes as the associated samples. A AECOM QAPP Worksheet #17 Page 5 of 10