ARCHIVED REPORTS_2019 SOIL MGMT PLAN (JULY-REVISED)

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22 February 2019 AGE-Project No. 14-3154 Page 5 of 12 the EHD, Regional Water Board, and CalRecycle. Verification and stockpile soil samples were collected and analyzed during and after excavation and removal activities. A description of the procedures and analytical results from the April 2018 remedial activities were presented in the BAI-prepared, Verification Report dated 14 December 2018. The soil cap and waste materials were removed up to the northern property boundary of Parcel B. During excavation and removal activities it was discovered the soil cap and waste materials of WU1 continued to the north and extended onto Parcel A as shown in Figure 3. Based on information collected from Trench 32 (T-32) and the limits of WU1 on Parcel B, AGE estimates W U1 extends approximately 25 to 35 feet onto Parcel A and is approximately 250 to 350 feet long (Figures 2 and 3). Trench T-32 was excavated to nine feet bsg north of WU1 and approximately 35 to 40 north of the parcel boundary. Native silty sand was encountered from near surface grade to 9.0 feet bsg in T-32. The only other trench excavated in the general location of WU1 on Parcel A was T-28. Trench T-28 was excavated to four feet bsg north of WU1, approximately 60 to 70 feet north of the parcel boundary, and approximately 50 feet east of T-32. Native silty sand was encountered from near surface grade to 4.0 feet bsg in T-28. Trenches T-28 and T-32 were advanced in July 2015 and trenching logs are included in Appendix D. No other borings or trenches have been advanced or excavated within the immediate vicinity of WU1 on Parcel A. The precise limits and dimensions of the remaining capped waste materials on Parcel A will be determined in the field during excavation and removal activities. Additionally, verification samples will be collected beneath the removed wastes on Parcel A to evaluate and characterize the area. It is anticipated that the small area of WU1 wastes beneath Parcel A is of similar character and composition as the wastes that were extensively characterized to the south beneath Parcel B. Analytical results of all soil, solid waste, groundwater, and soil-gas samples collected at Parcel B are summarized in Tables 1 through 8. 6.1. GEOLOGIC SETTING The regional geologic setting is situated within the Great Valley Geomorphic Province of California, an elongate, northwest trending structural trough running 400 miles through Central California. The Great Valley is bound to the north by the Klamath Mountains, the south by the Tehachapi Mountains, the east by the Sierra Nevada Mountains, and the west by the Coast Ranges. Approximately 32,000 feet of marine and continental sediment have been deposited almost continuously since the Jurassic. The northern and southern regions of the Great Valley are designated the Sacramento and San Joaquin Valleys, respectively. The subject property is located within the San Joaquin Valley.