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ti Mr.Hunt . ember P age 2 SEP 2 6 1991 SOIL SAMPLING, HANDLING, AND ANALYSIS EN4Pt'MIT/SERV CES HEALTH On August 13, 1991, the FAA excavated and removed the 1,000-gallon-capacity diesel tank adjacent to the FAA Stockton ATCT facility. A concrete anchor slab beneath the tank was left in place. Upon excavation,the tank appeared intact with no visible leaks or stains. No hydrocarbon odors were detected by ASI personnel. No groundwater was observed in the tank excavation. After the tank was removed from the excavation, three areas beneath the tank were sampled under the direction of Ms.Carol Oz,Environmental Health Specialist,SJCPHS,and in accordance with a permit issued by the SJCPHS (Attachment 1). 1. A 2-foot-deep hole was chiseled in the center of the anchor slab at the center of the bottom of the tank pit excavation. A soil sample,SCK-1,was collected by driving a brass liner into the soil at a depth of approximately 1.5 feet beneath the concrete slab,approximately 3.5 feet beneath the tank (10.5 feet below ground surface). This sample was collected at 1550 on August 13, 1991. 2. The northern end of the bottom of the tank pit excavation, (soil sample SCK-2), approximately 1 foot from the northern end of the tank at a depth of approximately 3.5 feet beneath the tank (10.5 feet below ground surface). This sample was collected at 1555 on August 13, 1991. 3. The southern end of the bottom of the tank pit excavation, (soil sample SCK-3), approximately 1 foot from the southern end of the tank at a depth of approximately 3.5 feet beneath the tank (10.5 feet below ground surface). This sample was collected at 1600 on August 13, 1991. The three soil samples were yellowish-brown, dry, massive, fine sand. The end soil samples were collected using a backhoe bucket. Precleaned, 2.5-inch-diameter, 6-inch-long brass liners were driven into the soil near the teeth of the backhoe bucket with a hammer. After removing the liners from the bucket, the liners were sealed with aluminum foil and plastic end caps with duct tape, labeled, logged, sealed in a plastic bag, and placed in an insulated cooler with ice. Samples were shipped by ASI field personnel under strict chain-of-custody protocol to Quality Assurance Laboratory of San Diego, California for analysis. The chain-of-custody form is presented as Attachment 2. The three soil samples were analyzed for total petroleum hydrocarbons (TPH) using California DHS methods, and benzene, toluene, ethylbenzene, and total xylenes (BTEX) using Modified EPA Method 8020. baa/rvcNon.lo-/0991