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JVXAWA�NAW Working To Restore Nature While excavating along the southern extent of the tank pit, a storm drain inlet (located immediately south of the excavation) was dislodged from its position An oily sludge and liquid substance was observed inside the exposed dram pipe A close inspection of the piping revealed the storm drain inlet had not been properly seated onto the drainage pipe when it was installed The drain inlet was removed and the oily sludge was pumped from the storm drain and containerized in DOT approved drums During the excavation process groundwater was initially encountered at a depth of approximately 16 to 17 feet The pit was dewatered by pumping groundwater to the building's sewage clean- out in accordance with a temporary discharge permit granted by the City of Stockton Municipal Utilities District A groundwater sample was collected by lowering a disposable bailer into the water in the pit The sample was submitted for analysis of total petroleum hydrocarbons as gasoline (TPHg), diesel (TPHd) and benzene, toluene, ethylbenzene, and xylenes (BTEX) by EPA methods 8015/8020 Analytical results are included in Table 2 Following excavation, confirmation samples were collected under the direction of Mr. Harlin Knoll of PHS/EHD A total of 6 sidewall and 2 excavation bottom samples were collected The soil sampling locations are depicted on Figure 3 Samples were collected from the excavator bucket at least three inches below the surface of the soil The samples were collected into prewashed brass liners Each liner was sealed with Teflon sheets and plastic caps, placed in air- tight bags, and preserved on ice pending shipment to Sequoia Analytical (DHS Cert #1210) in Redwood City, California Sample descriptions are included in Attachment 1 Soil samples were transported under chain of custody to the laboratory for analysis of BTEX, TPHg and TPHd by the methods described above Excavated petroleum hydrocarbon impacted soil was underlain and covered with 6-mil plastic sheeting pending laboratory analysis Stockpiled soil samples were collected and analyzed for BTEX, TPHg and TPHd by the methods described above Six 2-sleeve composite samples were collected from the stockpiled soil (approximately one per 250 cubic yards of soil). Sample locations are shown on Figure 3 Subsequent to excavation activities, the pit was secured by installing a chain link fence around the open excavation. Analytical Results No petroleum hydrocarbon analytes were detected in confirmation samples collected from the excavation pit Analytical results are summarized in Table 1 The water sample collected from the pit by bailer was reported to contain 3,100 ppb TPHg, 7 5 ppb benzene, 3 1 ppb toluene and 190 ppb xylenes These results are summarized in Table 2 1500591SXR-0194 FNi. 3