COMPLIANCE INFO_FILE 2 - Laserfiche WebLink

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• Ground water is encountered, and dewatering is not feasible. Excavation will continue if it appears to be successfully remediating soil contamination at the tank site; for example, if contamination decreases with deeper excavation and the source of contamination appears to have been the tank. However, no more than 75 cubic yards of soil will be excavated from the sides or underneath the tank. At the conclusion of excavation, a minimum of two soil samples will be taken from the excavation sidewalls and bottom, and the excavation will be backfilled with clean material and brought up to grade. The soil material excavated during tank and piping removal will also be sampled for analysis. 2.4.4 Open Pit Soil Sampling After removing the tank and fill materials, field screening will be performed to determine if soil contamination exists as a result of tank leakage. Field screening will include visual observation of soil discoloration or an oily sheen on the ground water; presence of elevated PID readings; and the presence of odor. Determination of soil contamination in the field will be based on field screening methods only, and not on laboratory analysis of soil samples. All observations will be noted in the project logbook including a detailed description of soil sampling ' locations. Two soil samples will be collected at the backfill and native soil interface at each end of the tank. Two additional soil samples will be collected from the excavation endwalls. In the event ground water is encountered in the excavation, the four soil samples will be collected from the walls of the excavation at the soil and water interface. Two additional soil samples will be collected from the piping trench. ® Soil samples will be obtained from the backhoe bucket when it is brought to the surface. Samples will be collected by scraping approximately 3 inches of cover soil away and carefully driving a brass tube measuring 2.5 by 6 inches into the soil until the tube is full. After removal, both ends of the tube will be immediately covered with aluminum foil, capped with teflon covers ' and sealed with duct or masking tape. A sample label will be affixed to the tube. To obtain the most accurate samples, care will be taken to minimize the amount of soil disturbance during 1 13 P • The excavation produces a structural risk to adjacent buildings, tanks or other significant structures. Soil PID indicate that the is from • staining and measurements contamination a source other than the tank. Such evidence would include increased PID measurements during further excavation. • Ground water is encountered, and dewatering is not feasible. Excavation will continue if it appears to be successfully remediating soil contamination at the tank site; for example, if contamination decreases with deeper excavation and the source of contamination appears to have been the tank. However, no more than 75 cubic yards of soil will be excavated from the sides or underneath the tank. At the conclusion of excavation, a minimum of two soil samples will be taken from the excavation sidewalls and bottom, and the excavation will be backfilled with clean material and brought up to grade. The soil material excavated during tank and piping removal will also be sampled for analysis. 2.4.4 Open Pit Soil Sampling After removing the tank and fill materials, field screening will be performed to determine if soil contamination exists as a result of tank leakage. Field screening will include visual observation of soil discoloration or an oily sheen on the ground water; presence of elevated PID readings; and the presence of odor. Determination of soil contamination in the field will be based on field screening methods only, and not on laboratory analysis of soil samples. All observations will be noted in the project logbook including a detailed description of soil sampling ' locations. Two soil samples will be collected at the backfill and native soil interface at each end of the tank. Two additional soil samples will be collected from the excavation endwalls. In the event ground water is encountered in the excavation, the four soil samples will be collected from the walls of the excavation at the soil and water interface. Two additional soil samples will be collected from the piping trench. ® Soil samples will be obtained from the backhoe bucket when it is brought to the surface. Samples will be collected by scraping approximately 3 inches of cover soil away and carefully driving a brass tube measuring 2.5 by 6 inches into the soil until the tube is full. After removal, both ends of the tube will be immediately covered with aluminum foil, capped with teflon covers ' and sealed with duct or masking tape. A sample label will be affixed to the tube. To obtain the most accurate samples, care will be taken to minimize the amount of soil disturbance during 1 13 P