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CAMBRIA t. STANDARD TANK REMOVAL SAMPLING PROCEDURES Cambria Environmental Technology, Inc. (Cambria) has developed standard operating procedures for collecting soil and ground water samples during underground storage tank removal. These procedures ensure that the samples are collected,handled,and documented in compliance with California Administration Code Title 23: Waters;Chapter 3: Water Resources Control Board; Subchapter 16: Underground Storage Tank Regulations(Title 23). Cambria's sampling procedures are based on guidelines contained in the California State Regional Water Quality Control Board Tri-Regional Staff Recommendations for Preliminary Evaluation and Investigation of Underground Tank Sites dated August 10, 1990. Tank Removal Sampling The objective of sample collection during routine underground storage tank removals is to determine whether hydrocarbons or other stored chemicals have leaked to the subsurface. If no ground water is encountered within the tank excavation,Cambria will sample native soil I to 2 It beneath the removed tank. Additional soil samples may also be collected at locations of obvious spillage to determine maximum concentrations in the surrounding soils. For underground storage tanks with a capacity of less than 1,000 gallons,one soil sample is collected beneath the fill end of the tank. For tanks with a capacity of between 1,000 and 10,000 gallons, one soil sample is collected beneath each end of the tank. For tanks larger than 10,000 gallons, 3 or more soil samples are collected beneath the removed tank. We also collect one soil sample for every 20 It of product piping. In cases where ground water is encountered within underground storage tank excavations, Cambria will collect confirmatory soil samples from the excavation sidewalls just above the soiUground water interface and a representative ground water sample from the excavation. The excavation is typically purged and allowed to recover prior to collecting the water sample. For tanks with capacities of 10,000 gallon or less, one soil sample is collected from the wall at each end of the tank excavation. For tanks with capacities greater than 10,000 gallons,or tank clusters,at least four soil samples are collected from the excavation walls next to the tank ends. Piping samples are collected in native soil 1 to 2 ft beneath the removed piping. One sample is typically collected for every 20 lineal It of piping unless regulatory agencies approve of different sampling requirements. The soil samples are collected in steam cleaned brass or steel tubes from either a driven split-spoon type sampler or the bucket of a backhoe. When a backhoe is used,approximately three inches of soil are scraped from the surface and the tube is driven into the exposed soil. Upon removal from the split-spoon sampler or the backhoe, the samples are trimmed flush, capped with Teflon sheets and plastic end caps, labeled, logged and refrigerated for delivery under chain of custody to a State certified analytic laboratory. The ground water sample is collected using steam cleaned Teflon or PVC bailers, decanted into a volatile organic analysis(VOA)bottle or other appropriate clean sample container,refrigerated and transported under chain of custody to a State certified analytic laboratory.