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N <br /> `- City Of StOCICt012 <br /> � Febrccary 6, 1997 A68108.O1B <br /> Page A-2 <br /> �.. Generally, soil samples selected for analyses typically represent those which the field <br /> screening indicated will be most likely to contain the contaminate of concern. In most <br /> instances the deepest two samples and/or and sample collected from just above groundwater <br /> -• are selected for analyses. Samples intended for chemical analyses are sealed with Teflon® <br /> tape and plastic end caps, labeled, placed on ice, and delivered to a laboratory, along with <br /> chain-of-custody documentation. <br /> Soil borings may be completed as groundwater monitoring wells, or abandoned by grouting <br /> with a sand-cement slurry. Abandonment procedures depend upon the boring depth, depth <br /> to groundwater, project objectives, and regulatory requirements. For a boring greater than <br /> 15 feet deep, grout is emplaced through the hollow augers which will extend to within 15 <br /> feet of the bottom of the boring. If required by the local regulatory agency, grout is <br /> '— emplaced by pumping through a tremie pipe which is extended to within 15 feet of the <br /> bottom of the boring. The tremie pipe or augers are withdrawn from the boring in 5-foot <br /> increments as the boring fills with grout. SOPs for groundwater monitoring well installation <br /> are described in a subsequent paragraph (if pertinent to this investigation). <br /> Soil cuttings generated during drilling are containerized in United States Department of <br /> Transportation (DOT)-approved drums, or placed on and covered with plastic sheeting, and <br /> stored on site in an area inaccessible to the general public. Typically, the stockpiled soil is <br /> .� characterized by collecting and analyzing composite samples from the stockpile. Twining <br /> can recommend an appropriate method for disposition of the cuttings based on the <br /> analytical results. Disposal will be the responsibility of the client. <br /> A-2 Standard Operating Procedures for Equipment Decontamination: Proper <br /> decontamination procedures reduce the potential for: cross-contamination among sample <br /> locations; and introduction of contamination from outside sources. <br /> Before, during, and following drilling operations, drilling equipment is thoroughly cleaned <br /> using a high pressure hot water (steam) washer. Steam cleaning condensate will be <br /> containerized for later disposal. Generally, disposal will be the client's responsibility. <br /> 4. Sampling equipment and any tools, measuring devices, or other equipment which will <br /> contact soil or any media being assessed will be washed in a low-phosphate soap and water <br /> solution, and rinsed in clean water before each use. The type of soap used will depend <br /> upon project requirements. <br /> A-3 Standard Operating Procedures for Sample Handling and Chain-of-Custody: ; <br /> --- Records are developed for samples which include: sampling date, sample type, location,job <br /> number, name of sampling personnel, and method of preservation. Each sample container <br /> is labelled immediately following collection. Chain-of-custody protocol, as described in <br /> United States Environmental Protection Agency, 1986, Test Methods for Evaluating Solid <br /> .� Waste, SW-846, Third Edition, is followed. Samples will be stored in an insulated container <br />