Laserfiche WebLink
City of Stockton A68107.OIB <br /> July 18, 1997 Page A-2 <br /> L 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 /> L 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 /> L 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 The tremie pipe or augers are withdrawn from the boring in 5-foot 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 /> Lare 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 /> I <br /> L 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 /> 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 0gerAlIngm l lin i <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 />