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CL Properties, VI E37801.02A December 6, 1999 Page A-2 groundwater,project objectives,and regulatory requirements. For borings greater than 15 feet deep, grout is emplaced through the hollow augers or a tremie pipe which will extend to within 15 feet of the bottom of the boring. The slurry is pumped through the annulus in the hollow-stem augers or the tremie pipe. Backfill is placed in one continuous operation from the bottom to the top of the borehole. When the annulusiborehole fills with the slurry, auger flights or tremie pipe sections are removed(no more than 10 feet at a time)from the borehole,allowing the slurry to uniformly fill the borehole to the surface. SOPs for groundwater monitoring well installation are described in a subsequent paragraph (if pertinent to this investigation). Soil cuttings (if generated during drilling are containerized in properly labeled, United States Department of Transportation (DOT)-approved drums, or placed on and covered with plastic sheeting, and stored on site in an area inaccessible to the general public. Typically, the stockpiled soil is characterized by collecting and analyzing composite samples from the stockpile. Twining can recommend an appropriate method for disposition of the cuttings based on the analytical results. Disposal will be the responsibility of the client. A-2 Standard Operating Procedures for Equipment Decontamination: Proper decontamination procedures reduce the potential for:cross-contamination among sample locations; and introduction of contamination from outside sources. Before,during,and following sampling operations,sampling equipment is thoroughly cleaned using a high pressure hot water(steam)washer or washed in a low-phosphate soap and water solution,and rinsed in clean water before each use. The type of soap used will depend upon project requirements. Well casing, screen, end caps,and centralizers will also be cleaned using the steam washer. Steam cleaning condensate will be containerized for later disposal. Generally,disposal will be the client's responsibility. A-3 Standard Operating Procedures for Sample Handling and Chain-of-Custody: Records are developed for samples which include: sampling date, sample type, location,job number,name of sampling personnel,and method of preservation. Each sample container is labelled immediately following collection. Chain-of-custody protocol, as described in United States Environmental Protection Agency, 1986, Test Methods for Evaluating Solid Waste, SW-846, Third Edition, is followed. Samples will be maintained at approximately 4°C. Upon arrival at the laboratory, the samples will be preserved for analysis as appropriate. Samples will be delivered under custody seal(s) to Twining's chemistry laboratory in Fresno, California. The Twining representative in charge of the field work transport or direct the transportation of the samples and custody forms to the laboratory,where the samples are transferred to the sample control department. A receiving clerk, or an authorized analyst, signs the custody forms, present a duplicate copy to the Twining representative, and transfers the samples to a laboratory analyst. The laboratory manager retains possession of the custody forms during analyses of the samples. The laboratory manager's responsibilities include monitoring the sample integrity within the laboratory. This involves assigning each sample a laboratory number and maintaining cross- reference between the sample's field and laboratory identifications. The analysts' responsibilities include maintaining accurate records of the samples analyzed along with the analytical data produced. This involves labelling chromatograms and maintaining the laboratory numbers on subsamples taken from the submitted samples,labelling glassware used in the analyses,and properly labelling sample extract containers with each sample's laboratory number.