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ATTACHMENT 2 FIELD AND LABORATORY PROCEDURES Exploratory Drilling and Soil Sampling Each soil boring will be drilled using an air rotary casing hammer drill rig or a sonic drilling rig, both equipped with 8-inch diameter heavy-walled downhole casing. The casing will be advanced following the drill rods in order to seal the boring as drilling proceeds to protect against vertical migration of contaminants. Soil samples will be collected at five-foot or ten- foot intervals (depending on drill rig capability) and a minimum of three soil samples will be analyzed, including the bottom sample. Soil samples selected for analysis will be based on PID readings and soil conditions. Additional grab soil samples may be collected from the cuttings for logging. Each boring will be logged by SECOR field staff under the direction of a California Professional Geologist using the Unified Soil Classification System and standard geologic techniques. Soil samples for logging and possible laboratory analysis will be collected using a California-modified split-spoon sampler. The precleaned split spoon sampler lined with three six-inch long brass or stainless steel tubes is driven 18 inches into the underlying soils at the desired sample depth interval. The sampler is driven by repeatedly dropping a hammer a free fall distance of 30 inches. The number of blows (blow count) to advance the sampler for each six-inch drive length will be recorded on the boring logs. Once the sampler is driven the full 18-inch drive length or the sampler has met refusal, the sampler is retrieved. Of the three sample tubes, the bottom sample is generally selected for laboratory analysis. The sample is carefully packaged for chemical analysis by capping each end of the sample with a Teflon sheet followed by a tight-fitting plastic cap. The sample will be labeled with site identification, sample identification number, sampling depth, sample collection date/time, and borehole number. The sample is then annotated on a chain-of-custody form and placed in an ice-filled cooler for transportation to the laboratory. The remaining soil samples are used for soil classification and field evaluation of headspace volatile organic vapors, where applicable, using a photoionization ionization detector calibrated to a calibration gas (isobutylene). VOC vapor concentrations are recorded on the boring logs. A physical description of the encountered soil characteristics (i.e. moisture content, consistency, odor, color, etc.) and soil type as a function of depth are indicated on the boring logs. In addition, the sample recovery and sampler penetration are also noted on the boring logs. Down-hole drilling and sampling equipment will be steam- cleaned prior to and following the completion of the soil borings. Down-hole sampling equipment will be washed in a trisodium phosphate or alconox solution between samples.