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• • Once set, the probe will be allowed to sit for a minimum of 2 hours to allow for equilibration time prior to testing and sampling. • Prior to purging or sampling, a shut-in test will be performed as described in Section 4.2.1 (p. 17) of the 2012 DTSC Advisory -Active Soil Gas Investigations. • A purge volume test will be conducted as described in Section 4.2.3 (p. 19) of the 2012 DTSC Advisory -Active Soil Gas Investigations. If VOCs are not detected at the first location, another purge test will be performed at a second location. If VOCs are not detected in any of the purge test samples at the two locations, a default of three purge volumes will be extracted prior to sampling. • Pentane will be used for leak detection. Soil gas sample depths will be evaluated using existing lithologs, where available, and with continuous core borings where lithologs are unavailable or where specific contacts are desired. The target depth for sampling is between 5 and 40 feet below ground surface. Multi-depth samples in the former pond areas and former potential source areas will be collected at approximately 5 to 10-foot intervals until soil gas has been delineated vertically to analytical detection limits, or just above the capillary fringe. If refusal occurs before the desired depth is reached, the sample location will be relocated a few feet away or the sample will be collected at the refusal depth. If an adequate soil vapor sample volume cannot be obtained from the desired depth, the sample location will be relocated a few feet away or the sample depth will be extended by approximately 2 feet. Purging and sampling will follow the recommendations outlined in Sections 4.3 and 5 (p. 23-26) of the 2012 DTSC Advisory-Active Soil Gas Investigations. Glass syringes will be used to collect the samples. STEP-OUT SAMPLES Soil gas will be delineated laterally and vertically to analytical detection limits plus a 100-foot buffer. Approximately six sample locations are included along a 100-foot buffer, as shown on Figure 2. Step-out locations will be determined after surrounding samples have been collected and analyzed and will either be collected at the end of the initial field work or at a later date. 5.5.3.2. Soil Sample Collection Soil samples will be collected using a direct push rig(Geoprobe). The soil samples will be collected in acetate sleeves during drilling of soil gas points. A portion of the Soil Gas and Soil Sampling Work Plan—Rev.4 7693-05 Former Kearney-KPF Facility Dudek Stockton,CA 15 September 2013