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Soil Sampling Field Standard Operating Procedure SWE-FSOP-405;Revision 1 Ahtna Southwest Environmental Operations • Samples may be obtained from the trench wall using a scoop on an extension or directly from the auger when it is brought to the surface. • Smearing is an important issue to consider when sampling with a backhoe. It is advisable to dress the surface to be sampled by scraping off any smeared material that may cross-contaminate the sample to ensure representativeness. Paint, grease, and rust must be removed, and the auger decontaminated before sample collection. • When collecting the sample, obtain material beneath the surface in the center of the auger in order to avoid incorporating sloughed material in the sample. • When collecting for VOC analysis, obtain samples directly from subsurface material in the auger. • The reusable sampling tools must be decontaminated before use when moving to a new sampling location. 4.2.4 Split Spoon Sampling Subsurface soil samples may be collected from soil recovered from a split spoon sampler when drilling with a hollow stem auger drill rig. For sampling from this device,follow these general steps: 1. Remove any pavement or sub-base material obstructing access to subsurface soil from an area twice the diameter of the drill bit, as necessary. 2. Ensure that the drill rig and all tooling are decontaminated before drilling. 3. Set up the drill rig with the hollow stem auger,the cutting head, and the center rod. Drill to the first sample depth. 4. As soil is brought to the surface with the auger flights, periodically remove these cuttings from the area specified in the work plan. 5. When the sample depth is reached, remove the center rod/cutting head assembly and deploy the split spoon sampler. Insert a liner(s) before sampler deployment, as necessary. 6. With the sampler shoe at the ground surface in the sample location, mark the center rod in 6-inch increments to allow blows to be counted. 7. Drive the sampler using the rig hammer. Use a full 30-inch drop as specified by the ASTM Method D-1586. Record the number of blows required to drive the spoon through each 6-inch increment. 8. Cease driving upon reaching the full sampler length or refusal. Refusal is when little to no progress is made for 50 hammer blows. 9. Pull up the center rod and sampler and remove the sampler from the drill rods. 10. Open the sampler to access the soil, careful not to disturb the soil. • If using a stainless steel liner(s), slide the liner from the sampler without disturbing the soil and seal the ends. Wipe the outside of the sealed liner with a paper towel and mark the depth on the outside of the liner with a marker. • If using an acetate liner that must be opened, cut twice along the length of the liner using a hook- blade utility knife. Typically, a ground cover should be placed in the working area so that soil unsettled from the sampler does not fall to the ground. Page 10 of 15