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ARCADIS Appendix A Appendix A Union Pacific Railroad CPT/HydroPunchTm Sampling Procedures Company Former Maintenance Facility Tracy, California CPT/HydroPunchTM technology will be used to obtain lithologic data and collect depth- specific groundwater samples from targeted permeable intervals based on the CPT results. CPT will be conducted using a piezocone connected by stainless steel rods to a hydraulic system that pushes the piezocone through the soil.The piezocone measures friction,tip resistance,and pore pressure,which are logged and used to evaluate soil types on a nearly continuous geologic log. CPT will be performed in accordance with revised (2002)American Society for Testing and Materials(ASTM) standards(D-5778-95).To collect the groundwater samples, the CPT rig will be used to advance hollow push rods to the bottom of the desired sampling interval. The push rods will then be retracted, exposing an encased filter screen and allowing groundwater to infiltrate hydrostatically from the formation into the inlet screen.A small-diameter bailer(approximately 1/2 or 3/4 inch)will be lowered through the push rods into the screen section for sample collection. Upon filling,the bailer will be retrieved and the groundwater will be decanted into the appropriate laboratory-supplied sample containers. Upon completion of the sample collection,the equipment will be retrieved to the ground surface and decontaminated. This process will be repeated as necessary to collect samples from additional depths at the same location.