Quality Control Considerations for Soil Gas Sample Collection Using Direct Push and Hand-Sampling Equipment

摘要

Soil gas samples are collected using a variety of sample-collection techniques with direct push drilling technology (direct push) or manual-driven hand-sampling equipment. Samples are collected on the premise that soil gas surveys are primarily used for two purposes: (1) as a preliminary site investigative tool, and (2) for the monitoring of ongoing remedial activities. The practicality of field use demands that soil gas surveys are accurate, as well as simple, quick, and inexpensive. Soil gas surveys are not intended for due diligence purposes related to property transfers. It must be determined whether, and what, other field parameters (such as temperature, soil moisture, and barometric pressure) need to be collected, measured, and recorded during soil gas sampling. When continuous monitoring is conducted, it can provide data that can be used in the report, as well as precisely guiding the field personnel to collect a sample at the most appropriate time to represent subsurface conditions of concern. The fieldwork that involves soil gas sampling must be conducted with precise sampling procedures with a range of acceptable variances that can be applied in actual sampling conditions, specified parameter monitoring, leak detection, and health and safety procedures. The soil gas samples that are collected must represent the soil gas that is in the subsurface lithology. When continuous monitoring of specified parameters is conducted, the soil gas samples must be collected in compliance with the appropriate procedure and at the appropriate time and conditions. Once the laboratory analytical reports of data are received by the project manager, a final report must be written. Ultimately, the entire project is conducted to represent actual subsurface conditions to provide data to develop a strategy to protect human health and the environment.