3 - Practical approach to sampling

Abstract

This chapter addresses the tasks of field implementation, such as sampling and field data collection and field QA/QC. The main features of the field tasks are sampling procedures, sample custody and tracking, preservation techniques, equipment decontamination, field screening, and record keeping. In environmental chemical data collection, the purpose of field implementation is to collect representative samples for the production of valid and relevant data. The collected samples must be identified with unique sample numbers, efficiently tracked in the field, stored in a secure location for the preservation of sample integrity, and then transferred to the laboratory with the information on their identification (ID) and the requested analysis. The chapter provides guidance on several basic aspects of soil sampling such as systematic sampling on a grid system, sample compositing, and sampling for specific chemical parameters, such as polychlorinated biphenyls (PCBs) and volatile organic compounds (VOCs). Sampling of water from surface sources—such as lakes, rivers, lagoons, or ponds—or from groundwater aquifers presents its own universe of practices and procedures. Field records document field measurements and field conditions at the time of sampling.