Chapter 2 - Sampling Methods for Site Characterization

Abstract

Abstract A site characterization is conducted where a hazardous substance has been released, and there is potential for the contamination to reach people or adversely affect the natural ecology. In some cases, site characterization is carried out to provide background information, to provide information on site sensitivity, or to monitor incremental impact from anthropogenic activities. When site characterizations are complete, they provide accurate information about the presence and distribution of target contaminants in relation to the background environment, thereby facilitating cost-effective and efficient remediation. The product of site characterization is a verified conceptual model. The conceptual model is developed from the analysis of site-operating history, regional geology and hydrology, validated results from prior investigations, and field investigation results. It identifies the contaminant sources, the receptors, and the pathways that contaminants can take to reach the receptors. Information about regional and site-specific geology/hydrogeology as well as knowledge of the contaminant fate and transport is necessary for making and revising sampling and analytical decisions. This presentation provides an overview of sampling methods and tools suitable to address most site characterizations. The basic sampling types discussed are the systematic, random, and judgmental sampling approaches. In addition to sampling procedures, sampling bias and sampling errors are introduced, leading to some guidance on sample handling, shipping, and chain-of-custody procedures. This presentation will focus on sampling methods for soil only.