Introduction to Field Sampling - Field Sampling: Principles and Practices in Environmental Analysis - page 1

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Introduction to Field Sampling
Often there is a great desire to start sampling a field without knowing anything about it or
its surroundings and without a well-developed plan. Such an approach will not lead to
success in understanding the levels of the component or components of interest contained
therein. Successful sampling depends on a careful, thoughtful understanding of the
characteristics of the field, the components it contains, the surrounding fields or areas,
and its history. In addition, sample handling, transport, and the analytical methods to be
used will be essential components of a successful sampling plan.
Depending on where you are in the United States or elsewhere, a field may be a large
or small area. It may have an area of thousands of hectares or less than one. In urban
areas or in industrial settings a field may be referred to as a site, and the two terms may
be used interchangeably. In some cases the two may be put together and termed a field
site. The term site is often used in two different ways or senses—that is, to refer to either
an area (field) or a precise location within a field. In the latter case it would normally be
the specific place from which the sample is taken.
In addition, the term field is used in a generic sense; that is, anytime someone leaves an
office, travels to a location, and takes a sample the person is said to be in the field and
field sampling. Anytime he or she is out of the office he or she is thus in the field. The
sample obtained might be air, water, soil, biological, or any other component of the
environment. Note that safety personnel have other definitions for the term field sample.
For the U.S. Occupational Safety and Health Administration (OSHA) a field sample may
be made for noise or for other safety concerns, such as guards on moving machine parts.
Although the emphasis here will be on field as a land area, the methods described apply
to field sampling in all respects. A sampling plan, a field sampling project notebook,
safety considerations, and so on, will all need to be taken into consideration in all field
sampling situations.
In this topic we will use these terms in a specific way. Field will refer to any area to be
sampled, including fields, water, sediments under water, and air. Site will refer to a
specific location in the field from which a sample is to be taken. Figure 1.1 shows a
landscape that would contain many fields. It also shows subsurface features that would
affect sampling. A field sample may be obtained by physically sampling all or a portion
of this landscape.