A Practical Approach for Site Investigation - Dealing with Contaminated Sites: From Theory Towards Practical Application - page 162

sufficiently close to the surface (for example within 4 or 5 m). During the Main
Investigation sampling of groundwater is as important as sampling of soil, but
obviously is also related to whether there is groundwater within any proximity of
the contaminants as found in the soil and whether these contaminants are mobile.
Sampling of soil gas obviously is relevant when there is a considerable unsaturated
zone, or when there is a contamination in the soil or groundwater close to the sur-
face. Sampling of soil gas is of major importance when there are buildings on the
site into which contaminants can evaporate.
In addition to the choices about where and what to sample, also the question “how
to sample” is to be answered. Previously, it was already mentioned that the inves-
tigation of contaminated sites still predominantly uses more traditional techniques
of sampling, taking samples from the soil and groundwater and sending these to an
environmental laboratory for analysis.
Descriptions of sampling apparatus and instructions on how to apply these are
available in national and international standards. This is essential, as not only the
applied sampling strategy will determine the representativeness, and therefore the
quality, of the samples, it is also determined by correct appliance of sampling
apparatus and sampling techniques.
Apart from actual sampling, other techniques are also available for obtaining
information on the contamination as well as on the geology and hydrology of the
site. These can be intrusive as well as non-intrusive techniques. Application of these
techniques, in addition to more “classical” sampling and analysis, can result in a
substantial enhancement of the image (the conceptual model) and understanding of
the local situation, allowing better informed decisions than would be possible when
only “classical” sampling and analysis are used.

Literature

ISO 10381-1 2003 en Soil quality - Sampling - Part 1: Guidance

on the design of sampling programmes

ISO 10381-2 2002 en Soil quality - Sampling - Part 2:

Guidance on sampling techniques

ISO 10381-3 2001 en Soil quality - Sampling - Part 3:

Guidance on safety

ISO 10381-4 2003 en Soil quality - Sampling - Part 4: Guidance

on the procedure for investigation of
natural, near-natural and cultivated sites

ISO 10381-5 2005 en Soil quality - Sampling - Part 5:

Guidance on the procedure for the
investigation of urban and industrial
sites with regard to soil contamination

ISO 10381-6 1993 en Soil quality - Sampling - Part 6: Guidance

on the collection, handling and storage
of soil for the assessment of aerobic
microbial processes in the laboratory