Environmental Engineering Reference
In-Depth Information
social sciences and psychology. Although relevant for the development of Risk
Assessment procedures and Risk Management decisions for contaminated sites,
most studies about “the nature of risk” do not address contaminated sites specif-
ically. From a natural scientific point of view, the current approaches in Risk
Assessment for contaminated sites are still rather loose assemblages of concepts and
methods borrowed from various disciplines (Ferguson et al.
1998
). Nevertheless,
Risk Assessment is considered a very useful tool in environmental policy since it
provides a rational and objective basis for priority setting and decision-making. The
use of Risk Assessment in contaminated site problems is nowadays advocated by
both regulators and industries.
23.5.1 A General Framework for Risk Assessment
for Contaminated Sites
At a general level, most EU countries have a common framework for Risk
Assessment procedures (Ferguson et al.
1998
, Ferguson and Kasamas
1999
).
Generally, the following protection targets are considered:
•
Human health
.
•
Ecological functions
.
•
Groundwater:
This risk is related to the dispersion of contamination in ground-
water. Criteria do vary among countries and so do protection levels. In some
countries, groundwater is protected as a resource that has to remain pure. Other
countries will use risk-based protection levels.
•
Construction:
Effects of soil contamination on structures and construction works
is explicitly mentioned in some countries. In other countries, this endpoint may
be more implicit.
Risk Assessment procedures focused on the two major protection targets (human
health and the soil ecosystem) have been described in detail in this topic, in
“Humans Health Aspects (Part III)” (
Chapters 5
,
6
,
7
,
8
,
9
,
10
,
11
, and
12
)
and “Ecological Aspects (Part IV)” (
Chapters 13
,
14
,
15
, and
16
). Risks related
to groundwater migration have been described in “Groundwater-Related Aspects
(Part V)” (
Chapters 17
,
18
, and
19
).
A general view of the different steps to be taken in Risk Assessment, from suspi-
cion to preliminary investigations and to conclusions about risks and communication
is illustrated in Fig.
23.3
. Risk Assessment of contaminated sites usually starts with
some suspicion about facts that may have led to the presence of soil contamina-
tion: handling or storage of relevant amounts of hazardous substances on the site,
accidents, spills etc. The next step often is a historical “recherche”; information is
gathered, which is available in archives and other accessible sources. This is usually
accompanied by a visit of the site. If these steps strengthen the suspicion, a further
investigation may be carried out and results may be compared with generic Soil and
Groundwater Quality Standards or can be evaluated using models to predict adverse
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