Page 183 - Materials Chemistry, Second Edition

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potential environmental contamination problems, risk assessment also affords a basis
for judging the need for mitigating actions. On this basis, corrective actions are
developed and implemented with the main goal of protecting public health and the
environment.

4.9.5 CORRECTIVE ACTION

A variety of corrective action strategies may be applied in case of contaminating
processes to restore sites into healthier and more ecologically sound conditions.
The processes involved will generally incorporate a consideration of the complex
interactions among the environment, regulatory policies, and the technical feasi-
bility of remedial methodologies. A clear understanding of the fate and behavior
of the pollutants in the environment is essential for developing successful cor-
rective action response programs, and also to ensure that the problem is not
exacerbated.
The design of corrective action response programs for contaminated site prob-
lems includes various formalized steps. In general, when the existing site information
has been analyzed and a conceptual understanding of a site is obtained, then remedial
action objectives should be defined for all impacted media at the contaminated site.
Subsequently, alternative site restoration programs can be developed to support the
requisite corrective action decision. Overall, risk assessment plays a very important
role in the development of remedial action objectives for contaminated sites, the
identification of feasible remedies that meet the remediation objectives, and the
selection of an optimum remedial alternative.
Risk assessment has become particularly useful in determining the level of clean-
up most appropriate for potentially contaminated sites. By utilizing methodologies
that establish clean-up criteria based on risk assessment principles, corrective action
programs can be conducted in a cost-effective and efficient manner.
These procedures can help determine whether a particular remedial alternative
will pose unacceptable risks following implementation and to determine the specific
remedial alternatives that will result in the least risk upon achieving the clean-up
goals or remedial action objectives for the site. Consequently, risk assessment tools
can be used as an aid in the process of selecting among remedial options for
contaminated sites.

4.9.6 ECOLOGICAL RISKS
Often, especially in the past, only limited attention has been given to the ecosystems
associated with contaminated sites, as well as to the protection of ecological
resources during site remediation activities. Instead, much of the focus has been on
the protection of human health and resources directly affecting public health and
safety. In recent times, however, the ecological assessment of contaminated sites has
gained considerable attention. This is the result of prevailing knowledge or awareness
of the intricate interactions between ecological receptors and systems and contam-
inated site clean-up processes.

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