Sustainability and Remediation - Dealing with Contaminated Sites: From Theory Towards Practical Application - page 901

1. In terms of regulatory and planning controls on environmental risks say to human
health, water and the wider environment, i.e. the needs are those that relate to the
desired end use of the site.
2. By setting practical boundaries such as the time and space available to carry out
remediation, but also limit the range of possible interventions.
Therefore the impact of considering “sustainable remediation” depends on where
in the decision making process it takes place. Sustainable remediation may be con-
sidered purely as an aspect of selecting the optimum remediation strategy for a
project where all land use and site development decisions have already been made.
This may often be the scenario that is faced by contaminated site management
service providers. In this situation, the impact of adopting a sustainable remedia-
tion approach might be less than if remediation options and their impacts are also
actively considered as part of the land use and overall project planning stages.
Earlier consideration of the sustainability impacts of remediation may provide
important additional sustainability gains.
For example, the trigger for Risk Management on a contaminated site may be
that the site use is to change from derelict (where risks were managed by institu-
tional controls) to a new shopping development. This trigger sets in motion a chain
of Risk Management decisions related to that land use. Let us say that for a par-
ticular development the financial model dictates a need for basement car parking,
this has the consequence that the remediation interventions required will likely be
ex situ. However, the contaminated material is not a groundwater threat and while
it has elevated levels of contaminants, would not pose a threat unless direct con-
tact took place. Sustainability might be an important criterion in choosing between
available remediation approaches such as off site removal, on site soil washing or
on site biopiling, favouring a biopiling approach in terms of waste generation, use
of resources, emissions, impacts on site neighbours, costs and other factors, for that
particular site .
However, if remediation impacts had been able to be considered at an earlier
stage of design making, the “improvement” in sustainability might have been greater
if for example undercroft car parking had been an option, and the contamination
managed by containment and in situ bioremediation, simply because soil excavation
was avoided. Fig. 20.5 illustrates this example scenario.
The question of when and how the sustainability consequences of these decisions
should be considered introduces the concept of a “framework” where there may be
multiple points at which sustainability is considered.
20.2.4 Frameworks
The sustainability of remediation is the consequence of a series of decisions that lead
up to a remediation project, and decisions made about what remediation method is
to be used within the scope imposed by these preceding decisions. It is important to
be aware that this raises two sets of questions: when and how should sustainability