Sustainability and Remediation - Dealing with Contaminated Sites: From Theory Towards Practical Application - page 919

An interesting point in this regard is where materials are reclaimed and re-used
during the project. Recycling, re-use and recovery have specific policy based mean-
ings, which will affect what can be considered for the policy-directed indicators. A
further difficult point is the use of materials to fill void space. Filling void space
in a landfill site is essentially consuming a waste management resource, whereas
filling void space at an on-site or off-site development project may displace virgin
materials or other recycled materials but does not consume a waste management
resource. However, the placement of the material may carry impacts, for exam-
ple risks from leachate, which would need to be considered in a sustainability
appraisal. This activity may also have wider sustainability linkages. For example,
it may create an opportunity to install ground source heat pumps and thereby reduce
the environmental impact of the subsequent development by providing a source
of renewable energy. Alternatively, it may be integrated with a “sustainable urban
drainage” system, and the linkage with remediation work may also reduce the cost
on implementing these additional opportunities.
The life cycle and system boundaries are different considerations. The life cycle
boundaries describe how far a particular trail of consequences should be followed
and to what level of detail. The system boundary describes the systems being
compared: what sets of operations are being compared.
The intuitive understanding most people have of geographical boundaries is a site
perimeter. However, the sustainability appraisal has to consider impacts and benefits
across the system and life cycle, which may occur:

• at the sites of production or application processes;

• at supplier sites (including how a project approach might affect waste collection);

• through transportation and distribution;

• through distant impacts for example effects on air and water, or distant effects of

increased traffic.

It may be useful for some appraisal purposes to distinguish between local and
distant effects, or other categories such as regional, national etc. Geographical
boundaries would need to be agreed to define such terms. The overall sustainability
appraisal is independent of these classifications. However, there may be reasons to
consider local and distant effects differently in selecting a remediation approach,
particular with regard to social impacts.
The duration over which effects are to be considered is also an important
consideration. Sustainability appraisal considers changes in indicators due to the
remediation work being assessed. The initial time boundary, t o, is the com-

mencement of the operations defined by the system boundary. The remaining time
boundary is of course the point in time beyond which effects are no longer con-
sidered. In absolute terms, assessments of effects based on emissions, such as of
greenhouse gases or toxic substances, or effects of the disposal of wastes should be
considered over very long periods. The overall sustainability appraisal is indepen-
dent of these classifications. However, there may be reasons to consider short and
long term effects differently in selecting a remediation approach, particular with

=