Geoenvironment Impact Mitigation and Management - Sustainable Practices in Geoenvironmental Engineering - page 354

geoenvironment by eliminating the direct stressor sources associated with the activities,
etc., of humans, i.e., exercising source control. Source control is, however, not an option
for natural events such as earthquakes, etc. Experience has shown, however, that source
control can rarely fully eliminate stressors delivered to the geoenvironment landscape. We
need to develop strategies and technologies to mitigate the stressor impacts and to under-
take remediation of the impacted sites to maintain the health of the geoenvironment. This
holds true for geoenvironment stressors generated from both natural and anthropogenic
sources.
We cite two recent examples of “incidents” (or “perceived” incidents) to illustrate the
importance of impact mitigation and management. The irst example concerns the per-
ceived geoenvironment impact incidents raised in relation to the construction and use
of pipelines across virgin terrain carrying bitumen and other similar products. The
concerns relate to perceived construction disturbance of sensitive landscape features
and expectations of pipeline failures (ruptures, leaks, etc.) discharging large quantities
of the product into the geoenvironment (i.e., onto the ground and also into receiving
waters). These concerns provide the geoenvironmental engineering profession with a
clear set of objectives for management of a sustainable geoenvironment. Other than
using more robust materials and prudent and sensible engineering practice designed
to protect the sensitive features of the geoenvironment in the construction of the pipe-
line as source control measures, impact avoidance and mitigation in this case requires
one to develop strategies and technologies that would: (a) protect the sensitive geoen-
vironment landscape features and habitats; (b) minimize or perhaps even eliminate
potential pipeline failure events; (c) provide strict monitoring of pipeline integrity
through instrumentation that sense pressure drops or other performance factors; and
(d) establish a disaster response protocol for effective immediate corrective action in
the case of a failure while implementing immediate geoenvironment remediation of
the contaminated region.
The second example is one that seeks to develop remediation schemes for an unexpected
disaster, namely, the fallout of discharged airborne radioactive cesium from the destruc-
tion of the nuclear power plants in Fukushima. The details of contamination of contiguous
land surface by radioactive cesium from this unexpected tragedy will be discussed in a
later chapter. For now, it is suficient to point out that implementation of remediation of the
land surface to precontamination levels is required, if original land-use activities is to be
restored, i.e., if original site functionality is to be restored.
10.2 Site Functionality and Restoration
The restoration of sites adversely impacted by natural causes or by anthropogenic activi-
ties requires one to establish restoration goals or objectives. The central question to be
addressed is “what does one want to have as a restored site”? Two distinct choices are
available: (1) restoration of the impacted site to its pre-impacted state or (2) restoration of
the site to an altered (i.e., different from pre-impacted) state that meets the requirements
of regulatory agencies and stakeholders. Both of these choices require one to establish the
functionality of the site, i.e., the functional purpose or purposes that have been served or
can be served by the site.