Environmental Engineering Reference
In-Depth Information
impacts are mostly physical in nature. These generally involve alteration of the suricial
and subsurface landscape features. Although these landscape alterations are evident as
physical impacts of the land surface features, they also have the ability to serve as sources
for stressors, as shown previously in respect to the example of AMD and the impact
generated from physical extraction of metal ores from the ground. In this case, the AMD
problem poses a very signiicant threat to the receiving waters and ultimately to the biotic
receptors. Another less dramatic health threat example is the undercutting of a slope to
facilitate the construction of a right-of-way for a highway system. Excessive undercutting
without proper analysis of the stability of the slope could produce a situation where the
undercut slope could subsequently trigger a slope failure. When such occurs, one needs
to be concerned with the safety of the human and animal populations in the affected
region.
The other grouping for anthropogenic stressor sources shown in Figure 2.3 is identiied
as operations. The impacts to the geoenvironment arising from this stressor-source group
( operations ) are the direct result of activities associated with midstream and upstream
industries such as the agroindustry (outside of physical cultivation of the land), reining,
mineral dressing, manufacturing, production and process industries, etc. The effects or
results of the impacts on the geoenvironment can be physical, chemical, physicochemi-
cal, and biogeochemical in nature. One needs to factor into the analysis the resultant or
potential threats to human health and other biotic receptors. Some examples of these are
(a) application of pesticides and fungicides as pest controls in support of agricultural activi-
ties leading to non-point source contamination of ground and groundwater, (b) landilling
of hazardous wastes resulting in the production of contaminants in the fugitive leachate
plumes, (c) discharge of waste streams from chemical and electronic industries resulting
in contamination of the receiving waters, and (d) isolation-disposal of high level nuclear
wastes in underground repositories.
2.3.3 Identifying and Assessing for Impact on the Geoenvironment
A useful procedure for performing a geoenvironmental impact scoping exercise is given
in Figure 2.4. The various steps shown in the diagram are guidelines and are designed to
provide one with speciic objectives or targets.
2.3.3.1 Stressor Sources
Knowledge of the stressor sources (i.e., cause or events) can be helpful in narrowing the
ield of study or investigation. Take, for example, the case of a chemical plant producing
various organic chemicals where inadvertent spills and fugitive discharges during storage
are suspected to have occurred. If the spills and discharges are identiied as the sources,
the stressors associated with the sources would be the chemicals involved in the spills or
discharges. The impacts to the geoenvironment can be readily identiied.
2.3.3.2 Nature of Impacts
It is important to have a proper knowledge of the kind of impact. This allows determina-
tion or estimation of the extent of the damage or improvement of the geoenvironment result-
ing from the applied stressors. Using the previous chemical plant example, the damage
inlicted on the geoenvironment is seen in terms of a contaminated site or ground.
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