Stressors and Soil Contamination - Sustainable Practices in Geoenvironmental Engineering - page 42

Stressor sources

Natural and anthropogenic

Nature of impact
Physical, mechanical, hydraulic, thermal,
chemical, biological, biochemical,
biogeochemical

Impact magnitude
Life-threatening, catastrophic, health-
threatening, geoenvironmental
degradation, troublesome,
inconvenient, etc.

Pathways and receptors
Exposure, contact, inhalation, aural, ingestion, biotic receptors

Costs and penalties
Health, impairment, death, destruction, economics

Protection, amelioration, remediation and rehabilitation
Avoidance, minimization, mitigation, remediation, protection,
restoration, etc.

FIGURE 2.4
Useful protocol for geoenvironmental impact scoping exercise. Scoping for impact assessment or determination
can omit the last step (remedial actions) if a quick assessment is needed. The last step is needed if one has the
ability to inluence decision making concerning implementation of the project or event.

Guidelines are necessary to prevent one from rendering judgments on impacts without
methodical and proper analyses just because the results of the impacts are dramatically
visible—as opposed to impacts that do not show visible distress signs. It is not the mag-
nitude of the distress caused by the impact that should determine what constitutes an
impact. As we have pointed out in Chapter 1, the results of many impacts do not manifest
themselves until many years hence. This is especially true for health-related issues. In
the most general sense, the guidelines used to determine what constitutes an impact to
the geoenvironment should be determined on the basis of whether the geoenvironmental
impact will:

• Generate direct and/or indirect threats and problems relating to public health,
natural habitats, and the environment. A good case in point is the contamina-
tion of receiving waters. These waters serve as habitats for aquatic species and,
in many instances, will serve as sources for drinking water. Not only is such an
impact a direct threat to the usable water supply for the human population, it is
also a direct threat to the food supply for the same population because of the likely
reduction in aquatic food supply for the population.
• Diminish the functioning of the ecosystems in the geoenvironment. An exam-
ple of this can be found in the degradation of soil quality due to many of the
activities associated with high-yield agriculture and mineral resources exploita-
tion. This is particularly important since soil quality is a direct measure of the