Environmental Engineering Reference
In-Depth Information
The renewable nonliving natural resources of prime importance are water and soil. They
are in essence renewable dynamic resources—characterized by recharge and replenish-
ment of these resources. However, when recharge and replenishment cannot overcome the
deicits in the nonliving renewable resources, these resources are no longer sustainable. A
good example of the preceding is the excessive use, overexploitation, and contamination
of water resources. A full treatment of these and other issues relating to sustainable water
use will be found in the textbooks dealing with this particular problem. The geoenviron-
mental concerns for water and soil are in respect to degradation in water and soil quality
due to their misuse and also due to contamination of these capital items. Discussions in
the previous chapters have shown that water and groundwater contamination, together
with soil contamination and loss of soil quality are the major downfall of sustainability
of water and soil resources—other than overuse, abuse, and misuse of these nonliving
renewable resources by humans.
The beetle diagram in Figure 13.1 provides a very simple illustration of some of the major
stressors on water, groundwater, and soil resources responsible for the unsustainable out-
come of the nonliving renewable natural resources. Other than the use, misuse, abuse, etc.,
by industry and humans shown in the top left-hand side of the illustration, most of the
stressors and their impacts have been identiied and discussed in the previous chapters.
Some of the key actions needed to drive the renewable natural resources of water, ground-
water, and soil toward sustainability goals and objectives are shown on the right-hand side
of the illustration. The major impact of contaminants on both water and soil resources is
degradation of the quality of these resources. In the case of soils, for example, degradation
of soil quality will lead directly to loss of productivity and lower agricultural yields. For
water, degradation of water quality leads directly to loss of drinking water status at the
upper end of water usage, to relegation for agricultural and industrial use, and inally to
nonusable.
Contaminants are chemical stressors that can severely affect water, groundwater, and
soil quality. These include land-based non point source contaminants such as herbi-
cides, pesticides, fungicides, etc., and point source contaminants from efluents, waste
treatment plants, and liquid discharges as wastes and spills from industrial plants (e.g.,
heavy metals, organic chemicals). Some of the methods and procedures for mitigating
of the major impacts from contaminant stressors, together with treatment and remedia-
tion options have been discussed in the previous chapter. Undoubtedly, there will be
more advanced and sophisticated methods developed in the very near future to meet the
challenges posed by these stressors. Unsustainable renewable natural resources become
nonrenewable, renewable natural resources, a condition that should not be allowed to
happen.
13.3.2 Geoenvironmental Management of Soil and Water Resources
From a geoenvironmental perspective, the actions shown on both sides of Figure 13.1
are some of the more signiicant actions that detract from, or lead to conservation and
recovery of nonliving renewable resources. The arrows that emanate from the total ellip-
tical shell indicate actions affecting the total land environment, i.e., both soil and water-
groundwater resources. Those arrows emanating speciically from the top or bottom
resources (water-groundwater resources and soil resources) indicate actions affecting
those speciic resources. Not all the pertinent or necessary actions for all of these are
shown. Only the more signiicant ones are depicted in the diagram.
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