Sustainable Water Management - Sustainable Practices in Geoenvironmental Engineering - page 102

are available to meet the required needs. If not, one needs to manage the system to allow
for recharge before depleting this resource. If water budget analyses show that the quanti-
ties are suficient, the quality of the groundwater will then need to be determined. It may
be adequate for industrial or irrigation purposes without treatment or perhaps with in
situ treatments, as indicated previously. Drinking water quality may require further treat-
ment. Most often this is accomplished by extraction pumping and treatment with a suit-
able sustainable method—to avoid harming aspects of the environment to protect others.
Evaluation of the most sustainable water treatment processes can be performed through
procedures similar to that previously described.
Twelve Principles of Green Engineering have been suggested to engineers as a way
to improve the sustainability of industrial processes (Anastas and Zimmerman, 2003).
The second principle is particularly relevant for the prevention of water contamination:
“It is better to prevent waste than to treat or clean up waste after it is formed.” In other
words, processes should be designed to reduce water use and the amount of contaminants
that reaches the water so that the water will not have to be treated later on. In the past,
many models have been developed for prediction of the impact of certain chemicals in
the environment such as the transport of contaminants from point and non-point sources
(Mihelcic et al., 2003). However, they have not focused on how to reduce or prevent the
contamination. End of pipe solutions were the main waste management strategy until
recently when green engineering has become more prominent.
Upon determination of impaired water quality, strategies would need to be developed
to prevent the introduction of the contaminants. Groundwater and surface water monitor-
ing and GIS systems, as mentioned previously, will enable the development of the man-
agement strategies. The GIS would incorporate all aspects of land use include the types
of ecosystems, landscapes, and water use. Monitoring will include determination of the
quantities of water, the quality in terms of nutrient and contaminant contents and bio-
logical monitoring as described previously. Models would need to be developed to predict
water discharge and recharges. All the information could then be combined to determine
the water management strategy for avoidance of water contamination and optimal water
use (Figure 3.17). All of these cannot be achieved, however, if the society is not educated
concerning water usage and its importance. Legal guidelines must also be issued and fol-
lowed to protect the quantity of resource water.
3.4.2.1 Evaluation of the Sustainability of Remediation Alternatives
Attention is focused on the problem of arsenic-polluted groundwater because contam-
ination of groundwater from arsenic is a major threat to human health, and because
this is both a man-induced and a naturally occurring phenomenon. In choosing the
remediation technologies to treat this problem, it is necessary to factor in the targets,
exposure routes, future land use, acceptable risks, legislation, and resultant emissions.
A schematic illustration of the criteria and tools for evaluating technologies and proto-
cols for environmental management of contaminated soils and groundwater is shown in
Figure 3.18. Speciic comments are included in Table 3.2 for the various technologies.
Other factors that need to be considered to evaluate site remediation technologies include
(a) disturbance to the environment, (b) energy use and consumption, (c) solid wastes gen-
erated, (d) emissions of contaminants and greenhouse gases into the air, and (e) water
and materials used.