Environmental Engineering Reference
In-Depth Information
surface watercourses could be an appropriate measure for the retention of suspended
particles and reduction of nutrients (Kao & Wu 2001). The combination of different
abatement measures with environmental corridors and buffer zones could be an attractive
option. One important consideration during the design of such structures is the need for a
correct evaluation of the quantity and quality of the storm water to be treated and the
respective characteristic values, as design storms and corresponding pollution
concentrations. This requirement emphasizes the need for a correct estimate of pollution
loads, based on reliable information from research investigations or monitoring programs,
as the basis for a reliable and cost-effective design.
5.3
Industrial areas and illicit discharges
Industrial pollution sources are regarded and controlled in most cases as point sources
and cover a wide spectrum of problems. Excluding large industrial enterprises, which
usually have provision for local effluent treatment facilities, the vast majority of the
smaller scale industries in the region lack such facilities and often discharge their
effluents without treatment into sewer systems (if they are available) or into the nearest
watercourse. Also, many of the existing industrial effluent treatment facilities are in a
poor state of maintenance and do not provide for the required treatment efficiency. The
storm water from industrial sites reaches the drain system, collecting pollution from
spreading raw and waste materials, oils, etc over the premises. As such, the industrial
areas become a significant source of diffuse pollution through surface runoff, or through
illicit discharges. Local authorities usually do not have the capacity to police and control
the numerous smaller or medium size industries and workshops, generating pollution.
From another point of view, governments try to encourage and support the development
of industries as a means for economic growth and well being of the population. Such
conditions create a difficult environment for the trade inspectorates and pollution
management authorities, which enforce the existing regulations. In very rear occasions,
penalties, even with respect to point sources of pollution, have been implemented and the
polluting industrial enterprises penalized. Such practice actually means that the burden of
pollution is transferred from the specific polluter, who is responsible for generating it, to
the local authority, the taxpayers and the future generations, who have to deal and live
with it.
In all cases of illicit discharges, from industries or from individuals, progress in the
process of diffuse pollution abatement could be achieved only if the public and all
interested parties realize the danger of such behavior and take their own responsibility for
pollution prevention. In addition, a strong political will, and good management practices
enforced by local authorities are imperative. The provision of a public involvement
program, allowing for the control and reporting of cases of illicit discharges could help
significantly.
5.4
Diffuse pollution and water reuse
Wastewater reuse is a promising strategy for a sustainable and effective use of the
available water resources and is of significant importance for arid climates, typical for
large areas in the Southern African region. The possible adverse effects of such a practice
