WATER QUALITY MANAGEMENT IN CONNECTED CATCHMENT- SHALLOW LAKE SYSTEMS - Integrating GIS, Remote Sensing, and Mathematical Modelling for Surface Water Quality Management - page 40

(e) The wastewater outfall configuration and effluent mixing
(f) The eutrophication status of the receiving waters
(g) The waste assimilative capacity of the receiving waters.
(h) The ecological changes that might be caused by wastewater discharges
(i) The potential effects of discharged waters.
Major problems affecting the water quality of rivers and lakes vary according to the specific situations
as mentioned earlier. Problems may arise from inadequately treated sewage, poor land use practices,
loss and destruction of catchment areas, inadequate controls on the discharges of industrial waste
waters, poor siting of industrial plants, deforestation, uncontrolled poor agricultural practices and a
lack of integrated watershed management. Some of the effects of the above are leaching of nutrients
and pesticides, threatened ecosystems, public health risks, erosion, sedimentation and deforestation
leading to land degradation. Many of these negative effects may have arisen from environmentally
destructive development and a lack of public awareness and education on the protection of surface and
groundwater resources.
To effectively control water quality, it must be described in precise technical quantitative terms to
allow the decision for effluent discharge limitations or a beneficial use of the water to be formulated.
In addition any requirements for water quality must be imposed with consideration of the concomitant
level of treatment requirements of wastewater effluents or water supply intakes upstream and
downstream from the point of interest.
Water Quality Management in Developing Countries
The water quality situation in developing countries is highly variable reflecting social, economic and
physical factors as well as state of development. And while not all countries are facing a crisis of water
shortage, all have to a greater or lesser extent serious problems associated with degraded water quality.
In some countries these are mainly associated with rivers, in others it is groundwater, and in yet others
it is large lakes; in many countries it is all three. Because the range of polluting activities is highly
variable from one country to another, and the nature of environmental and socio-economic impacts is
equally variable, there is no "one-size-fits-all" solution. There are, however, some common
denominators in the types of actions that are required for sustainable solutions (Ongley, 2000).
For the purpose of quantifying the water quality, numerical values of the concentration of various
substances present in the water samples are determined through physical, chemical and biological
techniques of analysis. Until today, in most of developing countries, the major quantification tend of
the water quality, is based on a statistical evaluation of a number of samples taken at various locations,
flows and times. Accuracy of the water quality quantification is related to the frequency of the data
acquisition and its statistical reliability. The process of quantifying water then involves a comparison
of the statistical water quality characteristics with water quality criteria or standards. Water quality
standards used throughout the world are generally either in the category of stream standards or effluent
standards or a combination. In the United States, although primary emphasis is on effluent standards,
stream standards are enforced where the effluent loadings exceed the waste assimilative capacity, as
determined by stream standards (water quality limiting cases).
Apart from effluent regulations and, sometimes, national water quality guidelines, a common
observation is that few developing countries include water quality within a meaningful national water
policy context. Whereas water supply is seen as a national issue, pollution is mainly felt at, and dealt
with, at the local level. National governments, with few exceptions, have little information on the
relative importance of various types of pollution (agriculture, municipal, industrial, animal husbandry,
aquaculture, etc.) and therefore have no notion of which is of greatest economic or public health
significance. Usually, freshwater quality management is completely divorced from coastal
management even though these are intimately linked. Consequently, it is difficult to develop a
strategic water quality management plan or to efficiently focus domestic and donor funds on priority
issues.