Environmental Engineering Reference
In-Depth Information
rainfall events, leading to a high infiltration rate of ground water to the sewer system.
Also, during power cuts, all inflow is directed to the river, as plants usually do not
have emergency power supply facilities. In addition, deteriorating economic
conditions have an adverse impact on the planned maintenance activities for regular
supply and repair of mechanical/electrical equipment, resulting in decreased plant
capacity due to breakdowns of equipment. All these reasons lead to a significant
contribution of unaccounted pollution from sewage treatment plants.
• Irregular collection of solid waste - The shortage of fuel and vehicle spare parts
recently has crippledthe management and timely collection of waste in the City of
Harare. For instance, in the City centre the refuse collection has become inconsistent,
resulting in the piling of litter around refuse containers. Collection of refuse in
residential areas at times is done once per fortnight.
• Regulatory instruments - The existing regulatory instruments to control storm water
pollution are sat-isfactory, but there are difficulties with their enforcement by the
municipal authorities. This is due to an insufficient staff establishment and in some
cases to political interference.
• The attitude of people towards litter - Cases of littering and polluting streets and open
spaces arecommon practice, indicating the fact that people are not aware or are
disregarding the causes of such type of behaviour. In the city center, street vending has
become a prevalent practice due to economic hardships, resulting in littering and
deterioration of the urban hygiene. The public's environmental consciousness is
relatively low. In some cases, bus operators wash/repair their buses outside garage
bays due to shortage of space for the fleet in garages or due to lack of knowledge that
their activities will pollute their drinking water supply source. Illegal and causal
dumping of waste at night is also prevalent.
• Public opinion polls - Results of polls to measure public attitudes continue to show
wide support forpollution control measures implementation, but strong economic
arguments are decreasing the political will to impose the cost of pollution control and
abatement. Some industries were willing to implement pollution abatement measures,
e.g. as the construction of particle separators or oil traps but they did not have the
expertise to do so and the market does not offer ready products for this purpose.
• Financial back up - At present, the council does not have special funds designated for
storm watermanagement, and the control of diffuse pollution is executed as part of the
activities for the pollution control program, but it is considering the implementation of
the “polluter-pays” principle to fund pollution control measures. Government has been
reluctant to impose land use controls on private property as the sanctity of private
property is a vital part of freedoms in society and is a strong emotional issue.
However, the recently introduced Environmental Management Act (2002) section 114
addresses this weakness. An order may be served to the owner, occupier or user of any
land, in cases of water pollution, including storm water, removing and disposing of
litter, refuse or waste from any land or premises. The introduction of such regulatory
instrument necessitates the use of better land use management practices and would
require changes, which often, are not popular with landowners.
