Harare,
Zimbabwe
(Jan
25 2007)
The pollution of
rivers, lakes and acquifers from domestic
and industrial wastewater discharges, mining
runoff, agro-chemicals and other sources in
now a growing threat to water resources in
most countries in Southern Africa.
According to a new
report titled: 'Water Quality Management and
Pollution Control' in southern Africa,
written by Prof Ngonidzashe Moyo, a
freshwater biologist at the University of
Limpopo in South Africa and Sibekhile Mtetwa
and other water resources development
experts, the quality of water supplies in
the Sadc region, once taken for granted, is
becoming the focus of increasing concern.
The water experts
say the solid, liquid and particulate waste
by-products of urbanisation and economic
activities are contaminating air, soil and
water quality.
Water pollution has
affected water quality and impacted
negatively on public health and functioning
of ecosystems including the rising cost of
water treatment.
The report suggests
that the main sources of water pollution are
untreated or partially treated effluents
from municipal, industrial and mining
wastewater discharges.
Runoff from
small-scale mining operations, urban
stormwater and runoff from agricultural,
livestock and poultry operations have also
impaired the quality of water in the Sadc
region.
In Zimbabwe, the
discharge of industrial and municipal
effluent has heavily polluted Lake Chivero,
Harare's principal water supply dam leading
to massive fish deaths in the lake.
Because of poor
original planning, Harare lies within its
own catchment area. This means that all the
city's waste, which passes through the
heavily industrialised and densely populated
areas flows into the lake.
This has
compromised the quality of the city's water
and contributed to the accumulation of
ammonia compounds that are causing fish
deaths on the lake every year.
Lack of resources
to upgrade sewage treatment works, lack of
funding to water quality management and
research, overcrowding, bureaucracy and poor
management of wetlands has led to the
eutrophication of the lake.
Prof Moyo said the
degradation of river water quality has
resulted in an increased risk to consumers
who consume water from the region's water
sources.
In the report, the
writers note that not all countries have
adopted (the World Health Organisation and
FAO water guidelines) or derived their own
standards.
"Tanzania, for
example, still has temporary drinking water
standards because they envisage that
adopting permanent standards, say for
fluoride, would present difficult economic
choices and compliance problems for a large
segment of he population," the water experts
noted.
Urbanisation is
increasing in the Sadc region and water
experts say most cities have not been able
to develop the basic utilities for water and
environmental services (solid waste disposal
systems, sewage treatment and industrial
pollution control) to keep pace with the
rapid growth.
They say existing
wastewater treatment facilities in many
countries in the region are overloaded and
facing serious difficulties in handling the
ever-increasing volumes of wastewater
generated by an increasing urban population.
"Many sewage
treatment works are old. Most have been
maintained poorly and overdue for
rehabilitation," water experts said in the
report on water resources management in
southern Africa.
In Zambia, for
example, inadequate sewage treatment and
sanitation has led to widespread
eutrophication of water bodies near towns
and cities.
Water experts
estimate that sewage treatment plants in
many Zambian towns are handling just 20
percent of sewage collected and even that is
not adequately treated.
The remaining 80
percent is lost into storm drains because of
leakages or blockages.
In Zimbabwe, the Firle sewage works in
Harare was designed to treat 72 000 cubic
metres of waste water per day, but the plant
now receives more than 100 000 cubic metres
of wastewater a day. The sewage effluent
which is partially treated and nutrient-rich
finds its way to Lake Chivero contributing
to its eutrophication.
In Tanzania, only
seven out of more than 52 urban centres had
some form of sewage system in the
mid-1990s. These sewage systems provided
only partial coverage, were aged and in need
of rehabilitation, the water experts noted
in the report.
"As much as 80
percent of the urban population in Tanzania
is not served by sewage and uses the
traditional pit latrines," the report
indicates.
The Mirongo river
which drains into Lake Victoria, receives
sewage from squatter settlements because of
the breakdown of pumps and stabilisation
ponds. The river is said to have turned into
an open sewer transporting tonnes of
industrial and municipal waste into Lake
Victoria every year.
As a result, Lake
Victoria is now heavily polluted with high
levels of poisonous metals and substances
which are affecting the lake's ecology.
Municipal sewage
discharge untreated or partially treated
into the ocean and marine pollution is now
of major concern in coastal towns throughout
the Sadc region.
Sewage from the
central business district of Dar es Salaam
and Tanga, water experts say, is discharged
directly into the Indian Ocean without
treatment.
Water resources
experts estimate that coastal urban areas in
southern Africa discharge more than 850
million litres of largely untreated
wastewater into the sea.
They say although
coastal pollution in Mozambique is still
comparatively light by global standards,
studies in Maputo harbour in the mid-1990s
indicated that the beaches of Maputo and
Beira were polluted from increased soil
erosion, human-induced pollution, domestic
and industrial residues and from ship
traffic and were not safe for swimming.
In Angola, water
experts noted, people fleeing the conflict
in rural areas settled in coastal, urban
areas resulting in overpopulation,
overburdening of sanitation facilities and
localised pollution.
The capital, Luanda
was built for 500 000 people, but the
population multiplied as the civil war
intensified leading to a fierce growth of
unplanned settlements.
There was virtually
no sanitation facilities, sewage systems and
refuse collection. Marine pollution in and
around major urban areas with large informal
settlements such as Luanda has in some cases
reached toxic levels, water experts said in
the report.
Industrial
pollution in Swaziland is impacting on poor
communities residing near waterways used as
receiving waters. The polluted water poses a
severe health risk to communities located
near the river who use it for domestic
activities, such as cooking, washing and
bathing.
Even in South
Africa, toxic and radioactive substances
generated from industries is polluting
rivers and causing long term contamination
of the aquatic ecosystems.
In 1991, the Atomic
Energy Corporation of South Africa caused a
huge spill of 80 000 100 000 tonnes of
caustic soda near the Hartbeesport dam
massive fish deaths and killing aquatic
animals.
Untreated
industrial waste from coastal areas in the
whole of the Sadc region is discharged into
streams and rivers running into the ocean.
Water experts in
the report noted that industrial waste is
found in ocean waters near major centres
dotted along the entire coastline form Dar
es Salaam and Maputo on the east coast, past
Natal and Cape Town to Walvis Bay and Baia
do Cacuaco, 15km north of Luanda.
Mining activities
in the region has led to the discharging of
heavy metals such as cadmium, lead and
mercury into the river systems strewn across
the Sadc region.
For example, the
Kafue river deteriorates substantially in
quality as passes through the Copperbelt
because of the concentrated waste
discharges.
The mining
activities in the Copperbelt have degraded
the Kafue river which is the source drinking
water for millions of people in urban areas
in Zambia.
Water experts say
the cost of treating water for human
consumption has risen sharply as the quality
of the raw water deteriorated due to the
mining activities.
Other issues raised
in the report, include the water quality
management and pollution control challenges
facing the Sadc region and a range of water
quality management strategies.
Natural factors
that impair water quality are discussed in
detail as well as the severity and extent of
the problems and consequences.
Existing pollution
control management systems in the region are
also evaluated as well as policy options.
A variety of pollution control options were
recommended and these included pollution
permits, self-regulation, economic
incentives and pollution penalties.
"The management of
present and future water quality in southern
Africa is fundamentally important if the
continued existence of both the resource and
the populations reliant on the resource is
to be ensured," water experts said in the
report.
"There is therefore
an urgent need for changing the
misperceptions among policy makers that
water pollution is not a serious problem in
the region."
They say
appropriate mechanism need to be established
to check the health of aquatic environments
and the effects of pollution on the biota
and human health.
Adequately equipped
laboratories are necessary for monitoring
purposes and individual laboratories in each
country must network.
Water experts also
noted that water quality specialists and
environmental engineers are needed and these
skills should be developed through
intensification training and education and
civil service reforms that encourage the
retention of specialists within the public
and private sector.
All stakeholders
including private sector, communities,
interest groups and individuals as well as
governments must have the will to
participate in tackling the water pollution
problems in a curative but also in a
preventive manner.
Water experts said
a vigorous public awareness campaign for
improving the understanding of key issues at
the political level should be promoted at
national levels and in the Sadc region.
Other important
interventions raised by water experts
include strengthening water management and
aquatic ecosystems laws, implementing the
polluter-pays principle, encouraging
self-regulation, economic incentives,
strengthening regulation and its
implementation and promoting public
participation in water resources planning
and management.
Water is a basic
right and everyone in the region has a role
to play to enhance its value and the
protection of river ecosystems.