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 South Africa.
According to a new report titled: ‘Water Quality Management and Pollution Control’ in South 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.
The water pollution in South Africa 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 waste water discharges.
Run off from small-scale mining operations, urban storm water 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 industrialized 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 South 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 South 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 South Africa is fundamentally important if the continued existence of both the resource and the populations reliant on the resource is to be make sured,” water experts said in the report.
“There is therefore an urgent need for changing the mis-perceptions 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 take part 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, carry outing the polluter-pays principle, encouraging self-regulation, economic incentives, strengthening regulation and its carry outation 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.