by Tinashe Madava
As industrial and development activities increase, southern Africa’s water experts are calling for parallel efforts to improve protection of the region’s fresh water supplies from pollution. Most SADC countries are battling to reduce water pollution which has trebled over the last five years due to increased industrial activity and sewage discharges.
Water pollution is the degradation of natural systems by the discharge or disposing of harmful substances such as sewage, heavy metals, pesticides, detergents and radioactive materials whether directly or through drainage or seepage.
A group of environmentalists meeting in Harare, Zimbabwe recently called for stiffer penalties against companies causing pollution. Recent fish deaths in Lakes Chivero and Manyame which supply water to Harare have been attributed to massive industrial pollution which has raised concern as to whether the authorities in Harare prioritise the protection of water sources.
It is only a matter of time before these pollutants breach the front-line of Harare’s water treatment works and bring social and economic impacts of a grander scale to the citizens of Harare,” the participants warned.
Dr goni Moyo, a fish biologist at the University of Zimbabwe attributed the Lake Chivero fish deaths to high levels of ammonia in the lake which had deprived the fish of oxygen. In Swaziland, the spillage of toxic chemicals from the Usuthu Pulp Company into the Usuthu River has resulted in a crisis similar to Lake Chivero’s.
Pollution is generally associated with industrial development and rapid increase in human population. Waste discharges from manufacturing industries are the primary sources of water pollution in southern Africa.
Industrialists are supposed to ensure that their waste water meets standards set by local authorities before entering the sewage stream. However, many small industries do not have such systems in place or just do not bother using them. At the same time, penalties for disposing of the waste are the same despite the amount disposed. Increasing demand, contamination and high costs of purification and conservation are some of the causes of serious water problems affecting Africa.
Angola’s untreated industrial waste from Luanda’s cement, battery, oil and soap factories and a petroleum refinery, spill into the Cacuaco Bay. People living around the industrial park have no sewer pipes resulting in very high pollution levels.
Mozambique has about 126 factories in and around Maputo which do not have treatment systems for their wastes. They drain their toxic waste into the environment.
In Tanzania, Msimbazi Creek in Dar es Salam is a victim of severe pollution from textile mills which release dyes, bleaching agents, alkalis and starch directly into the river. Researchers also found significant quantities of copper, iron, manganese and zinc in flour made from oven-dried fish caught in Lake Tanganyika. This was attributed to the disposal of industrial waste in the lake.
Zambia’s economic difficulties resulted in a breakdown of the general maintenance of sewage systems and industrial treatment facilities, according to recent environmental reports. Consequently, most streams in the inhabited areas have become recipients of untreated sewage and effluent, thus greatly affecting their purity as well as aesthetic value.
The state of environment report of Zambia says that the concentrations of copper, suspended solids, and nitrates are now tenfold. “The influence of effluent-carrying tributaries on the Kafue river on the Copper belt area can be seen by the substantial increase of chloride, sulphate, nitrate, phosphates and other ions between sampling sites, and before as well as after industrial areas,” says the report.
A group of environmental journalists visiting the Kafue river recently noticed that fishers were only catching one type of fish which was said to have survived extreme pollution levels in the river. Other types had disappeared.
Pollution is also a problem in Namibia, Rossing Mine’s containment pond leaked radioactive tailings into the Khan river system exceeding by eight times the previous biggest spill. “The main environmental concern at Namibia’s Rossing Mine is seepage and spills from the watered wastes causing radioactive contamination of water under the Khan river,” says the State of the Environment in Southern Africa, published jointly by SARDC, IUCN and SADC ELMS.
More often, water quality problems are thought of in terms of point pollution along the banks of the rivers and lakes, yet greater consideration should also be given to the contributions of wind as well as urban, industrial and agricultural systems.
Excessive use of nitrogen fertilizer pollutes the soils resulting in acidification which releases toxic substances into the soil. Much of the fertilizer dissolves into the ground water supply and is washed off into rivers and lakes.
Likewise, urban effluent releases an excess of nutrients such as phosphates, nitrates and sulphates into rivers and lakes promoting growth of the notorious weed, water hyacinth. Just one plant has the ability to develop to a huge carpet covering 140 hectares of the water surface and weighing 28 000 tonnes just in one year.
Over 46 percent of South Africa’s industrial waste is being disposed of in landfills located near urban areas and centres of industrial activity. Clean water sources are threatened with severe pollution from runoff and percolating water of toxic heavy metals such as lead, nickel and molybdenum.
Executive Director of the United Nations Environment Programme (UNEP), Elizabeth Dowdswell says that bad water management kills about 25 000 people each day worldwide. Half of the population killed by water pollution are children affected by water-borne diseases such as cholera, malaria, dysentery and parasitic diseases.
Co-operation is therefore needed between companies, governments, and other stakeholders to protect the region’s fresh-water supplies through developing comprehensive policies and research priorities to combat water pollution. An aggressive civil education campaign and strict monitoring of polluting companies might help to check pollution. (SARDC)
