Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems – 23 December 2010
A water time-bomb is ticking for millions of users of water from the Vaal River – by 2014, it will not be suitable for human consumption.
Researchers said the problem was caused by acidic water seeping from waste on abandoned mines and by the discharging of untreated acidic mine water into rivers and streams tributary to the Vaal River system.
A report released by the Department of Water Affairs revealed that, by 2014, the water drawn from the Lesotho Highlands water scheme to dilute the high level of pollution in the Vaal will not be enough.
“The increase in dissolved salts and [other pollutants], such as chloride and sulphates, in the river has major implications for domestic, industrial and agricultural water use,” the report said.
According to the department, the Vaal River system serves a population of 12million in Gauteng, the Free State, North West and Northern Cape.
But water scientist Anthony Turton said the pollution does not mean an abrupt end to the supply of water. “It means the water supply to municipalities, industries and agriculture can no longer be guaranteed,” he said. “Strategic industries, such as Sasol and Eskom, will suffer. Economic activity will slow dramatically.”
The research report said the cost of water will increase dramatically.
“Poor water quality affects the cost to the water users, due to additional treatment costs, loss in agricultural production and deterioration of water-supply infrastructure.
“There are also health and ecological impacts of a poorer water quality that will have to be considered.”
Researchers are also worried about the seeping of nitrates and phosphates, from fertilisers and sewage, into the river system.
These chemicals have caused excessive proliferation of algae and water hyacinth, which are expensive to control.
The report suggested that control of specific catchment areas – such as Waterval, Suikerbosrand, Rietspruit, Klip River, Mooi River, Koekemoerspruit, Schoonspruit, Vierfontein, Sand Vet and the Harts River – be maintained to ensure the development of water-quality management strategies.
It says that poor-quality water from those areas will eventually reach and pollute the Vaal River.
Linda Page, spokesman for the Department of Water Affairs, said the desalination of mine water was urgent.
“It was determined by additional research that the dilution of the salt load in the Vaal River will not be sustainable in the long term and that a desalination processes will have to be implemented,” she said.
“The desalination of the mine water, with its high salt load, is the most cost-effective method to achieve this.”
Effective desalination would assist the department in its attempts to ensure that there will be sufficient water in the Vaal River system until phase 2 of the Lesotho Highlands Water Project can be brought on stream by 2020.
She said the salinity of the Vaal River had been a cause of concern since the 1980s.
By: Sipho Masondo
Source: Times Live