By Sharon Davies
Water is considered the key limiting factor to development in the North West. The western part of the province is arid, encompassing the eastern part of the Kalahari Desert with a rainfall of less than 300mm a year. The central part is typically semi-arid receiving 500mm a year and the eastern part is temperate with 600mm a year.
Evaporation exceeds rainfall in most parts of the province and as a result, the North West Province relies heavily on ground water resources to meet its needs. Perennial surface water is scarce, and although the province has a large reservoir of subterranean water, this resource is recharged at less than 10mm a year.
The province is not only depleting its precious water reserves, but suffers from an additional problem – that of pollution of groundwater. This includes high levels of dissolved mineral levels, nitrates and fluoride concentrations in certain areas, caused by both natural and human-induced factors including mining and industrial activities, agriculture and domestic use.
Solid wastes and effluent from industry, manufacturing and households, as well as ammonium-based fertilisers and chemicals were considered the most important soil and water polluters in the province. But more recently the threats of radiation and radioactivity have been recognised in the province.
The main source of radioactive water pollution is from the acid mine drainage from gold mines in the more than 100 years of mining history. While spills might now be relatively well contained, this was not necessarily the case in earlier days.
The Brenk Report, released by the National Nuclear Regulator early August this year, warns that 100km of the Wonderfontein Spruit that runs through rich goldfields from Randfontein in Gauteng Province down to Potchefstroom in the North West Province, has been found to be dangerously polluted.
The report claims that the water in the river has absorbed polonium and lead, the radioactive by products of uranium and radium, which in turn are by products of gold mines. Experts say that people who drink the water or eat products irrigated or supported by the water could suffer from kidney and liver failure or get cancer; other symptoms include the hampering of growth in children and mental disability.
In the report, German physicist, Dr Rainer Barthel stressed that there was no natural water in the whole area that was safe for use by humans, animals or plants – pointing out the fact that the radiation and heavy metals exposed during mining was seeping into the ground and percolating through into the wetlands and waterways.
Authorities however, argue that contamination is highest in the mud and sediments of rivers and dams, and that the water itself, running into Potchefstroom’s main dam is not contaminated above acceptable levels. This however, offers little compensation to the 150 000 residents of Khutsong, who unlike other areas, rely solely on the river for their water source – and fails to consider what happens when cattle stir up the mud when drinking from dams and rivers, or the consequences of children playing in contaminated areas.
There are a number of issues that nearby Durban Roodepoort Deep and Harmony Gold Mines need to answer for, including the rehabilitation of Robinson Lake, used as an emergency leakage overflow more than five years ago. This goes beyond stating that they are investigating solutions and that mine effluent is contained in tailings or slimes dams, and that spills are rare and well managed.
While the outlook for residents, particularly farmers, affected by contaminated water is a cause for concern, there are a number of initiatives in place that will have a positive impact for the North West – both environmentally and economically.
Rainwater harvesting is a wonderful sollution – it lessens the extraction of water from our dams and rivers.