Water supply under threat from pollution
SAHR 2016: Sewage, acid mine drainage and climate change threaten the purity of our water supply.
Although South Africa’s water supply is almost fully allocated, the clean water supply that we have is under threat from a number of pollutants, according to researcher David Hemson writing in the SA Health Review 2016.
Only a quarter of the sewage released by municipal treatment plants into our rivers has been treated properly, and we have 986 municipal water treatment facilities that discharge 2 100 million kilolitres of treated water into river systems every year.
A study of rural groundwater systems found that the majority of those tested did not meet national water standards and that the groundwater systems were of inferior quality compared to surface water systems.
The Green Drop monitoring programme, which reports on the quality of waste-water treatment, found that none of the treatment plants in the Eastern Cape’s OR Tambo and Alfred Nzo districts had more than 50 percent compliance with national standards.
Meanwhile, acid mine drainage (AMD) also threatens to contaminate our water supplies as acidic water from decommissioned mines leaches into rivers. AMD has high concentrations of toxic heavy metals including cadmium, cobalt, copper, molybdenum, zinc and uranium. These can have serious health implications, particularly kidney disease.
Climate change is leading to rising temperatures, which will reduce the dilution effect of water, causing a higher concentration of these metal pollutants and pathogens such as E.coli and cholera – mainly from the inadequately treated sewage.
Although our annual rainfall is below the world average, our water consumption is above the world average – and “population growth and greater urbanisation will increase the demand for water supply in the future”, says Hemson in the SA Health Review 2016.
“Demand is anticipated to rise over the next 20 years, while the country’s water resources are considered to be almost fully allocated – leading to an ongoing critical period in water management,” says Hemson.
“The 2016 water crisis, precipitated by the worst drought since 1933, has resulted in widespread water shortages that are increasing stress on an already challenged infrastructure.”
Much of our water supply is wasted thanks to poor maintenance. In 2009/10, 78% of households in Mpumalanga and 69.5% in Limpopo reported interrupted water supply over the previous year. These were caused mainly by burst pipes, water leaks, poor general maintenance and insufficient water. In Mpumalanga, it usually took municipalities over two weeks to fix problems.
From 1990 to 2015, access to piped water and other improved sources increased from 66% to 81% of the rural population. But in the Eastern Cape’s OR Tambo, 34 percent of households still do not have adequate access to clean water, while a third of households in Alfred Nzo district and a quarter in Amathole (both in the Eastern Cape) also did not have access to clean water.
People are getting more concerned about the water quality too. “Less than two-thirds of households rated their water services as ‘good’ in 2013,” said Hemson, with households concerned about whether their water is clean, clear, tastes good and is free of unpleasant odours.- Health-e News.