Water scarcity: Rethinking wastewater recycling, re-use
Dam levels in the Eastern Cape have been steadily declining, despite the recent rains that have added some needed relief to our water resources.
According to a recent report by the Department of Water and Sanitation, the total storage of water in the Eastern Cape stands at 56.1%, compared to last year’s average levels of 66.4%.
This trend, coupled with the severe drought conditions that are affecting most parts of the country, an increasing population and industrial growth, and environmental degradation, we are forced to look at accelerated innovations in water resources and water services delivery to sustainably meet future water demands.
In her budget speech in May, the Minister of Water and Sanitation, Nomvula Mokonyane highlighted the country’s heavy reliance on surface water as a concern.
She added that it was for this reason that the Department was planning to ensure that there is mix of surface and ground water, which includes options such as groundwater, wastewater re-use (grey water); desalination and rainwater harvesting, among others.
Recycling, the re-use of waste water (grey water) and desalination are some of buzz words in the water sector nationally and internationally, having been publicised as possible solutions to alleviating the effects of the persisting water scarcity.
Wastewater re-use, recycled or reclaimed or grey water refers to former wastewater that has been treated to remove solids and certain impurities, and then re-used for a variety of applications including landscaping and irrigation, for example.
Although costly, many coastal cities appear to prefer desalination as a solution to the water crisis.
However, unlike its desalination counterpart, an added advantage of wastewater recycling and re-use is that it requires far less electricity, and affords both economic and environmental benefits to those who embrace it.
In our quest for innovative ways to ensure sustainable water supply, perhaps it is opportune to start dealing with wastewater differently and explore wastewater re-use and recycling as a resource rather than waste and as a way to expand the country’s pool of water resources.
Leading the cities in this area is Durban, which is home to the country’s first private wastewater recycling plant. The idea for the plant was born in 1993 out of concern for the area’s increasing demand and limited water resources. This plant was later commissioned in 2001.
The plant treats 47.5 million litres of domestic and industrial wastewater to ‘a near potable standard for sale to industrial customers, with the added benefit of a lower tariff when compared to the normal tariff for potable water.
As a result, the plant has helped to free up sufficient drinking water for approximately 300,000 people in the area. In turn, this has reduced the demand for potable water and the quantity of effluent that is returned to the environment.
Due mainly to the persistent drought conditions and groundwater depletion, non-potable uses are increasing.
Using Durban as a success story of how wastewater recycling and re-use can be managed and used, it is clear that the future of water sustainability lies in looking at sources of water that will not only mitigate the effects of the drought, but also complement the existing sources.
