Water reuse programmes needed to conserve precious resource

File picture: AP

File picture: AP

Published Aug 13, 2020


By Sheena Kumari

South Africa is a water-scarce country, and is experiencing increasing water scarcity because of changing climate and rainfall patterns.

It is estimated that by 2030 there will be a 17% gap between water supply and demand, which will have a major impact on both urban and rural communities.

Increasing urbanisation, the growing population, rising industrialisation and agricultural run-off, poor sanitation, poor maintenance of freshwater and wastewater systems, and the long-term consequences of acid mine drainage all contribute to worsening the water crisis.

Currently, more than 65% of the country’s water demand is met from surface water resources such as catchments, rivers, lakes and wetlands.

Long-term water quality data on these water bodies show that water quality has significantly deteriorated over the years owing to increased human activity. Intervention from relevant authorities for the protection of our freshwater resources from further degradation is critical.

Policies to improve water safety plans must be implemented and independent water quality surveillance programmes endorsed.

The current water quality framework should be restructured to include risk assessment models, skills and infrastructure development, and the measurement of new and emerging pollutants and pathogens.

Water quality monitoring should integrate with the 4th industrial revolution in areas such as cloud computing, and the use of advanced satellite imagery and geographic information systems coupled with modelling to assist in identifying the extent of surface water pollution in the country and finding sustainable solutions for future water resource management.

Wastewater treatment is an integral part of any water resource management programme.

Historically, South Africa was at the forefront of wastewater treatment technologies, but in the past decade wastewater treatment infrastructure has aged and failed, bringing the sector under constant scrutiny.

According to the Green Drop report by the Department of Water and Sanitation, most wastewater treatment plants across the country are working sub-optimally, and raw or partially treated sewage is reaching major rivers and dams, causing irreversible damage.

The proper management of wastewater treatment systems and the use of adequate, appropriate new treatment technologies to improve effluent quality should be a priority.

Globally, water reclamation has been recognised as a key component of the sustainable water management programme for more than 50 years.

Up to 60% of South Africa’s available freshwater resource is currently being used for agriculture alone, and the industrial sector is using between 13% and 16%.

With the demand for water growing exponentially, it is therefore vital to reuse the large volumes of wastewater generated by these sectors on a daily basis.

This could see a substantial decrease in the exploitation of fresh water/surface water, making cities more water sustainable.

It would also ensure a decrease in the volume of wastewater discharge and a subsequent reduction in the pollutant load to freshwater bodies.

Various reliable technologies and systems for wastewater reuse are being developed and implemented worldwide. In South Africa alone, there are several success stories in wastewater reclamation from various activities. For example, the direct wastewater reclamation plant for the production of drinking water in Beaufort West can produce 2.3million litres of water per day.

Recent droughts in the country have sparked several water reuse projects in various areas, showing the immense potential of the South African water sector in combating water shortages.

Water reuse programmes in remote rural areas may have to be dealt with differently, using decentralised systems and point-of-use household treatment technologies.

Unfortunately, despite the progress made so far, wastewater reclamation in South Africa is largely limited by negative public perception and lack of buy-in.

For water reuse programmes to succeed, we need robust public education campaigns throughout the country, from cities to remote villages, coupled with infrastructure development and a stringent water quality monitoring programme.

* Dr Kumari is a senior researcher at the Institute for Water and Wastewater Technology at Durban University of Technology.

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