Ethekwini Water and Sanitation – In construction plant for direct potable reuse of recycled water and desalination

Ethekwini is a coastal municipality in KwaZulu-Natal Province. South Africa has recognised the need for water reuse in its National Water Resource Strategy, Water Reconciliation Studies, National Development Plan and Sanitation Master Plan; as the country is fully using its available surface water resources, and running out of locations for future dams.

Ethekwini has been leading the way on innovative reuse by practising non-drinking recycling for some time, including for a paper factory and oil refinery, since 2001 (see Ethekwini 4). Now, eThekwini is exploring more non-drinking recycling plus direct potable reuse to help the municipality ensure a reliable and safe water supply in future. In future around 20% of the total demand of 1,100 million litres (290 million gallons) per day could come from reuse, groundwater supply, rainwater harvesting and desalination.

In 2020, Ethekwini Water and Sanitation partnered with Hitachi and Nedo to build and operate the 6.25 million litre (1.6 million gallon) per day Remix Water Demonstration Plant. This is an energy-saving, environmentally friendly desalination technology. It was built at the Central Wastewater Treatment Works, the ideal location as it is close to the ocean and can use existing infrastructure including the ocean outfall.

The demonstration plant tested and proved that the technology can produce drinking water that meets South Africa’s national water quality standards, and optimised the design. Now, the Remix plant will be upgraded to a capacity of 100 million (26 million gallons) per day, ready in the 2030s.