A R74-million 2 Ml desalination project was completed in only 32 weeks to allow South32’s Hillside Aluminium smelter in Richards Bay to continue operating despite severe water restrictions.
The project benefited from JG Afrika’s extensive experience in bulk water supply planning, in addition to bulk potable and raw water supply system, as well as water-treatment process design.
We were responsible for the overall conceptual solution development, as well as the detailed civil engineering works, raw water pipeline, pump selection and brine pipeline designs.
Innovative use was made of existing infrastructure that reduced construction costs and precluded possible delays.
Existing abstraction infrastructure at the harbour provides Foskor with an emergency alternative process water supply for the Mondi effluent that is used under normal operations. The existing abstraction infrastructure comprised two pump chambers, of which only one was being used. It was agreed that South32 would add a second pump, sharing a portion of the existing rising main to abstract the seawater.
A new 2,3 km 355 mm diameter HDPE pipeline traversing the area between the harbour abstraction and Hillside was constructed inside and alongside the South32 conveyors. Most of the infrastructure, including sections of the pipeline to transfer seawater, was already in place.
As the conveyor system runs adjacent to a wetland, environmental impacts and the required approval for a conventional buried pipeline were also avoided.
Meanwhile, an existing concrete slab within the Hillside complex and its relative proximity to the Hillside process water-storage reservoir and the deployment of a fully-containerised modular plant also assisted in accelerating the project.
The plant comprises raw-water clarifiers, ultra-filtration and reverse osmosis technology.
An existing 1,5 km 300 mm diameter pipeline between Hillside and the decommissioned Hillside smelter was also used for brine disposal.
Requiring minimal refurbishment, it was extended by 335 m to connect the Hillside smelter into the existing Mhlatuze Water licensed discharge outfall.