When elevated manganese threatened the quality of a rural town’s drinking water, Indus Water Solutions (IWS) identified the source of the contamination and upgraded the existing municipal water treatment plant to restore compliant potable water — without the cost and disruption of replacing the treatment system.
The challenge
A rural municipality began experiencing elevated manganese levels in its potable water supply, including noticeable discolouration following chlorination.
IWS was brought in to investigate the cause.
Our assessment found that acid mine water had entered the upstream catchment area, changing the raw-water quality feeding the municipal treatment plant. The existing treatment process was not adequately removing the increased manganese load, placing potable-water quality at risk.
The municipality needed a solution that could:
- reliably reduce manganese to acceptable drinking-water levels;
- integrate with the existing water treatment plant;
- minimise capital expenditure;
- avoid significant increases in operating costs; and
- be implemented without unnecessarily disrupting the community’s water supply.
The IWS solution
Rather than replacing the existing filtration system, IWS developed a retrofit solution around the infrastructure already available at the plant.
The existing gravity filters were upgraded using specialised manganese-removal filter media designed to capture manganese within the filtration process.
This approach allowed the municipality to improve treatment performance without installing an entirely new treatment plant or introducing a complex additional process.
IWS also developed an operating procedure for the upgraded filtration system and trained the plant operators to ensure that the solution could be operated and maintained effectively over the long term.
The result
Following implementation, manganese levels were reduced to acceptable levels in accordance with SANS 241 requirements for potable water.
The project delivered several important benefits:
Reduced manganese levels
The upgraded filtration process successfully addressed the elevated manganese concentration in the municipal water supply.
Minimal capital expenditure
Existing gravity filters and treatment infrastructure were retained and optimised rather than replaced.
Low additional operating cost
The solution required no significant additional energy demand or continuous high-cost chemical dosing.
Fast implementation
Retrofitting the existing filtration process allowed the manganese problem to be addressed without the lead times associated with constructing a new treatment system.
Sustainable treatment approach
The solution did not create an additional hazardous waste stream and made better use of infrastructure already installed at the water treatment works.
Improved operational capability
Operating procedures and plant-operator training helped ensure that the upgraded system could continue performing effectively after implementation.
Engineering more from existing water-treatment infrastructure
This project demonstrates an important part of the IWS approach to water treatment: the best solution is not always a new plant.
By first understanding the water chemistry, the source of the problem and the capabilities of the existing treatment process, IWS was able to develop a targeted upgrade that addressed the manganese problem while keeping both capital and operating costs low.
For municipalities and industrial water users facing changing raw-water quality, manganese, iron or other treatment challenges, optimisation of existing infrastructure can often provide a faster and more economical alternative to complete plant replacement.
Need help with manganese removal or potable-water treatment?
If your water treatment plant is experiencing elevated manganese, iron, discolouration, changing feedwater quality or difficulty meeting potable-water specifications, IWS can investigate the root cause and determine whether your existing plant can be optimised or upgraded.
Talk to Indus Water Solutions about a water-quality assessment, treatment-plant audit or manganese-removal solution.
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