Aging infrastructure continues to affect water quality in South Africa. To address this, Tecroveer recently completed the refurbishment of the Matwabeng Wastewater Treatment Works (WWTW) in Senekal, Free State. The project has added at least 20 years to the plant’s lifespan and helped bring the facility back into environmental compliance.

The plant’s mechanical and electrical equipment was non-functional resulting in untreated sewage bypassing the works into the existing oxidation ponds and partially treated effluent discharged into the Sand river. Since the commissioning of the works the plant has been producing a final effluent compliant with its water use licence.

“We approached each component of the plant with a clear goal — to restore functionality, reduce long-term costs and support easier operation,” says Tecroveer head of projects Piet van der Merwe.

Practical Upgrades with Operational Benefits

Tecroveer implemented a focused set of improvements to ensure stable operations that are sustainable into the future. Automation across the plant now allows for remote monitoring and reduces the need for operator input. Controlled aeration has been introduced, with process oxygen demand automatically met through PLC control of the variable speed drives—an approach that brings well-known benefits in terms of energy efficiency and process stability.

Tecroveer’s unique aerator/pump system serves a dual function, using aerators to both aerate and pump into the clarifier. As a result, activated sludge is returned under gravity, eliminating the need for conventional return activated sludge pumps. This simplifies operations and reduces energy consumption.

In the anaerobic and anoxic zones, Tecroveer installed its patented transfer mixers, which combine mixing and internal recycle pumping into a single unit. This design gently mixes and pumps the biomass under low-shear conditions without introducing oxygen, enhancing process performance. Additionally, automated scum removal was introduced to help maintain consistent operations with minimal manual intervention.

A detailed equipment assessment with the employer’s engineer, Miletus Consulting, identified cost savings that created room in the budget to support three months of plant operation and maintenance following handover.

Improving Access and Safety

The site’s layout posed several challenges, with limited access and steep gradients making maintenance difficult. To address these issues, Tecroveer worked closely with the project engineer and the municipality to implement a range of improvements. New access roads and pathways were constructed to improve mobility around the site. Jib cranes and gantries were installed to support the safe handling of equipment. High-mast lighting was added, and the site’s fencing was upgraded to enhance safety and security. In addition, risk controls were put in place to manage confined space work and other potential hazards.

“We looked beyond equipment and focused on improving how the site is used daily,” says Tecroveer project manager Riaan Smit. 

Local Involvement and Compliance

Local community participation and cooperation remains a priority; and the efforts of Matwabeng Local Municipality through an appointed Community Liaison Officer ensured a transparent process for local subcontractor participation. Community members received training in fire safety, chemical handling, first aid and construction supervision. Some have since moved into operational roles.

The company achieved a 97.7% environmental compliance score in collaboration with EnviroMatrix — their highest score on a project of this type.

The Matwabeng WWTW project shows how existing infrastructure can be refurbished successfully. By focusing on teamwork, practical engineering, stable operations and local involvement, most plants can be restored to their design intent.