As water scarcity intensifies, businesses are rethinking how they use every drop. Kirsten Kelly talks to Wayne Taljaard, the MD of WEC Water about water reuse.
“The upfront cost of water reuse is more expensive than simply using municipal water. However, water reuse provides valuable water security, safeguarding a business’ operations against intermittent water supply. Downtime due to water shortages can halt production processes, lead to lost revenue, unfulfilled orders, and increased operational costs,” says
He adds that water reuse plays a significant role in attaining Sustainable Development Goal (SDG) 6:Clean water and sanitation.
“By treating and reusing water, businesses and communities reduce their reliance on freshwater sources, protect ecosystems, and contribute to long-term environmental stewardship. It is far too easy to discharge effluent down a drain and make it someone else’s problem. Companies that actively reduce their discharge volumes and reuse water not only protect their operations from disrupted water services, but also demonstrate a strong commitment to environmental responsibility and social sustainability.”
Tackling the cost of reuse
NEWgenerator for Eastern Cape school
Taljaard believes that a company should firstly conduct a water audit; looking at where water is used in their systems and day to day operations and the quality and quantity of water needed.
“In reuse, water treatment can be tailored to fit the intended use – saving resources by not over-treating water where it’s not necessary. For instance, water used for cleaning floors and equipment may not need to be as highly treated as water used as a raw material in a manufacturing process.”
Wayne Taljaard, MD WEC Projects
By matching the treatment level to the specific application, the company can save on treatment costs, reduce freshwater demand, and lower wastewater discharge.
However, the opposite applies to domestic potable reuse that must be SANS 241 compliant. There has to be zero risk of contamination with multiple treatment barriers in place.
“Unfortunately, many of our wastewater treatment plants are not running efficiently and effectively. Therefore, any post treatment steps for water reuse could be significantly more expensive. To drive down the cost of water reuse at a municipal level, wastewater treatment plants should run as optimally as possible,” explains Taljaard.
With package plants, the cost of water reuse will always be impacted by scale. When looking at the cost per litre, treating 50 m
3 of wastewater will always be far more expensive than treating 500 m
3 of wastewater.
Projects
NEWgenerator for Khanyisani school, Eastern Cape
Over the years, WEC Water has been involved with multiple water reuse projects. Most recently, they have installed a small treatment plant at a shopping centre for grey water recovery, assisted mines in reusing water in their processes and for dust suppression and have worked on a housing development in Zambia where wastewater is treated to be reused for irrigation.
One of WEC Water’s most prominent water reuse solutions is an off-grid, non-sewered sanitation system (NSSS) that treats black water and basin water to a standard suitable for flush water. The NEWgenerator is a compact, off-grid, modular sewage treatment solution that can be housed inside a refurbished shipping container. It incorporates an anaerobic bioreactor to treat biological matter and breakdown solids, ultrafiltration to remove solids, sequential nutrient capture tanks, and chlorine disinfection. The NEWgenerator has been installed at various schools and undergone extensive pilot testing at different sites around South Africa.
WEC Water have recently been awarded a zero liquid discharge (ZLD) project for a large industrial client. ZLD is a strategic wastewater management system that ensures that there will be no discharge of industrial wastewater into the environment. It is achieved by treating wastewater through recycling and then recovery and reuse for industrial purpose.
“There is a growing interest in ZLD technologies across industries such as mining, power generation, and manufacturing, as companies seek resilient and responsible water management solutions to adapt to stricter environmental regulations and the increasing threat of drought,” states Taljaard.
He adds that water reuse is not a plug and play solution, and technologies and approaches will differ with every case.
3D render of a filter water treatment plant for a gold mine in the DRC
“There is an expectation that contractors should take on the bulk of the financial risk of projects such as these, but in theory, the client is generating this wastewater and there needs to be a shared risk. The Durban Water Recycling Project is a great example of a large scale water reuse project. There is enough industrial activity in South Africa that can create a healthy demand for treated wastewater. I am encouraged to see a request for proposal for a public private partnership for the design, finance, construction, operation and maintenance of a wastewater treatment plant in Umkomaas and Umdloti that will include a water reuse element. There is certainly a growing appetite for large scale water reuse projects.”
When implementing a water reuse project, WEC Water provides a turnkey service. The company specialises in engineering bespoke options that are designed to meet the exact requirements of a client, finding solutions for projects in complex locations with complex operating parameters.
“We walk the path with our clients from a project’s inception. The WEC Assist program even assists clients with the operation and maintenance of a client’s plants once commissioned. Our experience in different industries gives us the ability to tailor a solution to match a client’s specific requirements, while still being technology agnostic,” concludes Taljaard.
