Potable Water Filter Going Strong After 36 Years in Namibia’s Harshest Conditions

In the harsh and desolate area around the settlement of Okakarara, located on the Central Plateau of Namibia, three incredible water filtration systems installed in 1988 still continue to deliver superior performance after 36 years, ensuring that the surrounding communities enjoy clean water, while requiring no replacement parts, no human intervention, minimal maintenance and zero electricity.

Namibia is the driest country in Sub-Saharan Africa, subject to prolonged periods of drought and largely dependent on groundwater, especially in the vast and remote rural areas. The Waterberg-Okakarara Water Supply Scheme, situated on the the Central Plateau of the country, is case in point.

The implementing agency is NamWater, a commercial entity owned by the Namibian government.
The communities around Okakarara are utterly dependent on the water lifeline provided by the Waterberg-Okakarara Water Supply Scheme.

At the Waterberg Purification works – a surface water purification scheme – the raw groundwater is treated for subsequent supply to Okakarara and rural communities in the Waterberg Area.
The purification plant was designed by Lund Consulting Engineers CC. It encompasses a chlorination facility and three fit-for-purpose industrial water filters. After three decades these filters continue to play a crucial role in ensuring rural communities have access to potable water in this harsh and desolate area all year round.

A crucial aspect of this purification plant is its ability to remove suspended solids from the groundwater that is supplied via an open canal efficiently enough to meet drinking water standards. Because of the remote location of the plant, the filtration solution selected also had to offer simplicity of operation in an area with no electricity and limited manpower, that would also not incur high operational and maintenance costs or regular attention.

The design engineers from LCE relied on the technical expertise of the Superior Filtration team to find the right solution. The team recently visited the plant to check on the performance of the AGF filters after 36 years of continuous and autonomous operation.

“We were proud to see that even after three and a half decades our AGF Autonomous Gravity Sand filters are still producing high quality filtrate with extreme reliability and minimum maintenance, even in the harshest conditions. Since the installation of the filters 36 years ago, they have only been maintained once – to replace the sand. No other maintenance, upkeep or spares have been required, thanks to the high durability of these filters. It is the most reliable filtration solution with the lowest lifetime cost!” comments Albert Bam of Superior Filtration, which has supplied filtration solutions in more than 36 countries on 6 continents since 1984.

The water filters are three identical Superior Filtration, self-cleaning automatic valve-less gravity sand filters, connected in parallel.

These mechanical rapid gravity sand filters are “polishing filters” and require no external control system or electrical supply, while operator intervention is limited to periodic maintenance inspections. The backwash cycle initiation occurs autonomously and is driven entirely by built-in hydraulic design features.

“These filters are very efficient, operating with a mere 1.2 m to 1.5 m head loss, doing so entirely without any outside energy supply, and even backwash takes place without the need for backwash pumps and valves,”
– Ndangi Sales Director Africa.


“The results the filters continue to deliver have ensured that NamWater is considering using more AGF filters in some of their projects around Namibia,” says Bam. “AGF filters are installed in many areas around Africa and around the world. We are currently involved with more than six other AGF projects. With over 36 years’ experience, our team of filtration solution experts invest our time, energy and expertise upfront to ensure we offer a filter that is fit-for-purpose. The right filters reduce risk, increase uptime, minimises oversight and maintenance and reduces the lifetime cost of the filters.”

A small but critical component in the successful supply of water, the right filtration choice is a critical decision best made with assistance of specialists with a proven track record, who are fortunately just a friendly call away.

The Superior Filtration diagnostic team invites both design engineers and end users of filtration systems to make contact via telephone or WhatsApp and to benefit from our no obligation diagnostic service, and technical input.

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