Open Design Mold

Parallel to the high-tech G2RT toilet we also developed a simple version of urine separation technology that is intended for a smallholder context in remote rural areas, the Open Design Mold; conceived as an open design project, it provides local craftspeople with a pattern for a sheet-metal mold. The metal is inserted into a wooden frame and concrete is poured into the mold. Even in remote areas, concrete is widely available, which means that a considerable number of urine-diverting toilets can be produced locally – in contrast, the kind of distribution system needed for industrially produced toilet inserts is often lacking in these areas.

To test the feasibility of this idea, we built a prototype and sent the construction plan to our partner, Khanyisa Projects in Durban, South Africa. Following the instructions provided, skilled tradespeople in a local firm produced a urine separation insert and in the process also improved some of the manufacturing steps; that additional information was subsequently also incorporated into the instructions.

Production process by skilled tradespeople in Durban, South Africa.

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The negative mold is welded.

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The finished steel molds are then placed in a wooden frame before concrete is poured in.

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Performance test for the finished insert with the Urinator.

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Open Design Mold, Nepal 2021

An opportunity arose for a pilot project with local craftspeople and smallholder families in Nepal, more precisely in Darechok in the province of Chitwan, around four hours’ drive from Kathmandu, the capital. SEWA, a local NGO, was in charge of building the toilets, producing the information material, and training the families. The Open Design Mold was used as an interface for a double-chamber dry toilet (Ecosan system). The urine and wash water were collected in canisters and used to fertilize the fields, while the feces were dried for a year, which is why there were two toilets in each toilet building.

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Explanatory material provided by SEWA.

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Open Design Mold, Uganda 2023

Aid organization World Vision launched the first pilot project in which we did not take the initiative on implementation in a refugee camp in Omugo, in northern Uganda, that faces recurring drought and food shortages. In this context, using urine as a fertilizer should help improve farmers’ yields. The first step was a comparative test to demonstrate urine’s effectiveness as a fertilizer. Fields were laid out and fertilized using either urine, expensive industrial fertilizer, or no fertilizer at all. More than fifty farmers who took part in the pilot project were convinced by the results. The urine came from the toilets of four schools in which our open-design urine-diverting toilets were installed, along with urine storage tanks. Although the community in Omugo was well integrated into the project, some obstacles still had to be overcome: correct storage and the smell of urine during use, the water needed to dilute the urine, as well as concerns about eating crops fertilized with urine. As the program is scheduled to run for over ten years, there are grounds to hope that users will come to appreciate the benefits.

Corn fertilized with urine.

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Tomatoes fertilized with urine.

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A World Vision employee explains how to apply the urine fertilizer safely.

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Farmer Adubati stands in front of three demonstration plots: fertilized with urine (left), with NPK fertilizer (center), and without fertilizer (right).

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