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New-look emergency sanitation
Designing a better bog
LONDON, 19 September 2013 (IRIN) - When disaster strikes, what are the first things you have to get onto the plane? Shelter materials, blankets, food and medical supplies, and - for sure - the equipment for water supply and sanitation. Yet even Oxfam, known among relief agencies for being “good at drains”, does not have as much choice of sanitation supplies in its warehouse as it would like. Its recent “Design a Bog Day” was organized to get some new ideas from outside the humanitarian sector for better emergency sanitation in the future.
Even where there is a good product in the warehouse - like the Nag Magic, specially designed, made-in-India plastic latrine slab - Oxfam’s public health engineering team fret that it could be better. The Nag Magic slab is easy to install, with fixings included for skewering it into the ground, and it stacks neatly to go on pallets, but is still quite heavy. Could it be lighter, reducing air freight costs? And although it’s not expensive - just $46 delivered from India to Oxfam’s warehouse in rural Oxfordshire - could it be even cheaper? Pressure on costs is relentless.
The designers, engineers, materials specialists and manufacturers who gathered in Oxford for the brain-storming session were given four design challenges often encountered in the early days of an emergency. First, a better latrine superstructure - folding or flat-pack - to give people privacy and dignity. Then, cheap, lightweight trench linings to hold back sandy or waterlogged soil. And a hygienic tap for family water containers to encourage hand-washing. And, finally, a better design for the raised latrines that have to be used when it’s not possible to build traditional latrine pits to contain the waste.
The need for better above-ground latrines was brought into focus by a recent spate of emergencies in urban situations. Andy Bastable, Oxfam’s Head of Water and Sanitation and engineering coordinator leading the design day, says the demand is only going to increase. “As we move to 2035,” he told IRIN, “when [most of the world’s] population is supposed to be living in urban areas and there’s likely to be an increase in severe weather events, we are going to have more urban and peri-urban type disasters. Dealing with water and sanitation in an urban environment is quite different and requires different skills. It is doable, but it requires a different mindset.”
Problems on the ground
Karine Deniel, an emergency response expert, saw the problems on the ground in Haiti. “It was impossible to dig because of the land ownership or because of the concrete,” she says. “So the only solution we could give was communal latrines and chemical latrines, which people weren’t used to using and were very expensive. And you can de-sludge, but where do you put the contents?”
Some Design Day participants tackled de-sludging issues and came up with innovative ways of drying out the waste to reduce its volume, like using lenses to focus the sun, or convection currents. Others looked at better designs for the sludge tanks under the latrines. One clever suggestion was to use the kind of plastic wheelie-bins used for rubbish collection in many cities. They are easily available, robust, and stackable, with hinged lids and wheels for easy handling, and can be rapidly cleaned with a pressure hose.
Other groups were thinking up better enclosures, looking into the possibility of using modern styles of camping tents with sprung wire or inflatable supports. There was a lot of scribbling on the backs of envelopes, but Oxfam had provided a professional artist, Danny Burgess, to make the ideas come to life. One group was getting excited about the potential of Spraycrete, a sort of spray-on cement. Perhaps you could put up basic pole-and-fabric shelters in the first days of the emergency and then come along a little later with a compressor and spray them with concrete, turning them into more solid structures. You might even be able to dismantle the original frame and use it again for another latrine.
The pit-lining groups were also playing with ideas about new materials. Tubular liners are inherently stronger than rectangular ones, but transporting tubes also means transporting a lot of empty air. So could you use double-walled, inflatable plastic tubes? Even better, could you then fill them with builder’s foam, which expands to fill any space and sets rigid? Bastable liked that idea, but worried about the cost.
Bob Reed, of Loughborough University, who has been working in emergency sanitation for almost forty years, says one fundamental problem is an unwillingness to spend money. “There’s still a feeling that sanitation should be cheap,” he told IRIN. “But in the UK, for instance, nearly two-thirds of water charges are for sanitation, only one-third is for water supply. It’s much more expensive to get rid of human waste than to supply clean water. But institutions and organizations fail to grasp that, and they don’t make the resources available that they should.”