"Brilliant" $1.50 sanitation idea?
Hello, I came across http://www.fastcoexist.com/3029975/a-simple-yet-brilliant-150-sanitation-idea and was wondering... do you think this is genuinely useful, or is this just reinventing the trap seal?? Because for this to work, it needs water, and if you use water, you may as well put something tried and tested like a trap. What am I missing here? Thanks!
Hi Remi, this appears to be the Sato pan developed by American standards and being manufactured in Bangladesh. Where this is being sold directly into the market there it appears to be enjoying good acceptance due to its low cost, ease of transport and the fact that it requires only 100ml of water to flush. The flap retains a small amount of water to help retain the seal so it actually remain a water seal, but the flap system simply allows this to be significantly less than even a low flush water seal option.
WaterAid in Bangladesh is using these in a trial period through a targeted approach, i.e. for more vulnerable households. Initial user feedback is good, but the real test will be time.
This is virtually the same as a system called Watergate (long before the Watergate 'Plumbers' contaminated the brand) by Dr Peter Morgan in Zimbabwe and was patented by the Minstry of Health there, but he quickly abandoned the idea and developed the VIP latrine instead. This was because he chucked a brick batt down the latrine when demonstrating the robustness of the system and the flap, unsurprisingly, became detached. This is the first I have seen of the principle being applied to a situation where pour flush toilets would be the obvious first choice and so it may well be more successful in this situation. However I do still have reservations about the long term robustness and maintenance of the mechanism. The illustatration on the web page does demonstrate the ubiquitous lack of care in the design, and supervision of construction that seems to be common to all sanitation projects. The footrests place in the wrong position (far too far back) and pointing in completely the wrong direction (toe in instead of toe out). This is a common mistake which can also be found in the first WHO manual on the subject by Wagner and Lanoix! The surface of the footrests is going to be virtually impossible to keep clean as it is so rough and there does not appear to be nearly enough fall on the toilet floor towards the toilet bowl . For these reasons I would advocate not having footrests as it is far easier to achieve a smooth, dense, steel floated finish if they are omitted. However, if you really insist on providing them, I would recommend the plan layout of the Sanplat as used in Mozambique. The designer, Bjorn Brandberg, is the only person I know of to actually take the trouble to work out where to place the footrests to suit normal human beings. He did this by getting a range of people to squat on sheets of paper and draw around the outline of their feet.
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