Dear all,
Here I attach the first prototype model of the ecosan pan (3d printed). We may first go for development of steel mold with which this could be cast in the concrete floor itself, as initially the number of toilets may not be not so large. Please do share in case you have any information, views or experience related to casting in steel mold and the development of the mold itself.
Thanks,
Laxman Kharal

Dear Chris and Friends,

(Thanks Chris and sorry for this late response). A few points to clarify our context which is different from what Chris has suggested, though what Chris suggested are relevant in other context. This is from India (Andhra Pradesh and West Bengal) and moving sidewise for anal cleaning after defecation is one of the new features (here) we tried and which has been found to be better by the users than the ones that were tried here before, move back – it occupies less space as there is only one place for washing now instead of two that would have been in double vault model that we have, the defecation hole remains at the back (thus out of sight) while the user moves sidewise, and interesting we received the remark that this is also what happens during open defecation - moving sidewise (or at least not towards the back for washing after the business).

Chris, you are right “single-chambered” instead of double would have been more cheaper, but the preference in our case had been double alternating chambers though the cost is more for other advantages it has.

This is something we found liked and adopted by communities (where we tried), those (a) living in areas that are water logging or with the risk of contamination of groundwater sources from pit latrines that are being adopted in rural India and (b) with a garden to use the urine and the compost. We also found such group to be willing to contribute in the extra cost personally required in addition to the subsidy that comes from government for pit latrines (as these are about 50% costlier than the pit latrines). From 2012 to 2016 we built over 200 such toilets – starting from about 100 and then working in successions (of 20 to 50) in different locations. One of the other key features with which we have been able to obtain improvement in the ecosan model here is the arrangement of urine and wastewater pipe which in our case are well embedded within the concrete floor and are without any bends (this we consider another innovative feature). This we tried by finding that one of drawbacks in older version of such toilet was susceptibility of the urine and wastewater pipe to leak as they were taken down beneath the slab (actually exposed in the vault itself) and with bends making them susceptible to blocking as well.

We now have plan to work for scaling up this by (a) finding a way for working though the government so that the government system of sanitation delivery also has as workable provision of such toilets for the groups that deserve it (from the areas mentioned above); and (b) developing readymade pans as per this design (which is different than the ones that can be found in the market now as mentioned above).

We also wish to revisit our over 200 ecoan toilets to assess the status of use and performance from the users’ side along with testing of the drying matter – based on this to prepare more practical users guide to ensure safety – we have drafted methodology for this already. Finally we are also looking for people or organizations willing to review and comment on our draft methodology for revisiting these toilets and collaborate in taking this forward. Please share if you have any recommendations on how this work could be taken ahead and let us know if you wish to review the draft.

Thanks and best regards.

Dear Kharallaxman,

Thank you for this drawing. It seems to me that it would be more complicated for users to shift to the side for anal washing, instead of shifting backward, especially given the fecal drop hole.

Also, construction cost will be much less if it is a single-chambered UDDT with interchangeable containers, like the common polypropylene sacks that I mentioned.

Please tell us more about the overall context. Who are these toilets for? Who will build them? What are the budget constraints? Why not use beautiful manufactured Chinese or Indian squat pans? What part of Nepal? What is the climate like there?

Best wishes,
Chris Canaday

Saw that. We can make it much more robust without need of cement slab too. Can you tell me how many sets you need to start with and what would be the long term quantity, so that I can send you the quote or both the pilot as well as regular lots. Material will be ibre glass. Mail to chandra@ watsan.in

Dear Canaday and Colleagues,

I attach here the pdf of the AutoCAD drawing of the pan in 2D that I just completed. We will go next to develop its 3D drawing.
Thanks, Laxman

Dear Kharallaxman,

Please tell more about your project. Where will it be done? Who are the beneficiaries? What is the acceptable unit price? Why not use the beautiful, inexpensive Chinese or Indian manufactured squat pans?
www.gtz.de/en/dokumente/giz2011-en-appen...s-suppliers-list.pdf

Ferrocement floors for the entire rooms (120 x 120 cm? 3 cm thick) could be easily made at a central workshop, and then carried by 4-6 persons to trucks that transport them to the sites, if these are accessible by road.

Kris's mention of the possibility of using standard, factory-made, plastic funnels for the urine is, in fact, entirely feasible. I recommend the use of ones that are 25-cm diameter, placed at roughly a 45° angle.
inodoroseco.blogspot.com/2011/06/elegant...odoros-secos-de.html

I further recommend building single-chambered UDDTs with woven polypropylene sacks as interchangeable containers, since this reduces construction costs and gives us more control over potential flies and smells.
forum.susana.org/34-urine-diversion-syst...-southern-india#7558

We look forward to hearing more from you about this case.

Best wishes,
Chris Canaday

Thanks Makowka.
We may go for few thousands in that case. What may be the “prototype development - testing - refinement” process and what may be possible on this in Nepal? At present we are working on development of 3D drawing.

The problem you will have is the "few hundreds" part, as most efficient plastic forming processes require expensive molds that only become cost efficient at a few thousand pieces or so.

You can make concrete/ferrocement pans with a kind of "liquid tile" or epoxy paint, but by the nature of the material, they are heavy to transport and crack prone.

Fibreglass is another not too uncommon method, especially when weight and durability during transport is an important factor (such as here in Nepal, where fibreglass pans can be found in remote mountain areas).

It might be also worth looking into foam core fibreglass (aka "surfboards") for building complete light-weight slabs, but I have not seen that practically done. However by cutting the foam to the right shape, it might be a quite easy production method.

Last but not least: you can make relatively nice UDDT slabs on site by embedding large plastic funnels into normal concrete slabs where the urine is going to be collected. Just connect a rubber hose to the bottom of the funnel afterwards.

We are planning of developing new model of read-ymade ecosan (UDDT) pan in few hundreds to begin with. In this would appreciate hearing if you (a) have any view on the “material” the pan could be best developed in, and (b) know about possible manufacturing processes. Thanks.