Friday, December 4, 2009

Composting Possibilities

Ok, so this is a long long overdue response to inquiries I recieved from several people on the subject of composting latrines. I had started writing a post about it ages ago, then stopped and wanted to do more research on it, then forgot about it amidst other work, then remembered it again to look further into it, then i forgot to write up a response, and now I am back at it again, for real this time.

So, lets see. There are several ways that a composting toilet can work. But basically the idea is to limit wasted water, even maybe separating liquid waste from solid, to prevent the spread of pathogens, and to manage the solid waste and aiding decomposistion until it is ready to be used out in the fields or gardens.

Now, for our latrines. The idea of public latrines was brought up and floated about the village for a while before being nearly unanimously voted down. What people wanted, and understandably, was for each family to have their own latrine to clean and manage. Each household getting a latrine meant an emphasis on the utility and minimal resources and something easily incorporated into the already existing village layout. This meant pit latrines topped with a turkish toilet, aka a hole. Now this design works in its simplest form in most parts of the country, all you need to do is put a slab of concrete with a hole all reinforced with rebar over the pit and voila, your very own latrine. Our soil is super sandy in our area and so we are forced to modify the design slightly. We have to cement the walls of the pit, or as we are doing, brick it in. Also, we could have had the hole in the center of the slab, but this would need extra cement and rebar. Cheaper than that is to make a solid slab and fix a pipe to the side that can run to whatever one wants to have at the elbow bend, turkish toilet or a fancy seat or whatever. There will also be a 2m pipe coming from the corner going straight up, acting as a ventilation stack.

So then, with such a design, once it is filled, five or ten years from now depending on the size of the family and all that, a new pit can be dug and cemented for relatively minimal cost, and the slab and pipes can be moved over to that one. Then what to do with all that junk? I had been thinking about this from the begining though explaining it to the community has proved a bit challenging. They have little ideas about the usefulness of compost, but they do know about spreading manure in gardens and around field crops, so there is a base of knowledge.

One option, of course, is to simply do nothing with it, leave it there. This in fact opens up some other avenues of waste disposal. What can we do with these old razor blades, throw them down the latrine. What about broken glass, this old rusted metal or barbed wire? Even more dangerous, all these old batteries that just lay around in the sun and break open and invite young children to put them in their mouths. This seems such an obvious and immediate solution to this growing hazordous trash problem that for a while it seemed just easier to advocate that then try and push any other kind of strategy.

But doing composting is also an excellent benifit to the comunity and to the environment. One issue though is that the layout of the the latrines themselves does not yeild itself particularly well to making efficient compost. There is no way to stir, to aeorate the solid waste. While it may not be that hard to add good imputs like sawdust, this is not available in the village and might not be stustainable to try and push its use village wide, especially if people would have to go and buy it from a nearby town.

So I think I can explain the different sides of it to each family as we go. My plan all along has been to include some health lessons family by family about proper handwashing techniques, about where disease comes from, and the importance of having a clean environment. Then people can decide for themselves if they would like to try and see how the composting option works. Once their latrine is full, a new pit is dug and they can should leave the other pit, covered in grass for example, for several months or maybe a year for the cold compost process to break down the waste. Then they can empty the pits and use it as compost, as fertilizer, wherever it is needed in their gardens or in thier fields.

And then thats about that. Honestly any more complicated approach may work on a public latrine basis, but that is not what people want here. People do need latrines, any latrines, because now there is nothing. I will do my best to present all the information I have avaliable to them and explain it particularly to village representatives who can pass that information along after PCVs are gone. If a family wants to just throw trash down into it, it may fill up a little faster, but after it is full they can dig them selves a new one and the old one will decompose on its own and can be buried. If they want to be brave and try the compost thing, if they can get over the stigma of where it all came from, then they can go for that too, maybe not in the most efficient way but they have the basic tools and can do it for an added benifit of soil quality and a healthier environment.

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