Thursday, September 15, 2011

How to "M"AKE a Flyless Latrine

If anyone has ever traveled to a third world country (or maybe just used a poorly maintained port-a-potty) you know how important it is to have a fly-free experience.  After all, who likes to let flies make a landing strip of your posterior? Gross, creepy, and just plain old unsanitary.
We will look here at a few of different options regarding "improved latrines" as they are also called.  Bits and pieces are taken from my personal experience as well as a experimental study an organization called WaterAid conducted in Mozambique, Africa. As well as ESTAMOS, which is a Mozambique NGO (Non-governmental organization).

How hard can it be to put a hole in the ground, and turn that space into a modern toilet, much less a hole with some sort of shelter?  First you need to consider financial impact.  Modern facilities can be fine, but you will need to consider where the waste will go, how to get a water source, and what about parts when things break or wear out.  The other thing you must consider, is that many areas do not have the luxury of a backhoe or modern tools to dig a huge hole, and furnish it.  In many villages, families farm for a living, while maybe the leader of the house hold is gone for long periods of time finding other work.  This usually leaves a mother, taking care of her kids and any other relatives in the house.  She must also tend the farm, wash the clothes, cook the food, etc.  By herself, this can be quite an intimidating task.  Often it is much easier to just "help yourself" by finding a spot away from your house, that you feel will not effect you.  Of course we know that this can be the cause of water contamination, sickness, worms, or even death.  Village cooperation and know how become valuable in making this work, no only for the betterment of the individual, but the health of the community. 
Improvements in sanitation, can be a huge source of family pride, as they begin to realize, they are becoming a more healthy and productive member of the community.  As you will see later this can also be a valuable tool in maintaining a healthy environment.  Not only in bringing health, but becoming a player in their farms growth and giving back to the environment in the form of shade and food producing trees.
Now on to the latrine itself.  I will try to list a few different methods, and give the main ideas behind a flyless latrine.  There are many ways to do the same thing, but some basic principles stand.
A good location is a must.  Keeping a good distance away from a water source is key.  This also includes not digging into the water table.  All your work trying to make a more healthy environment can go down the drain (no pun intended), if everything leeches into the water supply.
In general 1.5-3 meters is the approximate depth to dig.  There are also arguments that up to 5 meters can be appropriate, but this is a pushing the maximum.  Some will line the pit, to keep the contents from escaping into the surrounding soil.  If you are able, this can be a good idea, but not necessary if a good location is chosen.
Another basic element is darkness.  Flies love light.  Building your facility with a walk around door can help some light from entering.  You want any flies that would end up in the pit to be drawn to a single light source, not the bright shinning around your posterior.  This light source should be in the form of a vent pipe.  A vent pipe has multiple purposes. One being an escape for the smell.  Another being a death trap for flies.  the vent trap should be covered with a mesh that allows in maximum sunlight, but doesn't allow flies to escape.  Flies will be drawn up the pipe, by the light.  They will not be able to escape thru the top. And by a very intelligent design, flies are not able to fly straight down, in such a narrow tube.  So by nature they will continue to try to "reach the light" wearing themselves out, thus dying and not becoming that torturous Airbus looking for a landing strip.  The hole where the waste is deposited should be covered, usually with a plug.  Many consist of a wooden block that covers the hole with a stick attached to it for easy moving, without getting too close to the opening.
Another factor that can assist in keeping a flies to a minimum is covering up fecal matter after each use. A generous covering of a soil and ash mixture will decrease the odor, dry the contents of the pit and increase the PH level which will accelerate the destruction of pathogens that cause harm.
Its helpful if the covering over the pit is made out of some material that can easily be washed to maintaining a clean environment.  Typically a cement slab is used. 
Three versions listed here are common for design and sustainability of the latrine.  The second and third seem to be the best for the good of all.  One way is to dig your hole, and when it gets close to being full, deal with what to do with it and where to build the new one.  This way is quite common, but not the best when thinking for the future.  Another way, which takes some know how and teaching, consists of a larger structure covering two pits.  This method is preferred as the latrine can be used indefinitely, with benefits for the whole family, even the community.  One pit is always covered, for safety.  When the first pit nears full, it is covered with soil, ash, kitchen waste, etc.  Then left to compost while the second pit is in use.  By the time the second pit it full, ideally 12-18 months, the first is composted and its contents are able to be removed and used as compost for the farm.  Done the right way, this can be a safe and nice alternative to needing a new location after use.  One of my favorite ideas, has a multi purpose to it as well.  The pit is dug approximately 1.5 meters deep.  When the pit is 2/3's full, it is covered with soil, ash and kitchen waste as well.  The plot is watered down well and the next day a tree is planted on top.  This way the ground used up will be put to good use, and the family will have a new shade and/or fruit bearing tree for the future.
Local and cultural regulations must always be considered, before any new latrine in constructed.  Always use any experts advice, and follow all laws regulating building and use.
Done right the improved latrine can be a safe, and productive addition for the family and community.  It  provides valuable resources for the future and meets an immediate need.
Dig a hole today, have a Mango tomorrow!!!