Half a croissant, on a plate, with a sign in front of it saying '50c'
h a l f b a k e r y
"It would work, if you can find alternatives to each of the steps involved in this process."

idea: add, search, annotate, link, view, overview, recent, by name, random

meta: news, help, about, links, report a problem

account: browse anonymously, or get an account and write.



Cheap Pit Latrine for Rural Communities

Yet another use for old cargo containers.....
  [vote for,

Supplies: One cargo container, a welding torch, two sections of sewer pipe (3m long each), paint and paint sprayer, and misc. local supplies (tarps, sheet metal, palm leaves, woven reed mats, bamboo, wood, whatever...)

Step One: Tow or barge a used, full-sized cargo container to a rural community. Cut off the container's floor and set it aside. Make repeating 2cm wide vertical cuts down all four of the side walls (optional / site dependent). Lower the structure into a rectangular hole of the same size so that the roof of the container sits at least 25cm above ground level.

Step Two: Get the floor of the container that was cut off in step one. Cut it in half the long way, creating two equal sections. Weld one of the two sections perpendicular to the exposed surface of the container to make a metal wall that runs nearly its entire length.

Take the other section of the floor, cut it up into squares, and weld them at 90 degrees to the upright metal dividing wall in way to make as many semi-private stalls as needed. Looking down on this from above, you would see two rows of stalls facing away from each other.

Step Three: Cut a circular 25cm hole in each stall --just let these metal disks drop into the cavernous pit of the empty container beneath. Similarly, cut one circular hole near each end of the container and weld the sewer pipes upright to create vents. Salvage these two latter metal disks to make rain caps for the vent pipes. Paint everything that is above ground.

Step Four: Use local materials and expertise to make a roof over the container that allows the vents to pass through unobstructed. There are a million ways to do this and local people will know what they want. Similarly, if locals want stools or benches above the latrine holes, they will build them the way they like them.

Step Five: Eventually, this thing will be mostly full and it will be time for round two or for something else. The top of the container was set above ground level so that it could be torched off at the ground and skidded over to cover a new pit when needed. The old pit is then filled up and covered with soil and planted trees. The trees will be a reminder not to go digging around there anytime soon.

Afterward: My work involves studying, writing, and teaching about conflict. For the last five months I've been doing field research in Central and South America. Rural, post-conflict communities often have urgent basic needs. I've read that simple community latrines are an imperfect but helpful solution for at least one of them. I think a small team could put this together in less than 48 hours with local support.

gribbler, Dec 13 2013

Tom devises a scheme to free Jim http://www.american...rry-finn/chapter-35
[bungston, Dec 15 2013]


       That's a lot of towing, cutting and welding. Would it perhaps be easier to just dig a hole?
pocmloc, Dec 13 2013

       //if locals want stools or benches above the latrine holes...// Wouldn't they want the stools to be under the latrine holes? ha
xenzag, Dec 13 2013

       A two hole outhouse of similar design stinks so bad you can taste it. Eight or ten pits together will make people sick.   

       If you ever need to implement such an outhouse finds ways to spread the holes over a wide area.   

       Add showers? separate urinals from shitters? wash out weekly to a containment pond?   

       Still have bad dreams from a hot summer and a hot outhouse. Weep
popbottle, Dec 14 2013

       //A two hole outhouse of similar design stinks so bad you can taste it. Eight or ten pits together will make people sick.//   

       While trench latrines typically make more sense for a larger group (dig a long trench to start, fill it in as you go), a pit outhouse can work quite well for large numbers of people. It requires a few things. First, decent drainage for moisture, at least a little bit of venting, and a certain amount of odor absorbing material. Lime is preferred, but wood ash works quite well, and is usually readily available in communities where such a latrine is needed.   

       However, the total required infrastructure for such a latrine is a shovel and a board. If you really need privacy, a few additional boards are nice.   

       Anything beyond that, such as this idea, increases the complexity without providing a major benefit.
MechE, Dec 14 2013

       //Lower the structure into a rectangular hole of the same size//   

       //I think a small team could put this together in less than 48 hours with local support.//   

       I would have thought you'd need some kind of heavy plant machinery if a small team is going to do the digging and lifting bit in under 48 hours.   

       This machinery has to be transported to the site, fueled, protected against thieves, and transported back again when the job is done.   

       Of course you can save a bit of transporting if you visit several sites, one after the other.
Wrongfellow, Dec 14 2013

       A non/pre-industrial community's wastes mostly consist of washwater, uncooked vegetation, food wastage (cooked and meat/bones), fire ash, urine and faeces.   

       They don't start off all lumped together.   

       Each has very different, uncomplicated optimum reusage/disposal characteristics. As long as they aren't treated as one stream they're actually easy to dispose of separately in environmentally and community friendly (or at worst neutral) manners.   

       What are //rural, post-conflict communities// ? refugee camps ?
FlyingToaster, Dec 14 2013

       Do all the fab work before you go out in the bush. Only final assembly and installation work on site.   

       You've got the makings for a substantially more civilized system than you're describing. There's no need for this to be a "drop & plop" system, particularly if there's any water to be had. Areas that are extremely arid will usually dessicate waste matter rapidly enough that getting it downwind is enough. I would think - correct me if I'm wrong on this - that the greater needs would be in areas with a water supply of poor quality.   

       Ideally you'd want this on a hill, so you have some slope, and can be above the water table, preferably away from the supply side. Bring in your shipping container on a flatbed semi; also bring in a bulldozer. With a ripper tooth.   

       If you have a slope, start at the uphill side of the site. You want an excavation just wide enough for the container, but you'll need to also accomodate the truck carrying it. Clear trees, if any; then turn around and take the topsoil from the slot uphill. Once below the topsoil, turn downhill again and excavate to the full depth, making the run-in and run-out shallow enough to be navigated by the truck. Fan out the overburden below the site so that it maintains a downward slope, or at least not uphill. This is going to form part of your leaching field, and you can't get the effluent to flow upward into it.   

       Once the slot is deep enough for the container (I don't expect this to take very long - I watched my uncle [a former SeaBee] excavate for his house, full basement depth, in about 40 minutes with a Caterpillar D-6) then bring the truck with the container and drive it right into the slot. Hook onto the container with the bulldozer and skid it off the truck - a bit of planning should land it right where it should be.   

       Use the dozer's ripper tooth to scratch trenches downhill for leach pipes. The number and size will depend on a number of things - soil type, slope, percolation, water input, temperature, and others - but install whatever number and length of perforated 4 inch PVC pipe is necessary and cover it up. The trenches may extend further than the overburden pile - this will also depend on site characteristics.   

       Trim the overburden pile to fill in the sides and ends around the container; drive the dozer over it to compact it. Then bring down the topsoil from up-slope and final fill over the cut.   

       (If you don't have the luxury of a hillside, reverse the direction of the cut and build a hill of your own. The leach field can be fairly flat, just as long as you scratch up enough of a hill that the container is above the level of the top end of the pipes.)   

       The container itself should have a receiver and a digester, two separate chambers separated by a divider extending from the top down not quite to the bottom. The water in the container will close the compartments from air circulation. (The digester stage will be running an anaerobic process, so you don't want it vented to fresh air.)   

       Put all the stalls on the top of the upper half of the container. Below each stall, install a length of 10 inch plastic pipe, sealed to the top of the container, and extending below the surface of the water below. This will function like the p-trap in your flush-style toilet, keeping the majority of the smell out of the drop pipe.   

       Then you just need to provide a bit of water - it's going to take several hundred gallons to get it started, but it doesn't have to be of any great quality. Just as long as it's not so toxic as to kill the anaerobes in the digester, it's good enough. Once it's running, you only need add enough to slowly move the sludge into the digester. A few dozen gallons a day will probably do the trick, depending on temperature, load, and leaching. (And how steeply the container is situated...)   

       Make sure you put some copper rods in the receiver - that will prevent mosquito larvae from living in it.   

       You usually don't have to add bacteria to start the system - it runs with the same organisms that are present in the human digestive tract, so the biosystem is self-planting. There can be problems if, say, your population all gets sick and are all treated with antibiotics; or if somebody dumps something into the system which kills it. Those are cases where you might have to re-plant, or even have to pump out the container - an eventuality for which you should probably leave an access hole.   

       So - there's my half-baked septic system for you. Can't guarantee it's worth... crap.
lurch, Dec 14 2013

       in general making any toilet/latrine/septic-pit system isn't complicated and easily done. The problem is when the local "authorities" start demanding payment from you. In general most of the world's economic problems, the Western developed world included, only come from the fact that laws quickly essentially ban the economy. The West only got where it is because in the past this wasn't so and and nowadays isn't so much, and in developing countries the government has a lot more power to interrupt people.   

       Though, I'd recommend to vent the vent pipes in the latrines themselves, to avoid making the rest of the village smell. Alright, didn't think that one through. Then I'd recommend buying long pipe to make sure you vent high up enough in the air to prevent the whole town from smelling too much.
EdwinBakery, Dec 15 2013

       Bringing the container in together with tools, machinery and skilled labor to chop it up and bury it as a latrine is sort of like bringing in a LandRover and mechanics, then disassembling it so the locals can use the built in clock for reliable timekeeping. Except the Landrover endeavor would be cheaper. This idea reminds me of my favorite chapter of Huckleberry Finn, where Tom devises a proper plan to liberate Jim. I have linked it for your reading pleasure.
bungston, Dec 15 2013


back: main index

business  computer  culture  fashion  food  halfbakery  home  other  product  public  science  sport  vehicle