Good latrines may be the difference between you and your neighbors surviving a multi-week or longer “Stuff Hits The Fan (SHTF)” situation or quickly falling ill and possibly dying from dysentery, cholera and other fecal born diseases that hit third-world countries without good sanitation even to this day.
Even if your family has a good hygene setup, if your neighbors don’t their contamination can make you sick, so having a “poop hits the fan” plan is a critical and often overlooked prep.
Good latrines save lives. Lots of lives.
Medieval Europeans didn’t lose more than 30% of their children before the age of five because they didn’t have antibiotics. They certainly didn’t lose that many because they lacked fancy imaging techniques. They lost most of them, as underdeveloped areas still do today, because they had poor hygiene.
So being good preppers all, if we found ourselves in a situation without public sanitation, surely we’d have the sense to dig ourselves a latrine and put up an outhouse over it, at least.
And then we’d get a big rain; and, like as not, our pit would fill with water, feces would go floating off downstream into the water supply, and then the walls of the pit would collapse and we’d have an outhouse sitting over a mucky mess. Or it could be the flies, breeding down there in the pit to rise in maddening swarms, then buzz off to land on our food, or our kids’ foreheads. Or maybe it would all seem just fine, as the wastes percolated quietly through cracks in the limestone to wend their way into the well water.
Latrine science
True, it’s not rocket science … but do most of us know, at this moment, how to construct even a simple latrine safely and durably?
I didn’t. The World Health Organization did though, and it published a very handy guide (1). The main points are summarized below, to free you from the need of spending your quality time clicking around following the search engine term ‘latrine’ while leaving you with a clue if the sewer systems go away.
Here’s an episode of our podcast that we did for a previous article (that this one supersedes) on latrines. Give it a listen.
Placement
The foremost thing is not to let the waste from the pit get into the water supply. That means the pit must be downhill from the water supply (or at least on the other side of a ridge so the water supply isn’t in the same drainage) but not on a flood plain and at least 2 m (6 feet; for purposes of this piece I’m just going to roughly round meters to feet) above the water table. If your water table is close to the surface, that may mean you have to build the latrine into a human-built mound. That’s more work, but is effective. Mound or not, it needs to be at least 30 m (call it 100 ft) from the water source.
The spot should drain well enough that the liquid wastes will filter away from the pit, but it shouldn’t be right over limestone bedrock, which has cracks that can serve as highways to get waste directly into the water table.
Nearness to the residence is a balance of convenience with possible odor. The WHO suggests at least 6 m (20 ft) distance. Keep the direction of the prevailing wind in mind when choosing a site, because downwind of the privy is no one’s favorite.
The Pit
The basic idea of a latrine is you dig the pit, put the outhouse over it, and use it for five years or so before it fills. Then you cover it over with dirt, dig a new pit, and move the outhouse. Minimum recommended pit size is 1.5 m deep x 1 m diameter (5 ft deep x 3 ft around).
To better size it to your group’s needs, you can use the formula .06 cubic meter/person/yr, then dig it a half meter deeper to account for the final cover of dirt. That’s about 2.3 m deep for a pit 1 m long x 1 m wide in total for 6 persons to use for 5 years (8 ft deep, 3 ft long and wide). The top half meter (1.5 ft) should be lined to prevent crumbling; more in soils that are especially sandy or clayey. The lining can be lots of things: stones, bricks, concrete blocks, slats of rot-resistant wood or bamboo.
The base here is made of mortared concrete blocks. You can line the lower pit with blocks too for support in loose soils, but below the top bit you don’t mortar, so wastes can filter out. Thanks to SuSanA Secretariat* for the images.
The Base
A base of solid material sits like a collar on top of the pit. It can be of concrete, sawn logs, bricks, etc. It’s job is to support to help prevent crumbling of the top of the pit while it holds the weight of the floor above.
The base needs to rise at least half a meter (1.5 ft) above ground level and have a mound that slopes up to it. This is to prevent rainwater from flooding out your pit, so this is an important feature (and one I at least had not thought of).
The Floor
The floor rests on the base and may overlap i). It needs a smooth surface that slopes toward the hole to ease cleaning. Concrete is good, but there are lots of choices so long as you think smooth and cleanable.
The hole through the floor into the pit is best made in a keyhole shape but can be round. Keep the maximum size of the hole to 250 mm (10 inches or so) so you can’t lose any small children down there! Here in the U.S. we usually build seats over the hole; squatter toilets are popular elsewhere in the world and both work fine.
This is a keyhole in the floor, with a seat over it (clearly you’d want a smooth, keyhole-shaped column connecting the keyhole in the floor to the keyhole in the seat). Thanks to SuSanA Secretariat* for the image.
Here they’re forming a concrete floor; the bucket is a placeholder for where the seat will go. The tube behind is for a ventilation pipe running from the pit out the top of the roof of the shelter; a nice touch which reduces odor (screen the top of the ventilation pipe). Thanks to SuSanA Secretariat for the image. *
The Lid
Be it a sitter or a squatter, the toilet hole needs a good, tight fitting lid. This is an important hygiene point. Flies love human waste as well as human food and will sit on both given the chance. They’re also fond of breeding in waste pits. A tight fitting lid both physically blocks fly entry and makes it dark down there. Apparently flies are afraid of the dark. Have a good lid and keep it down when the hole’s not in use.
The Shelter
Besides privacy, the shelter should protect the mound that leads up to the base, so make it big enough. Leave openings at the roof line to get air flow up and out. At least here in Missouri, it’s a great idea to use good screening on the vents to discourage wasps. The shelter’s door should also be tight fitting; closing it when the room’s not in use is another fly discourager.
A good shelter will reduce the number of insects you must share with; highly recommended. Thanks to SuSanA Secretariat* for the images.
Cover material
Latrines are made more pleasant by adding cover material of dried organics such as grass clippings or straw to reduce odors. This is a fine idea on many accounts, but will fill the pit faster and shorten the life of the latrine. Your choice.
There are certainly a lot of prepping topics that are more fun to think about, but honestly many of them are less important and less likely to be needed. While most of us wouldn’t relish needing to use a latrine, using a bad one is infinitely worse.
By the way, there is at least one useful option to the latrine approach. It’s called Humanure, and it’s a system for safely composting human waste. It’s described here:
1) WHO Simple Pit Latrines Fact Sheet 3.4. Accessed 1-17-18. http://www.who.int/water_sanitation_health/hygiene/emergencies/fs3_4.pdf
*By SuSanA Secretariat [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons
Thank you Spice for an article on field sanitation. Unless you have an experienced dowser in your group determining where the underground veins of water is pretty much an educated guess. An error in placement of your outhouse is both a waste of a LOT of work digging it AND contamination of your Water Supply for a long time. Thus my concern about outhouses. Also keeping the urine apart from the solids makes the air loving good bacteria work so much better. A urinal apart from the solids is best practice from an Army POV. Very few diseases from urine.
Personally from my experiences I strongly prefer the Human Manure system. Urine is too valuable post SHTF not to use it as a pest deterrent in your gardens-fruit trees as well as diluted 1 part urine to 10 parts water as a irrigating fertilizer. Some rate it as 5-5-5 fertilizer. All manure is needed for fertilizer and the Human Manure manual tells you how to use it safely.
Even an outhouse is better than the Pre-Thomas Crapper Toilet system of “Beware Slop” as they dumped the chamber pots out the window. No wonder so many died from diseases…. From what I’ve seen from recent American disasters plenty of people will just poop and dump it once the flush toilets fail almost like early Victorian Ages.
Got Pool Shock (with instructions on use) for shelf stable bleach (which lasts but 6 months or so?) for well decontamination and general sanitation?
Good article but no discussion would be complete without giving attention to hand washing.. Failing to do this will negate the efforts of the most opulent outhouse! Rigging a container of clean water so that it can be tipped to pour water over the hands and a bar of soap are essential adjuncts.
Good point; I’d’ve made it myself if I’d’ve thought of it. May I suggest people look for an article on a setup called the Tippy-Tap on this site? It’s an excellent hand-washing solution for this kind of situation.