[Thanks to T Millions who wrote to us asking for more commentary on vermicomposting, particularly as applied to humanure and local "health security"]
It might be the ultimate kapu. After all, everything from child molestation to necrophilia to bestiality to gang rape is now routine fare in online porn, and anyone who’s genuinely upset by that may commonly be mocked as an old-fashioned “prude”; but most Americans are still deeply shocked/upset by the idea of a composting toilet. In many municipalities you can’t get a permit for one — i.e. it’s illegal to operate one. In other countries however, such as forward-looking Sweden, the popular composting toilet called “Biolet” is being adopted by entire small towns/villages.
The association between flush toilets and Modernity, Sanitation, and Progress (not to mention class and race superiority) is very strong in Gringolandia. The “outhouse” and other non-flushing toilet concepts are a mark of the despised rural life for which urbanites often have a cringeing biophobic contempt (ironically, but perhaps inevitably, coexisting with a saccharine faux-nostalgia expressed in kitsch art); and they are a mark of third world poverty and “primitive” conditions. Flush toilets are right up there with SUVs on the list of “things those goddamn Greenies want to pry from our cold, dead hands” in the fulminations of online anti-environmentalist or cornucopian cranks. It is an outrage — nearly a heresy — to suggest that the flush toilet might not be such a cool idea after all.
Even those whose biophobia can be somewhat separated from their class, race, and national ego-extensions often remain convinced that human waste [I'll come back to that term later, to challenge it and the assumptions behind it] management is a highly technical problem which can only be solved by expert technomanagerial cadres and heavy technology — i.e. the way we’ve been doing it since the industrial revolution. Any less “scientific” and technocratic approach will, they fear, lead inevitably to outbreaks of cholera and parasitical infestation (conditions observed by Europeans among the poor of their own and other countries and “solved” by the introduction of centralised industrial sanitation). Basically, it’s caca and it’s dirty and we mustn’t touch it, that is a job for the Authorities; don’t try this at home, kids! Highly neurotoxic pesticides are available over the counter, for us to spray freely around our yards (and contaminate other people’s), cleaning supplies that mix into lethal chemical cocktails are readily purchasable without ID or age check, but we can’t be trusted to deal with our own — er — shit.
But what happens when the Authorities, and their centralised services, fail to meet the public’s needs? Many years ago there was a record winter storm in Santa Cruz County where I was living at the time; the power was out long enough that gravity-fed water supplies were exhausted, flooding had muddied and contaminated upstream reservoirs, and there was no rainwater catchment system in place. There was no power to pump cleaned water up to the city reservoir. A fairly big chunk of urban and suburban area was without water pressure for several days, and the most urgent aspect of this mini-crisis was “lack of sanitation” — i.e. flush toilets stopped working and there was no backup system. In a few more days, the city’s unflushed toilets would have presented an offensive smell and a potential sanitation crisis. The official response to this in larger-scale and longer-lasting disasters is to truck in “Portapotties” (basically, chemical outhouses with holding tanks, using various biocides to sterilise and perfumes to mask the smell of mixed sewage); but this again is dependent on clear roads, fuel for trucks, a supply of portapotties to bring in, the chemicals for the tanks, pumpout trucks to empty the tanks, and so on.
Centralised flush toilet systems are fragile, and this is perhaps the first and most obvious potential downside of our utter dependency on them for basic sanitation. In an epoch where we may confidently anticipate more extreme weather events — and where we are already experiencing the erosion of public services and the escalation of deferred maintenance costs in civic infrastructure — disruptions in centralised, fossil-fuel-powered civic water/sewage systems seem pretty much written into our immediate future. US bombing of centralised sewage treatment systems in Iraq greatly increased urban misery and inflicted disease on neighbourhoods with this kind of absolute dependency on a complex infrastructure; earlier, the blockade that visited collective punishment on Iraqis for over a decade prior to the most recent US invasion prohibited the import of chlorine and other chemicals on which the “modern” municipal water treatment regime is based, and this inflicted diseases (particularly in vulnerable children) and death on the civilian population. If all of Iraq had been equipped with composting toilets, the US might have found it harder to kill so many children with such deniability.
But vulnerability to terrorist attack (whether by the US, by other national bad actors, or by domestic insurgents) and to extreme weather is only one of the downsides of the flush toilet concept. At its heart, from 3000 BC on, the idea has been the perennial human wishful thinking of “send it elsewhere” or “sweep it under the rug”. To use fresh water to transport (flush away) human wastes to “somewhere else” implies (a) that you have an abundant supply of fresh water, (b) there is a “somewhere else” to dump them, and (c) that you don’t care about the impact on the “somewhere else,” or your population is small enough that the impact is slight and local biotic systems can absorb it. The subject seems to demand a certain crude bluntness of speech, so I’ll venture to suggest that this attitude may be summed up as “just shit in the river and the hell with anyone downstream” — once the shit has been carried away by the river, it’s not our problem.
In our increasingly crowded world — especially with massive urbanisation creating correspondingly massive concentrations of human wastes — we don’t have a “somewhere else” within easy pumping distance — there is always someone downstream. The enormous volume of human wastes produced by urban areas is such that it overwhelms the sink capacity even of large lakes and near-shore ocean waters; and the impacts on these waters are not minor and have other knock-on effects. Our traditional solution to this, predictably in our biophobic era, is to try to “kill the germs” in the waste stream by various means: this has often meant toxic chemicals, though more recently aeration and settling lagoons and wetlands are becoming popular, less-toxic alternatives. You can see from the Wiki page on sewage treatment how elaborate this process can get and how much infrastructure, how many electric pumps and motors and miles of pipe, are involved even in a semi-”natural” waste treatment process.
Dumping raw sewage into coastal or inland waters is disastrous, mostly due to the hypernutrient nature of the biotically rich waste stream which encourages massive algal blooms and hence anoxic post-bloom “dead zones”. [Here we should note that though raw sewage dumping contributes to these dead zones, the runoff of excess artificial fertilisers and pesticides from industrially-farmed land is currently believed to be the primary cause.] So what municipal waste treatment plants try to do is purify the waste stream — to make it safer to dump into coastal and inland waters. (We are still basically shitting in the river, just trying to do it more cleverly; and it’s a lot more work to “separate out the solids” after the waste stream has been diluted and mixed into runny sludge.). This requires — even without crude chemical biocides — significant energy investment; and in the process of transporting the waste stream to the energy-intensive treatment plant, we use up an enormous amount of a critical resource: fresh, potable water. But rather than go into a lengthy discourse on the dysfunctions and false economies of municipal waste management systems, I’ll recommend the entertaining and interesting Humanure Handbook by Joseph Jenkins — for Anglophones, the Bible of humanure composting and the contrarian voice of record when it comes to the culture of the flush toilet. Jenkins covers the design and function of centralised municipal waste treatment systems, city plumbing, the pressurised water mains needed to supply urban/suburban toilets, etc. — and the huge costs in water wastage, energy consumption, and maintenance overhead needed to keep it all running. He offers solid scientific analysis of the pathogenic potential of human wastes, and a solid explanation of the role of thermophilic composting in rendering humanure wholly benign. The book is available for sale in paper form, and for free online in PDF form.
The fundamental (so to speak) error in the way we have thought about human wastes for a couple of centuries is to think of them as waste at all, i.e. as dross or discard, a substance with no value — or a substance with extreme negative value (dirty, pathogenic, icky). The collection of humanure and urine into centralised processing centres to be biocidally or biotically neutralised and then dumped into bodies of water means that we have interrupted the nutrient cycle, turned what should be a circular energy diagram into a linear one. Instead of returning the excess or byproduct of our metabolic function to the soil that produced the food we ate — as every other living creature on Earth does in a healthy biotic system — we have intervened; we “flush away” our own metabolic byproducts and (in modern times) dump them far, far from the fields which fed us. We thus impoverish the soil (by removing nutrients, minerals, elements which are not replaced), and increase the cost of agriculture by having to replace artificially the missing nutrients, etc. If a herd of antelope grazing on savannah were to club together to have their manure removed by train to the coast and dumped on a beach, it would be no more absurd. As with electric cars, we’re firmly attached to the notion that “emissions elsewhere” somehow solves the problem.
The good news is that much of this elaborate, overcapitalised, centralised, vulnerable infrastructure is not necessary; that the pathogenic potential in humanure, while genuine, doesn’t merit the near-superstitious dread that the biophobic culture has instilled in us; and that it’s quite possible to return human “wastes” — i.e. to stop wasting them — to local soil, without high risk of epidemics, chronic parasitic infestation, etc. The process, not surprisingly, involves composting. And the nutrient cycle can be closed — for those with a bit of garden to call their own — right in your own back yard.
Jenkins is very keen on thermophilic composting, and his Handbook dwells primarily on the construction of thermophilic compost piles for the breakdown of nitrogen-rich humanure mixed with high-carbon dry plant materials (like sawdust, finely crushed dry leaves and grass, etc). This is very do-able and many have succeeded, building very simple “sawdust loo” toilets (you really don’t need an elaborate industrially-fabricated loo like the Biolet, though they do offer convenience and a reassuringly toilet-like look and feel). However if your household is small, or you haven’t the affinity for thermophilic composting that some folks do, another very do-able option is vermicomposting of humanure.
Here I can speak from experience, because after reading Jenkins’ book I corresponded with him and others on his forum and for two years did a living experiment: I used exclusively a sawdust loo in my surburban home. (I guess I can safely confess to this heinous crime now, as I no longer live there and the compost piles are fully mature and wholly inoffensive; I terminated the experiment about 1 year before moving so as to be sure the new owner would not inherit any too-fresh composting humanure.)
Here’s how it worked for me — in a temperate central California climate, in a neighbourhood with very high density, very small back yards.
I used a standard 5 gal white plastic bucket with one of the (several are available) stock plastic “convert a bucket” seats for comfort (those bucket edges really are not meant for sitting!). I used various high-carbon “bedding” material for the bucket. Sawdust where I lived was ironically rather expensive; I used at various times peat moss (from this I desisted quickly after learning how unsustainably and destructively it is “mined” from peat bogs); recycled newsprint “small animal bedding” from a feed/seed store; and (most successfully!) compressed coir bricks (available from garden supply houses and by mail order). The coir bricks are, alas, not local (they come from the coconut industry in the S Hemi), but they are an ideal high-carbon, hydrophilic (they like to soak up water), odour-absorbing medium, and worms seem to like the texture and granularity of bricked coir.
I would put some water in the bottom of a clean bucket and drop a coir brick into it; over an hour or three it would swell up to several times its compressed size and I’d have a “sawdust bank” for use with the toilet, filled with slightly damp, soft, grainy coir (a bit like potting mix in texture). A different bucket would be the working toilet. I’d fill the bottom of the working toilet 2 inches or so deep with nice soft coir. It was now ready for use.
One of the biggest concerns people have about composting loos is the smell. Omigawd, they say (or think — I know I did), that must stink! But the folk memory of stinky outhouses, or stinky bathrooms with inadequate flush toilets, is based on a fundamental “user error”. Urine mixed with excrement stinks badly. Urine allowed to age/ferment stinks badly. But excrement separated from urine and covered with high-carbon “sawdust” or equivalent material, protected from air and bugs, doesn’t smell much at all, and urine separated from excrement and not allowed to ferment doesn’t smell much either. So, how to do the separation?
Well, the fancy purpose-made composting loos have molded features for separating the wee from the poo, but if you’re strictly DIY the options are a bit more crude and limited. I simply peed in a different container. This isn’t always possible (I don’t think I need to spell it out for anyone) but as long as you manage mostly not to pee in the sawdust loo, it should be OK. Urine can be disposed of several ways. Those with big gardens and good privacy from neighbours can simply pee out in the back yard — so long as you don’t pee in the same place every time, you won’t over-nitrogenate any one patch of soil, and your plants will thank you. Those with little privacy and/or small gardens will want to pee indoors into a container which can then be emptied outdoors; I found that a gallon jug and a funnel worked pretty well (this is easier for guys, but women can manage with — for example — the Lady J female urination aid). Here’s an important tip I learned somewhere online: if you’re storing the urine in a jug (capped, of course) for several days, add some sugar to the jug. I am not sure how this works, but it seems to discourage the anaerobic bacteria that cause the sulphurous stench of stale urine, and promote some other kind of bacteria that don’t smell nearly so bad.
I found that as a lone pee-er (working full time, I used “normal” toilets at work and peed at home only on my own time) I filled a gallon jug a week. On Saturday morning early, I would nonchalantly take my gallon jug and pour it in long lines along the flower beds around my yard, giving each plant a modest dose, never pouring it all out in one place (except occasionally down a gopher hole to discourage the little marauders!). There was a brief “urine smell” for a second or so after pouring, but as it sank into the ground the smell vanished instantly. And I have to say, my roses and other yard plantings seemed to do exceptionally well during the experiment!
So that leaves the poo bucket to manage. The routine with the poo bucket was simple; you sit down and relieve your bowels as you would on any flush toilet; when done, wipe and drop the TP in, then instead of flushing, scoop (with a scoop or bare hands) enough “bedding material” (sawdust, potting mix, recycled newsprint pet bedding, coir) to fully cover this most recent deposit (I rather liked thinking of it as a deposit in the nutrient bank for my garden). Fully covering it is important. This is what keeps the flies and bugs away, and keeps the smell down. Properly covered, no whiff of excrement in the bucket should be detectible without the nose being positioned within a foot or so of the rim. If you cover it conscientiously and consistently (just like a cat covering up its own poo), the raw humanure shouldn’t touch the bucket sides or bottom and the bucket stays pretty clean.
There’s a tendency over the course of a few deposits for the accumulating material to form an unstable mound — this presents a risk of fresh deposits slithering down the mound and sticking to the bucket sides, which I found unaesthetic (and annoying to clean up). One way to overcome this is to dump in extra bedding material around the sides to make it all level again. Another is to press down on the mound (yeah, I know, Eeee-yew! — but it’s all covered with nice clean coir or sawdust, or should be) to flatten it a bit, and also add a bit more bedding around the edges to preserve a flat surface.
At the end of the week you have a somewhat heavy bucket full of damp sawdust or coir and humanure. Now what???
Well, out in the back yard I built a contained compost heap or bin. This I made with hardware cloth sufficient to form a cylinder about 3 feet across, which was reinforced with wooden stakes hammered into the ground in a shady spot under a tree and in a fairly private location (as much as anywhere was private in my tiny back yard overlooked by two-storey neighbouring houses). It was right next to a fence line. The bottom of the cylinder I filled in with cut-up yard waste: leaves, twigs, chopped-up small branches, grass clippings, old vegetable plants, whatever — to a height of about 1 foot. This was to ensure drainage and oxygenation at the bottom of the pile. I also built up a “wall” or insulating layer around the edge of the bin on the inside, of more yard waste — long switches from my fruit tree curved and woven together like a sloppy basket, and vines and long, flexible weeds bent to match the curve. This layer was to prevent the migration of any raw humanure to the visible (and smellable) edge of the bin.
I then dumped in my first bucketload, and covered it up with more high-carbon dry materials. I tried various kinds — “found” oak leaves swept up from neighbours’ yards and crushed by tromping on them inside plastic bags, for example — but my favourite turned out to be cocoa hulls from the garden store. Again, not local, but they were a wonderful worm bedding and — this really tickled me — they smell like chocolate! I would then rinse out the bucket and set it in the sun to dry and be sterilised with UV. (The rinse water went onto the top of the pile to damp down the latest layer of bedding.) A second (third if you count the bucket for the coir) bucket would then be brought in to be the new “working loo” for the next week. Each loo bucket spent one week out in the sun, and one week in service.
At first I planned to emulate Jenkins and do thermophilic composting. But I just couldn’t get the thermo reaction going. Maybe 3 foot was too small a diameter, maybe I wasn’t getting the carbon/nitrogen balance right; but I just never got heat. So I did some more reading on composting and decided to try worms. I ordered a pound of red wrigglers (tiger worms or Eisenia fetida) and a pound of nightcrawlers from a vermiculturist, and when they arrived, eagerly dumped them into the bin and covered the whole shebang with a layer of damp bedding.
Days went by. I resisted the temptation to dig into the bin to see how my wrigglers were doing. I dumped the loo each Saturday and hoped that the worms would do their thing. Due to the nature of the bin, I wasn’t keen on digging into it to check But I dumped the buckets on one side of the bin, leaving the other side less “fresh”, and after a few weeks I dug into the lower, staler side just to see what was going on in there. I was very happy to see hordes of red wrigglers; the nightcrawlers, however, all absconded (over the next month I found one or two — at night — elsewhere in the yard, and later read that they have a reputation for escaping from worm bins that are not fully enclosed).
The weekly routine went on. After about a year, the first bin was getting kind of full and I built a second one. My plan was to allow the first bin to sit idle for a year (so as to be quite sure of the vermicomposting process and natural, low-temperature composting for reduction of any pathogens), while using the second one. This is a well-known “worm loo” technique — to have two bins, one ageing and one in current use.
So, at the end of year 2, I dug into the original bin. I was delighted by the result. What I found in there was nothing but fluffy, rich topsoil that smelled like the duff from a forest floor. Magic! During the entire experiment, the only moment when there was any offensive odour was the instant of dumping the bucket into the bin; and this smell vanished as soon as fresh cover material was sprinkled on top. My neighbour right across the fence — his back door only about 12 feet from my compost bins — never noticed a thing (I know because I asked him, solicitously, if he was being bothered at all by my compost pile, and he said he hadn’t ever smelled anything and didn’t know I had one).
The beautiful topsoil went onto my garden beds. And I could have kept this up indefinitely; but I was planning to move within a year and felt I should not bequeath to some unknown new owner a half-composted 3-foot-diameter bin of humanure so I suspended the experiment and allowed bin 2 to age away for a year into sweet, inoffensive topsoil; I used it meanwhile for a kitchen compost bin, since the worms are equally happy with any decaying matter.
If the municipal sewage treatment facility had broken down during my 2 year sawdust-loo experience, it would not have affected me. I did not flush my toilet for almost 2 years, except after cleaning (scale and mildew build up even when you don’t use the thing); a guest occasionally flushed it, but seldom. One interesting side effect of my sawdust-loo adventure was the nagging sense, whenever I used a “normal” flush toilet (at work, at a restaurant, at a friend’s house etc) of waste — that I was wasting fresh water, and wasting fertiliser; I felt a kind of annoyance that this valuable material which so intimately belonged to me was being flushed away where I could get no use out of it and where it might actually do harm (to the local ocean biome, etc). The weekly chore of loo-emptying was not particularly arduous, no more so than the rest of the gardening chores of the weekend.
I installed a composting toilet on my boat — a pricey commercial unit because it is the only one that is ‘Coast Guard Approved’ and hence protects one from harassment by the US Coasties. However it is not worm-based and requires electricity (a fan for dehydrating the humanure/carbon mix) and works best at warmer temperatures than one generally experiences on a boat in BC in the winter. I still have plans to modify it — give it its own individual solar panel to run the fan, and work out some kind of worm processing component — but I have no doubts, after my 2 year experiment in suburbia, that a composting loo is quite sanitary, inoffensive (particularly compared to any holding tank I’ve ever met on a boat!), and simple to manage.
One last note, which I think bears some careful thought, is that the excrement of a healthy person (not parasitised or diseased) does not present a high disease risk — if it did, parents would be dropping dead from handling their babies’ diapers and caca-smeared bums. The prevalence of infectious diseases and parasites associated with “poor sanitation” in scenarios of extreme poverty is not a simple “human shit is making them sick” story. Inadequate clean water for washing hands and bodies is part of the story; contamination of drinking water with excrement is part of the story; and malnutrition is a very big part of the story, often overlooked. Malnourished people are far less able to resist parasitisation and disease; healthy people might shrug off exposure to bacteria that will take down a person with a weakened metabolism (for example, small children can be killed or made seriously ill by “food poisoning” that would only give a healthy adult a bad tummyache). The question of public health in the Third World is far more complex than “they need modern flush toilets” — but that’s a topic for a different day.
Another related topic beyond the scope of this basic how-to primer is the role of pharmaceutical agents in rendering humanure genuinely unsafe to release into the biotic world; not only overuse of antibiotics, but massive doses of hormones, SSRIs, and a panoply of other high-tech meds are present in the urine and excrement of those who ingest them; and these chemicals migrate along with human “wastes” into our water systems. Fungi may be more effective than worms for the breakdown and neutralisation of these dangerous substances — at some point we (FS) will have to do a quick intro to the work of Stamets on “mycoremediation” of hazardous wastes and damaged ecosystems. Vermicomposting may not be adequate to render safe some of the artificial toxins in humanure such as pharmaceuticals and industrial chemicals.
A more general topic, also beyond our scope here, is the nature of risk and risk assessment, i.e. what it means when something like a sawdust loo is perceived as insanely risky and dangerous to the body politic, but a nuclear plant is seen as safe and reasonable technology; when riding a bicycle is seen as dangerous and reckless, but driving an SUV is seen as safe and reasonable; when people who routinely eat food that has been sprayed with neurotoxins are convinced that organic produce is “dirty” and dangerous to eat; and so on. More is happening here than an objective assessment of risk: cultural values are being heavily encoded as risk perceptions.
Related keywords to Google for: Black Soldier Fly (Hermetia) Larvae as composting agents for manure management; worm toilet; vermicomposting; composting toilet; redworms; vermiculture; Biolet; Sunmar; waterless toilet; humanure; biogas digester.