Despite our complicated relationship with it, our poo could one day power our cell phones, tablets and laptops.
Eleonore Rartjarasoaniony stands in the middle of her yard, watching two young men in colourful overalls and rubber boots service her new waterless Loowatt toilet, which replaced her pit latrine a few months ago. At the Malagasy woman’s feet, two lean, long-legged chickens, amid a flock of fluffy chicks, peck at anything remotely resembling food.
Inside a wooden shack behind her, Rartjarasoaniony’s elderly mother greets customers through a small window that overlooks the narrow, unpaved street in the capital Antananarivo. That’s Rartjarasoaniony’s shop, in which she sells a bit of everything — kitchen sponges, eggs laid by her hens and freshly brewed coffee, which she hands out to customers in small metal cups, rinsed in a bucket of water from a communal pump. As she describes her new toilet in the soft Malagasy language — and Loowatt’s manager Anselme Andriamahavita translates — you can discern the word tsara, which means “well”, as in wellbeing and healthy.
Rartjarasoaniony switched to her new loo because it’s cleaner and safer than her outhouse. “My family of four uses it, and so do my three tenants who rent the next house over — it’s included in the rent,” she says. “Even my son can use it,” she adds, echoing the worries of all Malagasy mothers, terrified that their young children may one day fall into a pit and drown in faeces.
Like most people, Rartjarasoaniony and her tenants don’t have modern sanitation systems in their homes, which are built with bricks made from red mud. Although cellphones are ubiquitous in Antananarivo, flush toilets are not. Most people use “Malagasy toilets”, meaning outhouses. Out in the country, some villagers don’t even have those — when nature calls, they head to the bushes. But traditional pit latrines aren’t a hygienic solution, and not only because they smell and are hard to keep clean.
Antananarivo has so much groundwater that many residents grow rice in their yards. When torrential rains hit, everything floods. The waste from latrines rises and floats into the yards, houses, shops and streets. The threat is very real. In a neighbour’s latrine across the street, the grey goo almost reaches the pit’s surface, a clear menace come the next storm.
“When we used the pit latrine before and it rained, sometimes the water would come out,” Rartjarasoaniony says. “We were afraid of getting sick because of the filth.”
The dire shortage of toilets is not a problem unique to Madagascar. The World Health Organisation (WHO) estimates that 2.4-billion people don’t have access to basic toilet facilities and nearly one billion can’t even defecate in private, using fields, street gutters or creeks instead. Many countries, primarily in sub-Saharan Africa and South Asia, face similar sanitation problems, says Francis de los Reyes at North Carolina State University in the United States, who designs sanitation solutions for developing countries.
In many places building a flushing toilet system, as we know it, is nearly impossible. Some places don’t have enough water. Some have too much, which complicates water treatment processes because of floods and overflows. Others don’t have the means to build the water-based infrastructure. That’s why Loowatt, a London-based startup, came up with a flushing solution that doesn’t use water In Loowatt’s design, the waste is sealed into a biodegradable bag underneath the toilet with not a drop of water being spilled. Once full, the bag is replaced by a service team, and the waste is brought (yes, hand-delivered) to Loowatt’s pilot waste-processing facility, where it’s converted to fertiliser and biogas.
This very manual setup sounds archaic compared with the convenient Western arrangements. But sanitation experts think that in the era of climate change, when droughts and floods are becoming increasingly common, the West may have something to learn from the little waterless loos being piloted in Madagascan neighbourhoods.
With the world’s population increasing, places that historically relied on water for sanitation may have to reconsider how they flush.
When Loowatt’s Londonbased founder and chief executive, Virginia Gardiner, graduated with a bachelor’s degree in comparative literature she never thought she’d end up designing toilets.
But then she went to work as a reporter for an architecture and design magazine covering industry events. “I was the youngest on the editorial team. Nobody else wanted to go to the kitchen and bath industry shows, so I did,” she recalls. One of the things that struck her was that architectural concepts evolved constantly, except for toilets
She came to see the overall “bath culture” as wasteful and decided toilets were due for an upgrade.
When Gardiner did her master’s degree she focused on a waterless toilet system. In 2010, she founded Loowatt and ran a fundraising campaign based around turning shit into a commodity. In 2011, her idea won the Bill & Melinda Gates Foundation’s Reinvent the Toilet Challenge.
More funding followed and, serendipitously, a Canadian expat living in Madagascar heard about Gardiner’s project and became Loowatt’s first investor. That was the reason Loowatt launched its first single-toilet pilot and a small waste-processing facility in an impoverished Antananarivo neighbourhood.
The project killed two birds with one stone — giving people a toilet and converting their waste into biogas, generating enough electricity to charge cellphones. When that proof of concept worked, Loowatt scaled the project up to 100 toilets serving about 800 customers.
Loowatt toilets don’t look very different from Western johns, with their plastic seats and flushing handles, which come in the form of a pedal or a rope pull. But, instead of releasing a swirl of water into the basin, this move activates the white biodegradable film that envelops and seals the waste, pushing it into the collector underneath the toilet, all odour-free. Loowatt’s service team replaces the biodegradable bag once a week, or more often if it fills up sooner.
Equipped with a small pushcart and collection bins, a two-person team walks through the neighbourhood daily, gathering waste bags and doing repairs. The residents can also request service by text message when the bag fills up or if something breaks.
The Loowatt setup isn’t free — residents pay about £12 as a deposit for a toilet (which remains Loowatt’s property) and about £3 a month for service. For Madagascar, where some families exist on £1 a day, this isn’t cheap. But Rartjarasoaniony says she finds it acceptable.
Maintaining a pit latrine costs more.
“We have to empty it every six months and it is really expensive,” she explains, not to mention the unsightly mess it creates.
The process is done by emptiers — usually men who show up with buckets to chug the goo into containers, dropping splotches of repugnant gunk around the yard for her egg-laying hens to peck at.
Loowatt’s technician Edonal Razanadrakoto tinkers with Rartjarasoaniony’s toilet flushing mechanism. “In the older version of the toilet you had to push a pedal to make the bag seal the waste,” he explains, pointing at the plastic cogs and wheels. That mechanism ultimately relied on an internal rope, which often jammed and tore, so Loowatt switched to a sturdier, hand-pulled device. Now the toilets have to be upgraded. While Razanadrakoto changes the part, his coworker stashes the waste bag from underneath the toilet into a white bin on his pushcart and taps on the phone to update Loowatt’s online monitoring system: bag removed.
As the pair leave, Andriamahavita says another neighbour also wants to talk. “She was about to go to work, but heard we were in the neighbourhood, so she waited,” he says.
Middle-class Malagasies can afford certain perks, such as a TV, a stereo system, a smartphone, even a secondhand car. But a water flush toilet isn’t something an individual’s money can buy — even on a government salary, Andriamahavita explains.
The biggest problem with flush toilets is the infrastructure. “We don’t really have a sewage system like in the occident,” he says.
A flush toilet needs a sophisticated set of underground pipes linking it to a facility that can digest its output — a sewage plant that cleans the water, releasing it back into the rivers and oceans and reprocesses “biosolids” into fertiliser safe to put on to fields.
It takes the entirety of society to make sanitation work — an individual cannot master that challenge alone. Canadian epidemiologist David Waltner-Toews, author of The Origin of Feces, says it’s because humans have a very complicated relationship with their own waste.
A pile of shit begins to endanger humans almost immediately. Attracted to the nutrients — phosphorous, nitrogen and undigested proteins — inside that pile, pathogens swarm in. Some feed on it, others lay eggs. To stay healthy, people must keep their waste as far away from themselves as possible.
When our ancestors were nomadic they had it easy. They relieved themselves where they felt like and walked away from their precarious deposits. Sometimes they’d come back to where they took a dump last season to find fruit and berries growing, and made the connection that poo helps to sprout seeds. When people settled and began farming, they could no longer walk away from their waste, so they began to distance themselves from it, by accumulating it in pits, dumping it into rivers or shovelling it on to fields.
When people moved into cities, space became scarce and waste disposal got ugly. Waltner-Toews says that crowded living conditions prompted people to become more creative in getting the unwanted matter out of sight and out of mind.
The downstream approach was often the method of choice. Ancient Romans built communal bathrooms with rows of thrones akin to ours. The waste would fall into a gutter with continuously flowing water that carried it outside of the city wall by way of simple sewage routes.
The first flush toilet that used mechanical levers was invented by English writer and poet Sir John Harington, who built one in his home and another one in the palace of Queen Elizabeth I. Later, the Industrial Revolution and urban development locked the process of excrement removal into pipes and treatment plants, which treated sewage to levels that made it safe enough to release back into the world.
That worked well for the 19th and 20th centuries, Waltner-Toews says, but it also scaled sanitation to an industrial size. Treatment plants rely on a steady supply of water, which is not always available. The plants don’t recover enough nutrients from the sludge, so leftover phosphorus and nitrogen trickles into the water, helping to cause a number of problems including algal blooms.
The downstream solution just doesn’t work on a crowded planet, Waltner-Toews says. “In the 21st century, everybody is downstream from somebody else.”
For all these reasons, the Reinvent the Toilet Challenge called for more than just a clean removal of waste. Toilets of the future should recover valuable resources from the waste — energy, nutrients and clean water. They must operate without water, electricity and sewage plants as well as fit into poor urban settings. Yet they should be attractive enough for the high-income world to use
This last requirement makes sense: in a world where every appliance is becoming smarter, sanitation systems have to catch up. It was much easier for Mother Nature to clean up after the 300-million or so folks who lived on our planet 2000 years ago compared with the seven billion who live here today, or the nine billion who will live here by 2050. And the waste we produce will keep piling up unless a solution is found.
Big business, bigger health hazards
Sanitation is such a hot issue that there is now an international conference in faecal sludge management aimed at keeping the world clean of the crap humans produce. And for good reason — without an organised waste disposal system, society is doomed to languish in poverty and disease.
Open defecation, for example, is dangerous for several reasons. One is that woods and fields can be unsafe especially for women and children because of everything from crime to poisonous snakes.
But it also creates huge health hazards. When faecal matter makes it into drinking water, it spreads cholera, dysentery and polio, continuing the cycle of disease and poverty. The toll on health is enormous. About 842000 people in low and middle-income countries die every year from poor water, sanitation and hygiene, according to 2016 WHO numbers
That takes a toll on countries’ health systems and economies. De los Reyes says that, depending on the country, if you add up the cost of healthcare, lost workdays, absences from school and other missed opportunities, the economic toll can vary from 1%-4% of gross domestic product, and in some cases even higher.
There’s also an environmental price to pay for poor sanitation. A waste overload creates rivers devoid of fish and bubbling with methane, and groundwater contaminated with faecal bacteria, among other problems.
Building latrines doesn’t make waste disappear. Where space is not a constraint, people can simply close a full latrine and dig another hole. But when space is tight, such as in Antananarivo, where families are forced to share latrines, someone has to take out the trash.
In Madagascar, it’s usually men equipped with buckets. In Ethiopia, it’s also men, who pour kerosene on to the waste to mask the smell and drink heavily before descending into the pit to dull their senses. In India it’s often women of the lowest caste, the Dalits, who empty the pits by scooping the waste into woven baskets, which they carry away on their heads, teaching their young daughters to do it too.
The number of pathogens that can dwell in that sludge is mind-boggling: those responsible for hepatitis A and B, cholera, campylobacter, dysentery and salmonella, plus intestinal worms that can be inhaled.
Even when there is a public sanitation system, faecal sludge is often not treated to the appropriate standards before it is put back into the environment. In Dhaka, Bangladesh, only 2% is treated acceptably, the rest just gets dumped out there, De los Reyes says.
Nestled on a cliff overlooking mud houses and mango trees, Loowatt’s waste-processing site occupies about 400m2 and consists of a series of tanks linked by numerous pipes. At the system’s heart is the biodigester — a tank of nearly 30m3 that converts faeces produced by 800 or so people into about six tonnes of liquid fertiliser a month, which is sold to farmers. Three tonnes are sold as liquid fertiliser and the rest is turned into a tonne of compost and 500kg of vermicompost — nutrient-rich natural fertiliser chewed through by earthworms.
Diversifying fertiliser products helps to sell them, says Armel Segretain, a Loowatt engineer who moved from London to Antananarivo to oversee the implementation of the new sanitation model.
Compared with industrial treatment plants, this pilot operation is tiny, but its waterless setup significantly reduces the amount of sludge it must process. It also works on different chemical and biological principles than most conventional plants.
In established industrial sanitation systems, water constitutes about 95% of sewage mass. This waste must be filtered and purified with chemicals before being released back into the environment. Then the remaining biosolids are treated, Segretain explains.
Loowatt toilets produce much less fluid. Another big difference is Loowatt’s operation can also process leftover food — and with systems that produce less greenhouse gases than conventional treatment plants.
Just as with collecting waste, loading it into the biodigester is a manual task. Inside the contaminated chamber, Andriambololona loads white bags into a faeces extraction machine. The rambling apparatus lets out surprisingly little odour.
Outside, two workers load food leftovers brought from restaurants into a machine that resembles an oversized meat grinder. It works like one too, slowly mushing rice and veggie bits into a soppy slush that drips into a bucket in soggy glops.
The poo and slush are then loaded into a pre-digester tank and heated to 70°C to kill pathogens. To comply with Gates Foundation requirements, the pre-digester relies on self-generated energy — the hot water used in the heating is itself heated by the biogas the system produces. The pasteurised matter is then pumped into the biodigester. It’s covered with a huge inflatable bag that collects the methane released. As the gas builds up, the bag floats up into the air like an enormous balloon. When the bag is full, it’s larger than the digester itself, Andriambololona says.
To make the manual waste collection work, Andriamahavita explains that the digester site had to be “hyperlocal” — very close to the neighbourhood where the toilets are installed, which was hard, because space is a real issue in Antananarivo.
Gardiner says the biggest difficulty was orchestrating the manual waste-collection process, something that people anywhere aren’t generally used to. “What makes it hard to scale our technology rapidly is that it’s hard to support,” she says. “We have to have an operating service.”
To be an economically sustainable business, Loowatt needs to service about 5 000 customers. Gardiner thinks Loowatt can reach double that number by 2019, something she sums up as “ambitious but possible”.
Segretain adds: “Our objective basically is to be the main sanitation provider for the whole city of Antananarivo, probably in five to 10 years.”
Buy local, eat local and poo local?
The company is also working on introducing the concept to countries in Africa, Asia and Europe. In the United Kingdom, Loowatt toilets are being used at festivals and outdoor events, generating good revenue.
“Here in Madagascar, the average price we can charge people to use our toilets is £3 a month,” Segretain says. “In the UK, with our festival toilets, if people pay as they go, they pay £3 per use. It’s a completely different scale.”
For now, Loowatt’s UK-generated waste ends up at existing industrial treatment plants, not small hyperlocal biodigesters, as in Antananarivo. But, for Waltner-Toews, the idea of waste processing becoming more local is not far-fetched.
Just as some have realised that food is best produced and consumed locally, so countries might scale down waste-processing facilities to mediate what he calls the “redistribution of nutrients on the planet”.
When corn is transported from South America, tomatoes from Israel and strawberries from California to other locales, the nutritional balance of those ecosystems is altered.
“You’re taking all this biodiversity out of one ecosystem and creating these piles of shit somewhere else,” Waltner-Toews says. And because faeces isn’t shipped back to where the food came from, soils in some places are depleted and over-enriched in others. So if we’re trying to make growing and eating food a local issue, then why not our faeces processing too?
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