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slum in dakar, senegal
‘It is possible to structure pit-emptying services for poor communities with market and business innovation,’ says charity worker Doulaye Kone. Photograph: Misha Hussain
‘It is possible to structure pit-emptying services for poor communities with market and business innovation,’ says charity worker Doulaye Kone. Photograph: Misha Hussain

'We want to turn poo into gold': how SMS is transforming Senegal's sanitation

This article is more than 8 years old

In Dakar, an Uber-like SMS service has reduced the cost of emptying pit latrines by nearly half – and now customers can sell their waste to be turned into energy

On a stormy day in Dakar, Tina Gomis, a local woman in Sicap Mbao, laughs at the idea of selling her own excrement to the government. But this may soon become a reality in a city with a reputation for terrible waste management.

A pioneering SMS service and waste treatment system is dramatically bringing down sanitation costs in Senegal’s capital and, if successful, may even lead to customers making a small profit from their ordure instead of paying someone to take it away.

“We want to turn poo into gold; it’s not waste, but a raw material,” says Mbaye Mbeguere, from the Senegal National Sanitation Utility (ONAS).

It’s a far cry from the current situation where, according to ONAS, 80% of people in Dakar use pit latrines. But the high costs fixed by the pit emptiers’ association has driven many to seek cheaper alternatives, often at the expense of the environment and their own health.

“When the pits get full, people dig makeshift holes around their house to transfer the waste, but when the rains come all the faeces comes out,” says Gomis who lives in an area prone to seasonal flooding due to the high water table. “The kids are always getting sick.”

In Vietnam, recent studies (pdf) have shown that children are up to 3.7cm taller in environments with better waste management compared with villages with poor sanitation, due to a condition known as tropical enteropathy.

Now the text service – comparable to the Uber taxi app – has a database of 65,000 customers who send an SMS whenever they need their pits emptied. The computer sends out a tender to all the pit emptiers in the vicinity, triggering a bidding war.

The “Uber-ification” of waste management has broken the back of the informal pit emptiers’ union that fixed high prices for an unenviable job not properly regulated by the government, says Mbeguere.

“In the first year of the service, the average cost of emptying pit latrines decreased from $150 to $90 a year. For someone earning less than $2 a day, that’s a big difference,” says Mbeguere, who says the target for the service is $60 per year.

The breakthrough comes as countries prepare to adopt the sustainable development goals, which include achieving access to adequate and equitable sanitation and hygiene for all, and ending all open defecation, by 2030.

It’s a tall order. Dakar is the seventh fastest growing city in Africa – with its population of two million estimated to double over the next 15 years, according to research by the African Development Bank.

Dakar produces 1,500 cubic metres of faecal sludge per day but only 1,100 cubic metres are collected and processed in waste treatment plants – 400 cubic metres are dumped in the ground, on the beach or in the sea, according to ONAS.

“A lot of the growth in African cities is in informal settlements, which are growing faster than the infrastructure,” says Val Curtis, director of the hygiene centre at the London School of Hygiene and Tropical Medicine.

Lack of access to sanitation means private companies can step in, but costs are inflated because the emptiers typically lose 8% of their income to police harassment, and spend 30% on fuel and 12% on repairs, according to ONAS.

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The omniprocessor in Dakar dries faecal waste and burns it, to drive steam through turbines to produce electricity. The steam produced when drying the sludge is filtered, condensed and treated to produce drinkable water. Photograph: Janicki Bioenergy

Doulaye Kone from the Bill and Melinda Gates Foundation, which invested in developing the new SMS system as well as providing financial support to pit emptiers to buy better vehicles and equipment, says it’s not just about making sanitation sexy, but making it profitable.

“The initial goal is to demonstrate that it is possible to structure pit-emptying services for poor communities with market and business innovation,” says Kone.

While the automated SMS service is finding efficiencies in the market, a new waste management technology known as the omniprocessor is turning faecal matter into a commodity, such as electricity, ash for fertiliser and even water.

Designed by Janicki Bioenergy under the backing of the Bill and Melinda Gates Foundation, the $1.5m omniprocessor dries faecal waste and burns it, to drive steam through turbines to produce electricity. Meanwhile, the steam produced when drying the sludge is filtered, condensed and treated to produce drinkable water.

The omniprocessor can produce a net power of 250KW of electricity – which could run 25,000 households – and around 80,000 litres of drinking water per day (enough for about 35,000 people) – which could be sold to the national grid or bottled like mineral water.

While Curtis welcomes this innovation in the much-neglected field of sanitation, she remains cautious about the complexity of safely collecting and transporting human waste from pit latrines to the plant.

Many of these pits are down very narrow alleys, inaccessible to emptying trucks,” says Curtis. “The waste processing plants are far away as nobody wants to live anywhere them – so you need a solid business model for waste collection.”

The collection challenge has started to be addressed with the SMS service and the financial assistance being provided to the emptiers, but the system will need to be observed closely and scaled up in the future for the loop to be closed entirely.

In Dakar, Gomis is looking forward to making money by sitting on the toilet, but she draws the line at drinking water made from human excrement: “It’s disgusting! There’s only so much you can expect a person do.”

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