US quartet turns poop to fertiliser in Nairobi slums

Fork-to-farm: that is what a team of four American techies have ventured into by turning human poop into food.

Yes, the quartet is challenging the conventional farm-to-fork movement by making it a 360-degree affair: producing fertiliser from human waste collected in their chain of latrines located in Nairobi’s slums.

The fertiliser venture is a value add to their firm Sanergy, founded in 2011 — a network of small-scale sanitation centres across slums — to create a waste collection network and convert human waste into fertiliser and other by-products.

The latrines and now the bio-fertiliser are the brainchild of Massachusetts Institute of Technology (MIT) graduates David Auerbach, Ani Vallabhaneni, Lindsay Stradley and Nathan Cooke who came up with the idea of franchising toilets and turning poop into food.

The thought of consuming foods grown using fertiliser made from human waste might turn a few stomachs but this has not deterred Sanergy, a start-up that is hoping to turn poo into millions.

Sanergy is now fully in production of the organic fertiliser, churning out and sending to the market 25 tonnes every month.

The company — which has the backing of several international charitable bodies like the Bill and Melinda Gates Foundation — focuses its activities in several Nairobi slums where it collects human waste in a bid to curb the infamous ‘‘flying toilets’’ menace.

The firm says that it sells the fertiliser at Sh1,000 for per 25 kilogramme bag and Sh2,000 for a 50kg bag. By July the firm had sold over 190 metric tons of the Evergrow branded fertiliser and expects the business to break even next year.

The fertiliser was initially targeted at flower farms but the firm has since January branched out to farmers in various parts of the country including Nairobi, Meru, Kajiado and Nanyuki.

“Kenyan farmers need a sustainably made, domestically produced organic fertiliser that they can rely on and that won’t break the bank,” Mr Auerbach says.

“We are working with small holder farmers in various parts of the country to better understand their challenges and provide a sustainable solution to the productivity of their farms.”

Sanergy adds that it took three years of lab tests and trials before arriving at the final product.

The fertiliser is now certified by the Kenya Bureau of Standards and the Kenya Plant Health Inspectorate Service (Kephis).

The biggest concern in the use of organic materials is the presence of pathogens — bacterium, viruses and other microorganisms that can cause disease.

Mr Auerbach says that they have conducted numerous tests and the fertiliser declared pathogen-free.

The decision to go into production of the fertiliser was prompted by declining soil fertility which leads to lower output and threatens food security for the growing population, says Mr Auerbach.

“Unless farmers focus on restoring soil health, crop production will continue to decline. The most effective way to restore nutrients to the soil is to apply organic fertiliser to replace the organic matter that the soil is missing.”

Sanergy has created a chain of workers who ensure that the human waste is turned into a profitable venture.

At the base of the operation are those who run the toilets which are branded Fresh Life. The toilets are manufactured by Sanergy using light concrete blocks which are assembled on site. The pack comes with two cartridges (containers) for solid and liquid waste which are placed beneath the toilet’s floor.

The toilets are designed to separate urine from solid waste and are sold to franchisees who then operate them in slum.
An entrepreneur buys the toilet at Sh32,000 while a landlord and schools buy it at Sh29,000.

Those who cannot afford the units can apply for loans through Kiva, an online-based crowd-funded platform where lenders can loan an applicant as little as Sh2,500.

Safe and feasible

“We are still trying to partner with microfinance institutions but they are still sceptical about funding someone to buy a toilet,” Ms Edith Karimi who works with the company says.

Currently, 764 toilets have been sold and are in operation serving over 35,000 users every day. The toilets are found in Kamukunji, Makadara, Embakasi, Mathare, Mukuru kwa Njenga, Mukuru kwa Reuben and Mukuru Kayaba.

Operators charge members of the public between Sh3 and Sh10 for use. The service is free in the case of schools. Operators also pay a Sh9,000 annual fee for collection of the waste.

Each morning a team of about 40 Sanergy workers goes around collecting the cartridges and replacing them with fresh ones. The filled containers are transported in the slums using handcarts to several collection points where they are loaded onto trucks and ferried to a fertiliser production centre in Machakos County.

“To produce fertiliser we mix the waste with sawdust, wood shavings, lime, rice husks, other carbon sources and effective micro-organisms which eliminate pathogens,” Ms Karimi says.

“The mixture is then put in a biomax machine which mixes at high temperatures for about four hours.”

The waste is then piled in rows to compost naturally and takes about three months during which it is turned and mixed. Each batch is then tested before it is bagged for sale.

“This model allows for safe removal and collection of 10 metric tons of waste per week, otherwise normally dumped into waterways, to be converted into organic fertiliser and animal feed (which is currently on a trial basis),” the company says.

The product was submitted to the MIT Entrepreneurship Competition, at the 2011 MassChallenge Start-up Competition and Accelerator, and won the Sh8.9 million Diamond Prize.

The company has grown to a core staff of 200 besides operators of the Fresh Life toilets. The company is also experimenting with other products including biogas, animal feeds and liquid fertiliser which it says will be rolled out once they prove safe and feasible.