Ideas Thinkpieces

Cleaning up the Green City in the Sun

In most African countries, rural areas are lagging behind in terms of infrastructure development and access to utilities such as water, sanitation and health services. Private sector investment has clustered in the areas where these crucial elements can be found, the cities and towns, with millions of African youth migrating to urban areas. This is not a uniquely African phenomenon. Rural-urban migration happens everywhere in the world - the case of a young man or woman leaving home for the big city where prospects abound is an all too familiar story. As a consequence, aside from the enormous income inequalities existing between urban and rural areas, cities and towns are facing tremendous pressure on social services and amenities. In most African cities and towns, traffic gridlocks, congested hospitals, crowded schools and overflowing sewage pipes is commonplace.

Of the 10.7 million people living in urban areas in Kenya, Nairobi is home to one third of them. Kibera, Africa’s largest informal settlement, is located in Nairobi, in addition to Mathare, Huruma, Korogocho and Kawangware. Roads leading into and out of the city are gridlocked during morning and evening rush hour; Kenyatta National Hospital, one of the two referral hospitals in the country is struggling to cope with the number of patients in need of care; water service to residential areas is often rationed while a booming black market for piped water and electricity thrives in the informal settlements. The city is home to many top-tier hotels, hosts the African headquarters of dozens of multinationals, hosts countless regional, continental and global conferences, enjoys about 50% of Kenya’s GDP and its real estate is perennially in “best real estate market” lists. Given this backdrop of a vibrant, if under-equipped metropolis, Nairobi is facing a garbage crisis. More accurately, the green city in the sun has been experiencing a garbage crisis for over a decade now.

The Nairobi County (formerly Nairobi City) Council (NCC) has long been the main provider of garbage collection services in the city. Several private firms have cropped up over the years to provide this essential service in aid of a struggling NCC. Garbage, or municipal solid waste, is collected once or twice a week in most industrial and residential areas and delivered to the lone NCC-owned Dandora dumpsite, where the solid waste is piling up high owing to non-compaction, just about 8 kilometres away from the CBD. Every day thousands of slum dwellers try to eke out a living by sorting and collecting plastics, metals, glass and rubber from the waste heaps which they sell to recycling firms and other community-based organisations. A casual drive around the CBD and its environs provides proof that this is neither a sustainable nor an efficient way of managing municipal solid waste. Ikiara and company (2004) make the following damning assertion:

“Nairobi is literally under garbage. Of the estimated 1,500 tons of solid waste generated daily in the city, only about 25% gets collected. The rest is left in open spaces, markets, bus stops, drains and roadsides forming mountains of rotting, smelly and unsightly waste. Discarded polythene papers of all colours and sizes decorate the city landscape. Solid waste collection, transport, and disposal are thus generally chaotic” (Ikiara et al., 2004, p. 61).

Nothing much seems to have changed. According to the authors, about 375 tonnes of waste generated in the city would get collected, leaving approximately 1,000 tons uncollected. Daily. Kasozi et al. (2010) estimate that between 2,500 and 3,100 tonnes of waste are generated in the city every day. In a recently televised interview, the Nairobi County Governor (view it here, from 10:58) confirmed these numbers, informing us that now 2,000 tons of waste is being collected every day, a big improvement from the 375 tons being collected when he assumed office. Unfortunately, given that up to 3,100 tons are generated every day (likely much more, given that these numbers were put forward 7 years ago), if 2,000 tons are collected, 1,000 tons are therefore left uncollected, the same as Ikiara et al. found in 2004. Now, I am not assigning blame to anyone (well, perhaps past city council leadership?); merely presenting the facts as they are.

The dangers of poorly managed municipal solid waste are well documented. The solid waste in Nairobi tends to be a by-product of industrial, service and manufacturing processes i.e. chemicals, metals, textile derivatives, refuse from auto and equipment repair shops, refuse from construction sites, polythene bags, plastics, paper, etc. Poor management of waste materials such as these through open air combustion at the Dandora dumpsite, or at other illegal dumpsites across the city, generates and releases vinyl chloride monomers and dioxins into the atmosphere, polluting the air. Foul odour is the least of concerns however, bearing in mind the dangerous effects these pollutants have on the respiratory system. The World Health Organization considers these persistent environmental pollutants highly toxic, and on human exposure, dioxins can cause developmental problems, damage the immune system, interfere with body hormones and can lead to cancers. Media reports over the years (such as this and this) have confirmed that the garbage crisis is quickly escalating into public health issue. In a positive move, the Cabinet Secretary for Environment and National Resources, Prof. Judi Wakhungu, recently introduced a ban (see The Kenya Gazette, Vol. CXIX, №31, Special Issue) on “the use, manufacture and importation of all plastic bags used for commercial and household packaging” to the fury of the manufacturers of the stuff. That said, the public health concerns are very real. In a study funded by the National Council of Science and Technology, Mutune and company (2014) looked at African indigenous vegetables (such as kale, aramanth, pumpkin leaves, etc.) from 25 sites in the city and while their findings were varied, they concluded as follows:

“This notwithstanding, longterm metal exposure by regular consumption of such locally grown vegetables poses potential health problems to animals and humans. Further cleaning of the rivers needs to be done, and curtailing of all effluents and dumping of solid waste should be done to minimise contaminant leakage into water and soil that may be used for agriculture” (Mutune et al., 2014, p. 71).

Not only an eye sore but terrifyingly dangerous, I propose an idea that may help to improve the collection and management of municipal solid waste in Nairobi: waste to energy (WtE) technology. This would address the garbage problem sustainably through recycling, and generation of electricity that could be into the national grid, while considering the impact the system would have on the beneficiaries of the current model of waste management in Nairobi i.e. community-based organisations, garbage collection companies and their employees, recycling firms and their employees, all the people based at the Dandora dumpsite who sift and sort for glass, rubber and metals, etc.

Ikiara and company (2004, p. 66) mapped the solid waste value chain in Nairobi

WtE technology has been successful in Europe in the management of solid waste, so much so that Germany and Sweden are importing (see here and here) municipal solid waste from neighbouring countries to fuel incineration plants. Imagine that: a Nairobi so clean that it needs to buy solid waste from other counties in the country. Granted, in the NTV interview, the Governor speaks of WtE technology and its coming introduction in Nairobi, so I claim no novelty in proposing it. I do however propose the following implementation plan.

1. Sorting at source - Residents sort out solid waste into 3 categories, each in different coloured-labelled bags/ containers — glass and metals, paper and organics, plastics and other materials — prior to free collection by the NCC-designated agent (not less than twice weekly) while replacing the garbage bags/ containers;

2. Collection and delivery – Solid waste is delivered to the “Nairobi Waste Management and Solutions Centre” a.k.a. “Naiclean”;

3. Processing and treatment — At Naiclean, the metals are separated from glass by use of magnets. Once separated, these can be sold as-is to the existing recycling companies or community-based organisations. The paper and organics are directed towards biogas cylinders, where they are treated to produce biogas for firing the WtE chambers, and the residue is dried and compacted to produce briquettes which would be sold as an alternative to charcoal and firewood. Plastics and other residual materials are, in the end, directed into furnaces where they are used as fuel to propel turbines that generate electricity which is sold into the national grid.

Yes, this is a rudimentary proposal — I am no expert — but I think, if the right mix of minds coalesced around it, it could work. The existing system of collection and delivery can be used, with minor tweaks, as opposed to creating an entirely new one. People presently earning a living from the Dandora dumpsite can be trained and employed at either the collection, delivery or processing levels of the system. The financial investor who would fund the implementation of this project would earn revenues from (i) sale of electricity into the national grid, (ii) sale of glass and metals to recycling companies and CBOs, and (iii) the sale of briquettes. A feasibility plan, one that updates the statistics and incorporates the findings, recommendations and specific actions proposed in the Integrated Solid Waste Management Plan, can be carried out, and a prototype Naiclean system run for 6 months to assess the viability before full implementation.

Indeed, a more holistic approach would ensure that the production process uses as much organic or recyclable material as possible, and that consumers are educated and nudged to reuse and recycle as much as possible, with a view of reducing the quantity of solid waste produced. Yes, the Nairobi County government can always open a new dumpsite in Ruai or any other part of the city precincts. But that seems to me like it would merely be an act of kicking the can down the road, when the effects of solid waste mismanagement would manifest in more harmful ways, and intervention would cost much more. If an intervention must be made – and it must– let it be one that most holistically addresses the problem. We all want a clean Nairobi; I propose Naiclean.


Get new articles sent directly into your inbox


Academic references cited

  1. Ikiara, M. M., Karanja, A. M., & Davies, T. C. (2004). Collection, Transportation and Disposal of Urban Solid Waste in Nairobi. In I. Baud, J. Post, & C. Furedy (Eds.), Solid Waste Management and Recycling (Actors, Partnerships and Policies in Hyderabad, India and Nairobi, Kenya) (Vol. 76, pp. 61–91). Dordrecht: Kluwer Academic Publishers.
  2. Kasozi, A., Von Blottniz, H., Ngau, P., & Kahiu, N. (2010). Using local knowledge production and systems thinking approaches in the development of an Integrated Solid Waste Management (ISWM) Plan harnessing semi-formal systems: Lessons from Nairobi, Kenya. In The 20th WasteCon Conference and Exhibition (pp. 1–10). Johannesburg.
  3. Mutune, A. N., Makobe, M. A., & Abukutsa-Onyango, M. O. O. (2014). Heavy metal content of selected African leafy vegetables planted in urban and peri-urban Nairobi, Kenya. African Journal of Environmental Science and Technology, 8(1), 66–74.

First published on