Moving Solid Waste to the Right Place

Approximately 25 % of the estimated 3,000 tonnes of solid waste generated daily in Nairobi gets collected, yet only about 900 tons reaches the Dandora dumpsite, leaving the rest remaining unaccounted for – we don’t know where it is, how much it is and what kind of waste it is. This is the case for several cities in low-income countries, where about 57% of solid waste ends up in illegal dumpsites. Trends such as increasing population, changing consumption patterns, economic development, improving household incomes, growing urbanization and industrialization are expected to accelerate the gravity of this phenomenon.

Illegal dumpsites lead to a variety of problems in the urban community, from environment to local economy (figure 1). Direct consequences are diseases like typhoid, cholera and diarrhoea, contaminated water, clogged drainage and sewers, as well as negative impact on the local tourism.

problem tree - solid waste unaccounted for, low-income countries

Figure 1. Problem tree

But why does food, plastic, metal and other material get piled up around the city? Cities in low-income countries typically lack of formal systems for waste collection, sorting and recycling – often perceived as opportunities by local criminality. Citizens also play a key role in this scenario, having limited or no understanding of the consequences and dangers of illegal dumpsites. Although several initiatives are trying to raise the awareness among citizens, hoping to change the behaviour, right now millions of tons of solid waste are still out there and perceived as a problem that local governments are supposed to take care of.

However, we shouldn’t forget that in many developing countries solid waste management is one of the most expensive ventures, consuming 20-50% of a city’s budget – with no tax or fee structure to sustain solid waste programs. Then,  how could we trigger an efficient and affordable solid waste management for majors in low-income countries? Or, even better, how could we support them in turning solid waste into a resource?

Keep an eye on the dumpsite

Satellite images, drones and ground vehicles are all devices that increasingly find a place in solid waste management in developed countries: they are regularly used for the inspection of dumpsites. The combination of the three can enable the collection of a variety of data and therefore the identification of different types of solid waste – e.g., thermography for biodegradable waste and spectral signature for plastic and glass.

The adoption of these technologies in low-income countries faces two main hurdles: firstly, illegal dumpsites typically contain any kind of solid waste (i.e., plastic, food, metal, toxic, etc.), making the inspection and identification of material inaccurate; secondly, affordability is obviously a major concern for majors.

The first problem could be tackled by leveraging a machine learning algorithm. Citizens living in a certain neighbourhood tend to have similar habits in time: they collect the same type and amount of waste in the same (illegal) dumpsite. By regularly inspecting that dumpsite, we can approximate its characteristics and predict changes in the waste “inflow” (figure 2).

Figure 2. Regular dumpsite inspection to learn waste habits and forecasts

The obstacle of affordability can be addressed by a flexible revenue model and smart logistics. Cities need to inspect dumpsites due to urgency or to enable decision making. By adopting a “pay-as-you-scan” pricing system, majors can avoid big investments in drones and ground vehicles. It follows that these devices don’t need to be stored in the city but can actually be accessible from and serve multiple cities in the same region – proximity becomes essential to decrease the operational costs.

From waste to marketable raw material

By identifying, classifying and quantifying (previously) unaccounted for waste, municipalities can leverage essential information for prioritising their waste management. For example, increasing collection of plastic in the proximity of a water flow can be promptly identified, preventing potential disaster. Spotting toxic waste can enable prompt reaction. But is this information only valuable for the municipality? Is tackling environmental issues the only goal?

The data collected through the dumpsite’ inspections is open and visible to anyone online. Through an interactive heat-map, other municipalities, local businesses and informal waste collectors can see where, what and how much waste is in the city. Such information, combined with the price of each material identified, is the essential component to enable a marketplace of solid waste (resource). In this scenario, value is generate for multiple players in the ecosystem (figure 2).

Municipality – beyond taking informed decisions on waste management, majors can also display on the market the current solid waste situation, making the material available to businesses and municipalities in the region, which might be interested in buying it. For example, through a Dutch auction, plastic in excess can be displayed on the marketplace for a continuously decreasing price – depending on the plastic waste predictions enabled by machine learning algorithms. This way, municipalities can turn waste into a revenue source, deciding whether to use it “internally” or sell it out.
Local businesses – being aware of the solid waste displaced in their region and the material in excess, local business can have access to a new local marketplace (beyond the international platform Ariba), where they bid for the best price. In this sense, the Dutch auction matches the local supply and demand of solide waste. The buyers can also improve their partnerships with informal collectors, to design the best logistics in waste collection.
Informal collectors – having access to the status of the solid waste in a municipality, and monitoring prices and demand,  informal collectors can prioritise specific materials, improving the efficiency of their processes, particularly when sorting the (demanded) waste and  when planning optimal logistics. In the long term, this leads to greater market opportunities in waste collection, opening up to competitors and encouraging formalisation and  regulations by the government.
Citizens – a more efficient dumpsite management by the informal collectors and the targeted interventions of the municipality can lead, in the medium and long term, to smaller and “safer” illegal dumpsites. This is as an essential outcome to increase the lifestyle of a neighbourhood in terms of health and economy.

Figure 2. Added value for each player involved

Open questions

Data privacy – satellite images, drones and grounded vehicles are invasive devices – they take pictures of public and private areas. Data privacy is regulated differently from country to country. How can we convince stricter municipalities to invest in this solution?

Data quality – machine learning can provide a good understanding of the characteristics of a dumpsite. Is this data precise enough to support decision making?


This post is based on the creativity, expertise and commitment of my team : Shirley Ben-Dak, Stephen Machua and Tanja Rosenqvist, who worked intensively on “Bird Eye”, during the UNLEASH Innovation Lab, 2017 in Copenhagen.

Icons in problem tree and solution bridge: Tomas Knopp, The Noun Project
Icons in figure 2 – Mello (satellite), Marie Van den Broeck (dumpsite), (drone), The Noun Project


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