Nigeria generates approximately 44.5 million metric tonnes of solid waste every year, and a significant portion of it never gets collected. They ended up in open dumps beside waterways, and streets that flood not because of rain alone, but because drains are blocked with waste.
By Isqil Najim
On Thursday, 11th June 2026, Professor Adeniyi Saheed Aremu stood before a full auditorium at the University of Ilorin and laid out both a diagnosis of what is broken in Nigeria’s approach to waste management and a clear, evidence-based solutions for fixing it.
He was delivering the institution’s 303rd Inaugural Lecture under the chairmanship of Vice-Chancellor Professor Wahab Olasupo Egbewole, SAN, Professor Aremu titled “Municipal Solid Waste: Complexities in the Transition from Cradle to Grave.”
A professor of Water Resources and Environmental Engineering, former Managing Director of the Lower Niger River Basin Development Authority for two consecutive terms, Fulbright Scholar, and registered engineer with COREN, Professor Aremu has spent the better part of his academic career turning the subject of municipal waste into rigorous engineering science.
According to him, the global waste situation is already alarming, and Nigeria sits at a particularly exposed position within it. “The world generated about 2.6 billion tonnes of municipal solid waste in 2022,” adding that about 30 percent of that total is still either openly dumped or left uncollected worldwide.
In Nigeria, he said, most cities only practise the most basic version of waste management, generation, bin storage, and open disposal while bypassing the more productive stages of source separation, material recovery, recycling, and controlled landfilling entirely.
According to him, Open dumps release methane, nitrous oxide, and carbon dioxide into the atmosphere, contributing directly to climate change. Collection vehicles, when poorly routed, also emit significant quantities of greenhouse gases and air pollutants, compounding an environmental problem that already costs public health dearly.
What the research found
Professor Aremu’s findings based on field studies conducted across Ilorin and other Nigerian cities over more than two decades used Geographic Information System technology and mathematical modelling, to map waste generation points, factored in the indigenous footpaths that residents actually use rather than just formal road networks, and calculated optimal bin placement with measurable precision.
For a typical study area in Ilorin, he said, the most appropriate waste bin size falls between 1.47 and 1.8 cubic metres, and each bin should be emptied at least once every three days to prevent odour, pest infestation, and disease. Siting six optimally located bins, he found, was sufficient to achieve 100 percent waste capture coverage in the studied area.
In his recommendations, Professor Aremu called on government to promote on-site waste separation at the household level, with colour-coded bins that distinguish between organic waste, plastics, paper, and hazardous materials.
“Source sorting,” he said, “is the foundation of everything else — it makes recycling cheaper, energy recovery possible, and landfilling less damaging.”
He stressed the need for investment in smart waste management infrastructure, including Internet of Things-enabled bins fitted with sensors that transmit fill-level data in real time, allowing collection schedules to be driven by actual need rather than fixed timetables. This, he argued, would significantly reduce unnecessary trips and operational costs.
On spatial planning, he urged municipal authorities to conduct proper GIS-based analyses before siting any waste bin or landfill, noting that poorly located infrastructure wastes money and fails the communities it is meant to serve. He also called for regular data audits of waste volumes and composition, arguing that management decisions made without current data are rarely effective.
The case for Nigeria’s informal waste collectors
Perhaps the most humanising moment of the lecture came when Professor Aremu turned his attention to a group of Nigerians who keep cities partially functional yet receive almost no formal recognition for doing so — the informal waste collectors known across the country by different names.
In the North, they are called Baban Bola, Kọndem Iron, or Yan Ajaokuta. In Yoruba-speaking communities of the South-West, they are Bọ̀lọ̀-bọ̀lọ̀, Aṣalẹ̀, or Tulẹ̀tulẹ̀. In the South-East, they are known as Akpakara or Otuturu Ota. Different names, he said, for the same essential service.
These are the people who move through neighbourhoods with handcarts and tricycles, pulling recyclable metals, plastics, paper, and glass from waste bins and open dumps before formal collectors arrive.
According to him, they are already performing the material recovery function that most Nigerian cities have no formal system to carry out. “What one individual discards as waste,” he said, “can represent a highly valuable resource to another. That principle is not just philosophical, it is the operating logic of an entire informal economy that government has left to fend for itself.”
He said that integrating these collectors formally into the waste management chain would deliver measurable benefits at every level.
They already know the routes, the waste generation patterns, and the materials with resale value. Bringing them into a structured system, with identification, training, equipment support, and access to organised recycling markets, would extend the reach of municipal waste services without the capital cost of expanding government fleets. It would also generate livelihoods, reduce the volume of waste reaching landfills, and recover materials that currently rot or burn in open dumps.
“The stigma attached to workers in this industry, especially scavengers, must be denounced through public education,” he said calling on government to incorporate this workforce into President Tinubu’s Renewed Hope Agenda as a recognised category of environmental service providers rather than a problem to be managed.
“The roadmap to cleaner cities is guaranteed when we break these complexities into structured, actionable goals and apply engineering principles consistently.” he said.
