Waste collection in Bamako has long been the responsibility of small neighborhood-based associations and business groups, so-called Groupements d’Intérêts Economiques (GIE), which are coordinated by an association called ‘Collectif des Groupements Intervenant dans l'Assourissement au Mali (COGIAM)’.  Since the early 1990s, these were integral parts of Bamako’s waste management system and in charge of door-to-door collection and transport to waste transfer depots. About groups usually consist of five to 30 members and work for a fee that was directly paid by households. The groups typically use carts drawn by donkeys and the direct payment system incentivizes them to provide good services. They have been a crucial source of employment, particularly for young adults. Waste workers are also allowed to pick out recyclable waste to complement their salaries. The collected recyclable waste is sold to junk dealers. 
Over the years, COGIAM has provided training, protective equipment, and technical and financial support for its members, but also launched awareness-raising campaigns in the broader public. The association wanted to become further involved in municipal waste management, saying that this would ensure employment and a fairer distribution of benefits. It has also sought to coordinate and include informal waste pickers – who are mostly women and (often with children) working at dumpsites and transfer depots – into its activities and proposed the installing of a recycling unit that would provide more secure jobs for waste pickers. It argued that their organizing would allow them to directly sell recyclables to the industry and make them less dependent on intermediaries. 
However, in 2015, the Moroccan company Ozone became contracted for street cleaning, waste collection, and disposal services, which was announced as a “big cleanup” of the city that would set an end to the city’s longstanding waste problems. As part of the eight-year contract with the district and national government, Ozone took over a substantial amount of services that used to be managed in a decentralized manner by GIEs and, first, refused to integrate these. In the following, COGIAM started to negotiate a collaboration scheme for about 180 small sanitation groups and in 2017 reached an agreement with communal authorities that allowed them to resume door-to-door collection in certain neighborhoods. Despite that, the GIEs remained entangled in disputes over competencies with the private operator and public authorities. Moreover, also several years after the announced cleanup, the city’s waste problems have just aggravated further. Ozone by 2019 only collected about 30 percent of all waste so that in many neighborhoods waste accumulated and residents often stopped paying their fees and instead again contracted GIEs. 
Bamako’s waste collection problems are closely linked to the lack of an adequate final disposal site. For over a decade, most of the city’s waste ended up at the Doumanzana dumpsite, situated in Commune I of Bamako, in an abandoned quarry that was never designed to receive waste. After extraction stopped in the 1990s, its large cavity was increasingly filled with waste. In 2001, the site was officially opened as a landfill and, with the help of NGOs, secured and equipped with toilet facilities.  Doumanzana used to frequented by hundreds of waste pickers – mostly women and children who lived from what they could find in the trash and collected all kinds of recyclable waste that could be sold, such as bottles, clothes, metals, and electronic waste. A young kid, for example, reported: “We collected iron pieces that we sell to blacksmiths and people who come here to buy and export them” . However, waste has usually already been sorted previously by other waste pickers so that valuable trash was rare, while the community was exposed to smoke, infections, and the risk of an accident. As of 2013, a reported 670 people lived in squatted, self-constructed houses in the area of the Doumanzana dumpsite and, on average, earned about 100 CFA a day (€ 0.30) from picking waste. 
Locals living in the area and a nearby school from the beginning protested against the dumpsite. With increasing waste volumes, the sanitary conditions worsened and the site regularly caught fire. During rainy season mixed waste soaked in the water, which turned black. Locals, who then formed an association, pointed out that many of them have been living in the area already before the dump was created and since then had been enduring contamination. In 2011, a new massive fire broke out at the site and resulted in violent protests.  Students in a demonstration wielded banners saying “We die from the gases and smoke from the unbearable garbage”  and “No to violence” . Shortly after, authorities announced the stop of waste disposal and the launching of a project to remediate the site . However, the designated new landfill in Noumoubougou – which was constructed by the government without prior consultation of the district authorities – has still not become fully operational due to financial problems and delays in construction . Moreover, locals were opposed to waste disposal at the site and pointed to the deteriorating air quality .
Challenged by a political crisis and economic woes, Bamako’s waste problems have however further aggravated over the last few years. As of 2019, many parts of the city remained overfilled with waste that had been accumulating for months and several waste transfer stations had de facto become dumpsites, while constructions in Noumoubougou were still ongoing. Ozone was in a permanent search for new intermediary dumping grounds and had not serviced certain areas for long periods. Waste also started to pile up at central locations such as Marché Dabanani, where it even blocked parts of the street. As of 2019, only 70,000 households and establishments were registered for waste collection, while many others disposed of their waste irregularly in the streets or in drainage canals. 
The situation was especially problematic at two overfilled transfer depots in the Lafiabougou and the Medina Coura neighborhoods, where the health of residents was severely affected.  In Lafiabougou (Commune IV) waste accumulated next to a cemetery and formed a 20 meters high garbage hill that locals called ‘Kilimandjaro’. Incapable of bringing the waste elsewhere, Ozone was reported to burn parts of the waste, affecting residents with toxic smoke. They were also affected by diseases stemming from blocked sewers and the draining of waste with rainwater. In 2019, residents blocked the streets and demanded the closure of the site, which had already been announced but remained postponed.  In Medina Coura (Commune II) locals similarly suffered from the bad smell, breathing problems, and high malaria rates. In 2016, street protests took place to demand an end of the poor sanitary conditions but were stopped by the police. Later in the year, a school located near the dumpsite temporally closed because of intolerable stench. In 2018, the school administration announced its second strike and about 100 students held street demonstrations against the overflowing waste transfer depot. They demanded its relocation and stated that several of them had fallen sick from respiratory diseases over the past weeks.  The situation was similar in Bagadadji, where waste was piling up irregularly in the streets in order to be transferred to a waste depot in the Rail-Da commercial area, but severely affecting a local school .
Both the workers union of Ozone and COGIAM explained the waste problems with uncontrolled urban growth, the lack of a functioning landfill, insufficient space at transfer depots, and outstanding payments to the operators and employees . Ozone in 2019 claimed that it would try the best possible but that the city already owed them 19 billion FCFA (over $US 30 million) and it had difficulties paying its 1,400 employees, who had already gone on strikes . The district government claimed that the state government had not provided financial resources that were promised at the beginning of the contract with Ozone . COGIAM in turn again criticized public authorities for having misread the problems and attempted to exclude GIEs, which in the past were blamed for various problems in waste collection without acknowledging their contributions and experience in the sector. The association noted that certain problems, such as the removal and overcrowding of transfer depots and the lack of final disposal sites, made waste collection more time-intensive and hampered the image of collectors towards the population. 
In 2020, Ozone made new announcements to fulfill its contract objectives and to “revolutionize" the waste sector in Bamako, at a point at which the company’s employees were two months unpaid and the government was still indebted towards the company. The company announced the subcontracting of new companies and collectives, that waste transfer to Noumoubougou will increase, and to modernize the transfer depots in Lafiabougou, Medina Coura, Darsalam (Commune III), and in the market area, which would eventually put an end to the waste nightmares for locals.  In the meantime, the precarious conditions of informal waste pickers again became visible during the COVID-19 outbreak, when many of them continued to collect recyclables without any protective equipment or support from sanitary authorities . A women waste picker working at the Rail-Da dumping ground noted: “We are condemned to do this work and ruin our health. Many journalists have passed but nothing has changed” .