Treatment and safe disposal are the weakest links in the African sanitation systems

Sanitation coverage across many African countries has improved steadily over the last two decades. Toilets, pit latrines and septic systems are more common today than they were at the turn of the century, particularly in urban and peri-urban areas. Yet, despite this visible progress, sanitation-related health and environmental risks remain widespread. Polluted rivers, untreated wastewater and recurring outbreaks of waterborne diseases continue to affect large sections of the population. This persistent gap between sanitation access and sanitation outcomes points to a deeper structural issue: sanitation systems in much of Africa tend to falter not at the point of access, but at the stages of treatment and safe disposal of waste.

This disconnect between progress on paper and risks on the ground is increasingly reflected in quantitative sanitation assessments. According to the World Health Organization (WHO)/United Nations Children’s Fund (UNICEF) Joint Monitoring Programme, while over 40 per cent of the population in sub-Saharan Africa uses improved sanitation facilities, only 26 per cent had access to safely managed sanitation services in 2022, meaning that waste was treated and disposed of safely. This implies that for the majority of households, human waste is either not treated at all or not disposed of safely, demonstrating that the sanitation service chain breaks down after containment.

Empirical evidence from recent peer-reviewed studies confirms that treatment and safe disposal represent the most significant failure points in African sanitation systems. A 2024 regional review published on the journal PubMed Central documents that in many African countries, a substantial proportion of wastewater generated by households is discharged into the environment without adequate treatment, despite improvements in sanitation access. These findings align with global wastewater assessments by UN Water, which estimate that only 56 per cent of domestic wastewater worldwide was safely treated in 2020, with treatment rates in Africa falling below 30 per cent, and below 10 per cent in many low-income countries. This indicates that unsafe disposal, rather than a lack of toilets, is the dominant sanitation challenge.

This pattern is reinforced by a 2025 review in the journal Springer Nature of African cities, which finds that urban growth has consistently outpaced investments in wastewater collection and treatment infrastructure. The review highlights that fewer than 30 per cent of residents in most African cities are connected to sewer networks, while the majority rely on on-site sanitation systems such as pit latrines and septic tanks. Crucially, these systems are rarely supported by adequate downstream treatment infrastructure, resulting in wastewater and sludge frequently bypassing formal treatment and being discharged untreated or partially treated into the environment.

Further evidence from a 2024 article in the journal Environmental Systems Research indicates that even where wastewater treatment plants exist, they often operate well below design capacity due to unreliable energy supply, inadequate financing for operation and maintenance, and shortages of skilled technical personnel. Sector-wide assessments by the African Development Bank show that between 30 per cent and 50 per cent of wastewater treatment plants in Africa are non-functional or severely underperforming. These operational failures mean that treatment infrastructure frequently exists in theory but fails to deliver safe disposal in practice.

Understanding this gap requires a clear distinction between sanitation access and sanitation safety. International sanitation frameworks define “safely managed sanitation” as a condition in which waste is not only contained but also treated and disposed of in ways that prevent human contact and environmental contamination. Yet globally, around 3.5 billion people lacked access to safely managed sanitation in 2022, with sub-Saharan Africa accounting for a disproportionate share of this deficit, according to a 2023 report by WHO. This reinforces the conclusion that treatment and disposal capacity, rather than access alone, determines sanitation outcomes.

These shortcomings are becoming more pronounced as cities grow and waste volumes increase. Rapid urbanisation in Africa has led to continuous increases in domestic wastewater and faecal sludge generation. Available estimates indicate that less than 20 per cent of faecal sludge generated in African cities is safely treated, while over 80 per cent is disposed of untreated in open land, drainage channels or nearby water bodies. As population density increases, sanitation systems that were never designed to handle such volumes become increasingly strained, leading to predictable downstream system failure.

City-level assessments further illustrate the structural nature of this mismatch. The 2025 Springer review shows that investments in wastewater treatment have not kept pace with waste generation, even in cities with established sewer networks. Treatment capacity remains insufficient relative to growing wastewater volumes, making this imbalance a defining feature of urban sanitation systems across the region.

At the centre of this imbalance lies a persistent deficit in treatment infrastructure quality and performance. Wastewater treatment facilities in many African countries are insufficient, poorly maintained or operationally constrained. In South Africa, national audits have found that only around 13 per cent of municipal wastewater treatment plants consistently meet required effluent discharge standards, demonstrating that even “treated” wastewater often remains unsafe for environmental discharge.

These limitations are even more pronounced in contexts dominated by on-site sanitation. Faecal sludge management remains one of the weakest components of the sanitation chain. In Uganda, national estimates indicate that only about 3 per cent of generated faecal sludge can be treated using existing installed capacity, while in Kampala, treatment facilities can handle less than 45 per cent of the sludge produced, according to the Africa Urban Waste Management Review. The remainder is disposed of informally, underscoring that unsafe disposal is not incidental but a predictable outcome of limited treatment options.

The consequences of these treatment and disposal failures extend beyond sanitation systems themselves. Environmental assessments by UNEP indicate that over 70 per cent of nutrient and pathogen loads in major African rivers originate from untreated domestic wastewater. Rivers, lakes and wetlands receiving untreated effluent experience declining water quality, threatening ecosystems and communities that rely on these water bodies for domestic use, irrigation and drinking water.

Environmental degradation is closely mirrored by public health impacts. The WHO estimates that approximately 560,000 deaths annually are attributable to unsafe sanitation, with a substantial share occurring in sub-Saharan Africa. Importantly, these health risks persist even in areas where households have access to improved sanitation facilities, highlighting that access without safe treatment and disposal fails to deliver health protection.

Beyond infrastructure, governance and institutional weaknesses further exacerbate these challenges. Fragmented responsibilities, weak regulatory enforcement and limited monitoring capacity allow untreated wastewater and sludge disposal to continue unchecked, even where discharge standards formally exist.

Taken together, this body of evidence points to a clear and consistent conclusion: treatment and safe disposal are the weakest links in African sanitation systems. While access to toilets has expanded, treatment capacity has lagged far behind. Less than one-third of wastewater is treated, the majority of faecal sludge is unsafely disposed of, and a large share of treatment infrastructure is non-functional or ineffective.

The implications of neglecting these weakest links are far-reaching. Environmental degradation, public health risks and sanitation-related inequalities persist despite improvements in access. Informal settlements and low-income communities are particularly affected, as they are most exposed to contaminated environments and least served by formal treatment infrastructure. Without substantial investment in treatment and disposal systems, sanitation gains will remain fragile and incomplete.

This evidence does not undermine the importance of expanding sanitation access. Rather, it underscores the need to redefine sanitation success. Toilets and latrines are necessary, but they represent only the first step in a longer service chain. Completing that chain requires prioritising treatment and safe disposal as core components of sanitation planning. Until these stages are addressed with the same urgency as access, sanitation systems in Africa will continue to fall short of delivering the health and environmental outcomes they promise.