By Javier Mateo-Sagasta and Pay Drechsel, International Water Management Institute
Cities in Africa generate millions of tons of solid and liquid waste every year. Most of this waste is discharged untreated to water bodies leading to severe water pollution with deleterious effects on human health, ecosystems and economic activities.
Nevertheless, for decades, the fate and impacts of waste and wastewater have been poorly considered in the global development agenda, and particularly in Africa. In the lead up to the post 2015-Sustainable Development Goals it is now widely recognized that water quality related targets need to go beyond access to sanitation facilities and address the fate of wastewaters and their impacts on the environment, and be relevant for developed and developing countries alike.
Proposed targets are put forward under the Sustainable Development Goals (SDGs), and various groups in different fora have advocated to have the water quality challenge, including wastewater management, better addressed. As a response to these calls, the General Assembly’s Open Working Group on Sustainable Development Goals (OWG) has suggested in a draft proposal for member countries several goals and multiple targets where the different dimensions of water quality, including pollution control, wastewater management and wastewater reuse and recycling, are addressed.
One of the discussed targets is “By 2030, improve water quality by reducing pollution, eliminating dumping and minimizing release of hazardous chemicals and materials, halving the proportion of untreated wastewater and at least doubling recycling and safe reuse globally”.
Halving the proportion of untreated wastewater is very ambitious considering that globally, 92%of the wastewater generated in low income countries, and 72% in lower middle income countries is still discharged untreated to water bodies.In African countries the situation is not different and most wastewater and fecal sludge treatment is low or non-existent.
The table shows some examples of the better performing countries in the continent. To address this complex challenge and to prevent a regional water quality crisis investments in treatment will need to be significant.
|Municipal wastewater from production to use in selected countries of Africa (2008-2012)|
|Country||Collected of produced||Treated of collected||Directly used of treated||Directly used in irrigation of treated|
|Source: AQUASTAT (accessed on April 2015) and Global Water Intelligence 2014|
However, common solutions to treat wastewater and control water pollution that work in industrialized countries have not always succeeded in Africa. The attempt to implement conventional wastewater treatment plants has often failed due to poor operation and maintenance, or simply the frequent power cuts we are experiencing in far too many African countries.
This is very much related to limited institutional capacities, unsuitable (e.g. energy demanding) technology, poor cost recovery strategies and local communities´ insufficient capacity and willingness to pay for water services. The post-2015 development agenda needs to learn from these shortcomings and provide realistic pathways for pollution control and impact mitigation that can be achieved with adequate and affordable options.
Thus, while the wastewater industry sector welcomes the SDGs as an investment catalyzer, the sector will be challenged to learn from failures (Murray and Drechsel, 2011), provide appropriate technologies and contribute to their sustainable implementation.
Targets and indicators also need to cover aspects of water governance to provide policy, institutional and economic incentives to address this problem which remains a challenge even in the most developed countries.
With respect to reuse, the SDG target appears more manageable with the call of doubling current reuse. As formal reuse is not very common at least in sub-Saharan Africa, this target might be easier achieved than in those regions which already progressed towards their limits. However, the SDG targets need to consider that also a major portion of the untreated wastewater is already used directly or indirectly (diluted) in the informal sector posing risks for farmers and food consumers.
Indeed, informal wastewater irrigation is a common reality in much of the developing world and represents up to 90% of all current wastewater use (Mateo-Sagasta et al., 2015). Thus,for many African countries efforts to make existing informal reuse safe is not only a prerequisite but can offer an opportunity to show progress on the SDG reuse target, maybe more than by expanding formal reuse.
The WHO is ready to assist in this regard with various, also non-treatment options, to support risk mitigation. The 2015 launched WHO Sanitation Safety Plan Manual gives countries flexibility to monitor risk mitigation and transition from unsafe to safe forms of wastewater management and reuse, relevant to their context.
For references, please check
Mateo-Sagasta, J., Raschid-Sally, L., and Thebo, A. 2015. Global wastewater and sludge production, treatment and use. In: Drechsel, Pay; Qadir, Manzoor; Wichelns, D. (Eds.). Wastewater: Economic asset in an urbanizing world. Dordrecht, Netherlands: Springer. pp.15-38.
Both authors are affiliated to the International Water Management Institute IMIW.