The regulation of onsite sanitation in Maputo, Mozambique

This review identifies the potentials and constraints of using (partially) treated or blended wastewater for irrigation in order to assess the potentials in the context of cities in sub-Saharan Africa, specifically Maputo, the capital of Mozambique. Less than 5% of the wastewater produced in the region is being treated. Nonetheless, untreated, partially treated, and/or blended wastewater is extensively being used for agricultural purposes. Despite the last updated WHO 2006 guidelines for ‘wastewater use in agriculture’, authorities only consider the different water quality parameters at the point of use. Other aspects such as irrigation type, crop management and post harvesting practices, which clearly influence the contaminant log reduction, are simply ignored. Those parameters, however, are considered alternatives to a classic contaminant log reduction, which may be very beneficial for developing countries. In a more holistic approach, trade-off is favoured between the required water quality for irrigation, use of affordable treatment technologies, and adequate post-harvest strategies to reduce the current health risks to acceptable levels. Such a trade-off makes use of multiple barrier approach, whereby wastewater treatment and critical point barriers throughout the supply chain are combined. Thus, there is a long way ahead to achieve proper water reclamation for productive use; the current paradigm has to change. Current restrictive guidelines are unrealistic given current practices, and approaches more appropriate to the location's situation still need to be developed. A multiple barrier approach in combination with master planning is recommended to consider wastewater treatment and critical point barriers throughout the supply chain.

Use of (partially) treated municipal wastewater in irrigated agriculture; potentials and constraints for sub-Saharan Africa

. The increasing world population and growth of industrial
development lead to growing water scarcity that, combined with deficient
sanitation services, represents serious challenges, particularly in regions
like sub-Saharan Africa. Water reclamation is a promising approach to reduce
water scarcity, serving as a driving force for better sanitation services
and protecting the environment by treating sewage and redistributing for the
benefit of other water-dependent applications (e.g., industries). This paper aims to give an overview of the global trends on water
reclamation, with a focus on industrial use, and to derive lessons for
implementation of water reclamation projects in sub-Saharan Africa. Findings
show that extensive experience exists in technology and management practices
that can allow successful implementation of water reclamation projects in
the region. Under the conditions of deficient sanitation services and low
levels of technical expertise, the main challenge is to develop a framework
that can facilitate the integration of social and technological
methodologies and help in introducing water reclamation in water allocation
planning, including the development of specific legislation for industrial
water use and disposal.

/pdf/water-reclamation-for-industrial-use-in-sub-saharan-africa-a-123232ddzz.pdf

Water reclamation for industrial use in sub-Saharan Africa – a critical review

Hydrogeochemical aquifer characterization and its implication for groundwater development in the Maputo district, Mozambique

https://doi.org/10.1016/j.jenvman.2021.114285

Out of sight, out of mind: Understanding the sanitation crisis in global South cities

In Maputo, the capital of Mozambique, nitrate concentrations above 250 mg L−1 in groundwater have been reported. This happens due to the widespread use of latrines and septic tanks that allow for constant infiltration of its content into the soil and eventually to groundwater sources, a situation that is widespread in the Global South and represents a serious threat for human health and for the environment. This is a reflection of limited access to safe and adequate sanitation services, which the local authorities have set to improve in the forthcoming decades with a recently commissioned city-wide sanitation masterplan serving as a basis for the works. In this article, we aimed at understanding whether the infrastructure projected in the masterplan would lead to a reduction of nitrogen reaching groundwater. Currently, according to our calculations, almost 500 tonnes of nitrogen reach the city’s groundwater sources each year, with the masterplan potentially resulting in a 14% reduction, a small reduction due to its reliance on maintaining and expanding fecal sludge services, without considering investments to improve domestic systems (e.g., construction of contained systems). An alternative, not presented in the Masterplan and put forward by the authors, could be the construction of simplified sewers in two of the city’s most densely populated neighborhoods, with a potential 29% reduction in nitrogen reaching groundwater.

/pdf/mitigation-potential-of-sanitation-infrastructure-on-18se2r3sab.pdf

Iana Câmara Salim

Papers

Mitigation Potential of Sanitation Infrastructure on Groundwater Contamination by Nitrate in Maputo