The Missing Piece in Wastewater Management for Developing Countries
The problem with wastewater management in developing countries like Nigeria is that its citizens fail to understand the health hazard associated with wastewater. In 2018, The Guardian newspaper reported that residents in Lagos State were concerned about the deterioration of the wastewater treatment plants in the area, as the untreated effluents from these plants freely flowed into their homes seeped into groundwater which is their primary source of drinking water. Although they were concerned about it, there were no protests or public demands for the government to act, so the problem was left unresolved to date. Hence, these people live in areas where wastewater and open defecation is normalized.
Recognizing what wastewater is and its potential hazard is an initial step to solving the sanitation challenge in developing countries. According to Kamal and his colleagues, wastewater is any used water generated from various sources such as households, industries, commercial properties, and rainwater run-off. In developing countries, especially in Africa, the primary source of wastewater is from household uses, making sanitation and hygiene a paramount issue for its citizens. According to the United Nations (UN), identified examples of household wastewater consist of blackwater (excreta, urine, and fecal sludge) and greywater (kitchen and bathing water). The increasing urbanization of areas in Africa and other developing countries have made policymakers and world organizations such as the UN reconsider ways to manage wastewater.
Wastewater: A Health Hazard
According to the World Health Organization (WHO),, 2.5 billion people worldwide are at risk of many water-borne diseases such as dysentery, cholera, typhoid, trachoma, schistosomiasis, and intestinal worms as a result of poor sanitation. In Nigeria, the UN estimates that nearly one-third of the population lacks access to improved drinking water sources, and approximately two-thirds live without adequate sanitation facilities, which proves the need to manage wastewater effectively. In a commercial city like Lagos, 94% of Lagosians have no access to sanitary toilets.
Furthermore, the magnitude of the problem can be seen all over Nigeria, where only 23 out of 774 Local Government Areas (LGAs) are open defecation free. This problem has prompted the UN to disburse $60.4 million for the Water, Sanitation, and Hygiene (WASH) program, which focuses on solutions to manage Water, Sanitation, and Hygiene challenges in Nigeria. Under the four-year program, 500,000 families in six states are expected to have access to clean water and improved sanitation.
The Economics of Wastewater
Even though progress has been made through the WASH program, wastewater treatment in developing countries remains problematic. In developed countries, wastewater has been acknowledged as an economic and social development catalyst that can be transformed into clean water, nutrients, energy, and ash for fertilizers. The UN recognizes that the financial cost of achieving sustainable wastewater treatment facilities cannot solely rely on the public sector but must be supported by the private sector to achieve its goals. But the big problem to that statement is investors only view wastewater management and sanitation projects as a cost. To change this narrative, entrepreneurs and innovators must come up with ways of transforming wastewater from significant health and environmental hazard into a clean, safe, and economically attractive resource.
Deciding on the right system to treat wastewater can help achieve the above goal. There are two major systems recognized in treating wastewater: Centralized Wastewater Treatment System (CWTS) and Decentralized Wastewater Treatment System (CWTS). The CWTS is a treatment facility where the wastewater collected from multiple households is treated at a central location and disposed into a water body. In DWTS, the wastewater generated comes primarily from nearby single homes. The wastewater is collected, treated and disposed of, at or near the source.
Centralized Wastewater Treatment System in Nigeria
I grew up in the older parts of Abuja, which had the earliest city development plan and so we used a CWTS. I never had to see wastewater pumped out from septic tanks as we had pipes underneath the ground that transported wastewater to the central treatment facility. Unfortunately, this is not common in other areas of Nigeria, where the septic tank is more of the norm.
According to a study by Sunday Adesogan, there are only about 22 partially functional wastewater treatment facilities, and they are in almost the same parts of the country. Here is a map of the location of wastewater treatment facilities:
From the map, it can be observed that there is only one functional system in the North and only one in the Southeast, while the majority are situated in the South-south and Southwestern states. Most areas without a treatment facility rely on the septic tank for wastewater management.
Examples of Decentralized wastewater treatment system
When it comes to wastewater management for developing countries, decentralized wastewater treatment systems have been considered the best option as they are cheaper and require less technical know-how to manage it effectively. However, a country like Rwanda disagrees and is set to build a CWTS for Kigali City. When I read the story, honestly, I was impressed. I felt it was a bold and audacious step by the government since they were willing to invest 96 million pounds to achieve this facility. Kigali is said to be the cleanliest city in Africa and is one city I would love to visit.
Various types of DWS include:
- Septic tank
- Constructed wetland
- Onsite DWS: e.g. Bill Gates Reinvented Toilets
- Cluster DWS: e.g. Janicki Omni-processor
I will be elaborating on each of these systems and its potential to be the missing piece in wastewater management for developing countries like Nigeria in the coming weeks.
- A. S.M. Kamal, K. Goyer, T. Koottatep & A. T.M.N. Amin (2008) Domestic wastewater management in South and Southeast Asia: the potential benefits of a decentralized approach, Urban Water Journal, 5:4, 345-354, DOI: 10.1080/15730620802030056
- 2. United Nations (2019). Advocating for more Wastewater Management. https://sustainabledevelopment.un.org/topics/water/unsgab/wastewater
- Rwanda: Capital Kigali gets Central Sewerage System (2020). Afrik21.
- The Guardian newspaper(2018). Lagos Wastewater Plants Packs Up, Sparks Epidemic Concern. https://guardian.ng/property/lagos-wastewater-plants-pack-up-spark-epidemic-concerns/
- Wateraid (2020). Water, sanitation and hygiene capacity building and research programme to run in selected Nigerian universities- FG. https://www.wateraid.org/ng/press-releases/water-sanitation-and-hygiene-capacity-building-and-research-programme-to-run-in
- Samuel Oji Iheukwumere, Philip O. Phil-Eze, Kelechi Friday Nkwocha, Chukwuma Patrick Nwabudike, Peter Peter Umeh (2019). Assessment of Domestic Wastewater Disposal in Anambra State, South-East Nigeria. https://www.rsisinternational.org/journals/ijrsi/digital-library/volume-6-issue-4/190-199.pdf
- Sunday Adesogan (2013). Sewage Technology in Nigeria: A Pragmatic Approach. https://www.researchgate.net/publication/331096409_Sewage_Technology_in_Nigeria_A_Pragmatic_Approach
The Missing Piece in Wastewater Management for Developing Countries