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How to improve Sewage management in Nigeria


Sewage management remains a pressing challenge in Africa’s most populous nation, Nigeria. With over 200 million people, Nigeria generates massive volumes of sewage from homes, businesses, institutions, and industry.

However, investment and infrastructure for sewage treatment have not kept pace with rapid population growth and urbanization. As a result, the bulk of untreated sewage ends up discharged into the environment, causing severe pollution and public health hazards. This article delves into the key issues, impacts, causes and potential solutions to address the sewage crisis in Nigeria for improved sanitation outcomes.

The scale of the crisis

  • Only 16% of Nigerians have access to sewer connections able to safely remove waste according to the World Bank
  • 92% of sewage generated is released untreated into the environment per Nigeria’s National Water Resources Institute
  • Nigeria ranks second lowest in Africa on sanitation access according to the Sanitation and Water for All partnership

Health burden

  • Diarrhea is the fourth biggest cause of death in Nigeria, responsible for over 150,000 deaths annually as per the Global Burden of Disease Study
  • Nigeria has Africa’s highest number of people practicing open defecation – over 46 million people
  • At least 123,000 children under 5 years die each year from diarrhoea due to poor WASH practices

Weak and outdated infrastructure

Existing sewage systems constructed mainly during the 1970s and 80s were not designed for current population sizes. Treatment plants, sewer lines and pumping stations are outdated and frequently break down. Where facilities exist, operations and maintenance are typically inconsistent due to funding shortages and skills gap. This leads to system failures.

Limited institutional capacity

The agencies responsible for sewage management in states and local government areas are generally understaffed, underfunded and lack adequate expertise. Policies and standards for sewage disposal are often outdated or poorly enforced due to institutional weaknesses. These all contribute to poor outcomes.

Low investments

Government spending on sewage management remains dismal – just 0.14% of the total national budget in 2018. This works out to less than 2USD per person annually, far below the over 100USD recommended to meet SDG sanitation targets. The costs of upgrading systems are also quite prohibitive for lower-tier governments.

Technological limitations

Conventional centralized sewage systems require advanced technical expertise and significant energy inputs to operate, which poses challenges. Frequent power outages undermine systems. Spare parts are difficult to procure locally. Alternative decentralized systems which require less maintenance have been slow to gain traction.

Poverty and access to finance

With about 40% of the population living below the poverty line, many households cannot afford the high initial cost of installing flush toilets and septic systems. Public toilets are limited. Microfinance products to help construct toilets are still not widely available. This constrains access.

Social and cultural behaviours

While open defecation has reduced, about a quarter of the population still practices it. Some view faecal matter as harmless. Septic tanks are often poorly maintained or abandoned when full instead of being emptied. Such behaviours hinder adoption of hygienic sanitation practices.

Environmental and health impacts

Water pollution

The bulk of raw sewage and effluent from failed treatment systems ends up in rivers, lakes, and coastal waters around Nigeria through drains and runoff. Studies consistently show high fecal bacteria levels and presence of hazardous pathogenic organisms in surface water bodies. This renders them unsafe for drinking, recreation, or aquaculture.

Groundwater contamination

On-site systems like latrines and septic tanks located too close to water wells or constructed without concrete lining leach pathogens and nutrients like nitrates into groundwater aquifers. A study by Orebiyi et al in Ibadan found 55% of sampled wells contained nitrate above safe levels, indicating contamination by sewage intrusion.

Blocked drainage and flooding

Indiscriminate dumping of fecal sludge into storm drains and waterways blocks drainage channels. This contributes to frequent cases of flooding during rainy seasons, further spreading fecal contaminants into flood waters.

Loss of biodiversity

The discharge of organic, nutrient-rich sewage into lakes triggers algal blooms and excessive plant growth. This leads to eutrophication, loss of oxygen and eventual die-off of aquatic life forms, negatively impacting biodiversity. An example is the Lagos Lagoon which receives tons of untreated sewage yet could support a vibrant ecosystem.

Diseases outbreaks

Sewage contamination of drinking water supplies is the major pathway for transmission of diarrheal diseases. Bacterial pathogens in feces can survive for long periods in the environment. Common illnesses from ingesting or coming in contact with such pathogens range from typhoid, diarrhea, dysentery, cholera and hepatitis A. Regular disease outbreaks occur during rainy seasons.

Solutions and recommendations

Greater Investments in infrastructure

  • Federal government needs to follow through on its commitment to dedicate budget funding for urban sanitation and sewage management.
  • Funding should prioritize rehabilitation, upgrading and expansion of sewage treatment plants to improve their operational capacity and performance.

Strengthening institutional capabilities

  • Hire and train more personnel on sewage system operations, maintenance, and management.
  • Provide adequate budgets for procurement of treatment chemicals, tools, protective gear.
  • Implement rigorous inspection, monitoring and enforcement of effluent standards.

Leveraging appropriate technologies

  • Promote affordable decentralized systems like DEWATS, biogas generators, anaerobic baffled reactors for communities lacking sewers.
  • Implement NAWASS policy promoting reuse of treated wastewater for irrigation, industry etc.
  • Pilot eco-friendly systems like constructed wetlands for wastewater treatment.

Building local capacity

  • Train masons, plumbers and engineers on design, construction and O&M of decentralized sewage systems
  • Introduce sanitation curriculum in schools to build awareness and skills early.
  • Support local artisans and SMEs to make parts, tools and protective equipment locally.

Community engagement and hygiene promotion

  • Work with traditional and religious leaders to debunk negative myths and perceptions regarding human waste.
  • Use social media, radio and SMS campaigns to promote positive sanitation behaviors.