Integrated Wastewater Quality Assessment, Risk Analysis, and Rehabilitation Costing for Sustainable Sanitation in African Aviation Infrastructure

Abstract: The assessment of sanitation and wastewater management at Murtala Muhammed International Airport (MMIA), Lagos, was conducted to quantify sewage generation, evaluate effluent quality, and identify the rehabilitation needs of the sewage treatment plant (STP). Passenger and facility usage data indicated an annual sewage output of 1,117,087 cubic meters, equivalent to 255.04 cubic meters per day; when including contributions from service vehicles, the total increased to 275.04 cubic meters per day. Laboratory analyses revealed widespread non-compliance with benchmarks established by LASEPA, NESREA, WHO, and ICAO: treated effluent exceeded permissible limits for colour (854 Pt-Co versus 250), total suspended solids (154 mg/L versus 100), chloride (493 mg/L versus 250), chemical oxygen demand (201 mg/L versus 200), and biochemical oxygen demand (50.25 mg/L versus 20–50), while dissolved oxygen levels were critically low at 0.53 mg/L (versus ≥2). Microbial indicators persisted positive for total and faecal coliforms. Field inspections confirmed that the STP has been largely non-operational for over three years due to critical mechanical failures. The findings indicate severe risks of groundwater contamination, disease transmission, and regulatory violations. It is recommended that immediate rehabilitation, preventive maintenance, and the integration of sanitation strategies into the airport’s master plan be undertaken to restore compliance and resilience, thereby contributing to the achievement of SDG 6.