Greenhouse gas emissions from container-based sanitation systems in East African cities: a case study in Nairobi, Kenya

ABSTRACT Sanitation systems emit greenhouse gases (GHGs), which are estimated to comprise 3% of global emissions and pose challenges to sustainable development goals (SDGs), specifically SDG 13 and SDG 6.2, which are focused on climate action and sanitation. This study quantified GHG emissions from the containment component of the container-based sanitation (CBS) system, with a specific focus on Fresh Life Toilets (FLTs) in Nairobi, Kenya. Field measurements performed over 10-day studies revealed total GHG emissions of 15.72 kg CO2 eq/capita/year from faecal matter alone, excluding the emissions from urine. Nuanced variations in emissions were encountered, notably with higher methane production at the point of temporary storage (0.40 kg CO2 eq/capita/year) compared to values at capture and emptying, which were much below the detection level of the equipment used. This insight underscores the complexities of GHG dynamics within CBS systems, highlighting the ongoing necessity for research to refine and enhance precision in GHG assessments related to CBS. The results of this study contribute to elucidating the impact of climate change on CBS systems.