Safely Managed Sanitation for All Means Fecal Sludge Management for At Least 1.8 Billion People in Low and Middle Income Countries.

Although global access to sanitation is increasing, safe management of fecal waste is a rapidly growing challenge in low- and middle-income countries (LMICs). The goal of this study was to evaluate the current need for fecal sludge management (FSM) in LMICs by region, urban/rural status, and wealth. Recent Demographic and Health Survey data from 58 countries (847 685 surveys) were used to classify households by sanitation facility (facilities needing FSM, sewered facilities, ecological sanitation/other, or no facilities). Onsite piped water infrastructure was quantified to approximate need for wastewater management and downstream treatment. Over all surveyed nations, 63% of households used facilities requiring FSM, totaling approximately 1.8 billion people. Rural areas had similar proportions of toilets requiring FSM as urban areas. FSM needs scaled inversely with wealth: in the poorest quintile, households' sanitation facilities were almost 170 times more likely to require FSM (vs sewerage) than in the richest quintile. About one out of five households needing FSM had onsite piped water infrastructure, indicating domestic or reticulated wastewater infrastructure may be required if lacking for safe management of aqueous waste streams. FSM strategies must be included in future sanitation investment to achieve safe management of fecal wastes and protect public health.