Quantities and qualities of fecal sludge: Experiences from field implementation with a Volaser in 7 countries during a pandemic

Reasonable estimates for quantities and qualities (Q&Q) of fecal sludge that accumulate in onsite sanitation containments are fundamental the design appropriate management treatment solutions, from community to city-scale. There increasing attempts improve Q&Q estimates, but current approaches still at a conceptual level, not yet standardized with confirmed statistical relationships. To reach this we will need consistent planning, measuring, global collaborations. Hence, objectives study were: (1) assess compare seven cities communities, explore relationships could be used increase accuracy estimations; (2) test launch Volaser device measuring situ volumes sludge; (3) capture lessons learned field implementation collaborators countries during pandemic when no international travel was possible. The took place Ghana, India, Lebanon, Kenya, Sierra Leone, Uganda, Zambia COVID-19 pandemic. Q&Qs were measured 204 Volaser, laboratory analysis, questionnaire. Results indicate there differences Total Solids (TS) Chemical Oxygen Demand (COD) based on containment type, toilet source, whether is water connection premises. Based results study, together previously published open-source data, an empirical relationship Volatile (VS) TS 0.49 ( R 2 = 0.88) established using 1,206 data points. For COD/TS, significant observed. Developing such useful planning modeling approaches. An external evaluation conducted evaluate overall project management, technology transfer, effects collaborating Success factors new existing partners without face-to-face meetings included capacity experience analytical methods, relevant partner locality, strong quality assurance plan ensure comparability results. can taken forward as ways reduce carbon footprint, contribute resilient, inclusive development research projects.