title: Economic viability and critical influencing factors assessment of black water and grey water source-separation sanitation system.
abstract: The black water and grey water source-separation sanitation system aims at efficient use of energy (biogas), water and nutrients but currently lacks evidence of economic viability to be considered a credible alternative to the conventional system. This study intends to demonstrate economic viability, identify main cost contributors and assess critical influencing factors. A technico-economic model was built based on a new neighbourhood in a Canadian context. Three implementation scales of source-separation system are defined: 500, 5,000 and 50,000 inhabitants. The results show that the source-separation system is 33% to 118% more costly than the conventional system, with the larger cost differential obtained by lower source-separation system implementation scales. A sensitivity analysis demonstrates that vacuum toilet flow reduction from 1.0 to 0.25 L/flush decreases source-separation system cost between 23 and 27%. It also shows that high resource costs can be beneficial or unfavourable to the source-separation system depending on whether the vacuum toilet flow is low or normal. Therefore, the future of this configuration of the source-separation system lies mainly in vacuum toilet flow reduction or the introduction of new efficient effluent volume reduction processes (e.g. reverse osmosis).
authors.affiliation: Département de génie de la construction, STEPPE-École de Technologie Supérieure, Montréal, Québec, Canada. charles.thibodeau.1@ens.etsmtl.ca
authors.forename: C
authors.initials: C
authors.lastname: Thibodeau
authors.forename: F
authors.initials: F
authors.lastname: Monette
authors.forename: M
authors.initials: M
authors.lastname: Glaus
authors.forename: C B
authors.initials: CB
authors.lastname: Laflamme
mesh_terms: D003246:Conservation of Energy Resources; D018803:Models, Economic; D012498:Sanitary Engineering / Q000191:economics* / Q000379:methods*; D014865:Waste Disposal, Fluid / Q000191:economics* / Q000379:methods*; D014874:Water Pollutants, Chemical
chemical_list: D014874:Water Pollutants, Chemical