Faecal sludge management is a management system that safely collects, transports and treats faecal sludge (also called septage) from pit latrines, septic tanks or other on-site sanitation facilities. Selecting the most suitable faecal sludge treatment technology is not only about providing the best technology at the lowest cost, but also about sustainability, including social and environmental acceptance, and institutional feasibility. Faecal sludge is an offensive material that contains pathogens, can generate odours and cause surfacewater as well as groundwater pollution. It is raw or partially digested, slurry or semisolid form, the collection, storage or treatment of combinations of excreta and black water, with or without grey water. It is the solid or settled contents of pit latrines and septic tanks. It differs from sludge produced in municipal waste water treatment plants.
Faecal sludge characteristics can differ widely from household to household, from city to city, and from country to country. The physical, chemical and biological qualities of faecal sludge are influenced by the duration of storage, temperature, soil condition, and intrusion of groundwater or surface water in septic tanks or pits, performance of septic tanks, and tank emptying technology and pattern. Characteristics of faecal sludge may vary widely due to climate, toilet type, diet and other variables. Performing a waste characterization study to understand local conditions provides data that factor into treatment plant sizing, as well as estimating the value of the products that can be derived from the treatment process.