Sludge is a mixture of solids and liquids, containing mostly excreta and water in combination with sand, grit, metals, trash and/or various chemical compounds.
Faecal Sludge comes from onsite sanitation technologies, i.e. it has not been transported through a sewer. It can be raw or partially digested, a slurry or semisolid, and results from the collection and storage/treatment of excreta or blackwater, with or without grey water.
Septage or septic tank sludge is a term used to describe the partially treated sludge stored in a septic tank. It is one type of faecal sludge.
Faecal Sludge Management is a set of solutions that address the lack of training, regulation, and awareness of treatment options. A centralised treatment plant safely treats fecal sludge for proper disposal.
About 70% of Indian population has toilets connected to septic tanks/soak pits. These on-site systems are periodically emptied using 'Honey Sucker' trucks. The operators are untrained and do not follow safe practices. The faecal sludge is typically dumped without treatment into nearby water bodies and vacant land.