Though both mechanical and biological-based technology were used in TN, nonmechanised system using a combination of sand drying beds and constructed wetlands were used in most of the ULBs. Among the non-mechanised gravity based FSTPs, there were two variants of biological-based process used- in ULBs where fresh/ undigested fecal sludge (from Community toilets, hostels and other places where holding tanks collect fecal waste and have to be regularly emptied) was expected, fecal sludge stabilisation unit was included in the treatment process, whereas in other ULBs this is not present