Sanitation is the management and disposal of different types of wastes including human waste, to minimise harmful effects to human health and the environment.

The full cycle of sanitation (FCS) includes five stages, namely,
1) safe containment (consisting of toilets and septic tanks/drainage systems),
2) safe emptying services like de-sludging,
3) safe transport of waste by trucks,
4) safe treatment in sewage treatment plants / fecal sludge treatment plants and
5) safe disposal/reuse. The stages are explained in the diagram below.

Containment in full cycle of sanitation is the stage where the human waste is collected through toilets and stored in a containment structure like a septic tank or a twin pit.

Toilets are physical structures/buildings where human beings defecate. Toilets are of three types:
1) Individual Household Toilets,
2) Community Toilets and
3) Public Toilets.

Toilets that are with the premises of an individual house and are used by the people living in that house are called individual household toilets.

Toilets that are situated in a common place where certain number of families living within a community can use are called community toilets.

Figure 3: Community Toilet
Source: (Indian Institute for Human Settlements, 2017)

Toilets that are available in public places like bus stand, railway station, or parks are called public toilets.

Figure 4: Public Toilet
Source: (Indian Institute for Human Settlements, 2017)

Toilets are classified depending on their sanitary status. 1) Sanitary Toilet, and 2) Insanitary Toilet.

A sanitary toilet is a toilet which is connected to a septic tank or a twin pit because of which the waste does not leak into the environment.

An insanitary toilet is a toilet (such as pit latrines) where the human waste leaks into the environment as the toilet is not connected to any safe containment structures like septic tank or twin pit.

A septic tank is a rectangular structure placed underground to collect and store human waste coming from the toilets from which it is periodically emptied. The outlet of a septic tank is connected to a soak pit.

A soak pit is also a containment structure where the partially treated human waste from septic tank is collected and stored.

Septic Tank is a type of on-site system which is connected to the toilet, into which the fecal matter flows after being flushed. An ideal septic tank should have a minimum width of 750 mm and liquid depth of 1 m. The length should be 2 to 4 times the width. The dimensions of septic tank vary with the number of users. (Suitable sizes of septic tank are given in in the Operative Guidelines for Septage Management for Local Bodies in Tamil Nadu, 2014)