Construction of Bio-Toilet

Bio toilet is a decomposition mechanised toilet system which disintegrates and decomposes the human waste into water and biogas. Bio-toilet can be defined as a system in which human waste is biologically degraded into gas and water with minimal water.The decomposition is carried out by bacteria in the Bio-digestion tank. Bio-toilets are environment-friendly, low on maintenance, reduce the sewage problem and also reduces the water consumption in the toilets. Bio Toilets saves a lot of water and helps in keeping the environment clean. These bio-toilets can be installed anywhere avoiding the need for a big septic tank or a sewage facility.

Sewa team worked with engineers from IIT Delhi for the design and construction of the bio digester pit. The pit is cauldron shape built with bricks as per the design specifications below.

Over the cauldron shape radius,an outlet is made for the water to exit. The water outlet pipe can be connected to the farm etc. The inlet pipe is connected to the toilet unit. At the top of the dome (in the upper part),the gateway for gas pipeline is attached.

In a Bio Toilet design, rotten stool in contact with the bacteria in the bio digester chamber produces methane gas,Carbon-di-oxide and water.This gas is released into the atmosphere and the water is left in the fields so that it can be used in irrigation.The methane gas can be stored to use in the Kitchen stove or used in the methane generator to produce the electricity. It is an innovative method to decompose waste in an eco-friendly and economical manner.

Sewa started building bio toilet units in 2018. Since then, we have built bio toilets across many locations in India.

We have two toilet unit models that are connected to the bio digester pit :

First one is brick and motor non portable model suitable for permanent residents of Rural areas with low cost bio digesters.

Second one is portable prefabricated ferro cement slab toilet unit with low cost bio digester suitable for both Urban and Rural areas.

It takes us 4-5 days to build the toilet unit and the bio digester pit


• Hallow block/bricks.

• Any good brand cement - Ultratech cemento Ambuja cemento ACC & Birla cement..etc..

• White sand/Sand.

• Stone pieces.

• Concrete moulding/Prefabricated galvanised aluminium sheet for roof & rust proof angles.

• Rust proof PVC/Zinc coated hinges, Nuts & bolts.

• Normal Paint/white coating with chalk/Red oxide coating.

• 6 inch good quality Sanitary Pipes & 2 inch good quality fresh water pipes - Ashirvad CPVCo Finolex CPVCo Astral CPVCo Astral CPVC

• Concrete rings for soak pit/Bio Digester with concrete/Septic tank based on agreements.

• Red Oxide or floor tiles if needed.

• Rust proof painted metal doors/PVC doors/Wooden doors with rust proof metal coated sheets.

• Any good brand Indian toilet seat. - Hindustan & TOTO , Parryware, cera & Kohler.


• 4ft Deep foundation for toilets block/2 ft deep for an individual unit.

• Walls should be min 7ft height. 6ft height doors. 4:4 Inner dimension for an individual toilet.

• Soak pit of min 5:6ft & 6 ft deep for an individual unit.

• Natural ventilators with windows.

• Plastering Inside and outside as well.

• Small 2ft cement platform in front of the toilet.

• Concrete made Wash basin if needed.

• Kadapa stone for urinals partition.