The Bombay Sewage Disposal Project is a part of Mumbai city infrastructure for sewage disposal. The project includes Construction of Marine Outfalls at Bandra & Worli, Bandra Influent & Effluent Disposal Works, Aerated Lagoons at Bhandup & Ghatkopar at the Mumbai Shore lines in addition to various other components of the project. The marine Outfall tunnel was constructed at 65 m below ground level rising to 35 m below sea bed for a length of 3.7 km from shore to dispose degritted sewage at Worli and Bandra. The sewage is finally discharged into the sea through ten riser pipes of GRP surrounded by precast blocks and rock armour for protection against sea waves. Two marine dolphin posts are also constructed in the sea for marking the diffusers of the outfall. The construction was carried out using compressed air caissons and with divers.