- Mahanagar Sewerage Pipeline
- Gomti Nagar Sewerage Pipeline
- Kanpur nagar Sewerage Pipeline
- Agra Sewerage Pipeline
- Allahabad Sewerage Pipeline
As India develops, the population of the major cities keeps increasing and consequently the country needs to attend the growing demand for water supply and sewage. This is why Delhi Jal Board (DJB) -the government institution which manages the water supply, sewerage and drainage within the National Capital Territory of Delhi- is currently laying a 59km long sewer at the depth of 6 to 18 metres along the Yamuna river. The target is to contain pollutants from being released into the river by the three major drains, sending the untreated sewage to the existing Treatment Plant and allowing only treated effluent into the three drains.
The Project is divided into six packages, the works of two of them -Packages 4 and 5- were awarded from DJB to the Joint Venture formed by the companies DS Construction, Fegshun and Wabag. In order to complete part of the pipe jacking works of the Package 4, the JV acquired from TERRATEC a DN1600 Microtunnelling System composed of a Slurry MTBM, Slurry Transport System, Main Jacking Station, Intermediate Jacking Stations, Lubrication System and Separation Tank.
The hydraulic design of sewers and drains, which means finding out their sections and gradients, is generally carried out on the same lines as that of the water supply pipes. However, there are two major differences between characteristics of flows in sewers and water supply pipes. They are:
- The sewage contain particles in suspension, the heavier of which may settle down at the bottom of the sewers, as and when the flow velocity reduces, resulting in the clogging of sewers. To avoid silting of sewers, it is necessary that the sewer pipes be laid at such a gradient, as to generate self cleansing velocities at different possible discharges.
- The sewer pipes carry sewage as gravity conduits, and are therefore laid at a continuous gradient in the downward direction upto the outfall point, from where it will be lifted up, treated and disposed of