Turin Metropolitan area new median collector

In Turin, before the rain falls.

A new backbone to Turin’s sewer system will avoid overcharging the existing network and bring positive benefits to those living in no less than 80 surrounding municipalities, thanks to a reduction in pollutants in wastewater. 


Improving living conditions and environmental impact in a vast area of the region of Piedmont, south-west of Turin. This is the primary objective of an important €125 million project to design and build both a new median sewer collector and rehabilitate the existing system in the southern part of the city.

The project was created with the primary objective of avoiding overcharging Turin’s existing sewer network. The new collector represents a second backbone, parallel to the current one, now close to its maximum possible use. There is more: the work also promotes greater environmental sustainability. This is because it will also collect and store so-called “first rainfall waters”, which carry the largest number of pollutants such as hydrocarbons and mineral oils, with damaging effects on human health.

The new 14-km-long underground tunnel will be constructed using the mechanical tunnelling technique for the main and service tunnels, with the remainder of the subterranean connections completed using conventional methods. This new system will have a positive influence on 50 municipalities north of the city and another 30 to the south. How? By reducing not only the concentration of pollutants in wastewater, together with phenomena of backflow across the entire surrounding territory served by this important new project.   


A Few Numbers

The main tunnel, with an internal diameter of 3.2 meters and a length of 9.2 km, will be excavated by an EPB TBM at a depth of over 10 meters, while two micro-tunnelling machines will excavate 2.4 km of service tunnels, 1.6 and 2.2 meters in diameter. Another 250,000 cubic meters will be excavated using conventional methods. The Construction Drawings for the Turin Median Collector are currently being completed and works are scheduled to be completed in five years.