Leak-tight thanks to MC injection technology

The Tietê Project is considered one of the largest wastewater infrastructure development undertakings in Brazil. Since 1992, 1.8 million sewage connections have been installed in the São Paulo metropolitan region, with some 5,000 km of pipes and channels having been laid to collect wastewater underground and transport it to the region’s sewage treatment plants. As part of this network, the second section of an interceptor sewer was installed along the banks of the Tietê River in São Paulo in the mid-2000s. However, this was only connected to the main system in 2021 as part of the ITI 2 project phase. The remit included the construction of new manholes and sewers and their connection to the main interceptor, as well as the sealing of all leakages between the concrete joints. The client and planner was the company SABESP, which is responsible for both water supply and sewage disposal in 375 municipalities in the state of São Paulo. SABESP is regarded as one of the largest sewage utilities in the world. The construction and refurb work was entrusted to the AEE ITI 2 consortium comprising three São Paulo companies specialising in wastewater infrastructure: Aliter, Enpasa and Etesco. SABESP’s main concern was, firstly, to prevent any leakage of wastewater into the subsoil in order to ensure the long-term stability of the sewer pipes and the road above, and secondly, to stop the infiltration of groundwater into the sewers and thus reduce the amount of wastewater requiring treatment.