How to Rehabilitate 2,150 Meters of Drinking Water Pipeline with Trenchless Technology in Turin
In the spring of 2024, the trenchless rehabilitation of a 2,150-m long cast-in-situ reinforced concrete drinking water pipeline was carried out in the Italian city of Turin using the SAERTEX-LINER® H2O Type S+ XR Hygienic from SAERTEX multiCom. The old drinking water pipe DN 1000 mm, which has been rehabilitated, is located in a densely populated residential area in the west of Turin and extends into the neighboring municipalities of Collegno and Grugliasco.
The SMAT Group – Società Metropolitana Acque Torino is responsible for water supply as well as wastewater management and treatment in the Turin region. This rehabilitation project was part of a public procurement aimed at renovating the drinking water supply system of Turin and the Collina Torinese area with trenchless technologies. One of the main challenges of the rehabilitation project was the pipeline’s route, which passed through a residential area near both road and rail traffic. The construction work aimed to minimize the impact on residents and existing infrastructure.
To select the most suitable rehabilitation technology, detailed inspections of the drinking water pipeline were conducted first. These inspections primarily involved a video inspection of the pipeline and computer-aided calibration using laser technology, fundamental because of the variability of the pipe diameter due to the cast-in-situ reinforced concrete. This allowed the average internal diameter of the existing pipe to be measured in detail at 5-centimeter intervals. Based on the collected data, all relevant points of the rehabilitation process were documented. The measured values and the location of the pipeline within a densely populated area with heavy traffic ultimately led to the decision to employ trenchless rehabilitation using the SAERTEX-LINER H2O Type S+ XR Hygienic with a wall thickness of 9.3 mm. The smooth surfaces of this rehabilitation solution, combined with the thin walls, ensure maximum flow rates, which is particularly important in densely populated regions like Turin to optimally supply the population with drinking water.
Additionally, the close-fitting, standalone GRP liner takes on both internal and external loads, withstands up to 33 bar of pressure, and is classified as a Class A (DIN EN ISO 11295) or Class IV (AWWA M28) liner. With over 13 certifications worldwide and more than 400 successful installations, the SAERTEX-LINER H2O has proven itself globally.
For the rehabilitation project, the entire 2,150-m long pipeline section was divided into 20 segments, the longest installed SAERTEX-LINER H2O was 147 meters long, which were first manually rehabilitated to close any cracks in the pipeline. The detailed data collected during the inspections enabled SAERTEX multiCom to produce perfectly fitting GRP liners for each segment. To minimize the construction period, the installation of the GRP liners was successfully carried out by three companies– ROTECH as the main installation company, Idroambiente and Benassi. The total cost of the project amounted to €3,300,000. Thanks to the excellent collaboration among all project partners, the drinking water pipeline was rehabilitated within a short time and successfully returned to operation in June 2024 after pressure testing.
