Example of sewerage system rehabilitation using trenchless technology

The sewerage network in Poland, built in the early 20th century, has been losing its original water-tightness and flow capacity. To bring these characteristics back, rehabilitation works are performed. The initial capacity of sewers can be restored without affecting the urban environment thanks to the trenchless technology. The sewer subjected to rehabilitation receives a new internal leakproof layer capable of preventing groundwater infiltration as well as sewage leaks, which can contaminate the environment. This paper intends to compare the trenchless technology with traditional open cut trench excavation. In the study, two variants of trenchless rehabilitation were considered: one performed with the help of GRP panels and the other using cured-in-place pipe (CIPP) lining. Flow velocities and flow rates in the sewers before and after rehabilitation were compared. Also, selected economic and environmental aspects of sewer rehabilitation methods were examined.