Risk concerning rehabilitation of closed sewers wth internal diameter bigger than 1 m
In the last few years there have been executed some substantial rehabilitation project that concerned sewers with diameters bigger then 1 m. Those kind of sewers are used not only for drainage, but also for the retention. That is why most valuable rehabilitation solutions in this case are those methods which do not result in a pipe diameter reduction – and that would be the CIPP or construction chemicals usage. Both of the solutions are risky and demand thoroughness.

dr inż. Leszek Wysocki, Politechnika Wrocławska
Born July 1, 1954. An employee of the Faculty of Civil Engineering of Wroclaw University of Science and Technology since 1978. Author or co-author of dozens of scientific publications (including 3 monographs) from the field of underground infrastructure and water and wastewater structures. Author or co-author of hundreds of technical expertises related mainly to the sustainability of underground structures, especially the underground network infrastructure of cities.