Cork Lower Harbour Main Drainage Project
Cobh Dockyard to Monkstown culvert

For decades, up to 40,000 tonnes of untreated wastewater flowed directly into Cork Lower Harbour at the mouth of the Lee River every day. In order to protect the environment, the drainage system of the towns of Cobh and Monkstown as well as larger parts of the harbour area are being modernised or newly constructed as part of extensive infrastructural investments. A pipeline network of 30 km is being laid, along the route of which 4 pumping stations are being rehabilitated and 15 new stations are being built. One of the most interesting challenges of this project is the culverting of the Lee River to connect the sewage pipeline from Cobh to Monkstown with continuation to the newly built sewage treatment plant in Shanbally. A 400 tonne HDD Rig is used to pull in 2 parallel pipelines of dimension 500mm with a length of 1,100m in one go - the longest HDD drilling in Ireland to date. In order to be able to realise the high tensile forces required for this individual length, the network operator Irish Water opted for a PE100 pressure pipe in SDR stage 9 of the type GEROthen^® from Gerodur.