Installing a new gravity sewer into a deep wastewater pumpstation required trenchless construction from within the pumpstation’s temporary works. Kerry Drainage & Civil used its Perforator Micro-tunnel drill to install the new inlet while working on the critical path for the wider pumpstation project.
Kerry Drainage & Civil was engaged by Pipeline & Civil to construct the gravity inlet for the new Judges Bay Wastewater Pumpstation being delivered for Watercare.
The new gravity inlet was required to connect an upstream manhole more than 6m deep to the new pumpstation. With significant depth and tight site constraints, conventional installation methods were not practical.
Kerry Drainage & Civil developed a trenchless solution using its Perforator Micro-tunnel drill. The drill was set up within the secant-piled temporary works constructed for the main pumpstation, allowing the gravity sewer to be installed without extensive excavation through the constrained site.
The location of the drilling operation created an additional project challenge. Because the drill was operating within the temporary works for the main pumpstation, KD Civil’s installation was on the critical path for the wider project. Careful planning and sequencing were therefore essential to ensure the gravity inlet could be installed without delaying subsequent pumpstation works.
The gravity sewer was successfully installed using DN225 PVC Restrain pipe, with 1m pipe lengths installed from a small manhole shield at the upstream end. The trenchless approach provided the required connection while working within the restricted footprint and deep excavation associated with the new pumpstation.
