Pitt St wastewater renewal



Wellington Water


Connect Water


August 2023


Mobile Plant Fleet,Underground Services,Traffic Management,PE Welding, HDD Pit Drilling

Customer type:

Government & Local Government


Renew approximately 105m of 160OD PE100 SDR17 wastewater main, including all lateral connections to the boundary.

This was a small job that we delivered efficiently and to a high standard using trenchless techniques including dynamic pipe bursting and Horizontal Directional Drill (HDD) Pit Drilling to reduce disruption, risks associated with excavation and the amount of waste generated. 

To work in this steep, narrow street, traffic management planning team secured a closure of the street so that the work could be carried out safely and efficiently.


To address the constraints around excavation next to an existing retained slope - with limits on the length of allowed excavation - we used dynamic pipe bursting to install the main, reducing the amount of excavation required. This also reduced disruption, waste removed from site and carbon emitted by the construction project.


Meanwhile, we used the pit drill to install the wastewater main in a  footpath with constrained set back, The drill was able to be positioned on grade and alignment of the pipe so that the set back requirement was eliminated. A smart technique for this type of application.