HILLCREST CATCHMENT SEWER AMPLIFICATION

Photo: (top right) 450mm diameter drill string ready for installation. (centre right) drilling rig and mud mixing plant setup. (bottom right) 210m of 630mm diameter drilling string on rollers. (below) Pedestrian access over 800mm diameter drill string.

The Hillcrest  sewer catchment project was designed by the SKM/OPUS partnership with the North Shore City Council to prevent wet weather overflows  due to an under capacity  trunk sewer and infiltration.

 

CDS New Zealand Limited was contracted as the head contractor by the North Shore City Council to carry out the installation of the new 1.4km trunk sewer. The majority of the new sewer was installed in the carriageway and ranged in size from 355mmOD to 800mmOD PE sewer pipe.

 

All new pipelines were installed using the Ditch Witch JT8020 directional drilling with required grades often below 1%. The project scope also involved the installation of fourteen new manholes at depths of up to 5m and eight live connections to the existing sewer network.