The project entailed the design, engineering, procurement and construction of a 560m long DN 630 HDPE 100 PN 16 Sewer Rising mains pipeline to be installed using the Horizontal Directional Drilling method at Barwon Heads near the mouth of the Barwon River.

Coe Drilling mobilised to site in September 2010 following design approval and set up site at the Ocean Grove side of the river.

The CoeDrill 210 was supported by a NF1000 Mud Pump and 1000GPM Mud System.

The CoeDrill 210 was selected as the most appropriate HDD rig to use due to the limited clearing permitted at the site and following site establishment the Pilot Hole was completed in less than 7 days using a 6 •••” mud motor and 9 7/8” Drill Bit. A temporary steel mud return pipeline was installed across the river bed to allow controlled transfer of the drilling fluids during the hole opening operations. The final 32” dia borehole was completed with three reaming pass after which a cleaning pass was completed to ensure the integrity of the borehole prior to pipeline installation. The formation within which the majority of the drilling occurred was Basalt bedrock.

The DN 630 HDPE 100 PN 16 Pipeline string was fabricated in a nearby park before being manouvered into position for the pullback.

The pipeline was installed and following a Hydrostatic test, Coe completed the tie in connections and installed pigging traps and isolation valves. The completed works were handed over to Barwon Water Alliance in early December 2010.