2006 Commonwealth Games

The following article outlines a recent trenchless technology project undertaken by Kembla Watertech for City West Water in Melbourne and how the significant site issues were managed to achieve the expected objectives.

Background

AERIAL VIEW GAMES SITEMelbourne is the host city for the Commonwealth Games in March 2006 and with an array of purpose-built arenas, stages, stadiums and theatres, there is a constant feeling of excitement and anticipation about current and upcoming festivities, as Melbourne enjoys its reputation as the events capital of Australia.

The managing authority for this sewer rehabilitation project was Melbourne’s City West Water.  City West Water is a state owned enterprise that manages water supply and sewerage services for the City of Melbourne and the Western suburbs.  City West Water delivers water through a 3,615km network of water mains to approximately 290,000 customers.  It transports sewage through a 3,142km network of sewers.  With the vast majority of Melbourne’s commerce and industry within it’s boundaries, City West Water operates the largest trade waste business in Melbourne.

The majority of Commonwealth Games venues are in City West Water’s area of operation.

Kembla Watertech Pty Ltd has a schedule of rates contract with City West Water for the provision of sewer rehabilitation services.  Kembla has worked closely with City West Water since 2001 to deliver sewer rehabilitation services ranging from sewer relining, patch repairs and civil repairs.

Project Summary

City West Water required approximately 742 metres of 300mm & 225mm diameter sewer to be relined prior to Christmas 2005 to ensure that all works in the vicinity of the Commonwealth Games athletes village were completed prior to security lock down of the area.

The project consisted of 555m of 300mm diameter sewer and 187m of 225mm diameter sewer.  The route followed by the sewer started in the middle of a busy road adjacent to a tram crossing, wound it’s way through the Royal Melbourne Hospital’s Parkville Campus, around the boundary of Commonwealth Serum Laboratories Limited (CSL), along a creek and steep embankment, through a newly constructed wetlands and ended inside the boundary of the Commonwealth Games athletes village.  The route of the sewer is outlined on the aerial photograph as is the temporary pipeline set up to bypass the sewer flow during lining installation.

A great deal of co-ordination with all of the stakeholders was necessary to ensure the work proceeded smoothly so that the full advantages of trenchless technology could be realised.  Some of the issues encountered were trade waste discharges being received into the sewer 24 hours a day, landscaping and tree planting being carried out on the site where work was being undertaken, security fencing being erected, the need to maintain unrestricted access for elderly patients being treated at the Hospital, busy roads which had to be crossed by the sewer bypass pumping lines and safe access to various other authority assets.

Installation

Time was of the essence, but it was just as critical that the work was completed safely and without any environmental incident. Kembla chose to use its Enviroliner system for this project.  Enviroliner is a form of CIPP lining which provides a structural solid wall lining in long joint free lengths.  One of the major practical advantages of the Enviroliner system is the ability to install very long lengths in a single operation. This ability to tailor make the lining length to suit specific site conditions enabled Kembla to choose start and finishing points that provided least risk and least disruption.  This project highlighted this benefit where a 320m length of 300mm diameter lining was installed through a number of intermediate access chambers in a single 24 hour operation.

The existing sewer flow had to be bypassed during the installation of the liners and this presented the major practical problem.  The difficult location of some of the access chambers, the high volume of flow, the need to maintain services to the Hospital and CSL and the crossing of major roads all had to be taken into account. The final solution was to use two 150mm diesel suction pumps and twin bypass pipelines each 800metres in length. A route was chosen to minimise disruption and pre-planning located existing stormwater drains into which the bypass hoses were laid to transfer the flow under a major road without the need to excavate a trench or bypass the traffic. Low noise submersible pumps and eductor trucks were used to ensure the service to the Hospital was maintained at all times without any adverse side effect.

Conclusion

Because of the natural parklands, golf course and high profile location of this project any environmental incident would have been simply unacceptable.  Careful risk management planning of the entire installation and bypass procedures resulted in the 742 metres of sewer being completely rehabilitated in four days of site work without incident and to the complete satisfaction of the Client.  A shining example of trenchless technology at its best with benefits to both the Client and the Community