South East Water will invest more than $A50 million during the next four years and in excess of $A75 million over 25 years in major sewerage works for the Pakenham and Narre Warren area to ensure increased sewage flows are accommodated well into the future.
South East Water’s commitment of more than $A75 million over 25 years makes this the largest capital works project undertaken in the company’s history. The project will comprise five stages and will see the use of cutting edge Trenchless Technology to construct one of the biggest gravity sewer projects in Australia.
Not only will the project accommodate further development and increasing sewage flows in this growth corridor, it will also alleviate operational, environmental and social risks associated with limited sewer capacities.
Stages 1 to 4 are taking place during 2004-2006 (having started in April) and Stage 5 will take place during 2006-2008. Future works will continue during the following 20 years, ensuring the entire region is well placed for managing increased sewage flows as urban growth continues.
Specific works include:
“¢ the extension of the Hallam Valley Main Sewer (Stages 1 to 4); and
“¢ construction of a system to transfer excess sewage flows from Officer and Pakenham to the Hallam Valley Main Sewer (Stage 5).
During the planning phase of this project, South East Water conducted a full environmental assessment of the construction area. Biodiversity, archaeology, flora, fauna and native land vegetation were reviewed during the process.
Trenchless Technology will be used to construct most of this project, as the pipeline will generally be between 6 and 12 metres deep. Appointed contractors, GWC Group Pty Ltd, have purchased a tunnel-boring machine specifically for this construction – the longest construction of its type in Australia to date.
Trenchless Technology significantly reduces both visual and environmental impacts as an open-cut process would result in at least a sixty-metre wide construction strip and stockpile of excavated material.
There are two main benefits resulting from the construction of this major sewage pipeline, namely;
“¢ Relieving existing sewerage infrastructure (pipelines and pumping stations) that are now reaching capacity as a result of the rapid increase in land development over the last few years. At least five existing pumping stations will no longer be required once the project is completed therefore eliminating risk of pumping station sewage overload; and,
“¢ Providing capacity for future sewage flows from proposed developments in the Officer and Pakenham West areas.