POT COD Melbourne Water Western Treatment Plant
Brief
The 110 square kilometre Western Treatment Plant is responsible for processing half of Melbourne’s effluent treatment (approximately 40 billion litres) per year.
A leak of roughly 20ML per day was discovered around a lifting lug on a large diameter concrete pipe. The leak proved to be critical due to the amount of escaping effluent leaking into a freshly treated pond was exceeding the EPA license.
GEM Industrial was contacted during the planning stage to identify a solution that could be delivered in a very short timeframe. The preferred solution required a single 1800 mm pipeline to run adjacent to the lagoon and act as a diversion pipeline for the failed concrete pipeline.
The project was noted as being the first 1800 mm HDPE pipeline in the southern hemisphere and attracted much interest as a flagship example for the HDPE industry worldwide.
Challenge
Crews had to fuse the individual pipe segments within a confined area before being relocated to the installation point. Project specifications also required that the pipeline be constructed and laid along a narrow roadway which ran adjacent to the treatment ponds. The treatment ponds remained operational during the entire process and could not be disturbed.
The pipe material that was specified posed it’s own set of challenges as the 1800mm diametre pipe wall was only 50 mm thick – making it very difficult to extrude and keep round.
Solution
Once engaged, GEM imported the 24 tonne McElroy Talon from Tulsa, Oklahoma to Melbourne, Victoria. The Talon was in service within 6 weeks. Due to the narrow construction space, two separate lines were constructed – one towards the north of the project and one towards the south, with each section tied-in in place. Pipe was placed “end to end” in preparation to weld. Seven fusion welds were achieved each day with a total of 90 lengths of pipe being required and each weld was data logged.
