Wellington Water has this weekend installed a high-strength liner through the first of two 1.8km sludge pipelines beneath Mt Albert.
The unique operation took just over nine hours of continuous work led by the Germany-based team that manufactured the high-tech liner, and were given special permission by the Government to enter the country.
It followed weeks of preparation by New Zealand based crews to excavate the pipe at each end of the tunnel and ensure the liner could be drawn through smoothly. A four-tonne capacity winch, normally used for drawing power cables between pylons, was set up at one end, while at the other, the liner unspooled from giant drums located in a tennis court across a busy road.
Wellington Mayor Andy Foster, who visited the worksite earlier today, says it is encouraging to see this progress on a very challenging repair to a critical piece of Wellington’s wastewater infrastructure.
“Getting the liner through smoothly is a testament to all the hard work done, some of it in pretty miserable conditions by Wellington Water’s New Zealand-based teams. It’s clear everyone involved amongst all the different teams is totally focused on getting this repair done as quickly as possible.
“I understand this is one of the longest applications of this type of pipe lining operation, so I’m very pleased to see the team successfully complete this important first stage of the repair.”
Wellington Water’s Manager, Major Projects, Stephen Wright, says that while it’s good to have reached this milestone in the project, there is a lot of further work to do.
“Once we’ve connected the liner to the existing pipeline, we will thoroughly test it and the new pipework. If we see the results we’re looking for, we’ll be able to re-commission the pumps at Moa Point and put the first pipeline into full operation while we move on to the second pipeline. The good news is that having just the first pipeline operational will enable us to stop the trucking of sludge,” says Mr Wright.
The next steps in completing the work on the first pipe involve reconnecting the high-pressure pipeline to the network at each end, followed by the comprehensive testing programme. This process is expected to take approximately two weeks.
The liner for the second pipeline has been made and will soon be on its way to New Zealand from Germany. The technicians, who spent two weeks in quarantine in Auckland before coming to Wellington, will remain in New Zealand until that liner arrives and is installed.
Wellington City Councillor Sean Rush, who holds the three waters portfolio, expressed the Council’s gratitude to local residents.
“A particular thanks to resident who have experienced the sludge trucks passing through their communities and those who have put up with noise and odour during work on the Mt Albert Tunnel. We’re very grateful for their understanding during this essential project.”
Mayor Foster and Cr Rush get an update on progress and next steps for the Mt Albert pipe repair project from Elliot Altham, Waste and Wastewater Engineer, Stantec (left) and Josh Wright, Project Management Team Leader, Stantec (right).