Interflow breaks its Primus Line pull record to help protect Nelsons pristine coastline

Partnering with local contractors Beca Consultants, Ching Contracting Limited, and the Nelson Regional Sewerage Business Unit (NRSBU), Interflow’s rehabilitation of a decommissioned pressured sewer pipeline, breaks the previous company record with a 1.1km single pull.

After three years of planning, leading pipeline infrastructure company, Interflow, successfully rehabilitated a decommissioned pressure sewer pipeline off Nelson’s bay area.

In 2007, a 1.1km section of DN525 AC sewer in Nelson on New Zealand’s South Island, was deactivated. Passing under the Waimea Inlet, the pipeline was replaced by a new larger pipeline that followed the shoreline.

Fast-forward thirteen years to 2020, the NRSBU determined that there was significant benefit in rehabilitating and recommissioning the pipeline to increase the network’s capacity, provide operational improvements and eliminate capacity-based overflows.

“Our focus was not only how we do the project, but also how we can do it right. We looked at the problem at hand and then went out to find the best available asset solutions that would be suitable and also the most affordable,” stated Nathan Clarke, General Manager of Regional Sewerage and Landfill Services at NRSBU.

The right tools for the job

Options considered included slip lining with polyethylene, open excavation and re-lay, die-reduced close-fit polyethylene, and Primus Line, a flexible Kevlar-reinforced liner.

Primus Line was chosen on the basis of its ability to negotiate bends in the pipeline, long installation lengths, acceptable flow capacity and low environmental impact. Its long predicted service life delivered the required outcomes for this critical NRSBU asset, whilst still being cost-effective and providing rapid installation.

“The Primus Line product allowed us to do our work quickly and effectively,” said Nathan.

“Because of the chosen solution, we didn’t need to access the project’s entire pipeline to complete the job, rather, just the ends. This significantly reduced the impact of the rehabilitation on the inlet and confined works to easily accessible areas that were not ecologically sensitive.”

NRSBU’s decision to utilise Primus Line marked an excellent opportunity for Interflow to perform its first Primus Line job in New Zealand, with its crews prepared to break a new company record with a single pull of 1.1km under the Nelson inlet.

“As the pipeline we rehabilitated ran underwater, our crews operated with specialised equipment and great caution to ensure no discharges into the Waimea Inlet in order to protect Nelson’s sensitive coastline.” stated Interflow’s National Product Manager, Will Zillmann.

“We were able to quickly and effectively rehabilitate the pipe from the ends of a pressured sewer pipeline, therefore providing a cost-effective, sustainable solution for our customer.”

Unlocking potential across the country

It is estimated that New Zealand will need to spend up to $185 billion over the next 30 years to upgrade its water infrastructure. Part of the aim of the Three Waters Reform Programme proposed by the New Zealand Government is to consolidate that spend under four publicly owned water authorities and unlock opportunities for savings.

Following the success of this project, New Zealand now has a golden opportunity to consider its infrastructure needs on a larger scale and leverage technologies like Primus Line to reduce the cost and time associated with rehabilitation works.

Partnering for success

Interflow’s five-year exclusivity partnership with Raedlinger Primus Line presents a great opportunity for the companies to provide an innovative solution to both the Australian and New Zealand market.

Interflow’s stock of the Primus Line product on home soil also provides the opportunity for jobs to be completed at a fast rate, overcoming the supply chain setbacks many projects face. By having the cost-effective solution readily available locally, Primus Line swings the power back to customers, who can access a quality solution for a lot less.The 1.1km single pull record by Interflow opens the possibilities to how far the solution can go, with longer Primus Line single pull projects planned by Interflow over upcoming months.

Raedlinger Primus Line and Interflow’s commitment to innovation provides an exciting future for not only the two companies but the pipeline infrastructure industry at large, providing faster, cheaper, high quality solutions for upcoming projects.

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