News Archives - Pipe Management Australia (PMA)

Extended Life for 200m of Ageing Sewer Main, Trenchless Repair for Unitywater

Written by Pipe Management Australia | Jun 4, 2026 3:47:36 AM

Pipe Management Australia (PMA) recently completed a notable spiral wound PVC lining installation for Unitywater in Caloundra...

Industry: Wastewater Asset

Project Type: Spiral Relining 

PROJECT OVERVIEW

This 200-metre installation of DN700 is the largest single-shot installation of Ibtech’s Spiraline X system in the world and one of the largest expandable spiral liners ever installed. It demonstrates the productivity and scale that experienced crews, customised equipment, and the right supplier partnerships can deliver in the field.

The project rehabilitated a DN700 wastewater main, restoring its structural condition and extending its serviceable life without the disruption, cost or community impact of open-cut replacement.

 Project Details

Client

Unitywater

Location

Caloundra, Sunshine Coast QLD

Service Centre

PMA Maroochydore

Service Delivered

Spiral Wound PVC Pipe Lining

Host Pipe

DN700 wastewater main

Liner Length

200 m installed in a single-shot

Cage Size

660 mm (custom manufactured)

Cage Manufacturer

Ibtech - Made in Australia

Flow Management

Active flow monitoring, no bypass pumping required

Project Duration

3 days on site, single day installation


Why spiral Lining

PMA selected spiral wound PVC lining for this project because of one decisive advantage: it can be installed in a live wastewater main under active flow. There was no need to deploy a bypass pumping setup, no shutdowns, and no interruption to wastewater service for Unitywater customers throughout the works.

For a DN700 trunk wastewater main, a bypass arrangement would have meant high-capacity pumps, suction and discharge lines, generators and continuous monitoring for the full duration of installation. That comes with significant cost, additional plant on site, noise and fuel use, and an ever-present overflow risk if equipment fails.

Instead, the PMA crew wound and installed 200 metres of liner with wastewater flowing through the line beneath them. PMA monitored flow conditions throughout the installation and relayed real-time updates to the install crew, so they could adjust pace and approach as conditions changed. The network stayed in service, the team stayed informed, and customers were never affected.

engineering a custom SOLUTION

Spiral wound PVC lining requires a winding cage sized precisely to the host pipe. For this DN700 line, a 660 mm cage was required, and to keep the project on schedule, PMA worked closely with longstanding supplier Ibtech to have the cage custom-manufactured in Australia.

Ibtech were on site during installation, providing direct technical support alongside the PMA crew. This level of collaboration exemplifies the value of strong, locally based supplier relationships. Being able to specify, manufacture and deliver custom equipment for the specific challenges of a client's asset, then stand alongside the crew during delivery.

Backing Australian manufacturers also gives clients confidence that supply chains are short, responsive, and accountable.

Key Challenges

1

Restricted maintenance hole access

The existing maintenance hole bench had to be partially removed to position the winding cage. The PMA crew jack-hammered out the bench in situ to create the working envelope needed to wind a 200-metre liner from a single launch point.

2

A single continuous installation

Installing 200 metres of liner in one shot requires precision and stamina. The crew worked through several hours of continuous winding to feed the liner through the line - any interruption or fault during the shot would compromise the run.

3

Working through intermittent rain

Intermittent rainfall throughout the installation added complexity to site management and crew conditions but did not delay the project. The crew worked through it to keep the install on schedule.


methodology

The liner installation itself was completed in a single day, within a three-day program that sequenced pre-clean, installation and finishing works to minimise time on site and ensure liner installation conditions were optimal.

Day 1

Pre-clean with PMA Recycler

The host line was thoroughly cleaned with one of PMA's combination vacuum jetter recyclers, removing debris and preparing the pipe surface for inspection and lining.

Day 2

Final clean and liner installation

A second clean was conducted on the morning of installation with a PMA combo unit to ensure the pipe was in optimal condition. The custom 660 mm cage was then positioned in the maintenance hole, and 200 metres of liner was wound and installed in a single continuous shot.

Day 3

End seals, benching and final CCTV

End seals were installed at both terminations, and the maintenance hole bench was reinstated. A final CCTV inspection was conducted to verify the installation and provide Unitywater with a condition-verified handover.

outcome

PMA delivered Unitywater a fully rehabilitated 200-metre section of DN700 wastewater main in just three days, with strong outcomes across service continuity, cost, community impact and asset performance:

  • No bypass pumping required. Wastewater continued flowing through the live main for the duration of installation, with PMA actively monitoring flows and keeping the install crew informed throughout.
  • No service interruption to Unitywater customers and no flow shutdowns required at any point during the works.
  • Restored structural integrity to the DN700 main, extending its serviceable life and deferring the substantial capital cost of full replacement.
  • Avoided the traffic disruption, community impact and cost of open-cut replacement on a Caloundra residential street.
  • Eliminated the plant footprint, noise, fuel use and overflow risk that a bypass pumping setup would have introduced to the site.
  • Compressed total on-site duration to three days, minimising disturbance to local residents and traffic.
  • Installation quality verified at handover through final CCTV inspection.
  • Demonstrated that single-shot spiral lining can be delivered at scale on Australian wastewater networks, and reinforced the value of responsive, locally based supplier partnerships and Australian-manufactured equipment.


 Learn more about the work PMA is supporting on Unitywater’s network in their article.