Bohrtec machine guides sewer works

Bohrtec machine guides sewer works

In 2019, Downer Pipetech was engaged by Sydney Water to install 870 m of 226 mm uPVC sewer main for the future developments in the Spring Farm residential area of New South Wales.

With the project requiring the completion of 10 under bore sections, Downer engaged auger boring specialist Bortec Laser Bore from Narellan NSW, which uses machines from expert German supplier Bohrtec.

During consultations with experts from Germany, it was noted that geotechnical reports indicated displaceable soft sand, non-displaceable stiff clays and soft sandstone would be encountered.

These ground conditions suited either the Bohrtec pilot tube system for the displaceable soil, or the Bohrtec 406 mm FrontSteer system for the non-displaceable ground.

Although Bortec Laser Bore possessed both a Bohrtec BM 400 LSC and a Bohrtec 400 LS, it was decided the LSC machine would be better suited to the launch shafts due to its more compact design.

Bohrtec machine guides sewer works
Pits 10 and 11 – shoring boxes 6 m x 3 m; FrontSteer method. Image courtesy of Bohrtec


While the project proponents had top-quality Bohrtec machinery at their disposal, the works were not without their challenges and a range of equipment was required.

The required bore lengths ranged from 69 to 111 m and encompassed a total of approximately 830 m of boring across the project, while the launch shafts ranged from 6 to 13 m in depth.

Due to changing ground conditions, the pilot tube method was used in the softer displaceable soil, and the FrontSteer method was used in the harder non-displaceable clay and soft sandstone areas.

This method has both vertical and horizontal steering capabilities with an accuracy of up to ± 25 mm for drive of a length up to 100 m.

The connection point for the sewer was into an existing sewer access chamber 13 m deep in the middle of a roadway.

Bortec and Downer discussed the possibility of directly boring into the existing manhole and eliminating the excavation of the roadway to a connection, and Downer agreed to set up a platform in the existing access chamber in the roadway and internally core out a 600 mm core hole where the bore was to come out.

Bortec was able to use the pilot system to move through the soft sand and, with the use of the optical guidance system, could come out directly in the centre of this core hole.

Afterwards, the hole could be upsized and bored in the 406 mm steel pipes.

Manholes up to 13 m deep were constructed with tight access, with flat grades ranging from 0.45 per cent to 0.65 per cent with minimal tolerances between the bores.

A DN 406 mild steel casing was installed, with the DN 225 uPVC carrier pipe then inserted inside.Centralisers were also installed at 3 m minimum intervals, while the annulus between the uPVC and steel casing pipe was grouted.

Vacuum testing and CCTV of the installed sewer were conducted and all spoil and slurry from the launch pit was removed.

The project was completed successfully and within budget, with no recorded safety incidents, while the connection made to the existing access chamber was made without the need to excavate the surrounding roadway.

Thanks to the technical assistance from Bohrtec, the optical guided system was successfully employed when using either the pilot tube or FrontSteer systems in order to maintain grade and alignment as per design.

For more information visit the Bohrtec website.



Culvert relining

Pipe relining methods take socials by storm

It’s also the latest Buzzfeed fascination.

Trenchless relining methods have gone viral on social media, with Buzzfeed sharing a video on Instagram about “the satisfying trade you didn’t know you needed to learn about.” 

The internet media mogul posted the video, “A Crazy Way to Fix Pipes”, on 2 September, which has now received nearly half a million views. 

The video shows an innovative method for relining pipes that eliminates the need for excavation, making it a much more cost effective and time efficient solution that eliminates disturbance to the surrounding environment.  

The clip shows a sleeve covered in resin being pushed through the old or damaged pipe by a bladder of compressed air. 

The resin is coated on the inside of the old pipe and cures into a new, smooth lining. 

First, the old pipe is removed of any debris so the lining is able to fit through the pathway, then the pipe is inspected and measured so the lining and bladder can be cut to size. 

In order for the sleeves to turn into hard pipes, they are lathered in a resin with different chemical compounds depending on the use of the pipe. 

Next, the deflated bladder is inserted into the pipeline and pushed through the pipe. 

The bladder then fills with air and stays in place until the resin is cured. 

According to the video, jobs using this pipe relining method can generally be completed within two hours. 

The video now has more than 400 comments, with viewers commenting on the practicality and innovation of the solution. 

To view a list of pipe relining contractors, visit our directory. 

Auckland city skyline

Upgrades to Auckland stormwater outfall

McConnell Dowell has announced construction on the new Ports of Auckland Outfall Upgrade Project will begin in late 2021. 

The company was awarded the contract by Auckland Council in 2019 because of its extensive track record in marine outfall construction using trenches methodologies. 

The project will construct the last and most challenging section of the Stanley Street catchment network to mitigate future flood risks. 

Works will include culvert strengthening, excavation, chamber and outfall construction, and tunnelling to a maximum depth of 20 m. 

The new outfall will increase the stormwater capacity and provide greater resilience to Auckland’s downtown infrastructure, particularly for the Britomart Railway Station. 

A new 270 m inverted siphon pipeline will be installed using microtunnel boring machine (MTBM) with a diameter of 3 m. 

The outfall alignment will run under Quay Street behind the Port of Auckland and the old stormwater culvert will also be repaired and reinstalled.

Once completed, the new outfall will improve the resilience of Auckland’s downtown infrastructure. 

For more information visit the McConnell Dowell website. 

Generic stormwater drain

Bacchus Marsh network upgrades complete

The $20 million works include an upgraded sewer pump station, a new sewer pipeline and two new water pipelines with most of the projects completed in the past month. 

GWW General Manager Growth and Infrastructure Amanda Smith said with the local population projected to double to 46,000 in the next 20 years, this investment will ensure the network can meet demands for services for many years to come. 

“It ensures GWW can meet the demand for sewerage services for at least the next 15 years,” said Ms Smith.

“These projects have been safely delivered under COVIDSafe settings, demonstrating the concerted efforts of staff and contractors.”

Works included $6.7 million upgrade to the Grant Street Sewer Pump Station, $9.2 million in 8 km of sewer pipeline from Peelmans Lane to the Bacchus Marsh Recycled Water Plant, and $3.4 million on a duplicate sewer pipeline from Holts Lane to the Avenue of Honour.

These are only a few of the major projects that have been under development and construction across the service area. 

For more information visit the Greater Western Water website. 

Interior pipe image

VAPAR technology creates smart sewer and stormwater solutions

Sewer and stormwater sectors are challenged with ageing infrastructure and limited budgets, with much of the industry still using traditional methods to manage the pipe condition assessment processes, despite emerging technology and new opportunities enabling smarter work practices.

The current environment requires a rethink of how best to manage these networks, and VAPAR’s philosophy since inception has been to empower engineers and project managers to achieve more in less time.

By identifying inefficiencies and developing solutions through software innovation, VAPAR is revolutionising the industry with artificial intelligence (AI) and cloud storage technology.

Key benefits include automated defect coding with more than 5x faster results compared to manual methods, accuracy and consistency through algorithm-based processes, informative risk-based insights and a secure central location for all files.

In 2021, VAPAR launched its partner program of industry experts, bringing the VAPAR benefits directly to councils and utility companies and, since July, Veolia and Interflow have been at the forefront of this partnership.

Veolia develops smart water offerings that contribute to improving operational performance, and in 2020, the company joined forces with VAPAR to combine network operations and AI. 

Leading pipeline infrastructure company Interflow recently partnered with VAPAR to revolutionise its condition assessment service offering through the power of AI. 

Interflow Operations Manager Jason Dearing is optimistic that its partnership with VAPAR will result in tangible benefits for local councils and water authorities alike.

“By improving the efficiency and accuracy of our CCTV pipeline surveillance, we aim to save our customers time and money,” said Mr Dearing.  

“This will also benefit the communities in which we work, by streamlining projects so that disruption is kept to an absolute minimum.”

With the power of AI, cloud technology, and working with its ecosystem, VAPAR is rapidly digitising and centralising pipe assessment workflows.

For more information visit the VAPAR website.


CRL under Auckland city

Works on hold for Auckland supercity

Watercare commenced works on the Central Interceptor project in Māngere last month, with the 14.7 km sewer tunnel to run from Grey Lynn to the Māngere Wastewater Treatment Plant and expected to be completed in 2025. 

Once completed, it will be the longest bored wastewater tunnel in New Zealand. 

According to the Executive Program Director Shayne Cunis, the project came to a  halt in recent weeks due to recent COVID-19 outbreak. 

Mr Cunis said that under the public health response legislation, basic operations were still permitted, but expects the project’s operations to be able to return to “normal” when Auckland shifts to alert level 3.

Greater onsite restrictions for staff will still be in place after the alert level is downgraded, with workers having to maintain social distancing and onsite “bubbles”.

He said the latest lockdown will affect the time it takes to complete the project, but he remains confident it can still be delivered on budget.

Across town, developments on the $4.4 billion City Rail Link have also been stalled. 

A spokesperson from the Ministry of Business, Innovation and Employment (MBIE) said they were unable to confirm what operations will look like for the CRL and Central Interceptor projects under level 3 restrictions. 

For more information visit the Watercare website. 

SA Water installs new Murray Bridge water main

New water mains for regional SA

Works are scheduled to take place in major regional hubs including Gawler, Loxton, Port Lincoln and Port Pirie. 

All will receive a share of around 47,000 m in new water main, set to be installed over the next 12 months. 

SA Water General Manager of Sustainable Infrastructure Amanda Lewry said the program builds on the 31,000 m of water main upgraded across regional areas during 2020-21.

“Improving our services isn’t just about delivering good quality drinking water, it’s about maintaining the system that delivers it, to reduce the frequency of water main leaks and breaks and their potential impact on our customers,” she said. 

“Through smart investment, these ongoing improvements to your regional water network will help sustain the infrastructure’s long-term reliability.” 

Works will include replacing reticulated water mains as well as upgrades to larger pipelines and treatment plants. 

Ms Lewry said the water main upgrades across regional areas will ensure local residents and businesses can continue to access their water services, sustaining wellbeing and economic growth. 

She added that SA Water is looking forward to working with its construction partners do deliver an investment that secures the prosperity of communities in South Australia. 

For more information visit the SA Water website. 

$90m allocated for SA water infrastructure

The Premier of South Australia announced last Friday that a stimulus package of nearly $90 million would be dedicated to delivering a range of water services to the state.

The projects will range from delivering additional water to Barossa Valley wine producers, to supplying high-tech glass houses in Virginia.

The projects will be jointly funded by the Marshall Liberal Government, the Commonwealth, and partners under the National Water Grid Fund.

Minister for Primary Industries and Regional Development David Basham said the projects will provide a significant boost to South Australia’s agricultural industry.

Premier Marshall said these 10 projects across the state will grow jobs by delivering new and affordable water, enhancing water security and stimulating regional development.

“These projects will both support existing primary industries and allow for new and expanded agriculture to be undertaken in some of South Australia’s most important agricultural areas,” he said.

The delivery of the projects, including the installation of new infrastructure, is estimated to support around 800 jobs.

For a full list of the projects, including the new Nairne recycled water pipeline ($1.29 million) and the Barossa grape water source diversification ($9 million) projects, visit the South Australian Government website.


Palmetum receives $2.1m upgrade

The Palmetum is one of three botanical gardens in Townsville, covering 17 hectares and featuring a unique and diverse collection of plants from the palm family.  

The collection contains around 3,000 species of palm, many of which are rare and threatened in their natural environments.  

This week, the City of Townsville council announced the Palmetum would be receiving a $2.1 million enhancement to the irrigation network system.  

The upgrade is funded by the Queensland Government as part of a series of upgrades and new council infrastructure across Townsville.  

The installation will occur by under-boring throughout the garden to reduce the impact on the plants. 

Infrastructure Services Committee chairperson Kurt Rehbein said the funding would renew the garden’s existing network system, some of which is more than 20 years old, ensuring its security as a Townsville destination for years to come.  

“Palmetum is a beautiful space and is home to some incredibly rare and unique plant species that our staff work meticulously to care for, so ensuring the irrigation is up to standard is crucial for maintenance of the garden,” said Mr Rehbein.   

Member for Mundingburra Les Walker said the Palmetum irrigation upgrade would deliver much needed jobs for the local community.  

“This is great news for Townsville’s economic recovery, with 17 local jobs up for grabs thanks to the Palaszczuk Government’s investment in Townsville,” he said. 

For more information visit the Townsville Council website 

Planning approval granted for desalination plant, pipeline

This week, the New South Wales Government approved Hunter Water‘ s plans for a desalination plant at Belmont as a drought response measure.    

The plans are a reaction to water storage levels in the Lower Hunter, which recently reached its lowest point in nearly 40 years.  

The plant is designed to produce up to 30 million L of drinking water per day in response to drought.   

This follows in the wake of the most recent drought of 2019-2020, which saw the introduction of water restrictions for the first time in decades.   

The Hunter Water team worked closely with the NSW Government, key stakeholders, and the local community, and planning approval was issued yesterday by the Department of Planning, Industry and Environment.  

The desalination plant, once constructed, will receive direct ocean seawater intake by piping seawater from 1 km offshore.  

The intake structure would be installed at a depth of approximately 20 m, extending 5 m above the ocean floor, and the pipeline will be installed under the ocean floor via a trenchless tunnelling method. 

Hunter Water Managing Director Darren Cleary said desalination is one of the few water supply options that is not dependent on rainfall.  

This would mean that with the construction of a desalination plant, Hunter Water could continue to supply communities irrespective of changes in weather or climate.  

While the likelihood of having to construct the plant is low, it was imperative that Hunter Water sought planning approval, should it need to build in the near future.  

“Planning approval for the Belmont desalination plant gives us an additional tool to help close our supply gap during periods of drought, providing Hunter Water with the capacity to provide up to an additional 30 million L of water each day,” said Mr Cleary.  

Hunter Water said the project approval was supported by comprehensive environmental impact investigations, which evaluated the potential impacts that could be mitigated through detailed design and delivery.  

These assessments found that a trenchless method would have the least significant impact on marine life, while the intake would also be designed to reduce the chance of marine life being drawn into the pipeline.  

Construction of the desalination plant could take three years.  

For more information visit the Hunter Water website 

Watercare Central Interceptor TBM

Central Interceptor TBM launches

On 30 July, Tunnel Boring Machine (TBM) ‘Hiwa te Rangi’ (roughly translated, ‘vigorous growth’, a promise of a prosperous season) set off on her 14.7 km journey under Auckland city.  

 Auckland Mayor Phil Goff gave orders to start up the TBM at a launch ceremony at a construction site next to Māngere Wastewater Treatment Plant. 

The TBM began cutting at the bottom of the 40 m launch shaft and will travel north to its ultimate destination in Grey Lynn.  

The Central Interceptor is an NZD$1.2 billion (AUD $1.14b) wastewater tunnel, which, once completed, will be New Zealand’s longest bored tunnel.  

Providing both storage and conveyance, it will hold 226,000 m3 of water and provide significant environmental benefits to the area.  

Historically, heavy rain has overwhelmed the network, creating overflow into neighbouring streams.  

Mayor Goff said the Central Interceptor will reduce overflows into waterways and harbours, improving water quality and ensuring clean, safe beaches.  

Wastewater is to be stored and conveyed at the Māngere Wastewater Treatment Plant and the tunnel has been designed to operate for 100 years.  

Mayor Goff also said that, once operational, the Central Interceptor tunnel will stop more than 80 per cent of wastewater overflows from Western Isthmus.   

Hiwa te Rangi, according to Māori legend, is one of the Matariki stars to which Māori would send their dreams or aspirations for the new year. 

The name was chosen by students who attend school along the route.  

Soil conditions will dictate the TBM’s progress, which is likely to be around 12-16 m per day. 

The project is scheduled for completion in 2025.  

For more information visit the Watercare website. 

Primus Line breathes new life into historic trunk main in Brisbane

Earlier this year, Urban Utilities completed a multi-million-dollar rehabilitation project on this 130-year-old pipeline.

With the use of the trenchless technology Primus Line®, the project is expected to extend the life of the pipeline by at least 50 years, providing an economical solution with minimal impacts to traffic and nearby businesses and residents. 

The Ann Street pipeline is a cement-lined, cast iron pipe, and helps to supply water to the city centre and the inner-city suburbs.

During the morning and evening peak consumption periods, about 500 L of water per second flows through the pipe. 

Thousands of vehicles a day roll along the four-lane road, which is one of the busiest roads in Brisbane’s central business district, and businesses and bus stops line the traffic route. 

Replacing water mains in heavily congested urban environments can be a costly and disruptive process, so in this case trenchless technology was the key to success.

Given the location of the pipe, Primus Line was chosen as it could pass through several bends in the pipe and be installed using a few small pits, to minimise the impact on traffic. 


As Primus Line is a flexible stand-alone pipeline, which is installed with an annulus gap, it can withstand the operating pressures of the water main, but not the external loads from the traffic on the road above. 

The project at Ann Street was preceded by a detailed condition assessment of the host pipe and economic evaluation in order to ensure the existing pipeline could withstand external loads in the future.

The results showed that the pipeline had sufficient load bearing capacity to allow the use of a semi-structural lining system such as Primus Line for the desired service life of at least 50 years. 

The perfect choice 

Due to its unique three-layer structure, the Primus Liner combines flexibility with extremely high material strength.

As a self-supporting pressure pipe liner independent of the old pipe, it absorbs the entire operating pressure, while the old pipe merely functions as a conduit. 

In accordance with ISO 11295, Primus Line is an independent pressure pipe liner capable on its own of resisting without failure all internal loads throughout its design life.

It has the ability to negotiate bends of up to 45 degrees, allows for seasonal movement of the pipeline and ensures the required operating pressure of up to 11.3 bar. 

Despite the reduction in cross-section of the DN 600 pipe, flow calculations showed the client that the installation of a Primus Line DN 500, with its low friction coefficient of only 0.028, would still provide the required flow. 

Before the start of the project, a large- scale trial with a length of 350 m was carried out with the Primus Line system – developed and produced in Germany.

In a single day, the pre-folded liner was pulled into the 350 m field trial section of the Ann Street trunk main, formed into its circular shape with compressed air and successfully connected to the pipeline network.

Start of the major project 

The successful completion of the trial allowed for the commencement of the Ann Street project, where detailed design and construction planning was performed in 2019 by Urban Utilities.

Small excavations are
sufficient for the installation.

The initial stages of the project also involved cleaning and prepping the existing pipe to make it suitable for installing the liner, while the installation phase began in mid-2020 and was completed in early 2021. 

Most of the work took place at night and the small construction pits were closed during the day with large steel plates, to allow traffic to continue to flow.

The entire project was carried out by Urban Utilities’ own workforce, and the company had previously installed Primus Line on other rehabilitation projects in its service region. 

Urban Utilities had engaged Primus Line to provide training to its team, and kept the required necessary tools and spare parts in stock to perform Primus Line installations and possible repairs and maintenance in-house. 

The Primus Line team provided engineering support and accompanied the beginning of the measure with a supervisor.

Four installation sections were necessary to rehabilitate the 2.2 km long pipeline section, with the Primus Line system DN 500 PN 16 used to rehabilitate the DN 600 water pipeline.

Primus Line delivered the four liner sections pre-folded in a U-shape and wound onto drums.

The liner insertion into the old pipe was done with a winch and in the process passed through some additional smaller intermedia pits to reinstate valves and offtakes.

The liner was pulled through these pits and cut afterwards to install the Primus Line connectors and the necessary valves and t-pieces 

Special DN 500 connectors with a DN 600 flange were used to ensure the connection to the flange on the host pipe while keeping the pits as small as possible. 

A pressure test concluded the successful installation before the main was disinfected and returned to operation.

For more information visit the Primus Line website.

This article was featured in the June 2021 edition of Trenchless Australasia. To view the magazine on your PC, Mac, tablet or mobile device, click here.