CIPP making tracks in Wiltshire

A sewer dating back to the 1960s that runs alongside the Bristol to London railway line in the UK was recently repaired using CIPP. The ageing asbestos concrete (AC) sewer, operated by Wessex Water, had suffered a number of fractures and was relined using CIPP to safeguard it for the future.

A CCTV investigation of the 650 m long sewer revealed that it had lost structural strength and sections exposed to the elements had caused exfoliation of the outside surface leading to a number of ring fractures – a common problem for AC sewers.

Critical Sewers Team Senior Engineer Julian Britton said repairing the 375 mm diameter sewer in Corsham, Wiltshire, using Trenchless Technology had many advantages.

Mr Britton said “Without the use of this technology it would have been impossible to repair the sewer without closing this busy section of railway line which would have been extremely disruptive and costly.

“In addition, it meant that we could safely make improvements to support the pipe’s structure without the risk of compromising the asbestos cement pipe’s integrity.”

Once the cleaning was complete, the sewer was relined in two shots using liners measuring 325 m and 323 m.

CIPP in Singapore

In 2009, Public Utility Board (PUB), Singapore’s publicly-owned water utility, began work on a multi-year $US295 million rehabilitation program. This rehabilitation program is expected to be completed in 2014 and will upgrade over 700 miles of public sewers and 30 miles of pumping mains. PUB serves a population of over 4.5 million Singaporeans. These contracts are part of PUB’s ongoing rehabilitation program.

Relining company Insituform Technologies Singapore subsidiary, Insitu Envirotech, has been awarded four contracts totalling $US18.5 million. Under the contracts, Insituform will perform work for the PUB, and rehabilitate approximately 50 miles of sewer pipeline though the use of the CIPP process.

Insituform’s Vice-President Asia-Pacific Daniel Cowan said “Insituform looks forward to continuing its work with PUB and to the opportunity to bid on additional work as PUB continues its ongoing rehabilitation program. In addition, we continue to provide enhanced services to the market in Singapore by supplying local rehabilitation contractors with our CIPP tube. We expect to continue this offering by supplying CIPP tubes for PUB projects for many years to come.

“Singapore’s PUB is one of the most progressive water utilities in the world. With this project, which is Phase IV in its overall sewer rehabilitation program...PUB will be able to upgrade its system with little disruption to the people of Singapore,” said Mr Cowan.

A record-breaking installation in Helsinki

The Olympic Stadium in Helsinki, Finland, the location of the 1952 Summer Olympics, is undergoing a major renovation. One challenge was the vertical rainwater pipes in the 72 m Olympic Tower. Making changes to the structure of the tower is prohibited, and contractors were not allowed to excavate, so no new pipes could be installed. As well as the rainwater pipes, the outlets and connections were also in very bad shape.

The Public Works Department contacted Aarsleff Oy and asked if Aarsleff CIPP Lining could be the solution. The company said “We were honoured to be asked to work in one of the most well-known landmarks in Helsinki.”

After careful planning and calculation, Aarsleff Oy came to the conclusion that Aarsleff CIPP Lining could be installed in one 72 m stretch. The pipelines were cleaned, the side connections were installed, and the liners went up to the top of the tower as planned. Including all the preparation works, the job took only four days.

“So we can say it was a perfect job and a record-breaking installation altogether,” said the company.

CIPP doesn’t stop traffic in Australia

In Perth, Australia pipeline rehabilitation specialists Drilline Pty Ltd recently completed the CIPP relining of over 650 m of oviform sewer pipes through Perth’s city centre.

The project, commissioned by the Water Corporation, called for the rehabilitation of the gravity-fed sewer system along St Georges Terrace, the only road that bisects the city centre east to west without interruption.

The challenge was to complete the works with minimal disruption to the flow of traffic, while maintaining the integrity of the reline. The works program called for the CIPP relining of 650 m of gravity-fed sewers to be broken into seven portions, each portion including jet washing, pre-and post-reline CCTV surveys, reinstatement of junctions and refurbishment of the access chambers.

The project was further complicated by the need to access, monitor and King Vac (vacuum recovery) the private pumping stations servicing each of the office buildings along St Georges Terrace during the bypass periods, including Perth’s largest building Central Park. Drilline liaised with building management for each of the buildings prior to the commencement of the project and in the lead up to each new section. Working at night and weekends did reduce the flow, resulting in reduced risk to Drilline personnel and other stakeholders in the bypass component of the project.

Drilline successfully completed the St Georges Terrace Sewer Rehabilitation Project in a highly visible location, to exacting deadlines, within extreme time constraints and additional complex third party liaison without compromising the integrity of the oviform CIPP relining works or the safety of its personnel.

Drinking to relined pipelines in British Columbia

Increased demand for sewer and water pipeline rehabilitation in British Columbia, Canada, initiates a significant sewer relining contract.

Drinking water pipelines in Victoria, British Columbia are set to be relined in a project incorporating CIPP solutions. Over 11,000 feet of pipelines with 12 inch and 20 inch diameters will be fitted with HDPE liner in the project, which is aimed at causing minimal disruption to communities.

A $US4 million contract for the project has been awarded to Insituform, who has recently opened a new office in Montreal, Quebec. The project is expected to be completed in early 2011.