Kembla Constructions was established in 1992 in Wollongong. By 1993 the company had relocated to offices in Sydney in order to manage the increasing demand for their services. In 2000 they changed their name to Kembla Watertech.

Managing Director Chris Meredith spoke with Trenchless Australasia, reminiscing about the early days of the company.

“It was back in 1992 when a fold and formed lining system called the Ex method first came to my attention. I could see the potential for its use in Australia and signed a license agreement with the Japanese owners of the technology.”

Kembla installed the first Ex lining into a 150 mm sewer, south of Sydney. Fifteen years later Mr Meredith sent a CCTV survey crew back to the same pipe to check on the condition of the lining.

“I am happy, but not surprised, to be able to say that we found it in as good condition as the day it was installed,” said Mr Meredith. Major milestones for Kembla

The Ex factor

The Ex material and installation process has been refined over time to suit the specific Australian conditions. In conjunction with Vinidex, the sole supplier of Ex pipe to Kembla, 1,200 km of Ex lining has been installed in Australia.

The Ex method involves winching a specially formulated and softened PVC pipe into the sewer through the existing access chambers. Injectors are fitted to each end of the Ex pipe and steam and pressure are applied to expand the lining. The pipe then forms a tight fitting structural liner within the existing host pipe.

Innovative grouting

In 1996 Kembla was involved in Sydney Water’s infiltration and exfiltration program. The works started in Bondi and were based on chemical grout sealing. It became evident to Kembla that major deficiencies existed in the current grouting technology.

To improve the system Kembla introduced technology to CCTV survey house service lines (HSLs). Kembla also began a program of cleaning and de-rooting HSLs. Kembla also increased large gap sealing through the development of enhanced accelerator additives for mainline grouting.

The most important grouting innovation achieved by Kembla was the development of pre-fill grouting that enabled the grouting of HSLs previously classified as ‘cannot fills.’

NSW Environment Minister visits Kembla site

In 2004 Kembla completed work on the largest single sewer reticulation rehabilitation contract ever in Australia. The project, located in the Blue Mountains region west of Sydney, involved 184 km of cleaning, 71 km of lining and 3038 junction cut outs and sealing.

The New South Wales Minister for the Environment Bob Debus visited the site to witness the installation of an Ex lining.

Tiger T – making connections

In 2000 water authorities began to question the long term effectiveness of chemical grout sealing of connections to line pipes. Kembla said that although lateral grouting techniques were sealing the area, this could not match the fifty-year life expectancy of Ex type linings.

A persistent difficulty facing the Australian market is that the machinery and systems developed overseas are not generally capable of operating inside a 150 mm diameter pipe, especially with a lining installed.

Kembla launched an R&D program in 1999 for a repair system for branch connections called Tiger T [Figure 3]. The first trials were conducted for Brisbane Water in 2001. The purpose of the innovation is to provide an economical and quick method for repairing and sealing connections in a lined pipe up to and including the first joint in the branch pipe.

The company said that the majority of authorities are only responsible up to the first join in the HSL. Therefore the introduction of the Tiger T, extending past the first joint, has been a milestone event for trenchless repair in Australia.

Singapore digs Kembla

The Singapore Public Utilities Board approached Kembla in 2007 regarding the use of the company’s No Dig pipeline rehabilitation technologies. The project involved large scale sewer rehabilitation.

The Singapore Government has embarked on a project to dam the Singapore river outlet, gradually replacing the salt water with potable rain water. An important factor in the project is ensuring that effluent from the network of sewer pipes in the river catchment does not leak into the ground and reservoir. There are nineteen separate projects involved, with a total value of approximately $A160 million.

A Singaporean underground cable installation company, Teacly, signed a licensing agreement with Kembla. Teacly has exclusive access to the company’s materials, equipment and system processes.

Teacly has been awarded four contracts valued in excess of $A30 million. Kembla said that the majority of the work involves smaller diameter reticulation sewer, utilising the Ex method lining system. Over 60 km of Ex pipe have been installed and there is scope for future pipeline rehabilitation work in Singapore.

Planning for the future

Mr Meredith said “Kembla is proud of its reputation and the part it has played in developing and supporting the Australian Trenchless Technology industry. The company looks forward to continuing this role in the years ahead.”