Collaboration shakes up approach to sewer lining in the UK

Working with industry specialists, we’ve delivered an innovative ‘earthquake-proof’ solution to the problem of a damaged sewer pipe in Portland.

What was the problem?

A trunk sewer pipe had been damaged by unstable terrain on a cliff-side on the east coast of the Isle of Portland, in Dorset. 

A section of the Portland Combined Trunk Sewer next to the lower South West Coastal Path at Grove Point had been damaged by ground slips caused by heavy rain earlier in the year, forcing the area to be closed to the public due to safety concerns.  

Our teams had initially been unable to get to the remote site – a Site of Special Scientific Interest (SSSI) – to carry out significant repairs, with a traditional alternative involving locating over-pumping equipment in the environmentally sensitive area to safely divert flows from the sewer towards its treatment sites. 

That also opened up the possibility that we might have to install an overland pipeline of more than five kilometres at a calculated cost of as much as £14 million until 2030. 

Land movement had caused damage to the Portland Trunk Sewer alongside the lower South West Coastal Path
Land movement had caused damage to the Portland Trunk sewer alongside the lower South West coastal path

A ‘seismic’ step forward

In search of a solution, our team brought in industry specialists RSM Lining Supplies Global Ltd to come up with a rapid and viable alternative, which was completed for £1.6 million – nearly a tenth of the projected cost.

They recommended and supplied the innovative ‘earthquake’ liner, manufactured by UV material specialists BKP Berolina. Originally engineered for tremor-prone regions, the liner is uniquely designed to self-support the pipeline in the event of ground movement or collapse.

The earthquake liner being installed at the Portland Combined Trunk Sewer on the lower South West Coastal path on the Isle of Portland
The earthquake liner being installed at the Portland Combined Trunk Sewer on the lower South West Coastal path on the Isle of Portland

As the first repair of its kind in the country, the German-manufactured liner was recently installed despite considerable challenges posed by the location of the work. 

Previously, we had monitored and carried out only minor work to prevent the situation from deteriorating but with ground instability in the area increasing, RSM oversaw the installation of three UV ‘earthquake’ liners by contractors Lining Division Ltd in December 2024. 

Each measuring between 800 and 975mm in diameter and totalling 400 metres in length, the liners were transported from Germany in custom crates, with special storage conditions considered due to the location of the site. 

The liners were carefully delivered, using equipment including tractor trailers, with the installation carried out under the supervision of an on-site specialist, to ensure the highest standards were adhered to.

The earthquake liner being installed at the Portland Combined Trunk Sewer on the lower South West Coastal path on the Isle of Portland
The earthquake liner being installed at the Portland Combined Trunk Sewer on the lower South West Coastal path on the Isle of Portland

An innovative solution

Wessex Water’s Southern Sewer Renovations Construction Manager, Paul Musselwhite, said: “This was a complex project to help protect the integrity of a sewer pipe next to the coastal path that had been damaged by ground movement. 

"By our estimates, the alternative would have meant we were looking at installing an overland pipeline of more than five kilometres at a calculated cost of as much as £14 million in an SSSI area until 2030. 

"Instead, we worked closely with RSM to come up with an innovative solution that trialled a product that had never been used in this country before and a special note of appreciation goes to them for allowing a key team member to oversee and advise. 

"Its successful installation is a tribute to our collaboration with RSM and the fantastic support from the liner manufacturer in Germany, who flew over a representative to help oversee the installation. 

"It is also a testament to the specialist skills that our colleagues can bring to such projects that it was installed using our own in-house resources and teams, rather than an external contractor.

"Without the expertise and collaboration of all, this ambitious scheme would have required significantly more time and resources to achieve the same outcome."

RSM’s Technical Business Development Manager, Richard Wortley, said: "Throughout the operation, the team’s coordination was exemplary. 

"Wessex Water’s sewer renovation team maintained continuous pipeline flow throughout the repair, using a complex setup of 12 tankers and four tractor trailers operating around the clock. This seamless collaboration minimised disruption whilst ensuring the safe and efficient installation of the liners." 

The project reflects RSM’s mission to lead the global CIPP industry by delivering innovative materials, expert advisory services, and reliable solutions. 

RSM Sales Director, Phil Steele, added: “This milestone is a powerful reminder of what can be achieved when innovation meets teamwork. At RSM we’re not just solving today’s challenges—we’re building solutions that define the future of infrastructure."

"By navigating challenges with precision and delivering unparalleled support, RSM continues to set benchmarks for quality and innovation in sewer rehabilitation projects worldwide."