Morrison Water Services, part of M Group Services, have completed the successful spray lining of a 600 mm diameter cast iron wastewater rising main at Hatfield Colliery in Doncaster, UK.
The work was delivered on behalf of Yorkshire Water following a significant failure on the fractured wastewater main, laid in challenging ground conditions, 12 m below a stretch of East Coast Main Line track.
Temporary pumps were quickly installed and connected to the existing automated control systems to mitigate the flows (up to 350 l/s) and large bulk, 12 metre stepped excavation works were undertaken to locate and repair the fractured main.
Following the successful completion of the repair, a key priority was to safeguard the main against any potential future failures in the vicinity of the railway and in its deepest sections. The critical location of the main, along with the complex engineering that would be required to resolve any future failures, were key drivers behind the proposal to extend the asset life through the spray lining technique.
The spray lining solution was delivered using Axalta Corroless ACO Wasteseal material, a sprayable structural composite lining formulated as a carbon fibre reinforced, solvent-free and hybrid polyurethane coating. Navigating 22 identified half bends and 11 quarter bends, the lining head was used to apply a 6 mm thick coating of the Axalta material through the rising main.
In 2020, Morrison Water Services achieved WRc (Water Research Centre) accreditation for the insitu spray lining of sewer pipelines using the Axalta material and a specially converted Schur SR1000 Pipe Coating Rig in 2020. The coating is designed to deliver the strength and durability to be at least equal to the 50-year design life of cured-in-place pipe (CIPP) liners.
As well as increasing the asset life, the decision to spray line the main delivered significant environmental and commercial benefits. With just two excavations required either side of the railway line, the process proved to be less environmentally disruptive and enabled a significantly reduced programme that was completed in just four days.
The project also provided an opportunity for Morrison Water Services to collaborate with sister M Group Services business, IWJS, a leading provider of services to wastewater networks. The IWJS team undertook a gyroscopic survey of the main as part of the pre-works investigation and to inform the design process. A flail jet unit was then deployed to clean the main before it was drag scraped using a Schur Pipe Scraper (manufactured specifically for this project, to negotiate bends in the pipe), to remove any remaining deposits.
Following completion of the works, Jonathon LeMoine, Senior Project Manager at Yorkshire Water, commented: “We have some massive efficiencies to achieve this AMP in both financial and carbon. Lining will help drive these efficiencies through our programme and allow us to deliver more for less whilst significantly reducing our carbon footprint. We are excited to get going and reap the rewards that lining will bring.”
Morrison Water Services Head of Business Progression, Liam Saddler commented: “Spray lining is a critical tool that can play a vital role in delivering the carbon and efficiency challenges faced by many of our clients. Applying the lining material will not only protect the asset from future failures in such a critical and complex environment, it will also significantly increase the asset life, with the material designed to remain intact after the original rising main fully deteriorates. In the demanding AMP7 environment, the asset health deterioration of clean and wastewater infrastructure pipelines is creating a need for alternative approaches to pipeline replacement. The benefits of the spray lining material, and the quality of our application, have been proven in water networks over several decades and we are delighted to have this opportunity to play an important role in extending the asset life of sewerage infrastructure.”