CASE STUDY
UK's 1st Mainland Quick-Pig Installation at Severn Trent
How a new trenchless technology optimised spending and enhanced safety
The UK's first mainland Quick-Pig installation
The Severn Trent water treatment works near the village of Cropston lie on the edge of Bradgate Park in the Charnwood Forest in Leicestershire. Here the rising main undulates, with the ultimate discharge location at an elevation lower than the pump station.
Engineers working at the site suspect airlocks caused by this uneven environment in addition to wastewater arising from the processes on site may have been the reason for the varying flow rate of the pipeline. Every two years or so a team would tanker flows and would ice pig the pipeline. Following the operation, the flow rate would improve. But within months they were back to square one, with disruption once again returning restricting the disposal of wastewater from the site.
Not only was this frustrating for the team at Severn Trent, but it could also prove costly long term too with no obvious solution to overcoming the recurrent disruption to the flow rate. An alternative method of servicing the main was explored.
Network Operability Specialist, Andrew Warren, from Severn Trent had first been introduced to Quick-Pig for rising mains in 2022 by Nico Hindriks of Reinert Ritz at the UKSTT No-Dig Exhibition. The trenchless technology had been initially devised in Germany as a solution to the health and safety risks involved with going down a manhole to service a rising main. It also offered the team at Severn Trent a long-term solution to servicing a tricky and recurrent issue with water flow.
The Compact Quick-Pig Station
Unlike traditional pigging methods, the Quick-Pig uses a compact station that can be operated from the ground surface. No entry via a sewer shaft is necessary, and there is no need to worry about slippery steps or fermentation gases.
Pigs can be quickly inserted via a launcher and received with another station using the Quick-Pig receiving accessory unit made of PE 100 and V4A stainless steel. This can be inserted in the station without disrupting the operation. Quick-Pig already has a strong pedigree in Germany, where it has been used in over 1,500 installations and is now considered for all new rising main pipeline installations.
Here in the UK, the Severn Trent team decided to trial the technology on a two-kilometre, 80mm MDPE rising main pipeline. Two Quick-Pig stations were planned for the first test clean. These were completely installed in one day at a cost estimated at around £20,000. The team planned the Quick-Pig access points to ensure the pipeline could be cleaned and inspected without the need to enter a manhole at any point along the line.
Quick-Pig Infrastructure
Quick-Pig infrastructure can be used with a variety of different pipelines and is highly accessible. The stations at Cropston were designed for a PE100 pipeline with an outer diameter of 90mm, with individual dome heights of 900mm and 1,200mm.
A dome extends from the station to the pipeline. Removing the dome cover at the upper surface of the road provides access to an insert anchored in the piping system by a bayonet lock.
All pressure-tight bayonet locks are equipped with a quick coupling so the operator can easily work with external water when flushing the line.
The first test run in January 2025 was highly successful; gone was the need for an entire ice pigging team. Once installed, the entire rising main could be quickly serviced by just two individuals operating the Quick-Pig and pumping stations.
This two-person operation will now take less than two to three hours. Any problems with the varying flow of the pipeline near Cropston can now be quickly addressed as often as required with minimal fuss and cost.
Not only that, the flow rates have also been restored with flow rates prior to Quick-Pig on 25th July 2025 of around 11.5m3/hr to an improved ~17m3/hr post Quick-Pig.
The Quick-Pig station provided a convenient and safe solution for servicing the rising main, but it also delivered substantial cost savings. During a 5-year AMP period, regular ice-pigging every 12 months would cost an estimated £19,000.
Highly cost-effective solution
By installing two Quick-Pig units on one 2 kilometre rising main at roughly the same price, the annual servicing cost dropped to only £2,000 with more regular maintenance intervals. This investment will lead to significant long-term savings, making Quick-Pig a highly cost-effective alternative.
Flow rates at Cropston (m3/hr), indicating an increase following the Quick-Pig on July 25th, 2025
Having adopted the trenchless technology at the Cropston site, the team at Severn Trent has discovered how to transform a once costly and complex process into a simple and efficient solution. With a cost-effective, long-term method for serving a rising main, they are now excited to see how it works on other sites in the region.