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 No-Dig Live.
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 2km, 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 stations are designed for 90 mm PE100 pipelines, with dome heights of 900 mm or 1,200 mm. Access is through a dome cover at road level, leading to an insert locked into the pipeline with a pressure-tight bayonet and quick coupling for easy flushing. A trial in January 2025 showed the system could replace a full ice-pigging team: two operators can now service the entire rising main in under three hours. This has cut costs at Cropston, simplified maintenance, and boosted flow rates from about 11.5 m³/hr to 17 m³/hr.
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. By installing two Quick-Pig units on one 2km 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.
