Water and Effluent Treatment Magazine
Issue link: https://fhpublishing.uberflip.com/i/790461
TECHKNOW • A Ground Penetrating Radar investigation was carried out to establish the presence of voiding beneath the road • Directional drilling enabled a new pipe to be inserted under the full width of the dual carriageway, bypassing the leaking section of the original pipe • The drill head used a digitrack F5 locating system, with deep range Sonde • Line stops to complete mains connections minimised the disruption to some 10,000 STW customers NEED TO KNOW 1 There was the possibility of voiding beneath the A38 carriageway on existing leak 2 A Protected Species Survey was carried out to determine the ecological value of the site and identify any constraints 3 The site included two access points 4 The A38 is a busy commuter road near Derby THE VERDICT "This was a really innovative solution to improve water supplies in the area and it's great that we were able to complete the work with such little impact on the local community. This kind of drilling isn't possible in all areas but it's certainly an option we will consider again for other projects in the future" Bob Taylor, Severn Trent Water with deep range Sonde, a system that uses remote target steering to enable the drill head to be monitored 30m to the front and 30m to the rear in real time for depth and line during drilling. This method also allows the drill head to be monitored without the need for the operator to enter live roadways or cross waterways. A pilot hole was drilled from the launch pit up to the reception pit, at which point the drill head was removed and replaced with a back reamer, a process that was repeated four times to allow the hole to be back reamed out for the pipe to be pulled in. The entire process was completed within four days, ensuring that the open cut main laying works, testing, chlorination and sampling of the new main was completed in readiness for the final connections to be made. Alternative method With the mains connection programmed for September, Severn Trent Water arrived on site to carry out the mains shut-down but found that the existing pipe could not be shut off, requiring an alternative method to be found. The onsite team took the decision to line stop each end of the pipe with a bypass in place that would allow the existing main to remain live and avoid potential disruption to supply for Severn Trent Water customers. With this workaround in place, and the connection complete, the project was completed on time. Taylor says: "I'm delighted to say we were able to complete the work safely and with absolutely no effect to either traffic or water supplies to our customers – I'm pretty sure no-one realised what was going on. "This was a really innovative solution to improve water supplies in the area and it's great that we were able to complete the work with such little impact on the local community. This kind of drilling isn't possible in all areas but it's certainly an option we will consider again for other projects in the future." MARCH 2017 WET NEWS 15 hydraulic performance. Ovalised pipes are more likely to lose structural integrity and to accumulate sediment and detritus. Concrete pipes with their high inherent strength are designed to keep their shape throughout a long service life. So there's less risk of compromised performance. Why pick a lightweight? For details visit: concretepipes.co.uk/heavyweight T: 01179 814500 E: sales@cpm-group.com W: www.cpm-group.com SPONSORED BY SUPPORTED BY CHARITY PARTNER EXPERT SPEAKERS INCLUDE: WATER INDUSTRY ASSET MANAGEMENT CONFERENCE 10 MAY 2017 | BIRMINGHAM DRIVING EFFICIENCY IN A COMPLEX ENVIRONMENT The only industry event for senior strategy, regulation, asset management, capital delivery and engineering leaders within water companies and tier 1 contractors. Attend this CPD-certifi ed conference to: ● Get the latest information for PR19 ● Understand how to tackle asset resilience and risk management ● Learn how to optimise data to attract investment BOOK NOW events.wwtonline.co.uk/asset David Black Senior director, Water 2020 Ofwat Richard Price Director of engineering & construction Southern Water Mark Worsfold Director of asset management South West Water Richard Ratcliff Director of engineering United Utilities Keith Hutton Director of strategy & regulation Bristol Water Andy Clark Head of procurement & contract management Yorkshire Water Jason Tucker Head of integrated supply chain Anglian Water WWT-WIAM-130x180ad.indd 1 06/02/2017 13:26 pROjECT SpECS • Replace a leaking pipe under the busy A38 near Derby • Conduct a directional drill • Undertake a Ground Penetrating Radar investigation on the road's northbound and southbound carriageway