To combat this problem, the Health and Safety Executive has advised the GDNs to accelerate the replacement of all cast iron and ductile mains within 30 metres of buildings.
Replacing the old metal pipes with plastic gas mains has the effect of improving the security and reliability of the network, reducing the level of gas escapes and reducing the level of associated repair work, SGN tells Utility Week. Most importantly, this has reduced the risk of gas explosion by 60 per cent from pre-2005 levels.
Here’s a look at where each of the gas distribution networks is with the replacement of their gas pipes:
National Grid Gas Distribution
National Grid has more than 131,000km of gas distribution pipes serving 11 million homes and businesses in its networks. The company is carrying out an agreed programme of replacement work and within this RIIO period will be replacing 14,850km of pipes – approximately 1,856km per year – with an investment of £3 billion.
National Grid’s director of gas distribution Chris Train says: “Replacing the old metal gas pipes around the country is important to ensure our customers can continue to receive a safe and reliable gas supply to their property every day of the year. Our replacement programme is ahead of schedule overall, a trend we expect to continue throughout the RIIO period.
“We realise the impact these essential works may have on a community and individuals and this is why it is important that councils, parish councils, communities and individuals are kept informed throughout the gas mains replacement projects.”
National Grid uses various ways to keep customers informed of the work it is carrying out, such as letters, leaflets, drop in sessions in local communities, as well as using the media, social media, Twitter or quick response codes for some projects.
SGN
Between 2005 and the end of March 2014, SGN replaced 7,493km of old metallic gas mains with polyethylene plastic pipe, exceeding the Ofgem target of 7,299km. The firm has now replaced gas mains in around 60 per cent of its network in the south of England and nearly 70 per cent across Scotland.
The replacement programme will continue through the current price control and, by March 2021, SGN says it expects to have replaced a further 5,800km of gas mains approximately.
Future mains replacement targets will be the subject of negotiations between Ofgem, the Health and Safety Executive and the gas network companies in the next price control, RIIO-GD2.
The firm keeps stakeholders informed of the mains replacement programme using channels such as its website and social media accounts. It also produces leaflets, on-site posters and short videos to keep local homes and businesses informed about what they can expect from the work.
Drop-in information sessions held within local communities, where our project managers can address concerns and answer questions before work begins, is another way of engaging with customers to explain why the work is needed and what the replacement programme is all about.
SGN network director Paul Denniff says: “We invest significantly in the maintenance, refurbishment and replacement of our gas pipe network to deliver a safe and reliable supply to our customers, while helping to ensure the future of the gas network. In the current eight-year price control period, we will have invested £3 billion in our network, which includes replacing old cast iron pipes with durable plastic polyethylene pipes.”
Northern Gas Networks
NGN has replaced nearly 1,000km of ‘at risk’ iron gas mains since April 2013 and, in recent months, these have included some of the “most challenging” large diameter iron mains in the network. NGN says replacement is a “key part of its strategy” and “vital” ahead of the busy winter period when there is increased demand on infrastructure.
NGN head of asset strategy Gareth Mills says: “We invest heavily in our £90 million per year REPEX programme, replacing old metal pipes with investment carefully targeted so that we spend money where it will deliver the greatest customer benefit – improving safety, reliability of supply and reducing leakage. Re-engineering our replacement programme to focus on leakage reduction has seen a significant reduction in carbon emissions in recent years.
“Our local contracting model, which engages small, locally run engineering firms to deliver our mains replacement work, rather than relying on national contractors has delivered significant benefits since it was introduced in 2013 including improved customer service, stakeholder engagement and site safety. The approach is also continuing to help us to deliver a cost-effective mains replacement programme whilst supporting local jobs and generating around £70 million per year for the local economy.”
NGN has recently introduced collaborative hubs throughout the network which has resulted in better planned jobs which take account of local circumstances and stakeholder and customer needs from the outset.
“We continue to focus on strengthening our engagement processes with communities and stakeholders throughout the life-span of a project to reduce disruption and ensure customers are left with a positive impression,” says Mills. “We’ve streamlined our engagement process for mains replacement schemes and our customer care teams are now delivering more flexible end-to-end engagement, which is making us more accessible to those people we impact and considers how we can deliver wider benefits to the communities in which we work.”
Wales and West Utilities
WWU is 12 years into its 30-year gas pipe replacement programme across Wales and the south west of England. The company replaces more than 400km of old metal pipe per year and, in 2015, plans to replace 460km.
Every year it contends with 700 fractures on old metal gas mains and the associated disruption that they cause. The replacement programme has been designed to avoid disruptive and costly ad-hoc repairs in the highway.
Programme director Rob Long says: “Safety is always our number one priority, and the replacement programme is essential to make sure homes and businesses continue to receive a safe and reliable supply of gas now and in the future. Over the life of the programme, it is an investment of approximately £2 billion in our operating area alone.
The cost of distribution makes up approximately 16 per cent of the average customer bill. Included in that is the annual replacement programme, which, by 2020 will cost approximately £2.40 per customer, per year.
“We pay up front for the new pipes and that is passed on to customers over the life of the pipe, while the customers are also receiving the associated savings and benefits of a safe and reliable gas supply. Investment in new pipes now brings value for money in the long run, and avoids the need for ongoing spend on ad-hoc repairs to leaking old metal pipes.”
WWU says it tries to minimise the impact the programme has on homes and businesses, and is continually reviewing its communication and engagement strategies to make sure the communities have all the information they need.
“We work hard to emphasise the importance of our replacement programme – and the fact that it is essential to make sure homes and businesses continue to receive a safe and reliable supply of gas now and in the future – in all communication and engagement with communities and stakeholders,” says Long.