Waste not, want not

A trial to recycle trench soil has the potential to deliver £1.5m annual savings for client, National Grid, in the north west of England alone.

Every year, National Grid excavates thousands of holes in roads, footpaths and on private land during its work to repair and renew gas mains. And National Grid and its contractors spend millions of pounds transporting excavated material to landfill and reinstating the holes using expensive aggregate.

The advent of the new landfill and aggregate tax has - and will continue to - push costs up even further, with utilities charged £24 for every tonne of waste material that goes to landfill.

The use of landfill, and frequent heavy goods vehicle movements, are environmentally damaging - while the delay in reinstating holes leaves a potential public safety hazard.

In November 2005, May Gurney - working closely with UK Distribution - set about a trial to pioneer a recycling solution using SMR (Structured Material for Reinstatement) to refill holes with the excavated material. SMR bonds with the spoil, enabling it to be quickly returned to the hole.

The project aimed to: reduce safety liabilities; reduce the amount of waste going to landfill; reduce the use of virgin aggregate; and reduce vehicle movements and save fuel.

Martin Tomkins, National Grid Operations Engineer - Performance, and May Gurney Reinstatement Manager, Geoff Preston, selected a supplier, SMR Ltd, and implemented an 18-month plan with the agreement of the local highways authorities. From May Gurney's viewpoint, it was important to bring everyone together who needed buy-in.

Initially work was restricted to five holes a day. As confidence grew, the project gained momentum and became accepted good practice and SMR is now extensively used.

Over 1,200 tonnes have been placed on site to date, with an equivalent amount, normally destined for landfill, being recycled. With an average of 300 holes dug each week in the region, savings through reduced haulage, aggregate and landfill costs could be up to £1.5 million by the end of the year.

National Grid's Craig Horrocks said: "May Gurney are one of several term contractors with similar outputs so if you multiply the cost, safety and environmental improvements across all the retained networks the benefits grow dramatically. We want to share our knowledge and the lessons we have learnt with everyone in National Grid."