Recycling Issues
The National Grid’s Juliana Grando outlines some of the problems the company has encountered trying to take the Road to Zero in terms of primary aggregates.
National Grid’s metallic gas distribution network is currently in the process of being renewed. There are some 101,000km of mains within 30metres of properties that need to be replaced with polyethylene pipe.
This £300million project has been dubbed the 30/30 programme because it will take 30years to complete. The work will generate hundreds of tonnes of road spoil which National Grid likes to avoid sending to landfill.
We are currently landfilling around 37% of excavated spoil and using virgin aggregate to reinstate 25% of excavations. However, we have set a five-year Road to Zero target. This means sending zero tonnes to landfill and using zero tonnes of virgin aggregate for backfilling by 2010.
As a result, contractors are encouraged to recycle and use recycled, and as the environmental benefits of recycling in the context of trenchwork arisings are obvious – fewer raw materials, less landfilling and haulage – these targets should be easily achievable.
Sadly, this is not the case. National Grid is encountering a number of barriers and difficulties that make the Road to Zero a challenging target. So to increase clarity between stakeholders we set up a range of workshops across the UK.
Run in conjunction with The Environment Council, the workshops, which comprised contractors, suppliers, local authorities, utilities companies, WRAP and HAUC representatives, threw up a number of issues concerning recycled and stabilised materials.
The misinterpretation of definitions in the HAUC specification seemed to be a large barrier. It was leading to confusion as well as lack of clarity about when trials are needed. The acceptance of recycled aggregate is largely dependent on the interpretation of the specification.
Another issue raised by delegates was the complexity of the approval process. Understanding the specification takes time and makes many unwilling to change. Also, a lack of communication and sharing of information and experiences was seen as potentially leading to unnecessary repeated testing of materials.
Many felt a centralised independent body taking responsibility for trialling, approving and providing guidance on the use of recycled and stabilised materials would be beneficial.
“There is a fragmented approach and lack of third party guidance and adding such a central body would standardise communications across different parties,” said alliance manager Mike Elmer.
Other issues raised included consideration of the whole cost of using recycled and stabilised aggregate, which could be related in some regions to the lack of capacity, as well as lack of suppliers. Most participants felt that this particular issue could be associated with the lack of Government incentives to push the industry.
Actions identified included a WRAP commitment to developing a database with reference to which materials are used where on a national level. There was also a compromise from the utilities firms present to raise the need for a centralised independent body with the Government.
National Grid is confident these events have raised awareness, knowledge and commitment, as well as motivating participants to change existing practices in favour of recycled aggregate for reinstatement practices. This will help drive the company commitment on its Road to Zero.
