Time for a common-sense approach to recycling

Neil Roberts, Recycling development director at Tarmac, argues it's time to rethink commonly-held assumptions about sustainability and aggregates.

Here's a statement that won't surprise you. The construction industry is under pressure to deliver more sustainable products and working practices.

Here's one that might. Recycling is not always the most sustainable solution, let alone a practical one.

That might sound strange coming from a person in my position; indeed Tarmac is the only company in our industry to have a dedicated recycling division. However, I firmly believe that to date recycling has been driven by waste avoidance and not necessarily by customers wanting to buy recycled aggregates. By that I mean it has been the growing cost of disposal and increase in legislation to avoid landfill that has driven the growth of recycling of waste into aggregates. As the drive for more sustainable aggregates gathers pace and recycled aggregates become specified, we need to make the options clear to our clients and partners, many of whom automatically assume that recycling is always the best route, that it's time to adopt a common-sense approach.

To add some context, recycled aggregates clearly play an important role in reducing our demand on primary aggregates and cutting carbon emissions. This is certainly something that we endorse. The industry has enthusiastically supported the Government's drive to bring more recycled aggregates into play and Britain has sailed ahead in the European recycling league. 71 million tonnes of recycled and secondary aggregates were used in 2007 representing 25 per cent of the aggregate market.

But recycling is not the be all and end all. The overall carbon footprint of a project needs to be considered and, in theory, should be our reference point in deciding the most sustainable product or methodology for the job. Add to this quality and availability concerns and it becomes clear that recycled aggregates, while very important, should not be a default.

Taking the carbon footprint first. There's been much media coverage about 'food miles' - should people eat green beans from Kenya because of the carbon emissions generated in flying them over to the supermarket? This consumer dilemma can equally be applied to our industry - 'construction miles'. Recycled products which require a lot of transportation to site can generate a higher carbon footprint than non-recycled products available locally.

This all links into another consideration - availability. At the moment, recycled aggregates are not always available at the right time, in the right place or in the right quantities. This will change as the market evolves, but at the moment getting them in place may either add greatly to their carbon footprint - generating an unacceptable number of 'construction miles' - or create delays we can't afford in time-critical development projects.

Then there is the composition of demolition waste to consider. A lot of construction and demolition waste can have small quantities of plastic and other materials mixed within it. While recycled aggregates can contain a proportion of plastic and, indeed, the Specification for Highway Works stipulates that they can contain up to one per cent of 'other materials', in many cases the local engineer stipulates that product containing 'other materials' cannot be used. The WRAP Quality Protocol, which must be followed if waste is to cease being waste and become an aggregate, is set to be more vigorously enforced and should set the standards for all.

So, while more construction waste is being recycled, it is in many cases becoming more difficult. The crushing and screening of demolition waste and recycling facilities have been exempt from waste permits. However, this is currently being reviewed and under new Government proposals a waste permit may be required to crush demolition waste and operate recycling facilities. This is likely to stop the processing of waste at the demolition site as the costs and additional bureaucracy of permits becomes too much for small scale activities. As an operator of large recycling plants I should welcome this but from a sustainability view point it will increase haulage thereby increasing the carbon footprint as well as the cost of using recycled materials.

Cost, quality, product composition, 'construction miles' - they are all important factors. To be clear, though, I by no means want to be an apologist for an anti-green lobby. Recycled and secondary aggregates are clearly making an increasingly important contribution to the UK's aggregate needs and the development of recycled products is an area in which Tarmac is leading the rest of the industry. But we also recognise that the achievement of truly sustainable practice requires an intelligent approach. Let’s embrace recycling - but not think it is the cure-all.

 

For more information please Contact PR.

11 February 2009