Waste management and recycling offer major benefits in transport infrastructure
Guidance on recycling in transport infrastructure is provided in a new document produced by TRL Limited. Much has been achieved to remove obstacles to recycling, but some issues still need to be addressed. Dr Murray Reid of TRL Limited reviews progress on the road to recycling
As the modern world comes to terms with the fact that the planet’s resources
are finite, the pressure to increase recycling is affecting all sectors of the
construction and waste management industry. In many areas this requires a considerable
readjustment in attitudes. In the construction and maintenance of transport
infrastructure, as in many other branches of construction, there has in the
past been a reliance on using only high quality natural aggregates, and sending
any marginal or unfamiliar material to landfill. Transport infrastructure includes
the earthworks, pavements and drainage required for roads, railways, airports
These powerful drivers have resulted in an increase in the use of alternative
materials and in the development of in-situ recycling techniques. However, in
some areas progress has been slow because of real or perceived problems with
the application of these materials and techniques. Reasons often given for failure
to use recycling include a lack of specifications for the materials and techniques,
lack of appropriate test methods, concern about quality control and variability
of the materials and methods and difficulty in ensuring an adequate supply of
The waste management licensing regulations are often seen as a barrier, as it
is not clear whether alternative materials are classed as waste, and, if so,
whether they are covered by exemptions. Contractors are very reluctant to take
on the burden of a waste management licence, and the timescale required to resolve
these issues often precludes the use of these materials in construction contracts.
In some cases, the environmental regulators may be concerned about the use of
certain materials in terms of dust or gaseous emissions or contamination of
surface and ground waters.
Operators of recycling centres often experience difficulty in obtaining planning
permission and other approvals and adversarial conditions of contract can inhibit
the use of innovative recycling techniques. Overall, there is a lack of awareness
of the possibilities of recycling, coupled with a strong awareness of potential
To help overcome these problems and increase the amount of recycling in transport
infrastructure, TRL Limited (formerly known as the Transport Research Laboratory)
carried out a research project funded by DTI and the former DETR under the Partners
in Innovation programme. Lafarge Aggregates UK and the Hanson Environment Fund,
through landfill tax credits, provided additional funds. A steering group with
cross-industry experts supported the project team and ensured that all the important
issues were covered. The main output from the project is a guidance document,
entitled *Recycling in transport infrastructure. The document is targeted
at managers and technical personnel in the main stakeholder groups, including
local authorities, contractors, designers, producers of secondary/recycled materials,
environmental regulators, owners and operators of transport infrastructure.
The document consists of three parts. In Part 1 the main issues affecting recycling
in transport infrastructure are identified and discussed. Part 2 contains available
guidance on these issues. Because different stakeholders can have different
views on the same topic, sub-sections of the text have been prepared for each
stakeholder group. Some issues require further action: these are summarised
in Part 3 in tabular form for each stakeholder group.
The actions are ranked in terms of relative priority, timescale and nature.
Fourteen case studies are presented in an appendix to illustrate how greater
recycling can be achieved in a range of situations, and how common problems
can be overcome.
The project revealed that guidance is available for many of the issues that
were raised as potential obstacles to recycling. In recent years a number of
specifications have been developed to cover many of the materials and techniques
that are now available.
There have also been major improvements in quality control procedures. Materials
produced under a quality control plan should be at least as fit for purpose
as natural aggregates. Guidance was published by the then DETR on controlling
the environmental effects of recycled and secondary aggregates production. This
will benefit planning authorities and the owners and operators of recycling
Examples of the use of partnering and global costing by organisations, such
as the British Airports Authority, illustrate the economic and environmental
benefits that these approaches can bring A number of the case studies describe
the successful use of particular materials and techniques.
The current waste management licensing and exemption process, as it applies
to recycling in transport infrastructure, is described, and regional variations
in Scotland, Wales and Northern Ireland are given.
The available guidance indicates that recycling can be successfully carried
out, and local authorities have often been to the fore in taking new techniques
forward. Some areas of difficulty remain, particularly connected with the application
of the waste management licensing regime. This is acting as a significant restraint
on the use of alternative materials in construction projects, where the short
timescale of the projects means it is often impossible to resolve issues with
the environmental regulators in sufficient time to enable the materials to be
used in the contract. Variation in interpretation of the regulations between
different offices of the environmental regulators is often cited as another
reason for not using recycling. In return, the environmental regulators point
out that contractors often submit applications at extremely short notice, often
without sufficient information to enable them to make a decision. The Environment
Agency has a process handbook for processing waste management licensing applications,
which should ensure uniform treatment of applications throughout the country.
They also point out that the licensing process has statutory consultation periods
of 28 days built into it, and that contractors should allow a reasonable time
for this process.
Clearly, the waste management issues need to be streamlined if the full potential
for recycling is to be realised. The Environment Agency launched a construction
campaign in March 2001 to improve the environmental performance of construction
sites and to engage in more liaison and training with industry. In time this
may bear fruit with a greater understanding by each side of the other’s position
and a more constructive dialogue. Another idea that arose out of the TRL project
is to establish a National Industrial Forum where environmental regulators,
industry, infrastructure owners and operators and government could meet to discuss
problems such as these and agree ways to move forward. The idea arose out of
the constructive, but often vigorous, debates in the steering group over the
course of the project, which were very helpful in clarifying what the real issues
were and identifying ways to deal with them. Anyone with views on this topic
is invited to contact the author.
In the areas where progress has been made, it is because the stakeholders involved
have acted to address the problems, for example in the preparation of specifications
and design guides for new materials and methods. This has often involved commissioning
research to obtain the necessary data on which to base the specifications. Where
a number of stakeholders have acted in concert the results have been particularly
effective. A good example is the production of a quality control document for
recycled aggregates by a working group involving BRE, the then DETR, the Highways
Agency, local authorities (via CSS), the Quarry Products Association and a number
of aggregate producers and consultants. A similar approach will be required
to overcome the remaining obstacles to recycling.
*The guidance document “Recycling in transport infrastructure”
is available from TRL Publications, Tel. 01344 770783 or by email at email@example.com.
For further information on technical aspects, contact Dr Murray Reid, TRL Limited,
Tel. 01344 770283, email firstname.lastname@example.org.
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