7 March 2011, News release from CMT (Testing) Limited
'Under WRAP' - The Programme for Recycled Aggregates, the Quality Protocol & associated testing requirements. In 2000, the Government's Waste Strategy (England & Wales) appeared.
Aimed at sustainable development and waste management, its purpose was the promotion of re-using, recycling, composting and use of wastes as fuel. The Strategy has progressed with recycling increasing and landfill disposal reducing. Higher recycling targets are envisaged beyond 2009.
The Waste and Resources Action Programme (WRAP) was founded in 2001 as a direct result of the Waste Strategy. It carries a remit to "overcome market barriers to promote re-use and recycling".
WRAP has 12 current 'key programmes'. Of the 9 concerned with market development, 6 relate to particular materials: Aggregates, Organics, Plastics, Glass, Paper, Wood. At present, 25% of aggregate demand in the UK is met by recycled or secondary materials.
These are defined as follows:
Recycled aggregates: obtained via reprocessing of materials previously incorporated in construction; particularly concrete, bricks, blocks, demolition waste, rail ballast and asphalt;
Secondary aggregates: (Mostly) previously un-used byproducts from industrial processes, including pfa, steel slags, furnace / incinerator bottom ash, used foundry sand and certain recycled materials (glass, plastic). Some secondary aggregates can actually be naturally occurring, e.g. colliery spoil.
The WRAP Aggregates Programme & Quality Protocol
Commencing in 2002, with an objective of reducing demand for primary aggregates via promotion of the use of recycled and secondary aggregates, the Programme has produced a Quality Management Structure comprising Quality Protocols for England & Wales, Scotland and Northern Ireland. These cover production of aggregates from inert waste. The main requirements are:
In support, WRAP has produced checklists and guidance. These give details of the requirements of those producing and specifying sustainable aggregates, enabling producers to show that their aggregates arise from processes complying with the Quality Protocol, ensuring that end users have confidence in the supplier, the quality of materials purchased and their own compliance with Waste Management Regulations.
The EA has 'endorsed' the use of the Quality Protocol, referring to it when making decisions on how to regulate waste. This is important as the Agency consider that waste for re-use has to be fully recovered before it is no longer deemed to be waste.
They take the view that this point is reached for recycled or secondary aggregates, only when the recovered material is actually incorporated into construction. Under this view, without alternatives, use of waste aggregates would have to be carried out in compliance with a waste management licence or registered licence exemption and duty of care, with possible involvement of registered waste carriers.
Here the (WRAP) Quality Protocol offers an alternative, so long as the relevant requirements of the Protocol are met, the holder of the 'processed waste aggregate' is in a position to show that the material has been fully recovered to 'recognised industry standards' and is, therefore, suitable for further use as aggregate without the above licences.
Appendix C of the Quality Protocol gives EWC catalogue codes and corresponding descriptions of wastes that, 'provided there is no suspicion of contamination' are considered as inert wastes. The Protocol's requirement for visual inspection of incoming waste against established acceptance criteria should be sufficient to control this, but testing may help where doubt exists.
Certain laboratory tests, (gradings, fines content and, where necessary, particle shape) are required on a regular basis. In addition, sampling and testing is required to demonstrate suitability of the product for particular end uses. Here, Particle Density, Los Angeles Coefficient (resistance to fragmentation) and bulk density tests are required for all intended uses.
Beyond this, various geotechnical and chemical analyses (including sulphate/sulphate related tests) and testing of physical properties will apply for uses including:
Consideration of leaching potential/pollution risk for products used in construction
Information provided by WRAP shows that "the majority of recycled and secondary aggregates pose no significant risk to controlled waters when used in properly designed and constructed engineering applications that account for the sensitivity of the local environment".
This is consistent with the Quality Protocol which follows the EA's guidance on the Landfill Directive with respect to criteria for the acceptance of inert waste at landfill sites. This approach allows acceptance of recycled aggregates without leach testing as the criteria are met if the aggregates are "a single stream of materials from a known and reliable source".
For secondary aggregates or where doubt arises over contaminants and the potential for leaching from recycled aggregates, suitable leach testing and risk assessing may be required. CMT offer full sampling and testing services for WRAP or other purposes.
Call us for testing, risk assessing or further advice and guidance.
For further information please email CMT (Testing) Limited