Occurrence and utilisation of mineral and construction wastes

This report summarises the results of a study undertaken for the Department of the Environment as part of the minerals planning research programme by Arup Economics and Planning with specialist technical inputs from the Ove Arup Partnership. The study had three broad aims: 1) To provide a thorough account of the current quantities and uses of secondary aggregates and recycled/re-used construction materials; 2) To evaluate the relative costs of utilising such materials against the cost of the supply of primary aggregate alternatives; and 3) To assess the economic and physical constraints to the greater utilisation of these materials and to identify ways in which such constraints could be overcome. For most secondary materials the principal disadvantage associated with further use are the transport costs from source to the principal areas of market deficiency such as the South East. Whilst all aggregates are relatively sensitive to transport costs, there is usually less incentive for mineral waste producers to seek outlets for their material as a secondary aggregate because of the (generally) lower quality and lower prices they can command. There are other difficulties to be overcome, including customer acceptance of the product, and the need to maintain necessary standards of safety and performance, (where specifications may help) and the study has identified a number of actions that government could take to assist with greater utilisation of these materials. Nevertheless, the principal disadvantage faced is economic, arising in the main from transportation costs. Many of the environmental impacts resulting from the extraction of primary aggregates apply equally to the utilisation of secondary materials. This is because the processes are very similar namely, extraction from an appropriate source, processing often involving noise, dust and visual intrusion, and transportation to market, often using lorries. However, the longer term environmental concerns are: 1) the permanent loss of land-related amenity when aggregates are extracted, for which satisfactory restoration and aftercare can never fully compensate. Similarly, when the mineral wastes are tipped there is also a loss either of land-related amenity or of landfill space; 2) the beneficial use of an otherwise wasted material. The principal rationale for government intervention to bring about greater use of secondary materials is to secure environmental savings in terms of reductions of land-related losses from both primary extraction and waste tipping.