The use of aggregate recovered from incinerator bottom ash (IBA) has increased with pressure to protect natural resources and growth in the number of UK energy recovery facilities. Each year over 1 million tonnes of IBA is processed by aging, metal removal and size grading. The recovered aggregate (IBAA) can be used in a range of applications, subject to scenario-specific environmental risk assessments, such as those developed for the EA/WRAP Quality Protocols.
WRc carried out a risk assessment for the application of bound and unbound IBAA aggregate using a number of placement scenarios to model the release of contaminants. The risk to surface water, groundwater and human health from the modelled scenarios was shown to be low, as long as appropriate mitigation measures and best operational practice were followed.