Buried Tar and Bitumen Waste: Assessment and Disposal.

Coal tar and petroleum bitumen have different origins and compositions. Historic tar-bound products may contain substances relevant to hazardous-waste assessment. Other bituminous products may need a different classification. Calling everything 'tar' or 'tarmac' is not enough to specify testing or select a receiving facility.

Demolition fill can contain old roofing felt, waterproofing products, broken surfacing and residues from previous site activities. Layers of different materials may have been deposited together or at different times. A site investigation should record those differences rather than treating every black fragment as one uniform waste stream.

Review the site's history, the likely products and where they occur. Sampling and analysis should be chosen to answer the material-identification and classification questions. Polycyclic aromatic hydrocarbons (PAHs) may be relevant to a coal-tar investigation, but a generic PAH result should not be treated as a universal shortcut for classifying every tar-containing waste.

Where surrounding soil may be affected, the investigation must address that soil as well as the visible waste. It should also consider other relevant contamination, including petroleum hydrocarbons and heavy metals in industrial fill.

Some older building products used asbestos as reinforcement. That is a separate identification issue from whether a material contains coal tar. A result addressing one does not resolve the other.

Our asbestos roofing felt and bitumen guide explains the original building products. Where fragments are mixed through ground, use the asbestos-in-soil guide for the investigation context. Do not break, heat or burn material to identify it.

Agree the approach before excavation or loading starts. Different products and affected soil may need separate characterisation, storage and destinations. The waste description, classification and receiving facility's acceptance need to reflect the actual material, not a visual assumption that it is ordinary rubble.

Waste acceptance criteria (WAC) testing may be relevant to a proposed landfill route, but it does not replace classification of the waste as hazardous or non-hazardous. Records should connect the assessed material to the loads removed and the receiving facilities used.