Presenters: Ross McFarland, AECOM
Presentation title: Are we wasting money cleaning up some Polycyclic Aromatic Hydrocarbons (PAHs)?

A very common class of compounds identified on most former industrial land are the polycyclic aromatic hydrocarbons or PAHs. While some individual PAHs are certainly chemicals of significant environmental concern, many others are not, and yet some site cleanups can be unnecessarily remediated for reasons that lack scientific defensibility. This paper considers the common use of the group of PAHs that have been defined as the “USEPA’s 16 Priority PAHs” (tPAHs) as the trigger for site cleanup and waste classification. AECOM has reviewed the scientific basis of the tPAHs group’s threshold levels and through a more scientifically defensible approach, we have saved our clients many hundreds of thousands of dollars. A new site characterisation tool (RossPlot) has been developed to assist in better PAH characterisation for defensible decision making. Unfortunately, after nearly 25 years, it is only now becoming evident that this USEPA 16 priority PAH list may not be most appropriate measure for PAH contamination in soils. However, the wealth of data collected for tPAHs has necessitated that a technique be developed to make some use of this information. Ross Plot is a simple tool that can be created from an Microsoft Excel spider chart. The priority PAHs are ranked in order of boiling point to establish their solubility, bioavailability, carcinogenicity and their bio-recalcitrancy.
Event: WasteMINZ Conference 2014
Date: Wednesday 23 October 2014