Appreciable levels of toluene are seen routinely in volatile hydrocarbons reports for soils sourced from pristine northern Alberta wetlands. Often the concentrations exceed the Alberta Tier 1 Criteria for that location. Although it is now commonplace for commercial laboratories to assist clients in determining the likely origin of this compound, the process by which this is being done can be somewhat haphazard and inconsistent. Reasons behind this include the steadily increasing scope of knowledge on the topic and the lack of consensus on how best to apply this knowledge in the laboratory on behalf of the client.
In recent years simple diagnostic ratios, or the presence/absence of specific marker compounds, have been used increasingly to formulate a conclusion. Bureau Veritas Laboratories has evaluated these approaches and noted that along with their merits, there are also limitations for a small proportion of cases, which could potentially result in an incorrect interpretation. For these cases it is important to use all the tools in the toolbox prior to drawing any conclusions. The risk of undertaking a needless and costly remediation project is simply too great to not consider all available evidence prior to issuing an interpretative statement on a test report. Likewise, the environmental risks of an incorrect conclusion could be just as costly.