Justin Taberham is Director of Policy at CIWEM. He shares his thoughts on Part 2A of the EPA below.
Under Part 2A land is Contaminated when either Significant Harm (SH) or the Significant Possibility of Significant Harm (SPOSH) or the Pollution of Controlled Waters applies (PoCW). The determination is based on an assessment of whether after an assessment of Source-Pathway-Receptor relationships it is concluded that one or more of those conditions applies.
If we just consider the technical aspects alone, it does not surprise me that the distribution of determinations appears random. The implication is that Part 2A sites should mostly be in former industrial areas but this is not the case. Stoke, where I work, is a good example; despite the long industrial legacy there has only been one Part 2a determination in a city where Part 2A inspections are taken seriously. Conversely, leaking central heating oil tanks and old petrol filling stations are common sources that can occur practically anywhere in the country and I have anecdotal evidence that several such sites have become Part 2A determinations.
My interpretation of the implication of the IES research is that inconsistencies in the decision making process are causing the apparently random location of determinations. Until recently, there may have been some truth in this contention as a result of the absence of a satisfactory definition of SH or SPOSH. Collective wisdom was that decision makers should not only take into account by what factor a soil concentration exceeds a specified generic value, but should consider background concentrations in the area and socio-economic factors as well (a key question being, what is the bigger health risk, that from the contaminant or the worry of having your back garden declared a health risk).
The 2012 revised guidance on Part 2A had the objective of resolving such dilemmas. The basis of Part 2A determination is now much clearer, with the introduction of C4SLs and the concept of ‘significance’ being introduced into the POCW aspects, so one important point is that this study assessment is now retrospective.
In summary, some of the randomness observed by this research may be attributable to uncertainties in the determination process but if so the new guidance should be helpful. Nevertheless, there are so many technical variables that combine to create a Part 2A site, so it does not surprise me that a random distribution is observed anyway.
Further research might be directed towards looking at what effect the new guidance has, if any, in the geographic patterns of Part 2A determinations.