Presenters: Graeme Proffitt, Pattle Delamore Partners Limited
Presentation title: Myth, fallacy or stupidity? Some observations on contaminated land assessment


Discussions and research around the Ministry for the Environment’s proposed update of Contaminated Land Management Guideline No. 5 and the author’s review of reports from around the country have revealed a disturbing lack of understanding of some contaminated land fundamentals.  Hopefully the proposed update will help correct some of the existing poor practice. This paper, while not attempting to predict what might be in the update, explains some concepts that deserve to be better understood.  These include interrelated ideas around collecting enough samples to properly represent how a person is exposed to soil contamination, including some examples that demonstrate how easy it is to arrive at the wrong conclusion or, by chance, the correct conclusion for the wrong reason, why Appendix B in the current guideline deserves to be consigned to the nearest landfill, the myths around composite sampling and the misplaced need to “correct” the result for the number of samples in the composites, whether a hotspot is really a hotspot (often not), how soil contaminant standards are really supposed to be applied in assessments with a regulatory purpose and why we should not be too bothered about individual samples (which too often end up, in effect, representing and condemning  the complete site).  And if you haven’t presented at least a vague semblance of a conceptual site model, you really don’t get it!

Event: WasteMINZ Conference 2014
Date: Wednesday 23 October 2014