Strategies for the investigation of contaminated sites using field portable x‐ray fluorescence (FPXRF) techniques

Abstract

The remediation of contaminated land is a potentially complex exercise and is one which requires a sound approach to achieve a degree of remediation which complies with existing legislative guidelines. Current guidelines for the assessment and management of contaminated sites include staged investigations (Qld DoE 1998), which relate to past uses of the site under investigation coupled with a detailed study of the total extent of chemical (and other) contamination. In performing these site investigations, it is important that a sound approach is developed to collect, for subsequent chemical analysis, a sufficient set of samples at suitable locations in order to provide relevant information on the degree and extent of the site contamination. In this study an FPXRF spectrometer (NITON, Bedford, USA) was evaluated to assess its value in the sampling, collection and geographic modeling on the extent of a range of contaminant elements including arsenic (As) arising from the operation of a now disused plunge dip. Contamination boundaries and spatial distributions of As were determined both in‐situ and ex‐situ using this portable technique over a number of locations in and around the disused plunge dip site. These values were compared with concentrations found for collected samples using standard USEPA protocols, including ICP‐OES (Inductively coupled plasma ‐ optical emission spectrometry. Spectro, Kleve, Germany) and ICP‐MS (Inductively coupled plasma ‐ mass spectrometry. VG PlasmaQuad, Winsford, UK). A comparative assessment of this approach is presented in terms of recommending an enhanced strategy for future investigations of contaminated sites using such field portable techniques.