Motorways and the Mineralogy of Chromium Contaminated Land

metal determinations by chemical analysis alone are no longer sufficient. Our group (see references), initially funded under the NERC URGENT program, has applied a variety of mineralogical methods to chromate ore processing residue (COPR) which contaminates land around Glasgow, Scotland (Figure 1). These methods are underpinned by use of the Chemical Database Service (CDS) databases in some very simple but important ways. These include calculation of X ray powder diffraction (XRPD) patterns to aid in phase identification, as a source of structure details for starting models for Rietveld refinement of XRPD patterns and/or structure representation to illustrate mineralogical concepts of relevance to metal speciation, as well as a source of other basic crystallographic data. Approximately 2.5 million tonnes of COPR, produced by a ‘high lime process’ have been used as fill at a network of sites in and around Glasgow [4]. The COPR is derived from a former chromium works at Rutherglen, which operated between 1830 and 1968. Large areas are heavily contaminated with alkaline (up to pH 12.3) waste, often of granular appearance (Figure 2) containing Cr(VI), a known carcinogen of significant mobility.