The WACHEM database is a compilation of multi-element geochemistry of rocks unconsolidated surface material (regolith) and drill core collected by the Geological Survey of Western Australia. Samples have been analysed for a range of major element oxides, trace elements, rare earth elements (REE), and isotopes by a variety of analytical approaches at commercial, government and university laboratories. In most cases, analysis of unknowns has been carried out along with samples of know composition (reference materials), a second sample of the unknown (sample duplicate), and material which does not contain detectable amounts of elements of interest (blank). These data are included with analysis of unknowns, and these quality control data can be used to gauge the quality of analysis. For inclusion in the geochemical database, analytical data for each element in each sample must include the unit of measurement, lower level of detection (LLD) of that element, and an indication of the analytical technique (usually specified as a laboratory-specific code). To minimise the inclusion of spurious data in the database, analytical batch data are loaded with reference to a set of look up tables, against which data can be checked for consistency.