A geochemical investigation in the study area should be primarily focused on characterizing the complex chemical inventory of the groundwater, surface water, soil, rock, stream and lacustrine sediments, and soil gas. Geochemical site characterization includes a determination of geogenic background values and anthropogenic input. This distinction is possible only if the size of the area and the number of sampling points is adequate for a statistical evaluation. A geochemical investigation usually takes place following the geological, hydrogeological and geophysical surveys, the results of which are used for a focused and representative sampling strategy. The approach and the scope of a geochemical site investigation depend on the following:
the objective and phase of the investigation,
the contamination potential,
the compartment under consideration (e.g., the groundwater, soil, or air), and
the natural environmental conditions.