5. Assessment of geochemical background and groundwater age

Groundwater is a complex, three-dimensional body of water in which recharge phenomena, flow conditions and interactions with the solid environment (rocks, soils) can be highly localized. This means that, within a given groundwater body, the chemical, radiochemical and biochemical characteristics of the water vary both spatially (horizontally and vertically) and temporally. In comparison with natural conditions, these characteristics can be modified by anthropogenic pressures. Thus, the water quality of a given body of water cannot be represented by a single set of analytical values, and the degree of human influence cannot be established by simple comparison with a reference list