Structure and hydrogeochemical functioning of a sparkling natural mineral water system determined using a multidisciplinary approach: a case study from southern FranceStructure et fonctionnement hydrogéochimique d’un système d’eau minérale naturelle gazeuse au moyen d’une approche multidisciplinaire: une étude de cas du Sud de la FranceEstructura y funcionamiento hidrogeoquímico de un sistema de agua mineral natural con gas determinado usando un enfoque muldisciplinario: un caso de estudio del sur de Francia用多学科方法确定气泡天然矿泉水系统的构造和水文地质化学功能 : 法国南部一个研究实例Estrutura e funcionamento hidrogeoquímico de um sistema hidromineral natural gasoso determinado através de uma abordagem multidisciplinar: um estudo de caso no sul de França

Natural mineral waters (NMW), often used to produce bottled water, are of high socio-economic interest and need appropriate management to ensure the sustainability of the resource. A complex sparkling NMW system at La Salvetat, southern France, was investigated using a multidisciplinary approach. Geological and geophysical investigations, pumping test analyses, time-series signal processing, hydrogeochemical and isotopic data (both stable and radiogenic), and numerical modelling provided complementary information on the geometry, hydrodynamic characteristics and functioning of this mineral system. The conceptual model consists of a compartmentalized reservoir characterized by two subvertical, parallel deeply rooted hydraulically independent permeable structures that are fed by deep CO2-rich crustal fluids. The non-mineralized shallow aquifer system corresponds to a fissured layer within the weathered zone that is recharged by leakage from the overlying saprolite. This surficial aquifer responds rapidly to recharge (40–80 days), whereas the deep system’s response to recharge is much longer (up to 120 days). This research demonstrates the need for multidisciplinary approaches and modelling (quantity, hydrochemistry) for understanding complex NMW systems. This knowledge is already being applied by the bottling company that manages the resource at La Salvetat, and would be useful for conceptualising other NMW sites.