Le fonds géochimique naturel des eaux souterraines. État des connaissances et méthodologie

Groundwater geochemical baseline. State of the art and methodology

¹ IFEN, 61 Bd A. Martin, 45058 Orléans Cedex 1
² BRGM, service Eau, BP 6009, 45060 Orléans Cedex 2

Auteurs de correspondance : l.chery@brgm.fr ariane.blum@ifen.fr

Abstract

Within the setting of the groundwater quality evaluation system ("SEQ-eaux souterraines") and the Framework Directive application, we are faced with the problem of groundwater quality patrimonial state evaluation. It involves the knowledge of the groundwater geochemical background in order to detect every variation due to the human activities, and to predict water quality evolution in short and long term. A methodology applicable to the french geological context is suggested to facilitate geochemical background characterization. The freaks controlling the chemical composition of groundwaters are surimposed and make illusive a determinist approach applicable to all the aquifers. However, the suggested methodology proposes successive steps required for natural groundwater baselines identification, within the context of groundwater bodies definition, anthropogenic pressure identification, and quality objectives fixation for groundwater bodies restoration, due to Framework Directive setting.