Préservation et exploitation de la nappe de Dijon sud

Restoration and long term use of Southern Dijon Aquifer

¹ Lyonnaise des Eaux - Centre Régional Dijon Auxois Champagne 12, boulevard Docteur Jean Veillet – BP 26629 - 21006 Dijon Cedex
² ANTEA – Agence Rhône-Alpes-Auvergne-Bourgogne Parc Technologique – 3, avenue Jean Bertin – 21 000 Dijon

Auteur de correspondance : laurence.catherinot@lyonnaise-des-eaux.fr

Résumé

Southern Dijon Aquifer is a large renewable water body of 15 to 20 million m3. It is 20 km long and 2 to 4 km wide. Two aquifer layers are partly separated by a clay layer, and total depth is up to 63m. Water withdrawal started in 1960 but recently faced permanent diffuse pollution problems, originating from upstream industrial activity and agriculture. This would have ended in abandoning drinking water operation without a strong political willingness from local authorities to rehabilitate the groundwater aquifer. From 2003 to 2005, several studies and works have been undertaken. Upstream (Chenôve) water abstraction was continued with activated carbon water treatment, allowing water protection, and monitoring. Dowmstram (Marsannay-la-Côte), wells have been rehabilitated with the objective to avoid pollution transfer between aquifers and to manage water quality by selective abstraction from the two layers. Depending on water quality, upper aquifer water is either used for drinking water production (with pesticide removal treatment) or hydraulic barrier (with stripping treatment before disposal). Volatile organic compounds and hydrocarbons are monitored upstream of water wells. These works have allowed to restore and maintain long term use of the main capacitive aquifer of the area.