The aim of this publication is to contribute to the knowledge of a part of the Rhône plain alluvial system under the influence of two landfills. The hydrogeological environment of this zone is described using topographic, geologic, climatic and hydrologic information, allowing a 3D approach. This analysis confirms the complexity of the ground water flows of the aquifer between Sierre and Granges. The great diversity of the anthropogenic or natural element sources are responsible for the 3D heterogeneity of the water quality observed in this aquifer.