La Salinització de la conca del Cardoner-Llobregat al Bages

Abstract

The salt content in the rivers Cardoner and Llobregat endangers its supply to the Barcelona area. The chloride (Cl-) concentration is much higher than the advised level for water for population supply purpose. The Cardona salt geological stratum and its potash mining activity in the Cardoner-Llobregat basin (Bages, Catalonia) certainly are related to the salt contamination. The presence of potassium, which is only in the land surface after mining, discriminates between natural from the geological layer or artificial from the mining activity brine sources. The geographical distribution of major brine sources, as well as their Cl-/K+ ratio, demonstrate that the giant, sterile mountains of salt residues from the mining activity contribute the most to the salt content of the two rivers at present. Despite their incidence in the water quality, the mountains of salt residues from the potash mining are still growing in thousands of tons daily.