Effect of saltwater intrusion due to over-exploitation and earthquakes on mineralization processes of spring waters over the Massif Bokkoya (central Rif, Morocco)

International audienceThe study focuses on the monitoring of physicochemical parameters and major chemical elements of six springs and wells during two seasons. Waters from the coastal karst aquifer Massif Bokkoya Al-Hoceima were analyzed for their chemical quality, and their state of anthropogenic and/or natural contamination was quantified. The waters are highly mineralized and marked by a chloride-sodium or sodium-sulfate facies mainly linked to a process of marine intrusion and dissolution of evaporitic minerals included in the on-site rocks. This mineralization of marine origin is partly due to the intensive exploitation of groundwater but also to landslides in relationship with earthquakes, that are known in the area, and which accelerate the phenomenon of saltwater intrusion. The salinity shows levels C3 and C4 in a Wilcox diagram and waters were qualified as very hard. The comparison with quality standards shows that most of the water is not suitable for consumption, especially because of high levels of electrical conductivity (EC), total dissolved solids (TDS), and Cl- related to marine intrusion, together with the urban pollution factor which increases the content of NO3-