Groundwater Contamination by Wastewater in Figuig Oasis (Eastern High Atlas, Morocco)

The aquifer basin of Figuig is located at the eastern extremity of High Atlas of Morocco. It is a multi-layer aquifer system. The Triassic formation is characterized by clay and the Jurassic formation by the carbonate, while the Quaternary formation is formed by alluvial silts and sands. The present work focuses on the study of salinity and contamination of groundwater by discharges of wastewater into septic tanks in this region. The methodology used was to map the spatial and temporal variation of salinity and to define the spatial extent of the contamination. The results obtained for (1) salinity, (2) bacteriology (faecal and total coliforms), and (3) nitrates and (4) a simulation of contaminant transport using the MODPATH code indicate that the southern zone has high salinity and the south and southeast areas are contaminated by wastewater discharges. For this purpose, the quality of groundwater in the oasis of Figuig deteriorated over time. This work is expected to assist local authorities in developing plans and in reducing the pollution to acceptable levels.