The impact of the Oum Azza landfill on the quality of groundwater at the Rabat region (Morocco) ; El impacto del vertedero de Oum Azza sobre la calidad de las aguas subterráneas de Rabat (Marruecos). ; L'impact de la décharge d'Oum Azza sur la qualité des eaux souterraines au niveau de la région de Rabat (Maroc)

International audience ; A 110 ha dump, located in the Akrach shallow aquifer area in Morocco, was studied in order to characterize the quality of groundwater around the landfill, to delineate the contaminated area and to determine the factors favouring the contamination of groundwater. This dump is located in the city of Oum Azza (15 km south from Rabat), (Map 1). between the Akrach River in the west and the Sidi Mohamed Ben Abdellah Dam in the east. To assess groundwater pollution from this landfill, piezometric monitoring and Hydrochemical analyses were conducted on 22 wells. The results highlight a significant degradation in the groundwater quality, especially in the parts located in the direct vicinity downstream the dump. In the impacted areas, electrical conductivity was above 1100 μS cm-1, bicarbonates were higher than 508 mg L-1, chlorides, sulphate, and nitrates contents were higher than 850, 200 and 1 mg L-1, respectively. In addition we found high cadmium (50 - 100 μg L-1) and chromium (40 - 230 μg L-1) contents, i.e. much higher than the WHO guidelines for drinking or irrigation water. A principal component analysis conducted on this dataset highlights the absence of a prevalent principal component (PC), with the variance distributed across many PCs. The mechanisms responsible for the chemical variance of the hydro system are therefore numerous and fairly balanced in terms of influence. Finally, a hierarchical classification brings out three groups of observations, each group corresponding to a level of pollution. ; Un vertedero de 110 ha, ubicado sobre el acuífero superficial de Akrach en Marruecos, ha sido estudiado para caracterizar a la calidad de las aguas subterráneas al rededor del vertedero, de conocer la extensión del área contaminada y estudiar a los factores involucrados en esta contaminación. El vertedero se ubicado en la ciudad de Um Azza (15 km al sur de Rabat) (mapa 1), entre el rio Akrach al oeste y la represa Sidi Mohaed Ben Abdallah al este. Un control piezómetro y análisis ...