POLLUTION OF THE QUATERNARY AQUIFER OF MITIDJA (ALGERIA) BY NITRATES: ORIGINS AND IMPACTS ON THE QUALITY OF WATER FOR HUMAN CONSUMPTION

Abstract

The aim of the study is to evaluate the degree of contamination of the aquifer of Mitidja (Algeria) by nitrates and to determine the origins of this contamination by a statistical approach and to estimate the impact on the quality of the aquifer by the application of the Water Quality Index (WQI). The results show that the aquifer is strongly contaminated by nitrates with an average of 71.58 mg/l. These results were confirmed by the calculation of the Water quality Index (WQI) which varies between 59.29 and 190.25 with an average of 110.16, thus 60% of samples are characterized by a water of bad quality for human consumption. The Principal Component Analysis (PCA) enounce the anthropic origin of the nitrates which are regarded as chemical pollutants of permanent type and diffuse sight that their origin is agricultural.