EVALUATION OF SURFACE WATER QUALITY AND CONTAMINATION STATUS OF THE ZEREMNAVALLYSUB-BASININTHE SKIKDA REGION (NORTH-EASTERN OF ALGERIA)

Abstract

The purpose of this paper isto assess the quality and status of organic and metal pollution of surface waterof Zeremna vally sub bassin in the Skikda. , used the water quality index (WQI), the organic pollution index (OPI), the pollution index (PI) and the metal index (MI) according to the uses of drinking water, irrigation and aquatic life.The results of WQI revealed that 80% of the samples indicate a poor quality to non-drinking water, present a strong to very strong organic pollution for all use, except for the samples of the upstream of the study area (S1) and (S2) which present respectively good quality water and moderate pollution for all use, in S3 and S4 of the poor quality water with moderate organic pollution for drinking water and aquatic life and good for irrigation. The metal index (MI) and pollution index (PI) were calculated to assess the contamination of the water of Zeremna vally by metals (Cr ⁺, Pb ^{+ 2} and Zn ^{+ 2}).The values of MI and PI indicate aslight pollution of the water of the river, which is described as serious in the stations S9 and S10. This anthropic environmental degradation recorded downstream of the two urban communes due on the one hand to the intensive use of nitrogen and phosphate agricultural fertilizers and the absence of septic tanks in the neighboring anarchic settlements and on the other hand to the impact of leachates loaded with various pollutants from the Zef-Zef wilaya of Skikda.