Assessment of surface water quality of Mencha River, Northeastern Algeria by index method

Mencha River is one of the largest river in the region of Jijel, Algeria. The human activities such as urban discharges, industrial, agricultural and livestock have significant effects on the quality of water. Because of its importance in the agricultural activities and dense population residing at its banks, the river faces several challenges from various anthropogenic activities. This situation exposes surface water to a severe pollution. The objectives of this study are to use different indexes to assess the current pollution status in Mencha River. Indexes used in this study were Organic Pollution Index (OPI) and Microbiological Quality Index (MQI). Based on the data collected throughout this study, results indicated that the upper reaches of the river (station 01) has had good water quality (OPI=4, MQI=4), while the station 04 presented a poor quality (OPI=2.75, MQI=2.33). Indeed, several pollution sources exist in this site. The agricultural activity, among different sources, was the strongest point in the downstream section of the river, as it contains high amounts of chemicals, causing major decrement in water quality. The used indexes also showed that at stations 02 and 03, the water quality was moderate (OPI=3.25, MQI=3). This study can be used to support the evaluation of regulatory and monitoring decisions.