Bouwèdèo TOI BISSANG^1,, Ogouvidé AKPAKI¹, Gnon BABA^{1, 2}

Drinking water requires an acceptable physico-chemical quality in relation to water quality standards. They may not contain any substance which is harmful or which may harm the health of the consumer. In order to contribute to the control of water quality intended for human and animal consumption in the canton of Bangeli (in Togo), our study focused on the physico-chemical quality and the state of chemical pollution of the waters of this canton by using the water quality index (WQI) because of its usefulness in understanding water quality issues. A total of 28 points were selected, sampled and analyzed. The analyses are carried out in the dry and rainy seasons and focused on parameters such as pH, conductivity (EC), temperature, NH₄⁺, NO₃^-, NO₂^-, PO₄^3-, SO₄^2-, TH, Ca²⁺, Na⁺, K⁺, Fe et Cl^-. These results show that all the surface water and 66.66% of groundwater have an iron content greater than 0.3 mg/L. All the other parameters meet the standards except for one well where the nitrate content exceeds the standard value (50 mg/L). The calculated quality indices made it possible to realize that surface waters and 42% of groundwater analyzed are of poor quality (WQI > 100), so they require treatment before using as drinking water.

Canton of Bangeli, physico-chemical, water quality, quality index, poor quality