ASSESSMENT OF THE QUALITY OF DOMESTIC WATER RESOURCES: CASE OF THE SAN-PEDRO RIVER AT THE FAYE HYDROELECTRIC DAM (SOUTHWEST COTE DIVOIRE)

Surface waters are the most vulnerable to pollution and variations in the hydrological cycle. These waters are polluted by anthropogenic pollutants such as pesticides from agricultural activities and heavy metals from agro-industrial activities. The waters of the San-Pedro River reservoir at the Faye dam are expected to be used for the drinking water supply of the population of the city of San-Pedro. The objective of this study is to assess the chemical quality of the water in the San-Pedro River at the Faye dam based on the calculation method of the Water Quality Index (WQI). Thirteen (13) stations were sampled during the four (4) climatic seasons in 2021 and 2022. These seasons are: the large dry season (LDS), large rainy season (LRS), small dry season (SDS), and small rainy season (SRS). Chemical analyses were conducted on 27 physico-chemical and chemical parameters. The results of the Water Quality Index calculation indicate water unsuitable for drinking in all seasons. The quality of these waters is influenced by trace metal elements (TME) with average WQIavg, TME values of 1079.6 864.5 3007.6 and 3645.2 in LDS, LRS, SDS, and SRS, respectively. On the other hand, organic parameters have a less significant influence on the quality of this water, as evidenced by WQI values of 35.7 in LDS 53.9 in LRS 80.1 in SDS and 33.5 in SRS. Therefore, this water requires appropriate treatment before any use.