The primary water supply to the inhabitants of the tropical rainforest is surface water with limited water quality data. A hydrogeochemical study was conducted to identify the processes that control surface water chemistry and to examine the quality of water sources for domestic and agricultural purposes. In the two seasons, fifty-six water samples were collected from rivers within the study area. The primary ions and physicochemical properties (pH, EC, and TDS) of the samples were examined. The surface waters had a pH in the dry season from neutral to acidic to neutral (4.8–7.2), whereas in the wet season, the pH was alkaline to acidic to alkaline (5.1–9.2). TDS varied from 16.64–100.20 mg/L (dry) and 8.64–784.70 mg/L (wet) with 99% of the rivers within WHO guidelines, indicating negligible mineralization, hence fresh water. Sodium (Na+) and Bicarbonate (HCO3-) ions were dominant during the dry and wet seasons. Corrosivity and scaling analyses showed that the samples are highly aggressive (-5.45 to -1.01) but suitable for industrial purposes. Rock-water interaction and atmospheric precipitation are processes responsible for surface water chemistry with some minor evaporation. Based on the water quality index (WQI), the water quality in the study area ranged from excellent (71.5% dry; 92.8% wet) to good (25% dry; 3.5% wet) in both seasons for domestic use. Based on the RSC and SAR, all samples were considered suitable for use in agriculture.

 

Key words: Hydro-geochemistry, ion exchange, surface water quality, central Cameroon.