Role of hydrogeoenvironmental factors on water resources quality and its implication for water supply purposes in Ndé Watershed (Western Cameroon)

Abstract

The urban centers in Cameroon including several agglomerations within the sub-region suffer from problems of drinking water supply. This situation induces the population to use water from springs, wells, boreholes and rivers with unknown qualities as their main sources of water supply. This work aims to highlight the link between lithology, human activities, physico-chemical and bacteriological quality of water in Ndé watershed (West-Cameroon). To achieve this goal, field and laboratory works were done. Water resources are slightly acidic to neutral and low to moderately mineralized with a significant amount of iron (≤6.76 mg/L) and low fluoride (<1 mg/L). The chloride-and-sulfated-calcium-and-magnesium (CaMg-SO 4 Cl) facies have been identified. Despite the fact that Water Quality Index (WQI)<25, water resources are unsuitable for drinking purposes because of biological pollution showing parameters concentration above WHO standards. Hydrolysis of minerals in silicate rocks is the main source of putting in solution of dissolved ions in addition to anthropogenic, biogenic and atmospheric inputs. However, Gibbs’s diagram revealed chemical weathering of rock-forming minerals and precipitation as origins of the ions. It is currently known that the quality of these waters is controlled by hydrogeoenvironmental factors (geology, biogenic and anthropogenic activities) and unsuitable for drinking purpose (presence of total coliforms).