Study On the Vulnerability of Groundwater to Pollution in Bafoussam City, Western Cameroon

Abstract

Groundwater represents the most significant source of potable water globally, yet it faces increasing threats from surface-level pollution. This study provides a comprehensive evaluation of groundwater vulnerability to contamination in the city of Bafoussam, a critical urban and agricultural hub in the Western Region of Cameroon. The assessment was conducted using the SINTACS parametric method, a robust model that integrates seven distinct physiographic and hydrogeological parameters: Water table depth (S), Effective infiltration (I), Unsaturated zone (N), Soil environment (T), Aquifer environment (A), hydraulic Conductivity (C), and Slope or topography (S). These parameters were derived from a combination of remote sensing data, including Digital Terrain Models (DTM), and exogenous data sources such as lithological maps, soil analyses, rainfall records, and direct hydrogeological measurements. The primary objective was to map both the intrinsic vulnerability of the aquifer system and its specific vulnerability to prominent local pollution sources, namely fecal contamination from urban sanitation systems and nitrate pollution from agricultural activities.

The results reveal a complex vulnerability landscape across the study area. The intrinsic vulnerability assessment, which reflects the inherent susceptibility of the aquifer to contamination, indicated that 18.35% of the area exhibits high vulnerability, 37.47% has medium vulnerability, 31.46% has low vulnerability, and 12.72% is classified as having very low vulnerability. For specific vulnerability to fecal pollution, with E. coli serving as the bio-indicator, the analysis showed that a majority of the area, 51.78%, possesses an average or medium vulnerability. A further 30.24% demonstrates low vulnerability, while 17.99% shows very low vulnerability to this contamination type. Regarding agricultural pollution, for which nitrate was the chemical indicator, 8.37% of the area was found to have a high specific vulnerability, 12.37% an average vulnerability, and the remainder exhibited low to very low vulnerability. These findings underscore the significant risk of groundwater contamination from urban, industrial, and agricultural sources, providing critical data for the development of targeted water resource management and protection strategies in Bafoussam.