Assessment of Groundwater Quality and Health Risks in the Basement Complex of Gusau and Its Environs, Zamfara State, Nigeria: Heavy Metal and Microbial Insights

This study evaluates groundwater quality in the Basement Complex of Gusau and its environs in Zamfara State, Nigeria, a region heavily reliant on groundwater for domestic, agricultural, and industrial use. Thirty groundwater samples were collected from a variety of sources, including boreholes, hand-dug wells, and other wells across the study area, to assess their physical, chemical, and bacteriological characteristics. Key parameters analyzed included pH, electrical conductivity (EC), total dissolved solids (TDS), turbidity, heavy metals (such as iron, lead, and arsenic), and bacterial contaminants (including E. coli and total coliforms). The findings indicate that the groundwater is predominantly acidic to neutral, with pH values generally within acceptable ranges for drinking water. Electrical conductivity and TDS levels varied, reflecting diverse mineralization levels, with most samples falling within permissible limits for potable water. However, certain locations exhibited elevated concentrations of heavy metals, surpassing the World Health Organization (WHO) and Nigerian Industrial Standards (NIS) thresholds, posing potential health risks. Bacteriological analysis revealed significant contamination in several samples, with the presence of E. coli and coliforms indicating fecal pollution and highlighting a critical public health concern. These findings suggest that while the groundwater in the Gusau Basement Complex is a vital resource, it faces challenges from localized pollution and microbial contamination. The study underscores the urgent need for improved water management strategies, including regular monitoring, enhanced treatment processes, and infrastructure development to safeguard water quality. Recommendations include the implementation of geophysical surveys to better locate productive aquifers and the establishment of systematic hydrogeological data collection to support sustainable groundwater development. Addressing these issues is essential to ensure the provision of safe and clean drinking water, thereby protecting the health and well-being of the local population in Gusau and its surrounding areas.