Assessment of Groundwater Quality Using Water Quality Indices in Illegal Mining Communities: A Case Study of the Atwima-kwanwoma District and Obuasi East Metropolis, Ghana

Abstract

This study investigated groundwater quality in illegal mining zones within the Atwima-Kwanwoma District and Obuasi East Metropolis of the Ashanti Region, Ghana, employing both the Canadian Council of Ministers of the Environment Water Quality Index (CCME-WQI) and Nemerow's Pollution Index (NPI). The analysis revealed severe contamination across multiple parameters, including heavy metals, microbial indicators, and physicochemical parameters. The CCME-WQI values for the five towns consistently indicated "Poor" water quality, ranging from 26.8 to 31.1, reflecting significant deviations from acceptable water quality standards. Notably, Town A exhibited a cyanide concentration of 11.25 mg/L, while Town B recorded lead levels at 118.73 μg/L, both far exceeding permissible limits set by health authorities. The presence of Escherichia coli further exacerbates health risks, underscoring the urgent need for improved water treatment and management practices. This study demonstrates that the integrated use of NPI and CCME-WQI provides a comprehensive assessment of groundwater quality, revealing significant environmental and public health challenges. Immediate intervention, including regulatory enforcement, sustainable mining practices, and remediation strategies, is crucial to safeguard groundwater resources. The findings contribute uniquely to the understanding of water quality dynamics in mining-affected regions and advocate for a coordinated approach to mitigate environmental degradation.