Water quality analysis of rivers used as drinking sources in artisanal gold mining communities of the Akyem-Abuakwa area: A multivariate statistical approach

Abstract

The spatial pattern of water quality of rivers affected by artisanal gold mining but used as drinking sources in Akyem Abuakwa, was evaluated based on thirteen variables. At nine of the fifteen sampling stations, concentrations of arsenic, mercury, total dissolved solids, turbidity, water colour, nitrate-nitrogen and phosphate-phosphorus were found to be higher than WHO’s limits for drinking water. Cluster analysis distinguished four water quality categories - good, fairly good, poor and grossly polluted. Only rivers Subri and Kadee were classified as “good” for drinking purposes. Discriminant analysis revealed that, in order of importance, turbidity, arsenic, temperature, phosphate-phosphorus and total dissolved solids are the most important variables for identifying drinking water quality of river sources. Principal component analysis identified five factors with eigenvalues greater than unity and accounting for more than 80 percent of water quality variability. Artisanal gold mining accounted for more than 26 percent of the variability, with arsenic and mercury as the primary contaminants in the area. Other sources of contamination are agricultural activities and domestic waste disposal. The study recommends that local water quality managers design cost-effective strategies to effectively monitor and protect drinking water resources of the study area, particularly from miningrelated degradation.