Effects of surface gold mining on surface and groundwater bodies in Bibiani, Ghana

Abstract

A study of the water sources from Bibiani and its environs was conducted between November, 2009 and April, 2010 to determine whether contamination (of water sources) from (these parameters) physical, chemical and trace metal in Bibiani is as a result of mining or geochemical
and biochemical processes within the environment. This was done by collecting water samples from two streams, two rivers, three boreholes (BHs) and three hand dug wells (HDWs). These were analysed in the laboratory. Levels of Arsenic (As), Iron (Fe), Manganese (Mn), pH, Total
Dissolved Solids (TDS), Electrical Conductivity (EC), Temperature, Alkalinity, Hardness, Phosphate (P) and Cyanide (CN) in water sources were determined. Mining related contaminants detected in water samples were As, CN, Mn and Fe. It was observed that surface water pH values were generally higher than that of groundwater samples. As concentrations in surface water samples were higher compared to that of groundwater samples. Also, CN concentration in ground water samples was higher than that of surface water. Ground water contained higher concentration of Mn than surface water; the opposite can be said of Fe concentration in surface
water which was higher than that of ground water. The study also observed that pH, TDS, EC, total alkalinity, total hardness , Arsenic and total cyanide levels in the HDW and BH samples showed 100% compliance with the WHO and EPA limits while Mn and Fe levels indicated traces of non – compliance. Compared to WHO / EPA guidelines, few water sources had one or more
trace metal (Fe, As and Mn) levels outside acceptable limits for drinking. However, most of the levels were safe for human consumption.

Keywords: Surface, gold mining, quality, degradation, Bibiani