Borehole/Well Water Quality Analysis of the Peripheral Mining Communities of Gold Fields Ghana Limited, Tarkwa Gold Mine

Some parts of the minerals industry and the community have viewed water as an inexpensive commodity rather than an asset with significant value. It is important to recognize the role water plays in the environment and in the economic development of communities. This research assessed the quality of community borehole and well water provided by Gold Fields Ghana Limited, as part of its industry approach to water management. The research also assessed the impact of Gold Fields operations and other activities on the quality of the borehole and well water in its peripheral communities. Data was collected and analyzed on sixty four boreholes and wells over a period of three years. The study revealed that pH values ranged between 4.7 and 11.3. Out of the 359 samples analyzed, 3.6 percent was found to be basic while 8.1 percent was acidic. It was also found out that, samples with high pH values were taken immediately after concrete works were undertaken and the impact of the cement used is a contributory factor since cement increases the pH of water. Samples with low pH values were found to be from wells with unhygienic and unsanitary conditions. All the Communities recorded levels of faecal coliforms exceeding the WHO standards for drinking water except the wells located in the Huniso Community. High values of Manganese were recorded mainly in the Huniso wells. These trends could be due to the geology and rock formations of the area. The values at Huniso exceeding the WHO guideline of 0.33 mg/1 ranged from 0.37 mg/1 to 5.0 mg/1. Out of the 12 wells at huniso, three had consistent elevated values of manganese. Well HNS013 increased from 2.54 mg/1 in 2003 to 5.0 mg/1 in 2005, while HNS016 increased from 1.0mg/l in 2003 to 1.48 mg/1 in 2005. Conductivity Values were very low, confirming the low metal dissolution of the Tarkwaian rock. The community wells should be sited properly and must be kept in good hygienic condition to prevent contamination. It was observed that water from some of the boreholes is not potable and hence not good for drinking even though it could be treated. This was due to contaminants such as high and low pH values, high TDS values, high faecal coliforms which do not meet the EPA and WHO guidelines for drinking water. Cyanide values were at the detection limit or absent in all the samples taken. Mercury, lead, iron and arsenic concentrations in samples analyzed from wells around the TSF were very low. It is therefore evident that the operations of Gold Fields Ghana Limited, Tarkwa Gold Mine have not polluted the borehole and well water in its peripheral communities. All the possible contaminants from the company have been observed to be absent from the samples or in negligible amounts. Some of the contaminants observed in the boreholes/wells might be coming from other sources and must be critically investigated if these facilities will continue to serve as sources of drinking water for these communities. The study clearly underscores the need to deepen wells, relocate those which are near access roads and cottage industries, raise the basements of low lying ones and to keep a sanitary and hygienic environment around the wells.

Source: KNUST