The Impact of Mine Effluents on the Water Quality and Macrophyte Plant Communities in the Kifubwa Stream, Solwezi, Zambia

A study to assess the impact of mine effluents on water quality and macrophyte plant communities in the Kifubwa stream in Solwezi, Zambia was carried out in December 2015. The macrophytes species and water samples were collected from ten (10) selected sampling sites along the river. The initial sampling site was set at the point of pollution (effluents) entrance into the river. The other 9 sampling units of 30 m × 30 m were spaced at a uniform interval of 150 m throughout the 1.5 km section of the river sampled. Macrophytes collected at each sampling site were identified on site to family level using the Zambian Macrophytes Trophic Ranking (ZMTR) protocol developed under the Southern African River Assessment (SAFRASS). The abundance of macrophyte plant communities showed that family Polygonaceae had (27.5%), Cyperaceae, (23.5%), Amaranthaceae (17.6%), Hydrocharitaceae (17.6%) and Osmundaceae (13.8%) respectively. The Shannon-Weiner’s diversity index (H) was used to calculate the macrophyte diversity and the value used in a correlation analysis with potential of hydrogen (pH) and other water quality variable under investigation. The water samples were taken to the laboratory for analysis of water variables, namely, pH, Total Dissolved Solids (TDS), nitrates, phosphates, copper and zinc levels for each site. The pH was significantly (p 0.05) related to TDS, phosphates nitrates and copper pH was not significantly (p > 0.05) related to H and zinc. Calculated means for pH and TDS showed that they were within both the Zambian Drinking Water Standards (ZDWS) and the World Health Organization (WHO) guidelines. Phosphates, nitrates and zinc were all below both water standards. Only copper levels were above both water standards. The mine effluent that is being discharged in the Kifubwa stream does have an impact on the water quality parameters, especially that of copper. This requires regular monitoring of the stream effluents by the authorities that give the permission for the discharge.