Abstract:
Mining plays a vital role in driving economies, however, if not carried out properly and without effective Environmental and Social Management Plans (ESMPs); it can lead to significant environmental degradation, negatively impacting water quality and aquatic ecosystems. The study's main objective was to assess the effects of mining activities on water quality and the benthic macroinvertebrate population in two rivers surrounding Kaziwiziwi Coal Mine in Rumphi district, Malawi. Six sampling sites were purposively selected to provide a range of data points that captured the variability in water quality across different locations along the two rivers and, two sets of duplicate samples were collected at each sampling point for analysis. Data were analyzed using IBM SPSS statistical packages version 27. One-way ANOVA, Pearson Correlation, and principal component analysis (PCA) were used to identify key differences in water quality. Faecal coliform (FC) contamination was high across all sampling sites (309 ̶ 612 cfu/100ml) compared to recommended Malawi Standards (MS214:2013). Temperature (25.07 ± 0.06 °C), pH (7.53 ± 0.21), and electrical conductivity (EC) (37.66 ± 0.58 µS/cm) met World Health Organization and Malawi Standards for drinking water quality. Heavy metal assessment indicated fluctuating but generally acceptable levels of iron (Fe) (0.83 ± 0.27 mg/L) and lead (Pb) (0.03 ± 0.01mg/L), while zinc (Zn), copper (Cu) and cadmium (Cd), were undetectable. Benthic population trends revealed potential ecosystem impairments, with average score per taxon (ASPT) suggesting stress and low abundance of functional feeding groups such as shredders and scrapers. The study recommends regular water quality monitoring, remediation of FC contamination, and community engagement in sustainable practices to maintain ecosystem health and diversity.
