THE EFFECT OF CLAY MINING ON THE QUALITY OF RIVER EZE IN OZUBULU, ANAMBRA STATE, NIGERIA
In Nigeria, clay is a widely distributed and abundant mineral resource for major industrial processes with varied applications and uses. The unregulated means of harvesting clay resources has placed risks on water sustainability. Globally, water pollution is fast becoming a serious environmental problem caused by unsustainable human means of exploiting natural resources. The study investigated two clay mining sites and their effects on River Eze in Ozubulu, Anambra State during the rainy season. It employed survey and experimental methods. Laboratory analysis was used to determine the physiochemical parameters (pH, turbidity, TDS, EC, BOD, DO) of River Eze. The water samples were also tested for heavy metals (Pb and Zn) using spectrometer (AAS) analysis. A total of three (3) water samples were collected from River Eze and (1) water sample from River Odoakpu to serve as a control sample. The survey method included field observation, photography and structured questionnaires. A total of 150 questionnaires were randomly administered to the residents. Findings from the study indicated that (1) the water samples from River Eze had higher Biological Oxygen Demand (BOD) levels than the permissible limits of the Federal Ministry of Environment (FMENV) , (2) the pH values were within the permissible limit set by the World Health Organisation (WHO), (3) the EC, TSS, TDS were within the permissible limits of WHO/FMENV standards,(4) the control sample has low BOD of 20mg/l and other parameters were within the permissible limit of FMENV, (5) the heavy metal (lead) values were higher than the permissible limits of WHO standards, however, zinc samples analysed were within the permissible limit set by WHO/FMENV. It was evident that the nearness of the clay harvesting sites to Eze River is major cause of pollution. The results indicated that River Eze may have a toxic effect on aquatic ecosystem and the health of the rural dwellers that use the river water directly for domestic purposes without treatment. The study recommended effective Environmental Impact Assessment (EIA) practice, application of best sustainable practices for clay harvesting, enforcement of laws and policies covering environmental protection and regular water quality assessment.