Comprehensive Assessment of the Effect of Various Anthropogenic Activities on the Groundwater Quality

Abstract

Water pollution had become a major problem due to its’ negative impact on the human health. Effects of humaninduced actions on groundwater quality were examined in this study. The physicochemical, heavy metals and microbial parameters of groundwater, sampled during the two major climatic periods in Nigeria, were measured according to APHA approved procedures. Results obtained from laboratory tests revealed that anthropogenic activities had substantial effect on the groundwater quality. The groundwater TDS, nitrate, BOD, chloride and phosphate concentrations varied from 23.93 to 42.32 mg/L, 0.54 to 2.16 mg/L, 2.23 to 4.72 mg/L, 10.78 to 19.15 mg/L, and 0.22 to 0.36 mg/L respectively. Likewise, Cd concentration fluctuated between 0 and 0.001 mg/L, Cu varied between 0 and 0.149 mg/L, Fe varied between 0 and 0.293 mg/L, Pb varied between 0 to 0.105 mg/mL, Zn varied between from 0 and 0.768 mg/L, while Ni fluctuated between 0 and 0.001 mg/L. The findings revealed that areas with poor sanitary situations had poor groundwater quality, compared to the areas with improved sanitary situations. Regarding the microbial population, the highest Total Bacteria and Fungi Counts recorded in the groundwater were 1.11×102 cfu/mL and 1.23×102 cfu/mL respectively. Similarly, the highest recorded Enterobacterial spp., Staphylococus arurius, E. coli, Proteus spp. and Shegeela spp. populations were 26.22×102 cfu/mL, 1.23×102 cfu/mL, 0.41 MPN/100 mL, 0.12 cfu/ml and 0.30×102 cfu/mL respectively. Although, the groundwater physicochemical parameters and heavy metals concentrations were within safe drinking water limits; the groundwater was largely contaminated with pathogenic microorganisms, mostly during the rainy season.