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Enyigba in southeastern Nigeria is one of the agrarian communities facing water scarcity challenges. The open cast mining activities in the region are also compounding the water problems as a result of leakage of heavy metals that pollute the limited water resources. This study is conducted to document the current state of surface water contamination by heavy metals and its impact on domestic and agricultural uses. Thirty water samples were collected from five sources at both the upstream, middle stream and downstream of each of the selected sites. The heavy metals were analysed using the standard laboratory methods. Generally, the average concentrations of As, Cd, Cu, Pb and Zn in the studied water bodies were 17.68, 4.30, 3.14, 0.05 and 35.57 mg/l, respectively, which were above the WHO permissible limit. Contamination of water above WHO permissible limits with heavy metals in the surface waters, because of open cast mining, is considered a serious threat to both domestic and agricultural usage. The need for establishment of treatment facility, periodic monitoring of heavy metal levels, recycling plants and principal technologies to monitor the mine sites are hereby recommended.

This greenhouse study was aimed at determining the potentials of poultry droppings (PD) and cassava peels (CP) for nutrient-enhanced biodegradation of petroleum hydrocarbon (THC) in a well drained Typic Paleustults using the THC levels and degradation duration as remediation indices. The performance of the organic amendments was compared against the performance of NPK fertilizer. The soil was contaminated with crude oil at the rate of 50 t/ha, after which the soil amendments were applied in single and combined forms (25 t PD/ha + 25 t CP/ha, and 50 t PD/ha + 50 t CP/ha), with the control as 0 t/ha (without soil amendment). Soil samples were collected from the contaminated soils at 14, 45, 76, 131 and 201 days after the application of the amendments respectively. There were significant (P = 0.05) effects of the amendments and rates of application on the THC concentrations. A comparison of the effects of PD, CP, NKP fertilizer and PD + CP on the THC concentrations at 201 days showed decrease in the contaminant concentrations in the order: NPK fertilizer < PD < CP + PD < CP < Control. The percent THC degradation at 201 days for 50t CP and 100t CP were 23 % and 24 % respectively, while that of 50t PD and 100t PD were 34 % and 36 % respectively. For soils treated with NPK fertilizer and CP + PD, the percent THC degradation was 40 % and 41 % for 50t NPK and 100t NPK fertilizers respectively, and 26 % and 31 % for 25t CP + 25t PD and 50t CP + 50t PD respectively. The time required to completely degrade the THC in the soil followed the same trend. Although PD showed great potential for THC degradation, it will take less time to achieve 100 % degradation of THC in NPK fertilizeramended soil when compared with the other nutrient supplements.