Impact of Seasons on the Level of Heavy Metals in Omambala River as an Alternative Source of Drinking Water

Abstract

Access to potable water is vital for sustaining life and maintaining a robust economy. However, many surface and groundwater sources used for domestic purposes, including drinking, often face contamination by heavy metals. This study focused on the Omambala River in Otuocha, situated in the Anambra-East Local Government Area of Anambra State, to assess how seasonal changes affect heavy metal levels. The wet season samples were collected in July, August and September, 2023 while the dry season samples were collected in December 2023, January and February, 2024. It was observed that the river experienced significant volume reductions during the dry season and notably increases in the wet season. The research aimed to evaluate whether the river water is safe for consumption, following the procedures outlined in the Standard Methods for the Examination of Water and Wastewater as specified by the American Public Health Association. The heavy metals analyzed included iron, lead, zinc, copper and aluminum. Test results showed iron levels at 0.014 mg/l and 0.013 mg/l in the dry and wet season respectively. Lead concentrations were recorded at 0.02 mg/l and 0.03 mg/l in the dry and wet season respectively. Zinc levels were recorded at 0.92 mg/l and 0.88 mg/l in the dry and wet season respectively. Copper measurements were 0.08 mg/l and 0.09 mg/l during the dry season and wet season, while aluminum levels were 0.14 mg/l in dry and 0.13 mg/l in wet seasons. The study concluded that lead and iron average concentrations exceeded WHO limits, but showing no seasonal variation, while there were slight fluctuations in copper, zinc, and aluminum, but they were below permissible limits. The presence of these metals may stem from natural weathering or industrial discharge. Effective management of domestic and industrial waste discharges into the Omambala River is essential to minimize heavy metals contamination.