Physicochemical Alteration and Water Quality Index of Ede-Onyima Lake, Okarki-Engenni, in Rivers State, Nigeria

Abstract

Freshwater quality is deteriorating as a result of ongoing threats from both anthropogenic and natural sources, resulting in an overall loss of ecological integrity. To provide an easily-understandable summary of complex water quality data, water quality indices (WQIs) -the Canadian water quality index (CWQI 1.0) model -was used for two distinct purposes, to assess the portability of the water and its suitability for the protection of aquatic life. The Canadian Council of Ministers Environment's water quality index (CCME WQI) was calculated by combining three variables: scope (F1), frequency (F2), and amplitude (F3), to produce a single value between 0 (worst) and 100 (best) representing the water quality. Predominantly impacted by the F3, which resulted in a WQI score of 32. Ede Onyima lake was ranked “poor” indicating that it is unfit for human consumption and aquatic life protection. The lake was impaired by high turbidity (86 NTU), trace metals such as Fe (20.73 mg/L), Mg (8.67 mg/L), and Mn (5.92 mg/L) loads. Their remobilization during turbulent flow portends a harmful effect on the Ede Onyima's water quality, indicating the critical need for a cohesive lake watershed management system to sustain conservation purposes of the lake and sustenance lake-dependent livelihoods.