Water quality evaluation using water quality index and pollution model in selected communities in Gbaramatu Kingdom, Niger Delta, Nigeria

Abstract

Drinking water quality is a critical factor affecting human health particularly in natural resource-dependent countries including Nigeria. Hydrocarbon related pollution, mining waste, microbial load, industrial discharge and other anthropogenic stressors degrade drinking water quality in coastal communities and pose serious public health and ecological risks. This study evaluated the physicochemical properties of drinking water in selected communities (Okerenkoko, Kurutie and Oporoza) in Gbaramatu Kingdom, in the Niger Delta region of Nigeria, to assess the water quality using the water quality index (WQI) and pollution models. Nitrate, chromium, cadmium, copper, lead, aluminium, pH, total hardness, total dissolved solids, cyanide and residual chlorine were measured in twelve selected locations across three communities. WQI results of 139 to 44180 indicated that analyzed water samples exceeded the critical WQI value of 100, in addition the mean pH of the water samples recorded 8.11 ± 0.32, indicating unsuitability for consumption. Nickel ranging from 0.014 to 0.176 mg/L and residual chlorine 11.6 to 7407 mg/L were the major contributors to the degradation of water quality and exceeded the WHO recommended limit of 0.02 and 0.25 respectively. While groundwater had better organoleptic properties compared to surface and rain water, the geo-accumulation index showed that water sources vary from moderately to heavily contaminated with Ni and Cd. The WQI and pollution model results indicate that immediate action is required by stakeholders to address water quality deterioration (e.g., providing alternative water supply) as existing water resources in the area pose significant health risks to the local population.