Evaluation of the Adverse Effects of Incessant Untreated Effluent Discharge on Surface Water Quality

The study was conducted to evaluate the Idomila River in Ilese, Ogun State, Southwestern Nigeria, for its physico-chemical and microbiological characteristics as well as its wastewater discharge sources. A designed observational chart developed to verify, check, and inspect the upstream and downstream environmental conditions, field measurements and laboratory analysis of river water samples from upstream and downstream were carried out to determine the physico-chemical and microbiological characteristics of the water using accepted examination techniques. Data collected were analyzed by both inferential and descriptive statistical analysis (One-way ANOVA test) of SPSS software package. The results show the sources of wastewater to be from anthropogenic sources such as agricultural, and domestic activities. The average values of the physico-chemical and microbial parameters across the river section and locations of sampling are similar. The results of ANOVA indicated that the physico-chemical and microbiological qualities do not differ significantly except the total solid and total dissolved solid. The implication is that the dilution rates and fast movement of the river might be the cause, and on the other hands different wastes entering from upstream and downstream might differed. Although, most of the analysed water sample results were below the WHO recommended limits. There is need for adequate the management of domestic and agricultural wastes to lower the accumulation of pollutants in the river water and soil, and to minimize environmental degradation. There is need for further research using spectrometry methods to analyse the water and soil samples around the study area.