Assessment of groundwater quality of Benin City, Edo state, Nigeria

Abstract

The quality of groundwater of Benin City, Edo State, Nigeria was investigated between February and July 2008. Water samples were collected from functional bore holes from five locations (stations 1 – 5) and analyzed for physico-chemical parameters including heavy metals. Data obtained were compared with World Health Organization (WHO) standards. Temporally, there was no discernible pattern in the variations of these parameters. Analysis of variance (ANOVA) revealed that there was a significant difference (P<0.05) between the means of total dissolved solids (TDS), conductivity, phosphate, sodium and potassium at the study locations. A posteriori Duncan Multiple Range test (DMR) showed that these parameters were significantly higher (P<0.05) at station 2 (Uselu) than at the other stations. Of all the heavy metals, iron and lead occurred in concentrations above the WHO limits, while other parameters were within the WHO limits. The possible sources of impact and attendant consequences especially at station 2 are reported.

Keywords: Assessment, Groundwater, water quality, boreholes, Benin City.