Assessment of Groundwater Quality around Amaenyi and State Secretariat Dumpsites in Awka, Southeastern Nigeria

Abstract

The effects of two dumpsites located at Amaenyi and State Secretariat Awka on groundwater resources was investigated using hydrochemical parameters. A total of eighteen (18) groundwater samples were collected from areas in the vicinity of the dumpsites and analysed for various hydrochemical and biological parameters using standard methods. The results of the analysis were subjected to interpretations using various methods such as spatial distribution maps, water quality indices (WQI, HPI, Cd and MEI), comparing with international and local standards and statistical analysis. The results indicate that parameters such as Ec, TDS, Na+, K+, Ca2+, Cl-, NO3- and SO42- were in compliance with the acceptable limits of World Health Organization and Nigerian Drinking Water Standard. However, HCO3-, total hardness, COD, BOD, DO1, DO5, Pb, Fe, Cd and Hg exceeded the permissible guidelines in some samples. WQI rated 20% of the samples in Amaenyi as excellent, 30% (good), 10% (poor), 20% (very poor) and the remaining 20% is unfit for consumption while in State Secretariat area, 37.5% was very poor and the remaining 62.5% was unfit for consumption. HPI rated groundwater as highly contaminated while Cd classified most of the water samples to indicate low contamination except for sample A1 which was highly contaminated.  Also, MEI indicated that groundwater has low heavy metal pollution. The correlation analysis indicates strong positive relationship between BOD, COD, DO1, DO5, total hardness, bicarbonate, calcium and sulphate, lead, magnesium and chloride. It was concluded that groundwater in the study area is mostly contaminated and the contaminants is attributed to be from the waste dumpsites and other anthropogenic activities.