Assessing potential contaminants in groundwater in a typical open refuse dumpsite in Eneka, Obio/Akpor, Rivers state, Nigeria

Abstract

This study assesses the potential contaminants in a refuse dump. Standard sampling and analytical methods were followed. The results revealed that the groundwater is generally acidic with pH values varying between 4.01 to 6.01 in the boreholes around the dumpsite and basic in the boreholes away from the dumpsite. The mean pH value of 4.6 recorded in the dumpsite area is below the stipulated World Health Organization (WHO) pH tolerance range of 7 to 8.5 for potable water. The total dissolved solids (TDS) values obtained in groundwater varied from 601.5mg/l to 622.5mg/l and a significant attenuation of TDS concentrations in all wells could be observed down gradient of the waste dumpsite. The measured values of sulphate and nitrate in groundwater were below the WHO – stipulated value for each of the anion for potable water. The measured values of iron and lead in the groundwater samples were above WHO tolerance levels for drinking water in the boreholes around the dumpsite. The biochemical oxygen demand (BOD) measured values fell above the WHO tolerance levels of 0mg/l for potable water. The high level of BOD is indicative of pollution. The physico-chemical parameters of the groundwater samples from the waste dumpsite are below WHO tolerance limit of potability. The local groundwater flow direction is southeast in the two waste dumpsites. It is recommended that regular monitoring of the quality of water be carried out.

Key words: Groundwater Quality, Contaminants, Boreholes, Dumpsites, Eneka, Rivers State