Effects of Open Dumpsite Leachate on Groundwater Quality: a Case Study of Alakahia Dumpsite in Port Harcourt, Nigeria

The effects of dumpsite on groundwater quality were assessed. Dumpsite leachate and groundwater samples were obtained and analysed for the following physico-chemical parameters and heavy metals: pH, Total Dissolved Solids (TDS), Chemical Oxygen Demand (COD), Nitrate (NO3), Ammonium (NH4+), Total Hardness (TH), Copper (Cu), Cadmium (Cd) and Iron (Fe). The results obtained were compared with the World Health Organisation and Federal Ministry of Environment Standards for drinking water. The concentrations of the analysed parameters for the dumpsite leachate were generally well above the Standards, indicating that the leachate could contaminate groundwater. For the groundwater samples, the pH and Cd did not meet the required standards. The pH values ranged 4.19 ? 6.14, implying that the groundwater in the study area is acidic. The Cd values were < 0.05 mg/l. The COD values ranged 5.38 ? 8.60 mg/l. Although the concentrations of TDS, NO3, NH4+, TH, Cu and Fe were below the standards, the computed Water Quality Index (>752 for all groundwater samples) indicates that the groundwater around the dumpsite is unsuitable for drinking. The similar WQIs for all the groundwater samples suggest that the dumpsite had negligible impact on the quality of the groundwater. Furthermore, a strong positive correlation (> +0.65) was observed for most of the analysed parameters (TDS, COD, NO3, TH, Cu and Fe), indicating that they probably have common source. Generally, the concentrations of the analysed parameters decreased with increasing distance from the dumpsite, indicating that the groundwater sources closer to the dumpsite are at higher risk of getting contaminated than those farther away from the dumpsite.