Water Quality Assessment and Resource Potentials: the Case of Aba–Urban and its Environs, Niger Delta Basin

Аннотация

The quest for improved water supply to cater for the ever increasing population has given rise to the assessment of water quality and resource potentials in Aba-Urban and its environments. The area, which lies within the Niger Delta Basin is underlain by the Benin Formation that is highly aquiferous. Samples of sands and water were subjected to sedimentological and hydrochemical analysis, respectively. Result reveals that the aquifer is thick (over 100 m) and unconfined. The computed aquifer parameters indicate high yielding clean-sands with hydraulic conductivity values ranging from 1.13 × 10^–4 to 5.70 × 10^–3 m/s. The specific discharge is about 14.2 m/year while the average linear groundwater velocity is calculated to be 53.46 m/year. Hydrochemical investigations carried out on water samples from Aba River and the groundwater system revealed low dissolved geochemical constituents. Although, there is a slight increase from the north to the southern part along the flow path. In general, the groundwater is relatively enriched in Ca, Mg−HCO^-₃ions and is predominantly of bicarbonate constituents. However, in some places Cl⁻ ions dominate over HCO^-₃ions. This is common where the water has come in contact with domestic sewage. This kind of contamination is also accompanied by elevated concentration of NO^-₃ions. Generally, the groundwater in most cases meets the standard for human consumption and is a better alternative to surface water. Consequently an increase exploitation of the prolific Benin aquifer through more hygienic and safe methods will surely be the best way of improving the domestic water supply situation in Aba City.