Surface Water Quality Assessment of Offshore Field Y Using Geo-Spatial Interpolation and Mapping

Surface water quality assessment is essential for effective environmental management, particularly in oil-producing regions such as the Niger Delta, Nigeria. This study evaluates the physicochemical and trace metal characteristics of surface water in Offshore Field Y using geospatial interpolation and mapping techniques. Water and sediment samples were collected monthly from ten sampling locations within the study area and analyzed for key water quality parameters, including pH, temperature, electrical conductivity, total dissolved solids (TDS), biochemical oxygen demand (BOD), nutrients (nitrate, phosphate, sulphate, ammonium), major ions (calcium and magnesium), and trace metals (chromium, lead, and arsenic). Standard analytical procedures in accordance with ASTM and APHA guidelines were employed. Geographic coordinates of sampling points were acquired using GPS, and spatial distribution maps of selected parameters were generated using Geographic Information System (GIS) techniques to identify pollution trends and hotspots. The results reveal spatial variations in surface water chemistry influenced by natural geological controls, hydrological processes, and anthropogenic activities such as oil exploration, urbanization, and agricultural practices. Some parameters showed localized elevations relative to World Health Organization (WHO) guidelines, indicating potential environmental and public health concerns. The integration of geochemical analysis with geospatial mapping proved effective in visualizing water quality patterns and identifying areas of high pollution risk. This study provides baseline data for Offshore Field Y and underscores the importance of continuous monitoring and sustainable management of surface water resources in the Niger Delta.