Peter S. Rodriguez

The Buffalo River Area of Concern (AoC) is associated with heavy metal pollution. This paper used sediment core data to model the geographic distribution of mercury (Hg) and lead (Pb) within surface and subsurface sediments of a section of the AoC. Using ordinary kriging, a geostatistical interpolation technique, Hg and Pb concentration prediction maps were created. Standard maps were created by interpolating a prediction surface for the entire study area. In addition, spliced maps were created by interpolating prediction surfaces for three sections of the study area and merging these together to generate a quasi-continuous surface. The latter type of map was needed in order to account for the pronounced meandering nature of the river and to explore the potential existence of regional and local Hg and Pb sedimentation patterns. The results of this research show that there was trend in Hg and Pb contamination that increased from east to west (the direction of river flow), with peak values found in the mid region of the study area. Moreover, surface sediments were less polluted than subsurface sediments for both Hg and Pb. Hg contamination was less widespread but more concentrated compared to that of Pb. Finally, this study highlighted several Hg and Pb contamination hotspots, which could be targeted for future sediment restoration endeavours in the AoC.