Pollution History of the Savannah River Estuary

Alexander, C., Lee, R., Loganathan, B., Smith, R., Wakeham, S.,
Windom, H.
Skidaway Institute of Oceanography, 10 Ocean Science Circle, Savannah, GA 31411

As part of the NOAA National Status and Trends Program, 13 cores were collected from the Savannah River Estuary for the production of historical pollutant profiles. These cores, representing intertidal salt marsh, subtidal channel and abandoned boat-slip environments, were dated using Pb?210 geochronologies and analyzed for the metals Al, Ag,As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sb, Se, Sn, and Zn, as well as pesticides, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, and butyltins. Four contaminant-time patterns were identified. For Ag, Cd, and Zn, profiles show an increase in concentration up to the present time, indicating an increasing loading from non-point-source pollution. Cr and DDT isomers exhibit distributions characterized by maxima that get progressively shallower (and younger) down-estuary, representing redistribution of contaminated material. In one core, Hg exhibits a sharp subsurface maxima, indicating a localized anthropogenic input that has since been controlled. Pb, PCBs and PAHs exhibit subsurface maxima representing peak inputs prior to the institution of environmental regulatory controls. In comparison to densely populated and industrialized regions, the concentrations of most anthropogenic chemicals found in cores from the Savannah Estuary are low. Decreases in these components over the past few decades suggest that pollution control regulations have been effective, even while industrial and population growth has occurred. However, levels of inorganic pollutants are approximately twice what they were in the previous century and what they are in contempory nearby settings.