Is the Hyde Park Dump, near the Niagara River, still affecting the sediment of Lake Ontario?

Fifteen dated sediment cores from the four Lake Ontario sedimentation basins were analyzed by electron capture, gas chromatographic mass spectrometry for three fluorinated compounds originating from the Hyde Park Dump near the Niagara River. The compound concentration profiles in the sediment are in good agreement with the history of the dumpsite's use. The concentrations of the compounds start: to increase in the early 1950s and maximize in about 1970 in the main portion of the lake. The Hyde Park Dump was closed in 1975; however, the compounds' concentrations in the surficial sediments are still about 20% of their maximum. We attribute these relatively elevated levels to a combination of physical perturbations in Lake Ontario and continued migration of the compounds from the dumpsite. Using core burdens and concentration profile data, we conclude that the sediment of the Kingston Basin of Lake Ontario is not directly connected to the nearshore zone and that the compounds were transported to the Kingston Basin sequentially from the Rochester Basin. We also observed a change in relative abundances between the source and sediment for these compounds. The change was due to physical partitioning of the compounds between the sediment and aqueous phases in the lake.